Tuesday, January 23, 2007

Roof-Mounted Microturbines

Since we're talking over at Billy's blog about renewable energy. Billy actually suggested nuclear power as an alternative to fossil fuels, which I have no particular objection to, but I think it's charmingly old-fashioned of him since it's all about renewables these days!

(He's probably correct, though, that we're a long way from being able to make all buildings energy-independent or generate enough green power to power the non-independent buildings, and nuclear will fill that gap better than fossil fuels.)

At the McGee house, we are researching the possibility of a roof-mounted microturbine for our house. There's a lot of conflicting data out there, and most turbines to date have either been substantially too large for home installation (think the ones in the giant wind farms) or the small ones created too much vibration and destroyed your roof.

But a couple of UK-based companies have some exciting new microturbines out with high-tech vibration dampening designs. They mount basically like an old-fashioned TV aerial, up a pole on the side of your house to above the roof (the pole's a little fatter than I recall TV aerial poles being). There are also these neat new little ones that get mounted on the SIDE of skyscrapers and other tall buildings in "urban canyons," because apparently the sides of these buildings create their own winds blowing up and down the sides because the air has to go somewhere. Super cool!

This is the one we're looking at. Here's a picture of the Swift being installed, which gives you a good idea of the scale of it. (Windsave is another latest-generation microturbine getting a lot of good press.) The Swift costs about $2900 stateside, depending on exchange rates, but I don't know if that's if you buy it from a US wholesaler or if you buy it from the UK and then have to pay to ship and import. (We haven't gotten so far as e-mailing the company to ask!)

We're still in the research stage -- figuring cost, output, our energy use, whether our "site location" would make it worthwhile, Illinois's renewable energy grants, etc. -- and it may not pan out, but I think it would be so super-cool to have a wind turbine on my roof! Preliminary numbers suggest it could provide 1/2 to 2/3 of our electricity*; what I haven't been able to discover is if Ameren allows you to "sellback" to the grid when you're making more than you're using. (ComEd does.)


*Two notes: First, this is based on the Swift's generation rates in the UK. I have no idea how the wind there compares to the wind here. Second, we have gas heat, gas water heat, gas dryer, and gas oven & range combo. Those are four of the biggest energy hogs in the typical house (A/C and fridge are the other two), and they're all gas. So our electricity use is MUCH LOWER than someone with electric heat or electric appliances. A wind turbine will not lower our gas power use. Since you can't generate your own gas power by farting into the appliance, the only options there are to reduce use or increase efficiency. Which is why my thermostat is set at a chilly 63*F in the winter, and a balmy 80*F-ish in summer, but only when it's over 88*F-ish AND humid. (Although I confess I sometimes drop it into the 70s to be able to sleep when it's really stinky out.) I'm whinier about hot than cold, so my winter thermostat setting is more eco-brag-worthy. I'm totally after a programmable thermostat so I can drop the heat to 55*F overnight in the winter, at which point my Floridian husband will divorce me.

-------------end digression-------------

The idea is that in many areas, it's pretty windy when it's not sunny, and it's pretty sunny when it's not windy, so if you combine a small roof solar array (such as these types, which are flat to the roof and either form the roofing material or sit flat on top of it, so you don't have big ugly stand-up panels) with a microturbine, you can generate 90% of your electrical needs, depending, of course, on age and size and efficiency of house. Here's a site with Illinois solar maps to match the wind map above.

Check out DSIRE for state-by-state incentives for renewable power, including grants, rebates, tax incentives, etc. (In Illinois, for example, renewable energy home installations are property-tax advantaged.) The feds also have good information on various incentive programs, as well as tons of data and information.

In the meantime, we've sprung for a Smart Strip, which allows you to plug a "control" device, such as your CPU or television, into the blue outlet, and then you plug dependant devices, like monitor and speakers and printer, or DVD and X-Box, into the white outlets, and they're only allowed to turn on when the blue outlet is on. But the important feature here is that it prevents your electronics from sipping power while in "sleep" mode -- most don't truly turn "off" unless you disconnect them from the wall. They eat a slow but steady diet of electricty that can really add up. This cuts them all off except for the "control" device so they can't sip. The two red outlets let you keep things like your TiVo (don't want that turning off!) or your desk lamp independent of the "control" device.

There's a little tool called the Kill-a-Watt that you can buy to measure how much electricity any plug-in thingie in your house is using, either when it's on or when it's off and drawing "phantom" power. Transformers are the real enemies here. I have not personally used a Kill-a-Watt but ecogeeks I know who have think it's the best thing since sliced bread.

We're going to start with my computer array in the Smart Strip, and if it works (and our electrical use drops), we'll get a couple of others for the TVs. I'll let you know how it goes!


Tony said...

From what I have heard, Ameren has no choice but to "buy back" the power if you produce an excess. They charge you for the net usage on your meter and there is no question whether a meter will turn backwards.

Anonymous said...

I think you should do more research about being able to fart into the appliances and see if you can save some money. Many a fraternity has been able to heat up a room by lighting a few on fire. more beans Mr. Mcgee?

Tony said...

I should say mechanical meters will just turn backwards. I don't know about the new digital ones.

Bill Dennis said...

Renewable, reschnewable. Big deal. Ethanol is renewable, but it's not possible to produce enough ethanol and be able to feed the population of the Earth. Wind farms don't cant serve a wide enough population. Solar power, the same thing.

And ethanol is NOT environmentally friendly the way nuclear power is. The wastes from nuclear power do not cause global warning and the can easily be disposed of, provided politicians don't cater to environmental alarmists who for some odd reason prefer the pollution we have NOW.

The only way nuclear power doesn't make sense is if you cover your ears and shout I CANT HEAR YOU WHEN YOU STATE THE FACTS ABOUT NUCLEAR POWER.

Anonymous said...

Solar and wind power certainly could serve a wide enough population if everybody installed such systems on their homes and businesses. If one wind turbine generates 2/3rds of a residence's energy usage, the potential impact is huge. Of course, the energy companies would eventually have to change business models.

Nuclear power is cleaner than many alternative methods of power generation. However, safe generation and disposal are both very real issues that require planning, not rhetorical dismissal.

Ethanol is a mistake. It is renewable, and can be produced locally. However, the production of ethanol is at least as costly as the production of petrol, and ethanol is _less_ energy efficient. For example, a 30mpg car running on E85 fuel (85% ethanol) only gets about 21 mpg. Moving from petrol to a ethanol is stupid, especially when you can move to diesel, a fuel source with a higher energy potential (those couple of extra Carbon atoms make a big difference), or investigate biodiesels, etc. Of course, then what would we do with our federally subsidized overproduction of corn? We wouldn't want to consider growing anything else.