A friend recently put me in touch with a Queen’s student who is doing a project on renewable energy. He was wondering about the feasibility of putting a small turbine on a roof in downtown Kingston.

Here was my response to him:

Succinctly, I would really strongly recommend installing solar instead of wind, at least in this location. Here’s why:

1) The Ontario Power Authority has just (last week) released new feed in tariff prices. The useful info for you is that they are proposing paying $0.802/kwh for rooftop solar. That is crazy good, especially compared to small wind for which you might get $0.144/kwh if you’re lucky (they haven’t defined “community” wind).

This is part of the green energy act, which hasn’t passed yet, but word on the street is that Smitherman would like to be signing contracts in June. It seems likely to go through largely unmodified.

You might want to do net metering, or just do it to offset your own consumption though. Even in that case, I’d suggest solar, because I think it’ll get you more energy.

2) The Queen’s ILC shows an average wind speed of 3.5 m/s over the past year (note that the ILC access data wind speed numbers are in kph). Mind you, this is at the top of a tall building (Goodwin, so 5 storeys), and it’s got much better lake exposure than downtown Kingston. The downtown core has more taller buildings close by, is not really close to the lake (it’s close to the bay, which is more enclosed), and may not be as tall, so you’re probably looking at less than that.

Let’s optimistically assume 3.5 m/s. The information from the turbine manufacturer shows that you’ll get about 80 kWh out of this turbine in 1 year (I used a ruler against their annual power curve). Yeah.

3) Noise. From the looks of the turbine, they seem to have done some work that should help with some noise, so this may not be as big a concern as with some of the other small turbines. Of course, having not seen any numbers, that’s just speculation.

Paul Gipe (a big mover and shaker in wind) wrote an interesting article about small wind turbine noise. Just for reference, a turbine with an 80 m diameter rotor generally have guaranteed maximum sound power levels of around 104 dB(A), which generally maxes out at 9 m/s. Some of these small turbines rival that (up in the 80s and 90s). Ok, decibels are logarithmic, but so is human hearing. I think it’s crazy that such small turbines (a few kw output) generate anywhere near as much noise as the 2MW giant machines. Your turbine may be quieter, but it’s still going to be attached to a nice sounding box - your building.

5) Approvals? Solar is enough of a pain in the ass to get approvals for. My boyfriend is working on putting up panels on his parents’ house in Ottawa and he can tell you how frustrating that’s been. Wind is even harder to get approvals for mainly because of the tower requirement and the noise generated.

4) The case for solar:
The gubmint has insolation information for all of Canada. Here’s the info for Kingston.

The first table actually tells you how many kWh you should expect to generate in each month for every kW of installed solar at some given angles. This table shows that 1kW of solar will generate more power in the month of February than your turbine will generate in a year. 500W of solar would take January /and/ February to generate the annual output of your “500W” turbine.

Other considerations include warranty. Solar panels will probably come with a 20-25 year warranty. I’d be surprised if you got a 20-25 year warranty on a small turbine. Small wind generally needs a lot more maintenance, if only because of wear on the tower.

So, small wind won’t generate much power in your situation, won’t get you nearly as much money as solar, will make noise (who knows how much), and probably won’t last as long as your panels. I think the best choice is pretty clear. Even more economical is solar hot water. It is by far the cheapest way of offsetting consumed energy as long as you use a decent amount of hot water in your building.

Unfortunately, I don’t think roof mounted wind is a great solution in this case. Unfortunately, small wind usually isn’t. Good wind resource tends to be found a) out of built up areas, and b) high above the ground. In those cases, you’re better off installing bigger turbines. If you’re looking for something to do in a city, especially in Ontario, solar is a great option.

Posted in Energy |

You can follow any responses to this entry through the RSS 2.0 feed. Trackback from your own site.