Friday, February 01, 2008

Off Grid Solar PV - Measuring Progress

In a speech at the World Future Energy Summit recently, Department of Energy Secretary Samuel Bodman told the audience “the biggest source of immediately available “new” energy is the energy that we waste every day.” Those words reminded me of my own conservation efforts. My habit of turning off lights and resetting thermostats can almost be called obsessive-compulsive behavior. But my past efforts have not been particularly satisfying because I’ve never measured progress. Because of that, I had no real sense of accomplishment.

To generate interest, I’ve decided to track my electricity use over time. I was able to get records of my electricity use for the past two years from my utility company’s website. I entered that information in a spreadsheet, and could immediately see that past efforts have been worthwhile. My use of electricity was significantly lower in 2007 than it was in 2006, with the greatest reductions being in the most recent months. This was expected, since I’ve recently replaced a refrigerator and a TV with energy-star-rated models. Here is the data for November:

My electricity use in November of 2006 was 747kwh.
My electricity use in November of 2007 was 562kwh.

The 185kwh difference was a huge reduction, and perhaps somewhat of an anomaly. The October 2006 to October 2007 difference was only 22kwh. Still, I’m quite pleased with my overall progress. As my use of utility-provided electricity is going down, my use of solar- (PV)-provided electricity is increasing.

My current average monthly use of PV-generated electricity is about 12kwh. I’ll soon be applying a system upgrade, and expect my average monthly use of PV-generated electricity to be about 45kwh.

If I can continue to use less electricity, and generate more of electricity I use, I’ll eventually be able to meet all of my needs with solar panels. And while my figures seem to show that the date is many years in the future, it may be sooner than expected. In the not-to-distant future my wife and I will become empty-nesters. When the kids leave, electricity use will go way down. Unused rooms will be closed off, and we’ll seldom need to use lights or appliances in those rooms. Our laundry and dishwashing loads will decline. At the same time we’ll continue to replace worn-out appliances with energy-efficient ones. We’ll replace more of our lights with CFL’s, or perhaps with LED lighting.

I look forward to the day when I can finally flip the utility breakers off, and still live comfortably with energy from the sun. Last Sunday I used surplus PV-generated electricity to make toast. My batteries were fully charged at the time, so this was an opportunity to take advantage of solar energy that otherwise would have been wasted. I’ll be watching for more opportunities like this in the future. Energy Secretary Bodman would be pleased if he knew about my efforts, but more importantly, I feel good about what I’m doing.

Sunday Morning Toast - Courtesy of the Sun



Please take the time to answer the survey question; “How much electricity do you use each month?” Provide a monthly average if you can. Look for a line on your electric bill that states “total usage in killawatt hours (kwh).” Keep the information you’ve collected so that you’ll be able to measure progress as you take steps to reduce consumption.

John

7 comments:

Anonymous said...

I used 284 KWH last month and received a $36.61, I usually average $38.00 per month. I am cheap no heat and no AC

d said...

Hi SJ,

Really good to hear your progress. I'm unreasonably excited about my 1.29kWp grid-tie PV going in at the end of this month... B^>

I think that I don't want to go off-grid even if I could, because the Grid is a good thing in many ways, but I would like to be (a) a net exporter thus helping reduce others' carbon footprint and (b) immune to power cuts if they become more frequent in future.

In fact I'd like the Grid to extend world wide so that, for example, solar power from one part of the planet is running the lighting on the other side...

Rgds

Damon

PS. My usage for January was 214kWh.

d said...

BTW, in South Africa to help with their current electricity crisis they are proposing putting anyone using more than 500kWh/month on time-of-day metering: not necessarily more expensive if you do things like washing and charging batteries (etc) at night.

I think that it's potentially a really good way of educating users and just wrote to my MP (and MEPs) to suggest it for the UK/EU.

Would you support making it compulsory (to be careful with energy!) in the US?

Rgds

Damon

Solar John said...

I would like to see rewards for energy conservation which could be funded by higher rates for excessive consumption. sj

strider3700 said...

I get my bill bi-monthly and it's not exactaly at the end of the month accurate

This is with an all electric house as you can see I've made improvements.

2005 3098 KWH in 57 days 54.35 kwh/day
(programmable thermostat, replaced inefficient pump)
2006 2077 KWH in 62 days 33.5 kwh/day
(added wife)
2007 2262 KWH in 61 days 37.08 kwh/day
(added woodstove)
2008 1286 KWH in 58 days 22.17 kwh/day

My winter usage is rapidly approaching my summer usage (best is 15.4 kwh/day) The goal is to get the PC running off grid and get some solar hotwater going. Hopefully that will let me set another new low this year.

d said...

Hi SJ,

Please do summarise the final results of your poll in this article when it closes: I've already pointed a couple of politicians in its direction to see how the land lies!

Rgds

Damon

Solar John said...

Many thanks d. I'll post the final results. sj