Wednesday, 6 April 2011

Out of the fire and into the frying pan - but what about standing in the sun?

There seems to be a bit of a panic at the moment about radiation,
nobody's calling for more coal-fired nuclear power stations and
everyone is wondering what to do. Renewable energy seems like a great
idea, but what can we do to support it?

It's a bit obvious but buying solar panels is one option. Especially
in Japan, photovoltaics (panels that produce electricity) already have
a payback of less than ten years, with national and local government
subsidies and contracts with electric companies to buy electricity off
you at a premium rate for 10 years, so if you've got spare cash it
makes more sense than putting it in a bank. Especially a Japanese bank
where interest rates are a fraction of a percent. As well as directly
producing electricity, increased demand will mean higher production of
panels, which will mean more efficient and cheaper panels, so they
will be more affordable for more people.

Japan subsidised solar panels for around ten years from 1994, during
which time prices fell to well under a half. Grants began at 900,000
yen per kW of generation, more than you would pay now, but a little
under half the cost at the time. Installations increased from 539 in
1994 and peaked at 72,825 in 2005 when the grant had dropped to 20,000
yen/kW and was to fall to nothing. The number of installations started
falling after the government grants stopped, but picked up again in
2008 when grants were re-introduced.

For each kilo watt (kW) of panel, you get very roughly 100 kilo watt
hours (kWh) of electricity per month. If the orientation of the panel
veers from due south you get less, although it drops less than you'd
think. Even at 90 degrees it's worth installing, although east-facing
roofs are better than west-facing as they heat up less and efficiency
drops as panel temperature rises. Vertically, a bit over 30 degrees
from the horizontal is optimum, but again a few degrees doesn't make a
huge difference. If you have obstacles to the south, you'll get less
sun, but most radiation is around noon, and even at midwinter the sun
is 45 degrees above the horizon, so unless you're in a deep valley, a
forest or north of a skyscraper you should get most of it.

Each kW of panel costs around 600,000 yen. The price on the
electricity bill is around 24 yen per kWh. (That's 200 months - 17
years payback.) Until the end of March 2011, the national government
was offering a grant of 70,000 yen per kW installed, and you could get
a 10-year contract with the electric company to pay you 48 yen per
kWh. If you can use cheap off-peak electricity and sell all your
daytime electricity, that's a pay back of 90 months - 7.5 years. From
April 1st, the government grant went down to 60,000, and the electric
companies will pay 42 yen. Not as good, but still a pay back of 100
months - 8.7 years.

Wind power is a bit more tricky for individuals as you need a good
site, on the top of a hill, or offshore. You can't really just stick
one on your roof; if it was going to produce significant power it
would probably tear the roof off. There are some people in the UK who
have been building wind farms and helping others to: are part of
supporting community wind farms. Nobody ever heard of a community run
nuclear power station!

Comparing wind and solar, I suspect wind is more compatible with the
Westinghouse model for power generation--big plants and long
distances--and solar more to the Edison small scale model. Edison's
idea lost out to Westinghouse in the battle of the currents at the end
of the nineteenth century, along with several animals that Edison
electrocuted in a pyrrhic attempt to show how dangerous AC was. In the
worst irony, there are still US states that can use the electric
chairs his employees invented, for killing people. It looks like the
electric chair is on its way out, and also I'm optimistic that we're
going to see a move from the big scale model to the small scale model,
and smart grids with micro-generation, electrical storage and
intelligent devices, but that's probably more to do with my politics
than the technical and economic factors that are usually in control!

I think there is increasing momentum to move away from fossil fuels,
but just looking at CO2, nuclear seems like a good option, even to
some environmentalists (at least oustide Germany). In the 1990s
Britain had the NFFO (non-fossil fuel obligation) but this was set up
and almost exclusively used for funding nuclear power. I think going
from fossil fuels to nuclear is going from the fire into the frying
pan, rather than the frying pan into the fire, but it still seems a
bit hot!