Carbon offsets are something that trouble me, with the analogy to medieval indulgences clearly seeming relevant for at least some who embrace them. On the other hand, Energy’s Three Rs make much sense to me:
- Reduce energy use (through efficiency and conservation)
- Use Renewable Power as much as possible
- Remediate for any remaining polluting energy use
Remediation can take many forms, with paid carbon offsets being one of them.
Now, a question to ask (a soul-searching one) perhaps is how much individual action can count in the equation. Many evenings, I walk the office halls at the end of the day turning off lights. Turn off 5 kilowatts worth before a four-day weekend and I’ve probably “offset” my household’s monthly electricity use due to those reductions. Can I count it? How about a different equation?
Mornings, I bike and increasingly so with my oldest child. Often just to feel the air in our faces but also the way to get that missing milk or some bread for breakfast. 
On these morning rides, one particularly energy hog habit stands out, shining in our faces so to say: people leave their outdoor lights on. This is not all homes, perhaps about one in ten in the neighborhoods we bike. And, not all homes are created equal. Most only have on one or two bulbs, but there is one home we pass that has 24 bulbs (or nearly a kilowatt of electricity) on all night, every night. Sigh … this sight has been an irritant on our morning rides.
Recently, we decided to try to do something about this. No, not using slingshots against the bulbs. We decided to ask people to “Consider the Impact of Lighting the Night Sky”. I prepared a brief note (published in full at the end of this post). And, when we see a house, we fill in the relevant blanks and slip it into the mailbox. While it is cutting into the distances biked, it is providing some math exercise for my daughter and providing a path for Energy Smart action.
Consider those 24 bulbs. Let’s rate them at 40 watts each, which is 960 watts for 12 hours per day. That is 11.5 kwh/day or 4200 kwh per year. Over 4 megawatt hours just for some exterior lights for a home which is lighted by county streetlights! At the local utility rates, they’re paying roughly $275 for the electricity and those exterior lights are responsible for over three tons of CO2 emissions per year.
So far, we’ve dropped notes in over 50 mailboxes in a few days. Over half the houses have either not had lights on or fewer lights on the days following a note. Our rough calculation is about 2500 watts of less lighting so far on the morning bike rides. Potential impact: 11 megawatt hours of reduced electricity use, saving people over $700 in costs, and over 8 tons of reduced co2 emissions.
Okay, back to the opening … Do we get to count those eight tons as carbon offset? Does that mean that I can go out and drive an Hummer with a clear conscience? Of course not … The point is that we should all be doing things to help the general society, not just ourselves, move forward to a saner and healthier Energy Smart future.
The note:
Consider the Impact of lighting the night sky
Late at night and early in the morning, there are typically lights on outside your home.
Estimate # of watts left on in exterior lights ________
Estimated number of kilowatt hours per day: _________
Estimated number of kilowatt hours per year: _________
At 6.5 cents per kilowatt/hour, cost for exterior lights per year: ___________
Each kwh represents about 1.5 lbs of CO2. Your exterior lights are responsible for approximately _________ pounds or __________tons of greenhouse gas emissions (GHG) per year, contributing to Global Warming.
Would you consider reducing your exterior light use, saving money, and helping reduce damage to the planet?
You can put in motion sensors or more efficient lighting (both of which will pay for themselves in saved electricity costs) or perhaps simply choose not to pollute the night sky.
Thank you for your consideration.