This is the most efficient, most accessible form of renewable energy generation.
winsol3 wrote:All kidding aside. Solar lo-temp thermal - as in hot water heating is upwards of 60-80% efficient and makes lotsa hot water even on a very cloudy day.
It ain't free! a 30ft dish? I'd like to see a hobbyist build that. much less the stirling engine... tongue
Beating 15-18% PV efficiency ain't that hard. try biomass gasifiers.
I love the concept and efficiency of sterlings, and I hope to some day build a GEK gasifier, but I keep coming back to KISS (Keep It Simple Stupid). You have to consider reliability, maintenance, complexity and the number of failure points, and cost effectiveness. I've built all kinds of things in my lab (solar, wind, biogas, biodiesel, etc.), but what powers my house -- and a whole bunch of client's homes -- are regular PV panels.
I agree + disagree: Borrowing from Europe's example, and given that we burn gazillion tons of biomass slash piles into open air, we need to get a small-medium scale biomass industry going and start tying our houses together - as in district/community energy sharing/distribution.
I guess your point, Lew, is that renewable energy in the USA is for 'dummies' and must be plug and play. I would put in a solar hot water system FIRST - way before PV... unless ya'll don't need a hot shower .
From where I sit the issue is education + consumer smarts. Everyone need to educate themselves on some of the technical aspects of this - like a basic physics/electrical/mechanical trade school class.
When it comes to the holy grail (LCA-life cycle assessment) of solar PV vs. biomass gasification (ala Euro Style) = it is lopsided in the favor of biomass for multi-unit housing. Solar PV can't get close to 10-20KW for less than $10k. Solar PV is good for single residential - but solar hot water would still be my first recommendation.
you can get it (with charge controller) for about $2 to $3 per Watt
I can even send you to some decently priced retailers.
2 to $3 per Watt?!?!?!?
That would be much appreciated. The best prices that I'm seeing, here in Ontario, Canada, are $6 to $7 per Watt (plus the sales taxes/etc).
How about $1.80/watt? for PV... check out http://www.solar-electric.com/ I've had good luck with them over the last 10+years, very helpful and reputable. They're located in Arizona, so I don't know about shipping costs to canada.
Robert Isted wrote:The BEST solar energy system? Well if by “best” you mean “does does the most good”, then the best specific example of a solar energy system is one that includes the following components: a school, a bio-gas generating sewage digester, an algae pond and a vegetable garden. I’ll explain.
I recently heard a lovely story about a school in a poor rural part of South Africa. It used to be a typically dismal third world community with hungry malnourished and sickly kids, no sanitation, polluted local water and a terrible shortage of cooking fuel.
Then a foreign charity funded a sewage processing system which captures the bio-gas (mostly methane) from the anaerobic decomposition of sewage in a digester vat similar to a septic tank. The water discharged from the vat, which is very rich in nutrients and also organic contaminants, is then fed into a series of shallow algae ponds. With all the nutrients and lots of sunlight the algae grows prolifically, capturing the energy of sunlight to create algae biomass. The algae is collected and fed back into the digester vat to create yet more bio-gas. Meanwhile the water that flow from the algae ponds is no longer polluted but still contains quite a lot of nutrients. This water is then used to irrigate and fertilize the school’s vegetable garden. Here more sunlight energy is captured to create nourishing healthy vegetables. These vegetables are cooked in the school kitchen, using stoves running on the bio-gas. And now they have healthy, happy kids with decent sewage, clean rivers and plenty to eat.
Robert Isted wrote:The BEST solar energy system? Well if by “best” you mean “does does the most good”,....