My home's energy usage

[kevm14]

Oh boy, 2/3rds of my neighbors w/ equivalently sized houses and gas heat are more energy efficient than me (including electricity). Need moar granularity.

Oh thanks. My electricity seems to be the trouble. In the A/C months, I actually perfectly track the average (June to October) but then my electricity goes up (comparatively) in the heating months. 10 bucks says that's Ian's space heater. We could do better overall.

Big tube TV. But a replacement would probably cost me, say, $1,200. So my TV uses 245W (manual). Say we use it 8 hours a day. Say the new TV draws 100W. That saves $96.36/yr. I'd have to keep that new TV 12.5 years just to break even (if it lasts that long).

I still leave my desktop on 24/7, and we have quite a few incandescent lights still. I could save $9.64/mo if I used standby and assumed 6 hrs/day of computer on-time. Meh. Now the bulbs. If I can get a break-even point of 1 year, I'd replace all my bulbs. Let's see how that might work. I currently use a bunch of 65W floods and some 40W chandelier lamps. Let's say an LED flood uses 12W. If I keep the lights on for 5 hours/day, then the replacement bulbs should cost less than $15.50. This one might actually be possible. Especially with the National Grid rebates. I will look into this.

And check out my gas usage. I'm doing better than the average all the time (in May, I matched my "efficient neighbors"), and noticeably in the heating months. Looking at past bills, my electricity has gone up over years past (yeah I know the rates also went up) and my gas has actually gone down a bit. I'd say the attic insulation I installed has helped.

[Bob]

I am also going through a similar investigation right now with my house. I am concerned that the power bill is significantly higher than my old house at the same time of year. This house does have an electric hot water heater and electric range (ugh), whereas the old house was gas. One thing I did notice about the new house is that there are nearly no energy saving light bulbs anywhere in the house. I am not sure how much of a difference this could make to the bottom line, but I am going to try replacing the frequently used bulbs with either CFL or LED.

One other potential cause is the old worn out fridge.

I think the leading candidate is probably the aging hot water heater. I won't replace this until it fails so I will need to see what I can do with the other items.

By the way, there are other reasons to replace a big tube TV besides the electricity savings

[kevm14]

I bet it's the hot water heater. You could try replacing the heating elements as they tend to get coated in stuff and that kills the efficiency.

On Ask This Old House, they actually installed a heat pump to supplement the heating elements. Acting as A/C in reverse, it draws heat from the basement and pumps it into a loop that runs in/out of the water heater tank. You can think of it as the hot side (the condensor) putting heat into the water and the cold side (the evaporator) pumping cold air into the basement, hence removing heat. Anything it can't keep up with, the elements cover. Evidently it would provide a pretty substantial cost savings.

If your hot water heater is in your garage, then this should work even better. Basically the hotter the area around the hot water heater, the more efficient the heat pump will be. It uses some electricity to run a fan, a pump and the compressor, but that electricity is actually moving a significant amount of heat energy around, which already exists.

[Bob]

How much of a job is it to replace the heating elements? The hot water heater is in a crawl space under the house so the temperature stays pretty mild in there, never too hot, never too cold.

[kevm14]

You have to drain the tank. There's usually an element halfway up and at the bottom. They're threaded and probably can be purchased through home depot.

[Bob]

Yeah, I just watched a youtube video. It doesn't look too hard to replace the heating element.

Also, I believe my pressure release valve is leaking. I need to address that as well, possibly at the same time since both require shutting off the water, power and some amount of draining.

[Bob]

I replaced the temperature and pressure relief valve yesterday. It was very easy to do and fixed the slow leak that I had. I think this may have been the source of the mysterious water in the crawl space. Hopefully this will have some marginal impact on energy consumption as well. I may attempt the heating elements at some point as well.

[kevm14]

Started thread on old house...

New house electricity usage from 6/14 to 7/13: 654kWh

Half of that is heavy window A/C use in the July half of the bill, cooling my entire house (~2326 sq ft) on 4 units (31,200 BTU total). Most efficient neighbors are 431kWh. All neighbor average, though, is 1,277kWh!! Very similar square footage according to the report, so it is apples to apples.

I think this is fine. I submit that it doesn't cost $400/month to cool an entire house on window A/C (or central A/C). This bill was $122.

Base bill without A/C is around $90. So a full month of A/C should be about $150. Even if it was closer to $200 that is totally worth it for like 2 months out of the year.

[kevm14]

I submit that it doesn't cost $400/month to cool an entire house on window A/C (or central A/C). This bill was $122.

Got new bill for 7/13 to 8/12. 1174kWh. It was pretty hot though. $214.81. Still reasonable for a hot period - this is 24/7 cooling.

This is actually the most electricity usage I've ever had since moving here. There may be a small contribution from leaky toilets that run (have new gaskets - need to install) which runs the well pump more often.

[kevm14]

Got new bill for 7/13 to 8/12. 1174kWh. It was pretty hot though. $214.81. Still reasonable for a hot period - this is 24/7 cooling.

Energy report:
Usage: 1,174 kWh ($214.81)
Efficient homes: 636 kWh (~$116)
Similar home average: 1,590 kWh (~$291)

I wonder if those low ones are actually using air conditioning.