Friday, December 9, 2011

Solar Production Thru November 30, 2011

Our solar PV system is now 10 months old and we are generating 13% more energy than the original system estimate. I have updated my savings calculator model with the actual solar production to date. I still haven't gotten a real electric bill. I've only been paying the taxes each month ($2-3). I thought they were going to charge me once a quarter, but I guess it will be all at year end.

Total Production To Date:
Production: 2,740 kWh
Percent of Annual Predicted Production (2,781 kWh): 98.5%
Actual vs. Predicted Production Better/(Worse): +306 kWh
CO2 Saved: 4,521 lbs
Estimated Savings: $487.00

Monthly Production:
November 2011: 142.94 kWh
October 2011: 200.17 kWh (we had our house tented, so I estimate we lost about 20 kWh of production)
September 2011: 255.36 kWh
August 2011: 331.44 kWh
July 2011: 352.72 kWh
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Monday, November 21, 2011

Solar Production Thru October 31, 2011

Our solar PV system is now 9 months old and we are generating 16% more energy than the original system estimate. I have updated my savings calculator model with the actual solar production to date. I still haven't gotten a real electric bill. I've only been paying the taxes each month ($2-3). I thought they were going to charge me once a quarter, but I guess it will be all at year end.

Total Production To Date:
Production: 2,587 kWh
Percent of Annual Predicted Production (2,781 kWh): 93%
Actual vs. Predicted Production Better/(Worse): +360 kWh
CO2 Saved: 4,269 lbs
Estimated Savings: $476.40

Monthly Production:
October 2011: 200.17 kWh (we had our house tented, so I estimate we lost about 20 kWh of production)
September 2011: 255.36 kWh
August 2011: 331.44 kWh
July 2011: 352.72 kWh
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Monday, October 3, 2011

Solar Production Thru September 30, 2011

Our solar PV system is now 8 months old and we are generating 22% more energy than the original system estimate. I have updated my savings calculator model with the actual solar production to date. I only get an electricity bill once a quarter, so the billing data is based on an estimate.

Total Production To Date:
Production: 2,388 kWh
Percent of Annual Predicted Production (2,781 kWh): 86%
Actual vs. Predicted Production Better/(Worse): +438 kWh
CO2 Saved: 3,939 lbs
Estimated Savings: $441.78

Monthly Production:
September 2011: 255.36 kWh
August 2011: 331.44 kWh
July 2011: 352.72 kWh
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Friday, September 9, 2011

Solar Production Thru August 31, 2011

We are generating 20% more energy than the original system estimate. I have updated my savings calculator model with the actual solar production to date. I only get an electricity bill once a quarter, so the billing data is based on an estimate.

Total Production To Date:
Production: 2,132 kWh
Percent of Annual Predicted Production (2,781 kWh): 77%
Actual vs. Predicted Production Better/(Worse): +344 kWh
CO2 Saved: 3,560 lbs
Estimated Savings: $393.39

Monthly Production:
August 2011: 331.44 kWh
July 2011: 352.72 kWh
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Friday, August 12, 2011

Rants and Rays - Carbon Footprint Followup

Following up on a previous post. Here's an even better carbon footprint calculator from the US EPA. It is much more informative. What I like about it is that it provides specific actions/options for reducing your personal carbon footprint.

My household of 4 people has a carbon footprint of 27,097 lbs. of CO2 per year. Per person we generate 6,774 lbs. of CO2 per year. (Based on usage without Solar).




Suggested actions to reduce my carbon footprint:
  • Perform regular maintenance on vehicles.
  • Replace incandescent light bulbs with CFLs.
  • Turn up/down the thermostat during summer/winter by a degree or two.
  • Use cold water for laundry.
Vehicle emissions are very high so keeping it maintained or replacing with a more fuel-efficient vehicle saves a lot. Replacing ten 75-Watt incandescent light bulbs with 20-Watt CFLs would save $70/year and reduce carbon footprint by 545 lbs./yr.

Wednesday, August 3, 2011

Solar Production Thru July 31, 2011

We have generated over 265 kWh more energy than the original system estimate. I have updated my savings calculator model (with charts) with the actual solar production to date. I only get an electricity bill once a quarter, so the billing data is based on an estimate.

Total Production To Date:
Production: 1,801 kWh
Percent of Annual Predicted Production (2,781 kWh): 65%
Actual vs. Predicted Production Better/(Worse): +265 kWh
CO2 Saved: 3,014 lbs
Estimated Savings: $360.20

Monthly Production:
July 2011: 352.72 kWh
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Thursday, July 28, 2011

Rants and Rays - Key Pillars of Energy Management

My personal belief is that there are three main pillars to comprehensive Energy Management as a big component of the solution to Global Warming:
  1. Efficiency - "Waste Less" energy
  2. Generation - "Make More" clean energy
  3. Conservation - "Use Less" energy
Efficiency and Generation are more system/infrastructure changes. These require capital investments, but I believe they are are more easily achievable, since they are just changes to the equipment. For example, you can save electricity by sealing the air leaks in windows with caulking or right-sizing the HVAC unit. You can generate clean energy by adding solar panels.

Unlike the other two pillars, Conservation is dependent almost exclusively on behavioral changes, and thus is very difficult to implement and achieve. However, if our behavior can be changed, the impact and benefit is likely to be much more impactful and longer lasting.

Efficiency and Conservation are generally espoused to the end-user side while Generation is more of a utility priority. However, I believe that with solar the Generation pillar can and will be an important component in the future for the end-user. Per above, the results of Generation are more easily achievable since they are reliant almost entirely on purchase of equipment rather than a change in behavior.

Tuesday, July 26, 2011

Solar Production Thru July 25, 2011

We have generated over 265 kWh more energy than the original system estimate. I have updated my savings calculator model (with charts) with the actual solar production to date. I only get an electricity bill once a quarter, so the billing data is based on an estimate.

Total Production To Date:
Production: 1,742 kWh
Percent of Annual Predicted Production (2,781 kWh): 62.6%
Actual vs. Predicted Production Better/(Worse): +265 kWh
CO2 Saved: 2,891 lbs
Estimated Savings: $348.40

Monthly Production:
July 2011: 293.62 kWh (July 1-25)
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Thursday, July 14, 2011

24 Weeks Solar Production

Sorry I have been delinquent in my postings.

Total Production To Date:
Production: 1,595 kWh
Percent of Annual Predicted Production (2,781 kWh): 57.4%
Actual vs. Predicted Production Better/(Worse): +165 kWh
CO2 Saved: 2,647 lbs
Estimated Savings: $319.00
Monthly Production:
July 2011: 147.15 kWh (July 1-12)
June 2011: 313.90 kWh
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Thursday, June 9, 2011

Rants and Rays - What Is Your Carbon Footprint?

Have you ever wondered what your carbon footprint is? I found this great carbon footprint calculator on PG&E's website.

Based on PG&E's calculation assumptions*, my carbon footprint versus various averages (in lbs. of CO2 per year):
Before solar: 18,654
After going solar: 17,199
CO2 reduction from solar: (1,455)

Average Californian: 22,941
Average American: 32,607
Average Global Person: 8,750

Not quite there, but starting to do my part. Maybe my next car will be a hybrid.


*Note - All calculations are based on PG&E's assumptions. PG&E claims to have an emissions rate (electric) of 0.575 lbs CO2 per kWh which is very low. I think average base load for California is 1.3 lbs CO2 per kWh and my SunPower monitoring system has an even higher assumption of 1.7 lbs CO2 per kWh. If your utility has a higher carbon emissions rate than PG&E, then your carbon footprint could be significantly higher and the impact of installing solar panels even greater.

Wednesday, June 8, 2011

19 Weeks Solar Production

We hit a new all time daily high of 14.70 kWh this week.

Total Production To Date:
Production: 1,233 kWh
Percent of Annual Estimated Production (2,781 kWh): 44.3%
CO2 Saved: 2,046 lbs
Estimated Savings: $246.60

Monthly Production:
June 2011: 89.64 kWh (June 1-7)
May 2011: 332.10 kWh
Apr 2011: 295.18 kWh
Mar 2011: 262.25 kWh
Feb 2011: 206.07 kWh
Jan 2011: 38.50 kWh (1/26-1/31)

Weekly Production:
Week 19: 89.64 kWh
Week 18: 89.27 kWh
Week 17: 67.49 kWh
Week 16: 63.67 kWh
Week 15: 71.74 kWh
Week 14: 90.86 kWh
Week 13: 55.70 kWh
Week 12: 65.83 kWh
Week 11: 74.17 kWh
Week 10: 72.13 kWh
Week 9: 53.68 kWh
Week 8: 50.01 kWh

System Specs:
System Size DC (STC): 2.28 KW
System Size AC: 1.93 KW
System Size AC (California CSI rating): 1.63 KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 kWh
Direction: East facing

Friday, June 3, 2011

Rants and Rays - All I See Is Opportunity

I found that once I went solar, I was quick to notice other solar installations and places that would be ideal for solar.

I take the kids for bike rides on the Caltech campus, which is a few blocks from our house. I took this picture of one of Caltech's parking structures where they installed solar PV to generate electricity and provide shading for cars.

A few weeks ago we went on the Disney Cruise out of the Port of Los Angeles. As we were waiting to set sail, I snapped this photo of the solar PV installation on the rooftops of the World Cruise Center. This is part of the 10 MW of solar the Port of Los Angeles planned to install.

I work at Warner Bros. and the studio is on the leading edge of environmental and sustainability practices in the entertainment industry. In fact, WB's 600KW of solar PV was the first large scale solar installation in entertainment industry.

These are great starts to going solar. But if you really look closely, these solar initiatives have only just begun to crack the surface. Here is a map of the Caltech campus and a picture I snapped of the WB studio lot in Burbank. Looking at these, you will notice some solar, but what is more apparent is the vast majority of empty rooftops.

All I see is opportunity.

Wednesday, June 1, 2011

18 Weeks Solar Production

Our rolling 30-day average production is 329 KWH, which far exceeds the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total Thru 18 Weeks:
Production: 1,144 KWH
CO2 Saved: 1,899 lbs
Estimated Savings: $228.80

Weekly Production History:
Week 18: 89.27 KWH
Week 17: 67.49 KWH
Week 16: 63.67 KWH
Week 15: 71.74 KWH
Week 14: 90.86 KWH
Week 13: 55.70 KWH
Week 12: 65.83 KWH
Week 11: 74.17 KWH
Week 10: 72.13 KWH
Week 9: 53.68 KWH
Week 8: 50.01 KWH

Monthly Production History:
May 2011: 332.10 KWH
Apr 2011: 295.18 KWH
Mar 2011: 262.25 KWH
Feb 2011: 206.07 KWH
Jan 2011: 38.50 KWH (1/26-1/31)

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Tuesday, May 31, 2011

17 Weeks Solar Production

Our rolling 30-day average production is 328 KWH, which far exceeds the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total Thru 17 Weeks:
Production: 1,044.82 KWH
CO2 Saved: 1,776 lbs
Estimated Savings: $208.80

Weekly Production History:
Week 17: 67.49 KWH
Week 16: 63.67 KWH
Week 15: 71.74 KWH
Week 14: 90.86 KWH
Week 13: 55.70 KWH
Week 12: 65.83 KWH
Week 11: 74.17 KWH
Week 10: 72.13 KWH
Week 9: 53.68 KWH
Week 8: 50.01 KWH

Monthly Production History:
May 2011: 242.80 KWH (Partial)
Apr 2011: 295.18 KWH
Mar 2011: 262.25 KWH
Feb 2011: 206.07 KWH
Jan 2011: 38.50 KWH (1/26-1/31)

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Wednesday, May 18, 2011

16 Weeks Solar Production

Our rolling 30-day average production is 301 KWH, which far exceeds the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total Thru 16 Weeks:
Production: 987 KWH
CO2 Saved: 1,638 lbs
Estimated Savings: $197.40
Weekly Production History:
Week 16: 63.67 KWH
Week 15: 71.74 KWH
Week 14: 90.86 KWH
Week 13: 55.70 KWH
Week 12: 65.83 KWH
Week 11: 74.17 KWH
Week 10: 72.13 KWH
Week 9: 53.68 KWH
Week 8: 50.01 KWH

Monthly Production History:
May 2011: 186.14 KWH (Partial)
Apr 2011: 295.18 KWH
Mar 2011: 262.25 KWH
Feb 2011: 206.07 KWH
Jan 2011: 38.50 KWH (1/26-1/31)

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Wednesday, May 11, 2011

15 Weeks Solar Production

Our rolling 30-day average production is 306 KWH, which far exceeds the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 15 Weeks:
Production: 914 KWH
CO2 Saved: 1,516 lbs
Estimated Savings: $182.80

Weekly Production History:
Week 15: 71.74 KWH
Week 14: 90.86 KWH
Week 13: 55.70 KWH
Week 12: 65.83 KWH
Week 11: 74.17 KWH
Week 10: 72.13 KWH
Week 9: 53.68 KWH
Week 8: 50.01 KWH

Monthly Production History:
May 2011: 111.66 KWH (Partial)
Apr 2011: 295.18 KWH
Mar 2011: 262.25 KWH
Feb 2011: 206.07 KWH
Jan 2011: 38.50 KWH (1/26-1/31)

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Wednesday, May 4, 2011

Actual Solar Savings for First 3 Months

I saved $144 for the first three months of solar production. That's $48 per month, which is a little higher than the estimated average savings of $46.35 per month. I updated my SCE Rates Calculator model with my actual electric bills and solar production for February through April to calculate my savings (on the first tab in the blue cells).

Kinda funny. When I got my first bill, I was jumping up and down when it was $3. Then I read it closer and realized that it was just the taxes on the KWHs my solar PV system produced for the month. When you go solar, SCE bills you monthly for taxes but only quarterly for your net meter usage.

Tuesday, May 3, 2011

14 Weeks Solar Production

We hit a new daily high of 13.56 KWH - in fact, we produced over 13 KWH five different times this week. Our rolling 30-day average production is 311 KWH, which far exceeds the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 14 Weeks:
Production: 841 KWH
CO2 Saved: 1,396 lbs
Estimated Savings: $168.20

Weekly Production History:
Week 14: 90.86 KWH
Week 13: 55.70 KWH
Week 12: 65.83 KWH
Week 11: 74.17 KWH
Week 10: 72.13 KWH
Week 9: 53.68 KWH
Week 8: 50.01 KWH

Monthly Production History:
Apr 2011: 295.18 KWH
Mar 2011: 262.25 KWH
Feb 2011: 206.07 KWH
Jan 2011: 38.50 KWH (1/26-1/31)
System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 SunPower Serengeti 228 Watt
Inverter: 1 SunPower 3000M (SMA Sunny Boy 3000 re-branded under SunPower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Tuesday, April 26, 2011

13 Weeks Solar Production

Our rolling 30-day average production is 287 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 13 Weeks:
Production: 750 KWH
CO2 Saved: 1,245 lbs
Estimated Savings: $150.00

Weekly Production History:
Week 13: 55.70 KWH
Week 12: 65.83 KWH
Week 11: 74.17 KWH
Week 10: 72.13 KWH
Week 9: 53.68 KWH
Week 8: 50.01 KWH

Monthly Production History:
April 2011 (partial): 245.98 KWH
Mar 2011: 262.25 KWH
Feb 2011: 206.07 KWH
Jan 2011: 38.50 KWH (1/26-1/31)
System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Thursday, April 21, 2011

Economics of Solar

I found this great article titled "Economics of Solar Electric Systems for Consumers: Payback and other Financial Tests" by Andy Black, July 2009. Mr. Black is a solar financial analyst and CEO of OnGrid.net.

If you are interested in gaining a more in-depth knowledge of why solar makes financial sense, I think this article does a great job. It's quite comprehensive and covers system performance, electric rates, incentives and financial returns.

If you want a quick snapshot approximation of what kind of returns/payback you can expect, refer to Figure 14 on page 15 in Mr. Black's article. There are various case examples for 12 states. For some states, there are high usage and low usage examples. The returns are much better for high electricity usage customers since they are paying big premiums for Tier 3-5 electric rates. I like the Lifecycle Payback Ratio - it's nice and simple and tells you how many times over in savings you can expect to receive for the cost of installing the system.

Tuesday, April 19, 2011

12 Weeks Solar Production

Our rolling 30-day average production is 281 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 12 Weeks:
Production: 694 KWH
CO2 Saved: 1,152 lbs
Estimated Savings: $138.80

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Monday, April 18, 2011

Adding Solar Increases the Value of Your Home

According to the “Evidence of Rational Market Valuations for Home Energy Efficiency,” Rick Nevin, Christopher Bender, and Heather Gazan, Oct 1999, a home’s value is increased by $20,000 for every $1,000 reduction in annual operating costs from energy efficiency.

Using my home PV system for example, I expect to save approximately $550 per year on my electric bills. At 20:1, that would mean that I can expect to sell my house for $11,000 more now that I have solar. That's $3,600 more than what it cost me to install my PV system ($7,400 after the Federal ITC and rebates from my utility for my 2.28KW DC system). I'll get to reap the monthly savings while I live in my house and if I sell my home, I will get some, all or more of the cost back in the sale price.

Wednesday, April 13, 2011

11 Weeks Solar Production

This week we set another new daily production high of 12.99 KWH. Our rolling 30-day average production is 269 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 11 Weeks:
Production: 628 KWH
CO2 Saved: 1,042 lbs
Estimated Savings: $125.60

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Tuesday, April 12, 2011

Electric Bill Savings Calculator

I made a quick Electric Bill Savings Calculator.  In general, for the models I have in this Blog, I designate the input cells in green shading, which is what you should change based on your personal information. Items shaded in yellow are key results or items.

Steps:
  1. Enter KWH for each of the past 12 months from your electric bill into cells E9:E20 in the Calculator tab of the model.
  2. Enter the estimated solar production KWH into cells E26:E37 in the Calculator tab of the model. Please refer to my post on Solar Home Buyer's Guide Part 2 to estimate your solar production.
  3. Change the Region to your location in cell B4 in the Calculator tab of the model. This is based on my utility company Southern California Edison (SCE) - if you click to this link, there are PDFs of the region zones at the bottom of SCE's webpage.
  4. If SCE is not your utility, you may need to tweak some items. Override the Tier Rates (cells F4:O4 on the Calculator tab) with your utility rates and tiers. You can either override the Baseline Daily KWH in column C on the Calculator tab or change the amounts in cells B24:C32 on the SCE Tiers tab at the end.
Results:
  1. Average annual savings rate per KWH is shown in cell Q38 on the Calculator tab - highlighted in yellow.
  2. Annual solar production as a percent of your total electricity usage is shown in cell E39 on the Calculator tab - highlighted in yellow.
  3. Annual electricity bill savings as a percent of your total electricity bill without solar is shown in cell P39 on the Calculator tab - highlighted in yellow. You will notice that the $ savings % is higher than the production KWH % for solar. The reason for this is because you are offsetting the highest-priced electric rate tiers with your solar PV system and only paying your utility for the cheapest-priced tiers.
    • The tiered pricing is very important in your financial returns. If you are a heavy electricity user (bills that are in Tier 3-5), you are paying hefty prices to your utility. The higher your electricity usage, the more financial sense it makes to go solar.
  4. There are several graphical representations of your solar savings in the handful of charts I included in the model. Note that the text boxes in the charts need to be manually updated with the new totals you calculate if you want the charts to be accurate.

Monday, April 11, 2011

10 Weeks Solar Production

This week we set another new daily production high of 12.52 KWH. Our rolling 30-day average production is 263 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 10 Weeks:
Production: 555 KWH
CO2 Saved: 942 lbs
Estimated Savings: $111.00

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Friday, April 1, 2011

New Solar Production High of Over 12 KWH

Amazing. We set another daily production high of 12.04 kilowatt hours on Wednesday. First time we broke 12 KWHs.

Tuesday, March 29, 2011

9 Weeks Solar Production

We had some rainy days this week, but again, we set a new daily production high of 11.32 KWH blowing past the previous high of 10.67 KWH - must be the longer days in addition to the clear blue skies after a rain. Our rolling 30-day average production is 248 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 9 Weeks:
Production: 482 KWH
CO2 Saved: 800 lbs
Estimated Savings: $96.40

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Thursday, March 24, 2011

Solar Incentives and Rebates

There are plenty of subsidies and incentives available for solar photovoltaics (PV) as well as other renewables. The big incentive is the U.S. Federal Investment Tax Credit (ITC) of 30%. If you install a PV system at your home, you will get a 30% credit on your income taxes the following year (i.e., the tax credit is not a deduction; it is like a tax refund). The Federal ITC is available through 2016.

There are also incentives for solar and renewables offered in/by various states. But the general rule is "first come-first served", which means, the earlier you get in, the higher the incentive. So there is a big reason to buy solar now as opposed to waiting.

The DSIRE (Database of State Incentives for Renewables & Efficiency) website is a good source to find incentives (not just for solar) for your state.

California Incentives
In California, the state sponsored program is called the California Solar Initiative. California Solar Initiative (CSI) Trigger Tracker is a convenient tracker for the incentives for the big utilities (PG&E and Southern California Edison). The incentives are done based on "steps". The tracker shows the current incentive rate and where they are in the current step in terms of megawatts (MW) under review and MW remaining. The earlier steps in the program had significant incentives ($2.50 per Watt), but now they are down to Step 6 ($1.10 per Watt) for SCE and step 8 ($0.35 per Watt) for PG&E. These are still good incentives, but they are quickly being taken by others.

LADWP is still paying incentives for solar, but there are delays and the process and calculations are more cumbersome.

Pasadena Water & Power is still paying high incentives of $2.00 per Watt. They use the same basis to calculate the incentive as the CSI Calculator. You just apply it at $2.00 per Watt. So get it while the gettin is good.

Burbank Water and Power still has significant rebates available. They are on Step 4 which provides $2.36 (assuming BWP keeps the renewable energy credits).

Glendale Water and Power is currently on hold until July 1, 2011. If they keep with the same rebate schedule, 2011 incentives are still very high at $3.22 per Watt.

Wednesday, March 23, 2011

Japan Tsunami - Please Help

The Tsunami in Japan was terrible. They need our help with victims that lost their homes and loved ones and also to help contain the nuclear reactor problems. Here's a site that has a list of rescue/relief organizations - USAID.gov (President Obama mentioned the site when he was making his NCAA Basketball March Madness selections).

Tuesday, March 22, 2011

8 Weeks Solar Production

We keep setting new daily production highs. This week we had a day that hit 10.67 KWH, which helps to offset the low production on the big rainy days we had this weekend. Our rolling 30-day average production is 247 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 8 Weeks:
Production: 428 KWH
CO2 Saved: 710 lbs
Estimated Savings: $85.60

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Solar Training Class at the Audubon Center at Debs Park

This weekend I attended a solar training course at the Audubon Center at Debs Parks in South Pasadena. The Audubon Center is completely off-grid (i.e., it is not connected to the utility) and gets all of it's power from a 26KW solar PV system and a 10-ton solar thermal cooling system. Click link to find out more about the Audubon Center's Green Building.

The class was put on by Wade Webb (Vice President of Residential Operations and Quality Manager at Martifer Solar), who has been installing solar PV systems since 1995. Wade installed the off-grid solar PV battery system for the Audubon Center in 2003 and continues to provide maintenance for the system. When parts need to be repaired or replaced, Wade uses that as his hands-on training for the class. So in the class on Saturday, we actually removed a blown out inverter, replaced the internal controllers and reinstalled the inverter back into the system. Pretty cool. He holds classes there on every third Saturday of the month. Wade says we're going up on the roof at the next class.

Friday, March 18, 2011

Note on the Ads

I recently added ads from Google and links to Amazon and other sites into my blog for a couple reasons. First, I think I can use the panels along the side not as advertising, but as a convenient "index" or "resource guide" tool which are links to source materials I used in researching solar and that I refer to in my blog posts - most of these are links to Amazon and other sites that will bring you away from my Blog. Second, this is my first Blog, so I'm curious as to how these ad links work and how helpful they are (i.e., I want to learn). I will be putting the true ads from Google below the "About Me" section and at the bottom of my Blog. That way they are out of the way.

I hope these ads do not an inconvenience to you. If so, please post a comment and let me know how to make it better.

Tuesday, March 15, 2011

7 Weeks Solar Production

We set another new daily production high of 10.53 KWH. Our rolling 30-day average production is 242 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 7 Weeks:
Production: 378 KWH
CO2 Saved: 627 lbs
Estimated Savings: $75.60

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Wednesday, March 9, 2011

Rants and Rays - Carbon Leverage

I believe that saving the planet is a worthwhile effort, but the challenge is rationalizing the costs. I believe that the costs can be justified, but we need to think smarter and look at things in unconventional ways.

Let's take the concept of "leverage", for instance. The conventional way to look at leverage is using debt to finance a purchase. In my Buyer's Guide Part 3 post, I showed how financial leverage (mortgage refinancing) can be used to eliminate your upfront costs and maximize your returns from solar. Now, what if we apply the same concept of leverage to CO2 emissions (carbon footprint)? Here's the leverage my solar PV has on my carbon footprint.

Annual Electricity Usage:
Dirty energy provided by Utility: 4,732 KWH
Clean energy provided by solar: 2,781 KWH
Total usage: 7,513 KWH

Annual Cost of Electricity (Year 1):
Without solar: $1,200 ($0.1597 per KWH)
Increase in cost to have solar: $48 ($0.0064 per KWH)
Total with solar: $1,248 ($0.1661 per KWH)
Increase in total cost: 4%

Carbon Footprint (CO2 emissions):
Without solar: 12,772 lbs.
Reduction from solar: (4,728) lbs.
With solar: 8,044 lbs.
CO2 reduction: 37%

Conclusion:
It costs me only 4% more to have solar, but I have reduced my carbon footprint by a whopping 37%. So, for every 1% increase in cost, I save 9.25% in CO2 emissions. In other words, I have a 9.25 to 1 leverage on CO2 emissions - this is what I term "Carbon Leverage". That is huge leverage and, ultimately, enormous value. On a higher level, the point I'm trying to make is that costs and carbon metrics should not be viewed independently of one another. On the contrary, they are mutually dependent and should be viewed holistically to truly evaluate the cost-benefit analysis. Looking at it this way, I think it would be difficult to find another value proposition (environmental or not) where you could spend $1 and get $9.25 of value in return. If you think of solar from that perspective, it's very difficult to justify NOT going solar.

A Utility really doesn't have the advantage of leverage. According to a U.S. Department of Energy study on levelized costs, Advanced Gas Turbine technology costs $0.1035 per KWH to produce whereas Solar PV costs $0.2107 per KWH. It would cost a Utility 2x as much to source their energy from solar rather than natural gas. Using the same methodology as above, it would cost a utility 100% more to achieve a 100% reduction in CO2. The result is a Carbon Leverage of 1:1, which means there is no leverage (i.e., they need to spend $1 to get $1). No wonder utilities are resistant to going solar.

The Carbon Leverage that individuals can obtain far exceeds the leverage that utilities can achieve. That's just one of the reasons why I believe that solar PV really is more of an "individual-scale" technology than a "utility-scale" technology. But that's another topic...I'll post about it in a future installment of Rants and Rays.

Post-publishing note: I recently found that the term "Carbon Leverage" already exists, so I can't take credit for coming up with it. In a study on Clean Investment Budgets, the term carbon leverage is used in the context of incenting poorer countries by giving them higher emissions budgets. By giving them higher budgets, poorer countries are able to sell the excess emissions (like renewable energy credits) to richer nations in exchange for money/capital. This capital can then be leveraged to invest in cleaner and more efficient technology by poorer nations. Carbon leverage in this context is a financing mechanism for richer nations to transfer to poorer nations to effect global climate change. In another study by the Oxford University's Smith School of Enterprise and Environment, carbon leverage is used more similarly to how I defined it above. It's kind of cryptic, but on page 15 they talk about creating a market for renewable energy credits that would be worth less than the equivalent reduction in CO2. This would then create carbon leverage similar to my example above (i.e., since the renewable energy credits are sold at a discount, there are greater than 1:1 reductions in CO2 emissions).

6 Weeks Solar Production

We set another new daily production high of 10.33 KWH. Our rolling 30-day average production is 230 KWH, which is higher than the target average of 228.6 KWH to achieve the CSI estimated annual production for our system.

Total After 6 Weeks:
Production: 311 KWH
CO2 Saved: 521 lbs
Estimated Savings: $62.20

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Monday, March 7, 2011

Rants and Rays - CO2 Savings and Emissions

When my brother looked at one of my solar production posts, he exclaimed, "Wow! I didn't know that much CO2 was created by our utilities. Are you sure you are saving 339 pounds of CO2 for only 199 kilowatts hours of electricity? Seems like an awful lot." When he said that, I was even a little incredulous. How can you create 1.7 pounds of CO2 pollution by producing only 1 KWH of electricity? So, I had to look it up.

Here are some pollution rates (per KWH) based on the major fuel types (1999 rates from a U.S. Department of Energy Study):
Coal: 2.095 lbs
Oil: 1.969 lbs
Gas: 1.321 lbs
US Average: 1.341

While my solar monitoring system uses a higher than average carbon assumption, either way, 1.34 or 1.7 pounds of CO2 per KWH is still a lot. And it really adds up. U.S. electricity generation plants emitted 2.27 billion metric tons of CO2 pollution in 2009 according to the U.S. Department of Energy's Electric Power Annual 2009 study. Way too much!

To put this into more everyday terms, a typical refrigerator, for example, uses 188 watts per hour. For the year, it will use 1,647 KWH and have a carbon footprint of 2,175-3,450 pounds of CO2 per year, depending on your utility's fuel source mix. Here's a site on how much electricity common household appliances use. Conserving electricity and being more aware of what and how we use electricity are some things we can all do to help save the planet.

Thursday, March 3, 2011

5 Weeks Solar Production

We set another new daily production high of 10.2 KWH on Sunday, blowing past the previous high of 9.6 KWH. And I just realized why. After a day of rain in SoCal, the skies are blue and absolutely clear of clouds and smog. See Current Production Chart thru 5 Weeks.

Total After 5 Weeks:
Production: 250 KWH
CO2 Saved: 415 lbs
Estimated Savings: $50.00

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Tuesday, March 1, 2011

Rants and Rays - The 4 C's of Solar

"Rants and Rays" is my posting of various thoughts about the solar industry. I hope to make this a regular "column" in my blog. Here is my first installment.

There is a catch phrase that all good marketers know - the 4 P's (product, place, price, and promotion). There is also a lesser known model called the 3 C's (customer, company, and competition), but I digress. I was thinking about the challenges and opportunities of solar and came up with a similar catch phrase that I term the "4 C's of Solar" (depicted in a triangle):
  • Conscience: Conscience is the desire to go solar. It is the desire to do the right thing and help the environment.
  • Cost: Cost represents the obstacles to going solar. Cost is the real and perceived price of solar. Cost is also the time and effort to initiating a solar plan.
  • Change: Change is the action of going solar. It is actually doing something to be part of the solution.
  • C-nowledge: Knowledge is the tool to make the Change and bridges the gap between the Cost (obstacles) and the Conscience (desire). Personally, I believe there are more perceived obstacles than real ones. Knowledge can help dispel the misconceptions and can allow one to make truly informed decisions.
This is probably a truism for many things, but I think it works well with solar. This is also the purpose of my blog - to share knowledge about solar. Hopefully, people will find it useful and go solar too.

Thursday, February 24, 2011

Pictures of My Solar PV System

I finally climbed on my roof to take some photos of my solar PV system.

We have a low-pitched roof, we have trees in our front yard and our PV system sits on our second floor which makes our PV system only visible from one side of the street. Street View.

These days, panels are made to be nice and sleek. Roof View.

We only had enough space next to our Electrical Panel for the Shut Off Switch, so the Inverter had to be placed about 10 feet away on an empty wall space. The installers did a great job running conduit under our house to minimize any blemishes that my wife might complain about ;).

In one of my earlier posts, I mentioned the importance of having the installer do a physical site visit and evaluation. Here's a picture of some of the Roof Obstructions that would be difficult to identify from Google Maps or Bing.

Installer: Martifer Solar (Matt Rakocija)

Wednesday, February 23, 2011

4 Weeks Solar Production

Yippee!! We set a new daily production high of 9.6 KWH on Sunday.

We had a few days of rain these past couple weeks so our current daily average declined slightly to 7.3 KWH per day. But I'm very happy with this production level. February is supposed to be a low production month, yet we are very close to our average daily production target of 7.6 KWH to reach the CSI Estimated Annual Production of 2,781 KWH for our system. See Current Production Chart.

Total After 4 Weeks:
Production: 199.3 KWH
CO2 Saved: 338.8 lbs
Estimated Savings: $39.86

System Size DC (STC): 2.28KW
System Size AC: 1.93KW
System Size AC (California CSI rating): 1.63KW
Panels: 10 Sunpower Serengeti 228 Watt
Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
Estimated Annual Production: 2,781 KWH
Direction: East facing

Installer: Martifer Solar (Matt Rakocija)

Thursday, February 17, 2011

Part 3 of 3: A Home Buyer's Guide to Purchasing a Grid-Tied Solar PV System - Finalizing Your Decision

This is Part 3 of 3.  Please refer to earlier posts for Part 1 and 2.

I started researching solar over a year ago and got really excited about the opportunities. I started getting quotes from installers in May, put a deposit on a system in September and the installation was completed and we started producing electricity on January 26 , 2011. I hope this Guide will help you with your solar choices.

Steps in the process:
  1. Get a general understanding and overview of solar PV systems for the home. (Detailed in Part 1 post)
  2. Determine a rough estimate for your solar PV system. (Detailed in Part 1 post)
  3. Find installers and request quotes. (Detailed in Part 1 post)
  4. Standardize your quotes so you can compare and evaluate them on an apples-to-apples basis. (Detailed in Part 2 post)
    • Evaluate your quotes and your options. (Detailed in Part 2 post)
    • Evaluate your financials.
      • I created a Solar Financial Model (that's what I do all day at work - build models) that you can use to evaluate your savings/returns. You'll need to use the estimates you calculated from Steps 4 and 5 and enter them into the GREEN cells in this model. Note - I changed the link because Google Docs tends to distort spreadsheets making it a little difficult to read. If you Save the file to your computer, you can see it in plain Excel.
      • One of the key drivers of the financial returns is the energy price increase assumption. I received a quote that showed my returns based on a 7.6% annual price increase. I should find a study to get a validated figure (another thing on my list to do), but it's a safe bet that energy prices will rise at a faster rate than inflation. You can change this assumption in my model. Also at the bottom of the model are sensitivities for your returns based on different annual price increase assumptions.
      • If you are buying the system with "cash", then you will want to look at the ROI section. If you are financing the purchase through your mortgage (refinance or home equity loan), then you will want to look at the ROE section. Even if you can not time your purchase with your mortgage, it still makes a lot of sense to buy your solar PV system now because of the rebates and tax credits currently available which will phase out over time (I purchased my system at a 43% discount). Then when you do eventually refinance your mortgage you can roll up the cost and you'll start seeing the better ROE returns.
      • Note on the Annual Return calculation. If the Annual Return shows #NUM! or DIV/0! errors, it's OK. Actually, it's great because it likely means that your annual savings exceed your annual payments from the beginning so a return can not be calculated (i.e., you have an astronomical return on your investment). Interest rates were so good that I was able to maintain the same monthly payment even though I refinanced my new mortgage from a 30-year loan to a 15-year loan. The annual return for my solar system is 81%. If I assumed a 30-year mortgage with an interest rate of 6% in the model, I would get one of those errors because I would save more money than it cost me from Day 1 and have no net out of pocket costs at all.
      • Solar Leasing. I did a cursory look into leasing (another item to add to my list that I will try to update in the future), but it didn't make sense in my situation because I was going to finance my purchase through my mortgage.
    • Select an installer.
      • Your installer will be your primary resource, so you should choose one that you trust and feel comfortable working.
      • Your installer will typically warranty their installation and repairs for 10 years, so you might also consider the longevity of your provider.
      • I didn't find a good review site for installers - but, then again, I didn't search very hard for one. I think this is something that I will look into further and add some links.
      • I mostly relied on contacting references provided to me by the installers. 1 Block Off the Grid, Cooler Planet and others have good questions and things to consider. Some of the questions I asked were the following:
        • What is the size of your system and when did you have it installed?
        • Has the performance of your system met your expectations? Have you noticed a drop off?
        • Have you had any issues with the system (inverter failure, problems with the panels, monitoring, etc.)? How were they resolved?
        • Have you had any roof leaks? How were they resolved? Was the Installer at fault?
        • Does Installer provide any ongoing services to you?
        • How satisfied are you with your PV system?
        • How satisfied are you with Installer?
        • What would you do differently if you had to do it all over again?
    • Other factors to consider.
      • What is the condition of your roof? If it needs replacing, then it is better to have it replaced before or in coordination with the installation of the solar. Our roof had a few more years of life left, but we would need to replace it unless we moved so we had the roof redone in coordination with the solar installation (now it's good for another 40+ years). The solar installers installed the standoffs in the middle of the roofing process so that they would not need to make any penetrations in our newly shingled roof.
      • What kind of shingles are on your roof? Installers have no problems with composite shingle roofs but they may have issues with wood shake and tile roofs. Many installers do not like installing solar on wood shake roofs since they have to replace all of the shingles that they crack and break during installation of the PV system. With tile roofs, installations are also more difficult. Some installers will not work on these roofs or will charge you more for the installation.
      • What is your shading and tree situation like? We considered a South-facing configuration for our home, but our neighbors to the west of us have some big oak trees that would create significant shading in the late afternoons and in the winter months. While we get along with our neighbors, we did not want to inconvenience them to trim their trees every few years. Instead, we decided on an East-facing orientation because there would be no shade issues. To minimize the hassle and additional maintenance, we felt it was well worth sacrificing the 200 KWH per year of production (6.8% lower) of the South-facing configuration.
      • Aesthetics. My wife only had one stipulation when I bought our PV system. She told me, "just make sure it doesn't look ugly." Fortunately, I was able to accommodate her on her request quite easily. However, if you have a high-pitched roof that faces the street, you may want specialized panels that are flush with your roof.
    • Go solar and enjoy the sunshine.
      • At some point you have to take a leap of faith that your system will be reliable and produce the electricity you expect. I will be posting my solar production so you can have at least one live data point.
      • Upsides. They say that solar adds $20 for every $1 you save in electricity per year to the value of your home.
    Below is a summary of my home PV system:


    System Size DC (STC): 2.28KW
    System Size AC: 1.93KW
    System Size AC (California CSI rating): 1.63KW
    Panels: 10 Sunpower Serengeti 228 Watt
    Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
    Estimated Annual Production: 2,781 KWH
    Direction: East facing


    Cost of System Before California Utility Rebate (Installed Cost): $13K
    Cost of System After California Utility Rebate: $10.5K
    Cost of System After Federal Tax Credit: $7.4K

    Cost per DC (STC) Watt: $5.73
    Cost per AC Watt: $6.77
    Cost per AC CSI Watt: $8.01

    Installer: Martifer Solar (Matt Rakocija)


                                            Mortgage                Electric Bill           Total Mo. Pmt
    With Solar                         $1,050            +           $ 54             =         $1,104
    Without Solar                  $1,000           +          $100             =         $1,100
    Difference                                 $50                         $(46)           =           $       4
    It costs me only $4 more per month to have clean energy.

    Wednesday, February 16, 2011

    3 Weeks Solar Production

    We had problems getting our monitoring system up and running during the first week, so I had to run outside and check the system every day. Now that it's working, I can check it from the internet - so much better. See my daily production chart.

    After 3 Weeks:
    Production: 147.0 KWH
    CO2 Saved: 249.9 lbs
    Estimated Savings: $29.40

    System Size DC (STC): 2.28KW
    System Size AC: 1.93KW
    System Size AC (California CSI rating): 1.63KW
    Panels: 10 Sunpower Serengeti 228 Watt
    Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
    Estimated Annual Production: 2,781 KWH
    Direction: East facing

    Installer: Martifer Solar (Matt Rakocija)

    Friday, February 11, 2011

    Part 2 of 3: A Home Buyer's Guide to Purchasing a Grid-Tied Solar PV System - Evaluating Your Quotes

    This is Part 2 of 3.  Please refer to earlier post for Part 1.

    I started researching solar over a year ago and got really excited about the opportunities. I started getting quotes from installers in May, put a deposit on a system in September and the installation was completed and we started producing electricity on January 26 , 2011. I hope this Guide will help you with your solar choices.

    Steps in the process:
    1. Get a general understanding and overview of solar PV systems for the home. (Detailed in Part 1 post)
    2. Determine a rough estimate for your solar PV system. (Detailed in Part 1 post)
    3. Find installers and request quotes. (Detailed in Part 1 post)
      • Standardize your quotes so you can compare and evaluate them on an apples-to-apples basis.
        • Each installer will probably have slightly different configurations and panels made from different manufacturers. Therefore comparing one quote to another is very difficult since each quote really is it's own customized product. In addition, there are many different numbers and definitions that are difficult to understand and keep straight. 
          • Personally, I got a multitude of quotes and configurations that ranged from 1.84KW to 2.58KW in size, different array directions (South, West and East facing), different shading assumptions, and of course different panels and inverters. There was no way for me to compare the quotes accurately based on what the installers gave me alone. So I found it essential to find a price/performance metric that I could use as a standard benchmark to evaluate my options.
        • Before I get to the metric I found to be most useful, I want to define and describe a lot of the measurements upon which the installers will base their quotes and with which you will need to derive a standard metric.
          • DC Rating STC. This is the name plate rating of your system based on Standard Test Conditions (STC) and this is the size of your system that your installer will quote you. When somebody asks you how big your PV system is, this is what you will give them. I think this has flaws as a benchmark because the performance in real world conditions can vary among different panels.
          • DC Rating PTC. This is the DC size of our system based on PVUSA Test Condition (Photovoltaics for Utility Systems Applications) which is closer to real world performance than STC. Many refer to PTC as "Performance Test Conditions". I think this is better than DC STC.
          • Inverter Efficiency. Solar PV panels produce electricity on a Direct Current (DC) basis but need to get converted to Alternating Current (AC) through your inverter so they can feed back into the grid (your house runs on AC power). This is how well your inverter converts DC to AC. The more efficient, the less electricity loss you have in the conversion.
          • AC Rating (based on PTC). This is the the DC PTC Rating multiplied by the Inverter Efficiency. This is your real standard system size before design factor adjustments. The AC Rating is the base metric you will want to use. Further down, I will describe a variation of this base metric that I prefer to use (based on CSI rating).
          • Shading Derate Factors. The performance of your system will be affected by the shading the panels will receive over the course of the year. When your installer does a site visit, he should do a shade test and provide you with a detailed shading report with his quote. The shading derate factors will be needed to accurately assess your design factor adjustments.
          • Array Tilt. This is the angle that your solar panels are positioned relative to the ground. Your panels will most likely be the angle/slope of your roof. The ideal tilt depends on where you live. In my area in Los Angeles, the optimal tilt is 17 degrees.
          • Array Azimuth. This is the direction that your solar PV system is facing. The array azimuth is shown in degrees with True North being zero degrees and South being 180 degrees. The ideal direction is South facing (180 degrees).
        • As mentioned above, the AC Rating is the base metric you will want to use to compare all of your various quotes, but you will need to further standardize your quotes to compare them on the same basis.
        • I found the CSI Calculator , a utility rebate calculator for the California Solar Initiative, to be the easiest tool to standardize my quotes. Even if you do not live in California, I would still recommend this calculator for you. In addition to ease of use, what I like about this calculator is that it is an official and industry standard calculation rather than an estimate produced by your installer (call me a cynic).
        • The PVWatts Calculator is also another good calculator (can be used for any place in the world) developed by the National Renewable Energy Laboratory. Most calculators, including CSI, are based on the PVWatts calculations of solar radiation (how much annual sun). Again, like the CSI calculator, you can estimate your annual and monthly PV production and savings. If you live outside of California, you may want to use this to get your final estimated production. You will need to provide (or use their defaults) additional design factor adjustments, so it is a little more complicated than CSI. Also note that the dollar savings may be understated if you use their cost per KWH for your area because this is based on the total average and not at the higher tiers which your solar PV system would likely offset.
        • Steps to standardize your quotes:
          • I would suggest using your most preferred quote or the system setup that you think you are likely to purchase. Make sure you have an accurate shading report for this quote because that will be one of the critical assumptions you will use. Using the CSI Calculator, you will use the same assumptions for the following inputs/factors:
            • Shading Derate Factors (monthly percentages from the shading report from your installer)
            • Array Tilt (degrees)
            • Array Azimuth (degrees)
            • Also use the same basic information including Utility, Customer Type, Incentive Type and Mounting Method.
          • The only variables that are not standard will be the make of the panels/modules, number of modules, make of inverter, number of inverters and quoted cost of the system.
          • After inputting the assumptions into the CSI Calculator, you will have a report that will tell you your estimated Annual Production (Annual kwh), AC Rating (CEC-AC Rating) and CSI Rating. I like the CSI Rating because this is the performance rating (AC Rating multiplied by the Design Factor adjustment). You can save PDF versions for the reports you run for each of your standardized quotes. You will now have the performance for all of your quotes based on the same assumptions.
          • Click this link for a step-by-step guide with screen shots for using the CSI Calculator.
      • Evaluate your quotes and your options.
        • After you have standardized the quotes and created various scenarios through the CSI Calculator, you can now start to compare and evaluate the different quotes.
        • The first step is to determine how the installers stack up against each other. Even though most installers will quote you based on Cost per DC Watt Installed (STC), I think the better metric is Cost Per AC Watt because this captures the conversion to AC and real world inefficiencies. Personally, I like using the Cost Per CSI AC Rating because that captures all of the design factors including direction of your array in case you are deciding between different roof placements. Using Cost Per AC Watt as your price/performance metric, you can now compare the installer costs for all of your quotes irrespective of system size, direction, etc. You can go back to your installer and question the system cost and see if they come back with a better price.
        • The next step is to determine the best position of your PV system. The ideal position is South-facing, but the shading of your roof and other factors may make it less ideal. Using the CSI Calculator, you can run another scenario with your top quote choice by changing the direction and shading derate factors while keeping all other assumptions the same. This will calculate your estimated Annual KWH production with the new array direction that you can compare to your top quote choice.
        • At this point, you will be able to determine which installer is offering you the best price and what direction/configuration will produce the most solar energy. Click link for Solar Quote Comparison Spreadsheet. Note - Google Docs tends to distort spreadsheets making it a little difficult to read. If you Save the file to your computer, you can see it in plain Excel.
      • Evaluate your financials. (Detailed in Part 3 post)
      • Select an installer. (Detailed in Part 3 post)
      • Other factors to consider. (Detailed in Part 3 post)
      • Go solar and enjoy the sunshine. (Detailed in Part 3 post)
      Below is a summary of my home PV system:

      System Size DC (STC): 2.28KW
      System Size AC: 1.93KW
      System Size AC (California CSI rating): 1.63KW
      Panels: 10 Sunpower Serengeti 228 Watt
      Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
      Estimated Annual Production: 2,781 KWH
      Direction: East facing

      Cost of System Before California Utility Rebate (Installed Cost): $13K
      Cost of System After California Utility Rebate: $10.5K
      Cost of System After Federal Tax Credit: $7.4K

      Cost per DC (STC) Watt: $5.73
      Cost per AC Watt: $6.77
      Cost per AC CSI Watt: $8.01

      Installer: Martifer Solar (Matt Rakocija)

                                              Mortgage                Electric Bill           Total Mo. Pmt
      With Solar                         $1,050            +           $ 54             =         $1,104
      Without Solar                  $1,000           +          $100             =         $1,100
      Difference                                 $50                         $(46)           =           $       4
      It costs me only $4 more per month to have clean energy.

      Thursday, February 10, 2011

      2 Weeks Solar Production

      Total production and savings after 2 weeks.

      Production: 95.3 KWH
      CO2 Saved: 162.0 lbs
      Estimated Savings: $19.06

      System Size DC (STC): 2.28KW
      System Size AC: 1.93KW
      System Size AC (California CSI rating): 1.63KW
      Panels: 10 Sunpower Serengeti 228 Watt
      Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
      Estimated Annual Production: 2,781 KWH
      Direction: East facing

      Installer: Martifer Solar (Matt Rakocija)

      Monday, February 7, 2011

      Part 1 of 3: A Home Buyer's Guide to Purchasing a Grid-Tied Solar PV System - Getting Started

      I started researching solar over a year ago and got really excited about the opportunities. I started getting quotes from installers in May, put a deposit on a system in September and the installation was completed and we started producing electricity on January 26 , 2011. In a separate post, I described my reasons for going solar. In this post and following posts, I will focus on what I did, how I evaluated my solar options, what resources I found useful and other models/tools I put together to help me in buying my grid-tied solar PV system.

      I've separated this Guide into multiple parts so I could provide more explanation in each step while limiting the size of each post. I hope this Guide will help you with your solar choices.

      Steps in the process:
      1. Get a general understanding and overview of solar PV systems for the home. 
        • While I did most of my research online, I did find a useful book in the library titled Got Sun? Go Solar by Rex A. Ewing and Doug Pratt. The book was a great starting point and it provided me with a good practical overview and guide for understanding solar (and wind) for the home. Some of the items in the book that I found useful were the requirements and considerations in choosing a PV system (simple grid-tied or battery system) and the simple rules-of-thumb to help me easily understand and estimate energy production and other output. The authors also had lots of technical information (e.g., electrical calculations) and their opinions on some of the components and manufacturers that they used over their many years of installing PV systems (kinda like a Consumer Report for solar). All of this information was packed into less than 100 pages of text making it a quick read and nice reference guide.
        • Cooler Planet provided good overview information. I used this site mainly to create my checklist of things to consider (Solar 101 tab) and to to get a rough estimate the size and cost of the system I wanted for my home before I started calling installers (easy to use calculator in the Solar Tools tab).
      2. Determine a rough estimate for your solar PV system.
        • Pull together the last 12 months of electric bills. This is your starting point for evaluating what size system will make sense for your energy usage. This is also the first thing an installer will ask you for so it's good to have it at your fingertips.
        • In California, electric rates are based on a tiered system. There are five tiers with significant price increases as you move up from the lower tiers to the higher tiers. Tier 1 is also called "Baseline" and is very inexpensive, whereas Tier 5 can be very expensive (in my area it is 3X). In my area, the Baseline usage is 13.8 KWH (kilowatt hours) per day in the summer and 10.5 KWH per day in the winter and the rates are as follows:
          • Tier 1 (Baseline) 11.8 cents per KWH
          • Tier 2 (101-130% of Baseline) 13.8 cents per KWH
          • Tier 3 (131-200% of Baseline) 23.0 cents per KWH
          • Tier 4 (201-300% of Baseline) 26.5 cents per KWH
          • Tier 5 (Over 300% of Baseline) 30.0 cents per KWH
        • Optimally, you want to build a PV system that will cover your higher tier usage. If you are a heavy energy user, solar really makes a lot of sense because you are paying expensive rates.
        • My electricity usage is in the Tier 3 range most months and I bought a PV system that should offset around 40% of my usage. Looking back, I think I would have gotten a bigger system since it really wouldn't have cost me much more per month. I think it's similar to the saying about buying a house - buy the biggest one you can afford - since it's a little more difficult to add on to your system later.
        • Before I started calling installers, I used the Cooler Planet Calculator to get a rough estimate the size and cost of the system I wanted for my home (based on what percentage of energy I wanted to offset with solar).
      3. Find installers and request quotes.
        • As with most things, it's important to get multiple quotes. It's also very important to find an honest and reliable installer that you trust as your installer will guide you and be your primary resource for your new solar PV system. Of course, it's best to find some personal referrals. If not, there are sites that can provide recommendations for installers.
          • Cooler Planet Mentioned above. I got referrals for some local installers here and I ended up purchasing my system from one of them.
          • 1 Block Off the Grid evaluates and negotiates a group/volume discount rate with a designated installer for a particular area. The installer they recommended was very knowledgeable and the pricing was great. I think they are a great starting point. To me, they are like CarsDirect for solar - they'll provide you with a good installer at a good price. I would have been happy going with the installer 1BOG recommended.
        • The installer will have an initial phone call with you. He will likely ask you to get onto Google Maps or Bing to look at your house configuration and have you provide your electrical usage over the last 12 months.
        • The installer will then schedule a site visit so they can see your house and gather information to do a true assessment of your solar possibilities. Using a Solmetric SunEye, Solar Pathfinder or similar tool, the installer will be able to get an accurate reading of your sun and shading for every month of the year. Click this link for an example of one shade report I got for my house. With a site visit, the installer will take measurements of your roof and will be able to note any physical obstructions (eg, steam vents, dormers, DirecTV dish, etc.). It is very important to get a site visit in order to get an accurate assessment of your solar potential and where to put your system. Surprisingly, some installers do not do site visits before they give you a quote - I was told by one installer that they would do a site visit "if I was really serious".
        • After the site visit, the installer should be able to give you a comprehensive quote(s) for your solar PV system based on the tilt angle and direction including hardware, cost, estimated electricity KWH production and $ savings, utility rebates (significant in California and other states) and other items.
        • You may go through a few iterations of various configurations, size, placement, etc. of your system with the installer. Ask your installer a lot of questions since he will be your primary resource throughout the process.
        • In my opinion, if you have gotten to this point, you have made the biggest step in going solar because you have actually started the process going instead of just "sitting around and thinking about it". And, most of the work up to this point is actually done by the installers who are preparing all of the quotes for you.
      4. Standardize your quotes so you can compare and evaluate them on an apples-to-apples basis. (Detailed in post for Part 2)
      5. Evaluate your quotes and your options. (Detailed in post for Part 2)
        • Evaluate your financials. (Detailed in post for Part 3)
          • Select an installer. (Detailed in post for Part 3)
            • Other factors to consider. (Detailed in post for Part 3)
              • Go solar and enjoy the sunshine. (Detailed in post for Part 3)
              Below is a summary of my home PV system:

              System Size DC (STC): 2.28KW
              System Size AC: 1.93KW
              System Size AC (California CSI rating): 1.63KW
              Panels: 10 Sunpower Serengeti 228 Watt
              Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
              Estimated Annual Production: 2,781 KWH
              Direction: East facing

              Cost of System Before California Utility Rebate (Installed Cost): $13K
              Cost of System After California Utility Rebate: $10.5K
              Cost of System After Federal Tax Credit: $7.4K

              Cost per DC (STC) Watt: $5.73
              Cost per AC Watt: $6.77
              Cost per AC CSI Watt: $8.01

              Installer: Martifer Solar (Matt Rakocija)

                                                      Mortgage                Electric Bill           Total Mo. Pmt
              With Solar                         $1,050            +           $ 54             =         $1,104
              Without Solar                  $1,000           +          $100             =         $1,100
              Difference                                 $50                         $(46)           =           $       4
              It costs me only $4 more per month to have clean energy.

              Wednesday, February 2, 2011

              Week 1 Solar Production

              It's so nice to see our meter spinning backwards. I can't wait to see my first electric bill.

              Week 1 Production: 44.0 KWH
              Week 1 CO2 Saved: 74.8 lbs
              Week 1 Estimated Savings: $8.80

              System Size DC (STC): 2.28KW
              System Size AC: 1.93KW
              System Size AC (California CSI rating): 1.63KW
              Panels: 10 Sunpower Serengeti 228 Watt
              Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
              Estimated Annual Production: 2,781 KWH
              Direction: East facing

              Installer: Martifer Solar (Matt Rakocija)

              Thursday, January 27, 2011

              My First Day Producing Solar Energy!

              Yippee!!! We just got the sign off on our brand new 2.28KW Solar PV System for our home. We are now producing clean energy and doing our small part to help the environment.

              Day 1 Production: 7.0 KWH
              Day 1 CO2 Saved: 11.8 lbs
              Day 1 Estimated Savings: $1.40

              System Size DC (STC): 2.28KW
              System Size AC: 1.93KW
              System Size AC (California CSI rating): 1.63KW
              Panels: 10 Sunpower Serengeti 228 Watt
              Inverter: 1 Sunpower 3000M (SMA Sunny Boy 3000 rebranded under Sunpower)
              Estimated Annual Production: 2,781 KWH
              Direction: East facing

              Installer: Martifer Solar (Matt Rakocija)