Saturday, January 17, 2009

Reducing home energy use 101

Earlier, I outlined my plan to reduce our home electricity use by 10 to 20 percent by the end of the year. In a house already filled with compact fluorescent bulbs, this will be no easy task.

My most recent electricity bill arrived in the mail this week, so I now have my benchmark kilowatt numbers. It's enough to make me queasy.

We used a total of 19405 KwH in the past 12 months. The average U.S. family uses 10,656 kilowatt-hours of electricity each year, or about 888 kwh per month. We were well below average before we installed our new furnace.

Our highest usage months were March, at 4,801 KwH (I think this is because our previous two bills were estimated, and didn't take into account our new furnace), December 2008 at 2,289 KwH, and August, at 1,520.

Our electricity usage has skyrocketed in the past year. I know what the culprit is.

In September 2007, we replaced our 1957 gas furnace with an electric heat pump. Electricity is not my first choice for home heating and cooling. But, we really wanted a geothermal system, which is supposed to be as earth-friendly as you can get. every month where we really needed heat or air conditioning sends our Kilowatt hours through the roof. Even our lowest use month is still twice what it was before we installed the new furnace.

Except for the huge amount of electricity it uses, the furnace has been great. I assume it's also more efficient than our old furnace, which at 50 plus years old was not the model of Energy Star efficiency. Although, I am not skeptical of geothermal's claim to reduce CO2 emissions and instantly turn your home into an Energy Star house. That electricity has to come from somewhere, and where we live, 78 percent of it comes from coal fired plants. But, we'll just have to deal with it and try to reduce our use in other ways. We aren't replacing it again.

In the interest of full disclosure I must admit we have another electricity loving vice: a hot tub. Not the model of efficient use of natural resources, I know. But we are clumsy and tend to get injured a lot playing sports, so we consider it therapeutic. We run the tub from September to July.

So, numbers in hand, our goal is to reduce our usage by 1,940 to 3,881 kilowatt hours a year. Our monthly average use is 1,617 kilowatt hours. Our monthly goal is to reduce usage by 161 to 323 kilowatt hours a month.

These are big numbers. As I said in my earlier post, we are planning to tackle this with a combination of upgrades large and small.

This month, We have already managed to implement part of our plan to reduce our kilowatt addiction.

* We installed the final three Energy Star windows in our house. We began this project last year, but because we are old fashioned, we only do what we can pay for out of pocket. We couldn't afford to do all of the windows at once, so we put off the last three (which we deemed to have less impact on our home's leakiness). Now, all of the windows are finished. The company also came out today to repair some window locks on the first set, so all of the windows should now be securely closed against the freezing outside air. This was our most expensive project, at $1,633.
* We have ordered the new doors for the kitchen. This doesn't sound like an energy issue, but it is. The door between our frozen garage and the kitchen is hollow and lets all that cold air right into the house. This is the second-most expensive project on our list, at $600. It is a close tie with another project slated for the laundry room.
* We have one final task: to find an energy efficient cat door. Put gingerly, the new thick door will cut off access to the "kitty loo", so we need to put a door in it. Hopefully we can find one that doesn't leak. Is there such a thing as an Energy Star cat door? I'm about to find out.

Considering we are midway through out first month, I think we are making a decent bit of progress. It's going to become more of a challenge once the big projects are out of the way, as it will be harder to find places that we can cut.

On the agenda for this year, to help with this goal,

* We hope to purchase a front-loading Energy Star washer.These are a good bet all around, and should be much more efficient than the top-loading model we bought when we moved into this house. I will do some research on brands and post my findings here.
* Invest in some LED lights, to replace some of the much-used CFLs we have around the house.

Who knows what we will need to do. It seems like every project we do leads to another project we hadn't even thought of before. It seems our house is an onion.


Gene said...

Holy electric-powered cow, Batman! That ground-source heat pump is using a lot of electricity. We have gas heat (and of course a much milder climate), but last month's PG&E bill showed us using 316 Kwh (for a 32 day billing period).

We've got a hot tub, too, but it hasn't been running in a while. It probably won't until I find some sort of solar-powered heater (hot water + photovoltaics for the pump).

If you haven't already, you might buy or borrow a Kill-a-watt to figure out which appliances, etc. are using how much electricity, and how much vampire power (i.e., power when turned off) they're using, too.

Re: the cat door, I think you'll have to do a double door to get any sort of efficiency. One door through the wall, then a little kitty foyer, then another door. If there's any sort of air pressure difference, even that may get blown open one way or the other, though.

DeniseT said...

I realized our furnace was using a lot more than it was supposed to be using.

We had it repaired today. apparently there was a disconnect between the thermostat and the furnace, which meant the furnace was running all the time, even though the house was freezing.

Now that that's fixed, I notice the furnace actually cycles off. This should shave a big chunk off of the electric bill.

Apparently, it's been malfunctioning for the last year. We only realized it because we are having 20 below weather right now.