The following piece on energy conservation was written by a reader who has contributed some excellent comments to the site.  David Fay writes from Harvard, MA where he and another son run Energy Metrics, an energy audit and consulting company.  If you live in the New England area, check them out for a home audit.  If you don't live in that area, enjoy his experience and advice!
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After a year of improving the energy fitness of my old house, I've begun to brag to friends about the huge reduction in electricity usage my family and I have achieved. Our most recent electricity bill was less than half of what it was a year ago (see our electricity consumption graph here: Energy Metrics electricity consumption graph ). The first thing they all want to know is how we did it.

I tell them about replacing our incandescent lights with CFLs and LEDs. And the automatic setback thermostat that replaced the old Honeywell we kept forgetting to turn down at night. Not to mention the rigid foam insulation I mounted on the ceiling of our unheated basement. And stopping up all those air leaks with my shiny Italian foam gun, the smart power strips to vanquish the power vampires, and the insulating curtains in our dining room. I even refer them to my blog on improving the air flow in our furnace.

The next question I usually get is: you save electricity by insulating and air sealing? You bet we do. Our oil-burning furnace uses 300 watts for the burner and 450 watts for the blower -- whenever it is on (see the furnace cycling in the winter months here). The less heat we need, the less electricity we use.

As I look back on it, we've accomplished a lot this past year. But somehow, as I'm telling my energy story, it never feels as if I'm accounting for all the savings. So I reviewed my electricity charts and the notes I keep on what we've changed, to see where all that electricity has gone. What I discovered was that, sure, the energy saving technologies have done their job, but what was even more important were the behavioral changes, not all of which were even part of the program.

I'm a little embarrassed to admit that probably the biggest change of all was when my youngest son moved out in July of 2009. Not only was that one person less in the house -- fewer lights on, fewer computers, fewer showers -- but, as a night owl, he was a particularly energy intensive person. His bedroom lights burned all night, every night as he worked away at his computer. And that computer wasn't just any computer, it was a top-of-the-line game-playing screamer that would have required the construction of a new power plant if it weren't burning its kilowatt-hours while everyone else slept.

So there was that and there was the slow downward creep of our thermostat as we got used to a cooler and cooler house in the cold months. My philosophy was to drop the temperature a degree at a time and wait for a reaction. (side note: I try the same thing in my home!) If I didn't hear any complaints in a week, down it would go another degree. I'm not saying we have ice forming in the toilet bowls but we've found we can live comfortably at 65º during the day and evening and 50º overnight.

And I can't forget TED, our energy monitor. While TED is a technology, and a pretty nifty one at that, its main benefit is in changing our household behavior. As is well-documented, just knowing how much electricity you use motivates you to reduce it. Here's an example. Once my son moved out, we had three active computers in our house - two laptops and a desktop. Our two laptops use so little power when sleeping that they're below the horizon. But the older desktop uses 100 watts even when it's sleeping. However, if you put it in standby mode, the disk spins down and it uses only a few watts. The problem is, once the monitor is off, there's almost no visible difference between the two states so it's hard to tell whether we have remembered to engage standby. So every evening before I go to bed, I check our current electricity level on my iPhone to see whether we have reached our normal baseload of about 100 watts (for the whole house). If that desktop is still on, I know it right away. Likewise for anything else that has inadvertently been left on. It takes a small effort to do an energy check every night, but it's worth it. Anything added to our baseload is going to burn for the next 7 hours or so.

I can't put a number on it, but, after reviewing our energy history over the past year, I think the biggest changes have come about from alterations in the way we live -- in the number of occupants of the house and in the decisions we make about how much energy to use. These are not huge changes, nor are they difficult ones to make, as long as you can be consistent and persistent. And they add up. Energy saving technologies have their place, but behavioral changes are the first place to look for savings. And guess what? They don't cost a penny. Talk about return on investment.

All this was brought home to me recently after I made a presentation to our local Board of Selectmen about energy consumption in our town buildings (I serve on our town energy advisory committee). After running through my graphs detailing the energy reductions the town has achieved in the past two years, I reviewed the many energy saving technologies that had made these savings possible, from new boilers that burn waste oil to building management systems to high efficiency fluorescents.

As I left the building after my talk, I ran into Farmer Paul, my next door neighbor, who had been in the audience. Paul is a muddy boots Yankee farmer whose ancestors settled our village of Still River 12 generations ago.

"Pretty impressive improvements, " said Paul.

"And lots more to come."

"But it all comes down to what my father always used to tell me."

"What was that?"

"TURN OFF THE DAMN LIGHTS!"