A few months ago, I wrote a blog comparing the number of negawatts you could produce by giving away Compact fluorescent Light bulbs (CFLs) to the amount of electricity you can produce with a rooftop photovoltaic system. The CFLs had photovoltaics beat six ways from Sunday, and I concluded that you could do better by putting the money you were considering investing in a PV system in a Bank CD, and using the interest to give away CFLs. Since I actually believe my own calculations, I set out to do just that.
I offered a $2 a bulb rebate (up to $5) for anyone who bought CFLs and sent me a receipt. Apparently, $5 is not enough money to get most people off the couch, and I did not get a single receipt sent to me (the offer is still on, by the way.) However, I also give away CFLs (usually something interesting like an outdoor spot or a candelabra bulb… most of my prospects have already replaced everything they can with the twisty type) to potential clients who come by my office, and the blog started making the rounds of the internet, eventually making it to Marc Dreyfors, who is on the board of the Environmental Educators of North Carolina (EENC). EENC was planning their annual conference, and they usually offset the carbon from their conference by giving away CFLs, and Marc had the bright idea of asking me to fund it.
They calculated (with the help of Clean Air Community Trust) of
Asheville, that they needed to replace 51 60-watt incandescents with CFLs to offset the 16.7 tons of Carbon their conference was expected to produce. My thought was: “we need to think bigger than that!” because I wanted to offset some of my own carbon as well. They were fine with that, they just didn’t want to be greedy.
In the end, I funded the replacement of 320 60-watt bulbs (with 11w CFLs) and 80 100-watt bulbs (with 25w CFLs). After the tax deduction, that cost me about $600, and EENC was able to use my grant to persuade Progress Energy (their local utility) to stump up a $500 donation to expand the program further.
I arbitrarily decided that EENC would get half the carbon offsets from my donation for their work, and I’d get the other half for coming up with the cash. Assuming the bulbs we gave away are used just 1 hour a day, that means that all my CFL giveaways are saving someone over 12 kWh of electricity each and every day, which is more than my wife and I use. With the help of a programmer-friend, I’m tracking the progress on my website. (on the right hand side.) Note that the offsets cost only about half a cent per kWh over the lifetime of the bulbs, about a third of the cost of buying green tags from someone like Sterling Planet. If I tried to produce 12kWh a day with a PV system here in Colorado, it would cost about $12,000 after all the rebates, and I’d save about $170 a year on my electricity bill.
Now I just have to do the calculations to figure out how many bulbs I need to give away to offset my use of natural gas, gasoline for my wife’s Prius, and biodiesel for my Jeep.