On Tue, 19 Oct 2010 13:32:09 +0100, David Hansen wrote:

I hate that measure as it can be twisted by the spin doctors.
Generally
a "household" is taken to be around 1kW,

1 kW for what time period?

Eh? Consumption. 1kW being consumed not 1kWHr which is a fixed
quantity of energy.

Ours, over 24hrs, isn't quite 1kW, normally 20 units/day which gives
a mean load of 800ish W. It can spike for a minute or two to 7kW, but
that doesn't make much difference to the mean as it's so short.
Obviously at night it's lower (about 300W) but the evenings with
lights, TV computers etc the consumption can get up to 1.3kW.

The spin doctors could take the night consumption of the house (300W)
rather than the more realistic evening consumption of 1.3kW depending
on the light they want to shed from their article. Which sounds
better to the great unwashed?

"Our Grenbol Savvy 2000 wind trubine will generate enough electricity
for 6,000 homes". (Using 300W).

or

"Our Grenbol Savvy 2000 wind trubine will generate enough electricity
for 1,500 homes". (Using 1.3kW).

or

"Our Grenbol Savvy 2000 wind trubine will generate 2MW of
electricity."

How the calculation is done for wind ...

Average load of an average house from those figures (4,700kWHr/year)
is 537W. A quick google gives similar ball park figures, just over
5MWHr/year for a family with two kids at school, parents working,
4.8MWHr/year for a couple, both working. So 4.7 is a bit low but not
excessively.

Getting back to Teddington Lock, 600 homes at 537W/home gives a 322kW
instalation, less than my lowest guesstimate.

--
Cheers
Dave.