Free Solar Panels! Today Only! | Searching for Green

Sorry, the offer just expired…. In fact, to be honest, there was none :-). It was just a simple idea: what if the the kind government would fully subsidize the installation of my 3kW roof solar system, so I would get it basically for free? The condition would probably be to keep the panels on the roof for 20 years, and to sell all the electricity back to the grid for the current 12c/kWh rate.

The only things I would pay would be the ongoing insurance and meter fee. Are you curious about the result? $1772 in after-tax profit after the first inverter change, in year 12! This means $148/year! It’s still money, but would you let someone drill holes into your roof for this amount?

Now we have a sobering perspective of the solar panels technology today. They are not sustainable by themselves at such a low scale. And, unexpectedly, that’s NOT because they’re too expensive. Mass production or technological advances might eventually lower the price. Unfortunately, the real enemy is a lot harder to defeat: it’s the methods of generating cheaper electricity.

So the main culprit is the low “density” of the solar power. In a normal year, my 3kW solar panels can generate:

3kW x 1200 kWh/kW = 3600 kWh

Compare this with our yearly electricity usage of around 4200 kWh, and you can see that we cannot generate enough solar electricity for ourselves. And we are far from being the average Ontario household, which uses 1000 kWh/month!


2 Responses to “Free Solar Panels! Today Only!”

  • Pieter H:

    You are only using 4200 kWh per year? How are you doing that? I’m at 8400 kWh per year because I hardly ever use the airco.

  • icabrindus:

    Hi, Pieter!

    Maybe it’s a smaller house. Ours is 1300 sqft and we started recording in 2008 (5500 kWh). I don’t think we do anything special, I thought we were pretty normal until I saw the statistics :-).

    Another explanation may be that we all leave house during the day, so nothing but the fridge and the furnace is working. I expect us to consume more if one of us was at home all day.

    What we did in the beginning:

    – CFLs all over the place (none of us minds it)
    – timers for the bathroom fans
    – replaced the old thermostat with a new programmable one
    – no big-screen TV (32″ CRT only)
    – new refrigerator and electrical stove (better insulation for the oven?)
    – keeping an eye on the kids to turn off the lights when leaving the room (a lost battle, but we try)
    – we only have a 9000 BTU portable A/C
    – not using the porch lights :-)
    – we don’t use the electric dryer at all (DW hates it since it ruined something). The laundry machine is an old inefficient top-loader, though.
    – we cook at home almost exclusively, but do it in batches on the weekends, so we don’t use the stove a lot during the week, mostly the microwave oven.
    – we splurge with some outdoor incandescent string lights in the winter (DW didn’t like the cold-white LEDs we tried); around 100W, but they’re on a timer for only a few hours after dusk.

    In 2008:
    – thoroughly air sealed the house, so potentially the furnace works less; this may explain part of the 2008-2009 difference
    – new efficient dishwasher (we didn’t have one before)

    In 2009 we did some improvements (I don’t know how much of a difference it makes until until next Jan 1st; there’s almost no difference so far for the first 8 months):
    – hi-eff furnace with variable-speed ECM
    – improving the attic insulation
    – power bars all over the place – and we shut them off when not in use
    – shutting down the computer overnight

    So minimal things, I don’t know which of them makes a difference. The big gap between 2008 and 2009 may be due to the weather, as the 2009 summer was really mild, so we may have used A/C only a couple of times.

    If you have a smartmeter, you can see online your house’s consumption when everything is off (overnight). For my house it’s between 150 and 200W, probably the refrigerator, the furnace blower (circulating the air even in the summer), the garage door opener and a bunch of digital clocks. At maximum, this means 1752 kWh/year, 40% of my total!

    Hope this helps,

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