Posted by mscir on March 30, 2005, 10:36 pm
Wintry Canada to Use Solar Power to Heat Homes
Mar 30, 2005
TORONTO (Reuters) - Canada, better known for snow than sun, plans to
build a 52-home solar powered community in Alberta that will harvest the
sun's rays in summer and use them to heat homes in winter, the
government said on Wednesday.
The Drake Landing development, already under construction in the western
province, will be the first of its kind in North America. Officials say
it will cut greenhouse gas emissions by 260 tonnes a year and supply the
homes with more than 90 percent of the heat they need.
"This system significantly reduces greenhouse gas emissions and
demonstrates the importance of using clean, renewable energy sources,"
Tommy Banks, a Canadian parliamentarian, said in a release.
Under the scheme, solar panels mounted on garage roofs will collect
energy from the sun and store it underground. Come winter, the thermal
energy will heat homes through a central district heating system.
Some C$.5 million ($,5 million) has been invested so far in the
project, which is jointly funded by the governments of Canada and
Alberta and by a number of Canadian companies.
Posted by DJ on March 31, 2005, 2:04 pm
Interesting. Anybody know who's gear they use? I know Edmonton, in
Alberta, is one of the best places in Canada for "most sunny days", but
I'm wondering about their numbers.
I'm no expert, but last I heard, to run a house for radiant heating,
you needed to have, for instance, one 4x8' panel per 250 square feet of
living space, and another one per adult for domestic hot water, as the
"rule of thumb".
That's a helluva big garage. Just sayin' ;-).
Posted by nicksanspam on March 31, 2005, 8:11 pm
For $6K per home :-)
Sounds expensive. We might 90%-solar-heat a home with lots of insulation
and airtightness with a $00 plastic film sunspace and some fin tube or
thermal mass under a ceiling.
We might do this less expensively for a bunch of houses. If they have
common walls, great. Otherwise, they need lots of insulation and enough
isolated low-mass sunspace to keep warm on an average day, with a large
common collector and heat store with a small S/V ratio for cloudy days
and DHW, with a large common greywater heat exchanger.
I paid $76 for my last 14'x96' plastic greenhouse, plus another $00 for
a 4-year poly film cover... 3 people can put one up in a field in 1 day.
Whitewashed on the north, it might collect 0.8x96(12x700+7x440) = 882K Btu
on an average 26.5 F Dec day in Albany and lose about 6h(T-31)32'x96'/R2,
which makes T = 127 F.
If each 300 Btu/h-F house needs 5x24x(65-26.5)300 = 1.4 million Btu for
5 cloudy days with a minimum usable 80 F temp, the 52x1.4M = 73M Btu
might come from a 12'x92'x73M/((127-80)62.33) = 22.5' deep trench in a
single greenhouse or 5 12x92x4' trenches in 5 greenhouses with 20x100'
folded EPDM liners and foamboard floating on top with a layer of poly
film over the board and water flowing over the film and under another
during the day.
Posted by Cosmopolite on April 1, 2005, 12:10 am
That's ok for Albany, Nick, but up here in the Edmonton area, we
have average annual of 35.5 deg.F , average January of 4.5 ( occasional
-40 at night at my place ) and 5589 annual heating degree-days.
Water under poly makes a good skating rink.
Insulation is the key.
Posted by nicksanspam on April 1, 2005, 1:05 am
...Whitewashed on the north, it might collect 0.8x96(12x700+7x440) = 882K Btu
on an average 26.5 F Dec day in Albany and lose about 6h(T-31)12'x96'/R2,
which makes T = 286 F, theoretically-speaking :-)
The NRCC 1981 Solarium Workbook says Edmonton is 2 C in January, ie
35.6 F, about 10 F warmer than Albany, with 1033 Wh/m^2 (327 Btu/ft^2)
per day on the ground and 1832 Wh (581 Btu) on a south wall.
So the greenhouse above might collect 0.8x96(12x581+7x327) = 711K Btu
on an average 35.6 F Jan day and lose about 6h(T-40)12'x96'/R2, which
makes T = 246 F, theoretically-speaking :-)
Either way, this seems easy.