4 ms·

Are there actually ecological impacts from offshore wind turbines? From what I've read, they rarely hit birds. Bats are another story, but I don't think there a

by what 17y ago

Are there actually ecological impacts from offshore wind turbines? From what I've read, they rarely hit birds. Bats are another story, but I don't think there are too many bats flying around offshore. On a side note, there's not much potential for wind turbines in most places, the wind just isn't strong enough: http://www.nrel.gov/gis/images/map_wind_national_lo-res.jpg http://www.nrel.gov/gis/images/map_wind_national_lo-res.jpg http://www.nrel.gov/gis/images/map_wind_national_hi-res.jpg http://www.nrel.gov/gis/images/map_wind_national_hi-res.jpg

jacquesm 17y ago
If you put up a building with a bunch of windows birds will fly in to them and occasionally get killed, so yes, windmills will kill birds, but: Windmills are portrayed as 'bird slaughterhouses', the reality is that while bird killings do occur they're nowhere near as frequent as the FUD would have you believe. If it were the blades would be dripping blood, and a good place to shop for dinner would be at the foot of a windmill tower. I've had a 5 meter (15') very fast running (600 RPM) mill up for well over a year and not a single dead or injured bird was found near it. Big windmills rotate a lot slower (even if the tip speeds are roughly identical) so are easier to spot as obstacles, the small mills turn so fast the blades are visible only as a blurry disc. As for the side note, that's 30% of the total landmass of the continental united states usable, that's not 'not much potential', that's enormous potential.
- what 17y ago
  Wikipedia claims an average power consumption of ~12kW per person in the US (but it's marked as needing a citation). Assuming a wind power density rating of good (500W/sq m), you would need to harness all of the energy in a 24sq m area per person. There are >300M people in the US. Plastering turbines over that 30% of the landmass would serve only half the population. (Note: I'm no expert and maybe there is some glaring oversight in my quick calculation.)
  - jacquesm 17y ago
    12kW is not a power consumption but a momentary rate, power consumption per person is rated in KWh per unit of time, or in oil equivalents, about 8 tons of oil per US citizen per year. Also, wind power is not delivered in cross section on a surface parallel to the ground but on one at a right angle to the ground. There are other forms of renewables besides wind, such as hydroelectric dams, geothermal power and solar. A combination of those would be called for anyway. And since it is much cheaper to save a Watt-hour than it is to make one conservation is where it all begins, currently the US uses about double the amount of energy per person compared to the rest of the developed world. I'm fairly sure the US could increase its 7% in renewables to a much more significant fraction without any breakthroughs in technology, say up to 20% or so. That alone would be a major relief. Right now there are iirc about 35GW of installed power in wind turbines in the US, that's about 25,000 turbines. I've been out of the wind energy scene for 5 years now, I was mostly interested in the smaller scale anyway, but there is a surprisingly large amount of energy in wind power and we are using only a very small fraction of it. Keep in mind too that the total energy consumption of a country is used to power lots of different stuff, transportation is going to be the hardest to convert, but anything that runs off the grid is fair game for being powered by renewables, and in all those per-capita energy uses all those different categories are lumped together.
    - what 17y ago
      Ok, you seem to be more knowledgeable on the subject than I am and I probably misinterpreted the chart as well. I was just trying to say turbines aren't the end all solution since most places don't seem to have enough wind. But there should definitely be push for using more renewable energy sources and improving the associated technologies. Also, maybe you can give me some numbers so I can plug them into this formula. What is the wind conversion efficiency for a turbine? What is the typical rotor diameter? And how many turbines per unit area on a typical wind farm? energy generated per turbine = efficiency * (power per unit area) * area * time total energy generated = (available area) * (turbines per unit area) Then I can redo my calculation using 29 PWh as the total energy consumption for the US (http://en.wikipedia.org/wiki/Energy_in_the_United_States http://en.wikipedia.org/wiki/Energy_in_the_United_States). Just curious now, don't want to start an argument or anything.

by what 17y ago

jacquesm 17y ago

If you put up a building with a bunch of windows birds will fly in to them and occasionally get killed, so yes, windmills will kill birds, but: Windmills are portrayed as 'bird slaughterhouses', the reality is that while bird killings do occur they're nowhere near as frequent as the FUD would have you believe. If it were the blades would be dripping blood, and a good place to shop for dinner would be at the foot of a windmill tower. I've had a 5 meter (15') very fast running (600 RPM) mill up for well over a year and not a single dead or injured bird was found near it. Big windmills rotate a lot slower (even if the tip speeds are roughly identical) so are easier to spot as obstacles, the small mills turn so fast the blades are visible only as a blurry disc. As for the side note, that's 30% of the total landmass of the continental united states usable, that's not 'not much potential', that's enormous potential.

what 17y ago
Wikipedia claims an average power consumption of ~12kW per person in the US (but it's marked as needing a citation). Assuming a wind power density rating of good (500W/sq m), you would need to harness all of the energy in a 24sq m area per person. There are >300M people in the US. Plastering turbines over that 30% of the landmass would serve only half the population. (Note: I'm no expert and maybe there is some glaring oversight in my quick calculation.)
- jacquesm 17y ago
  12kW is not a power consumption but a momentary rate, power consumption per person is rated in KWh per unit of time, or in oil equivalents, about 8 tons of oil per US citizen per year. Also, wind power is not delivered in cross section on a surface parallel to the ground but on one at a right angle to the ground. There are other forms of renewables besides wind, such as hydroelectric dams, geothermal power and solar. A combination of those would be called for anyway. And since it is much cheaper to save a Watt-hour than it is to make one conservation is where it all begins, currently the US uses about double the amount of energy per person compared to the rest of the developed world. I'm fairly sure the US could increase its 7% in renewables to a much more significant fraction without any breakthroughs in technology, say up to 20% or so. That alone would be a major relief. Right now there are iirc about 35GW of installed power in wind turbines in the US, that's about 25,000 turbines. I've been out of the wind energy scene for 5 years now, I was mostly interested in the smaller scale anyway, but there is a surprisingly large amount of energy in wind power and we are using only a very small fraction of it. Keep in mind too that the total energy consumption of a country is used to power lots of different stuff, transportation is going to be the hardest to convert, but anything that runs off the grid is fair game for being powered by renewables, and in all those per-capita energy uses all those different categories are lumped together.
  - what 17y ago
    Ok, you seem to be more knowledgeable on the subject than I am and I probably misinterpreted the chart as well. I was just trying to say turbines aren't the end all solution since most places don't seem to have enough wind. But there should definitely be push for using more renewable energy sources and improving the associated technologies. Also, maybe you can give me some numbers so I can plug them into this formula. What is the wind conversion efficiency for a turbine? What is the typical rotor diameter? And how many turbines per unit area on a typical wind farm? energy generated per turbine = efficiency * (power per unit area) * area * time total energy generated = (available area) * (turbines per unit area) Then I can redo my calculation using 29 PWh as the total energy consumption for the US (http://en.wikipedia.org/wiki/Energy_in_the_United_States http://en.wikipedia.org/wiki/Energy_in_the_United_States). Just curious now, don't want to start an argument or anything.