In alt.solar.thermal Christian McArdle
wrote:
So you'd need 24m? of roofspace for your 3kW,

Do you know that it used 24sm, or that it is a 3kwp AC system?

That sounds perfectly reasonable. I'm surprised you can get so much from
a small area.

My Kyocera flat panels would need 26 sm for a 3kwp AC system.

middle of a hot sunny day, was making about 450W of non-storable
energy, this is why I am skeptical about the 40%

http://rredc.nrel.gov/solar/codes_al...ATTS/version1/
Projects a "3kw AC" rated system delivering 5783kWh/yr in San
Francisco, CA, USA; 3163kWh/yr in London.

On that basis, I would expect the peak AC watts to be 55% of my peak. I've
recently seen of 450 (adjusted) watts at 10:30am, with a peak for that same
day at 1548 (adjusted) watts. My panels are not due south, nor are they
elevated optimally.

450W would usually easily cover my electrical usage. Wouldn't help at
night, or for brief peak usage when the washing machine element fires. It
would, however, cover my lighting and electrical goods.

Since it is only claiming to provide 40% of the energy, it must be grid
tied, so the washing machine can still draw as it needs.

If the system was 3kwp-AC, it could deliver 3163kWh per year.
250kWh per month might be 40% of an efficient home's needs.

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Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5