Interestingly, while big wind can generate far cheaper power than big solar, small wind turns out to do quite the opposite.
A comparative turbine test performed over the last 12 months in Zeeland, Holland revealed that small wind turbines generate very little power for the money. The smaller the rotor, the less power. So I did some comparisons between small wind and solar. I found something surprising.
Small wind could cost 10 times the cost of residential solar to make the same power.
The energy yield was measured in an average wind speed of 8.5 mph over the year.
Here are the results, translated for the U.S. reader, with the comparative solar costs:
(If you are European, the original measurements in meters etc can be found here at LowTechMagazine)
The smallest one they tested is barely in the energy business: at $6,129 to make 6 kwh a month, doing nothing but give green energy a bad name.
Airdolphin at $24,747 (or the WRE 030 for twice that at $41,620!) to get 33 kWh a month.
WRE 060 $52,444 for 41 kWh a month, or the (relatively!) cost-effective Passaat at $13, 029 to make about 48 kWh a month.
Montana (16 foot rotor) costs $26,359 and makes 224 kwh a month.
If you wanted to zero out your usage you would need a lot of these turbines!
It almost makes more sense to think of these tiny turbines as the power equivalent of individual panels in a solar array.
Here in the US electricity use ranges from an incredibly low 200 kwh a month (if you are a frugal treehugger in a tiny house) up to to 2,000 kwh a month in your palatial mansion with those ten plasma TVs.
To see how much power you would need to generate, look at your electricity bill. Somewhere in all that fine print that keeps you from understanding all those billing charges is the usage in kwh per month. Now see how many kwh a month you get from one turbine. Divide your usage need by the turbine output to see how many you’d need, then multiply the turbine cost by the number of turbines needed: Even our frugal treehugger would need 10 Ampairs at $12,710 each to make 200 kwh a month.
200 kwh a month from Ampaires: $127,100! — Solar? About $15,000
By contrast, solar panels to make 200 kwh a month would cost about $5,000; installed with inverter about $15,000, before rebates which cut that in about half.
The rotor spans of the tested wind turbines ranged from 3 feet to 16 feet. The largest was more cost effective than the smallest. But wind turbines with a rotor diameter of 16 feet are not safe on most roofs! But if it is small enough to fit on a roof; it is not generating enough energy to be worth doing.
Keep your residential roof for a green roof, pv, or a solar hot-water system.
It is perfectly possible to 100% power a house with a solar array that’s about the size of your living room and kitchen put together on your roof. But with wind power? Not possible.
Near the test site, ironically almost by way of illustration of how to do it right, is a humongous wind turbine, churning out real power for the neighborhood cost-effectively.
That huge turbine supplies local needs for a per household average of $6,441!
Susan Kraemer writes at CleanTechnica, CSP-Today, PV-Insider , SmartGridUpdate and GreenProphet and has been published at Ecoseed, NRDC OnEarth, MatterNetwork, Celsius, EnergyNow and Scientific American. As a former serial entrepreneur in product design she brings an innovator's perspective on inventing a carbon-constrained civilization: If necessity is the mother of invention: solving climate change is the mother of all necessities! As a lover of history and sci fi, she enjoys chronicling the strange future we are creating in these interesting times. Follow Susan @dotcommodity on twitter.