Rants and Rays - Carbon Footprint 1 Year Later

After 1 year with solar, I recalculated my personal carbon footprint. I used the carbon footprint calculator from the US EPA.

With solar, my household of 4 people now has a carbon footprint of 25,103 lbs of CO2 per year (6,276 per household member). This is a reduction of 1,994 lbs of CO2 from the 27,097 lbs of CO2 (6,774 lbs per household member) we used to generate before we had solar PV on our roof.

The results are pretty incredible, but there is still a long way to go. I think reducing our car emissions would make the biggest dent. I just helped my parents get a Prius hybrid, so I'll take some credit there ;).

Year 1 Actual Solar Production Thru January 2012

After 1 full year, our PV system generated 2,927 kWh of electricity which was 5% more than the original system annual estimate of 2,781 kWh. I've only been paying $2-3 in taxes each month (SCE informed me that they would be billing me in May for the balance of usage charges), so our final billing has not been updated. Here is an Excel file of our actual solar production and savings.

Total Production for Year 1 (1/26/2011-1/25/2012):
Production: 2,927 kWh
Percent of Annual Predicted Production (2,781 kWh): 105%
Actual vs. Predicted Production Better/(Worse): +146 kWh
CO2 Saved: 4,829 lbs
Estimated Savings: $539.41

Monthly Production:
January 2012 (1/1-25): 105.98 kWh
December 2011: 90.01 kWh (we lost about 20 kWh of production from Pasadena windstorm power outages)
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

Happy Birthday - Our Solar PV System Is 1 Yr Old

Happy birthday solar PV. Installed January 26, 2011.

Solar Production Thru December 31, 2011

Our solar PV system is now 11 months old and we are on pace to generate 8% more energy than the original system annual estimate. I've only been paying the taxes each month ($2-3), but SCE just sent me a letter informing me that they would be billing me at the end of January for the balance of usage charges.

On December 1, we were hit by hurricane level windstorms in Pasadena, which knocked out the power at our house for 4 days. Since we are grid-tied, my solar PV system went on automatic shutdown until the grid was back up. We lost about 20 kWh of production during those 4 days. If I had a battery backup system, we would have had electricity through the entire mess.

Total Production To Date:
Production: 2,820.6 kWh
Percent of Annual Predicted Production (2,781 kWh): 101%
Actual vs. Predicted Production Better/(Worse): +213 kWh
CO2 Saved: 4,654 lbs
Estimated Savings: $508.00

Monthly Production:
December 2011: 90.01 kWh (per windstorms above, we lost about 20 kWh of 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

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

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

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

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

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.

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

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.

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

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

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.

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