Wind power
This was initially a comment in response to a question of themink17's, but became somewhat longer than fits a comment so I've moved it here.
Why is wind power a useless option for most places? The summary version: The output of wind farms in most environments is unstable and unpredictable. People expect power availability at all times, so to make power availability meet user demand sufficient backup generation capacity and/or energy storage is required to meet the worst-case difference between peak user demand and wind farm output. As worst-case wind-farm output is zero, you need to be able to store or generate enough energy to cover peak demand.
Unless you have other options like hydro, that backup / make-up capacity usually means fossil fuel power - probably gas if you're going to be rapidly adjusting output. Gas plants, and fossil plants in general, are really expensive to build, staff, maintain and hold ready to operate - whether they're actually running or not. If they're only in use for short periods to cover generation gaps, the price per watt-hour for that use will have to be much higher to cover the plant's costs during idle / low-output periods or nobody will actually be willing to operate the backup plants - or you'd need huge gov't subsidies to make it viable.
Energy storage isn't a viable alternative because there's no current energy storage technology with even remotely close to the energy density required to cover (say) a day's peak demand for a small city - if you pump water uphill into dams for hydro, use vast battery arrays, whatever. Also, battery storage systems all have very high costs, degrade over time, and are environmentally rather nasty. As if that's not bad enough, energy storage tends to have horrible efficiency so you're going to have to put a lot more power into the storage system than you get out.
As if that's not bad enough, it turns out that for some (many?) places peak power demand coincides with minimum wind power output. In the UK, for example, demand is greatest on cold, still nights when wind power output is basically zero. With a wide enough wind grid you could possibly transfer power from areas with better weather for power generation, but your transmission losses will be huge, and there's no guarantee other places do have better weather either.
So: To use wind power you need as much fossil generation capacity as you had anyway, but you use it less and have to pay to maintain it and your wind power generation. You have much lower emission of greenhouse gases (even after the emissions costs of wind farm construction, operation and maintenance) .... but your energy costs a lot more. Not just the premium you expect to pay for current renewable generation sources, but the added cost of paying for the often unused backup fossil generation capacity as well.
If you want wind power you have to live somewhere with insanely reliable wind and be prepared to accept brownouts, or you have to be prepared to pay like you've never paid before. Few people will accept either option.
My personal opinion is that we need to get used to the idea that power will be more available at some times than others - and not always predictably so. Industrial plant and processes already adapt to power availability to an extent (see, eg, Alcoa's refineries) but that needs to extend to things like home air-conditioning, refrigeration, water heating, etc, all of which need to become more aware of grid service levels and need to be more opportunistic about power use. We also need to dramatically cut regular household power use, especially idle use, and get used to the idea that non-critical services might just not work if generation capacity is overloaded.
(Yes, I know the above lacks external supporting references - if anyone takes issue to claims above please let me know and I'll follow-up with appropriate supporting refs. Right now I'm out of time).
Why is wind power a useless option for most places? The summary version: The output of wind farms in most environments is unstable and unpredictable. People expect power availability at all times, so to make power availability meet user demand sufficient backup generation capacity and/or energy storage is required to meet the worst-case difference between peak user demand and wind farm output. As worst-case wind-farm output is zero, you need to be able to store or generate enough energy to cover peak demand.
Unless you have other options like hydro, that backup / make-up capacity usually means fossil fuel power - probably gas if you're going to be rapidly adjusting output. Gas plants, and fossil plants in general, are really expensive to build, staff, maintain and hold ready to operate - whether they're actually running or not. If they're only in use for short periods to cover generation gaps, the price per watt-hour for that use will have to be much higher to cover the plant's costs during idle / low-output periods or nobody will actually be willing to operate the backup plants - or you'd need huge gov't subsidies to make it viable.
Energy storage isn't a viable alternative because there's no current energy storage technology with even remotely close to the energy density required to cover (say) a day's peak demand for a small city - if you pump water uphill into dams for hydro, use vast battery arrays, whatever. Also, battery storage systems all have very high costs, degrade over time, and are environmentally rather nasty. As if that's not bad enough, energy storage tends to have horrible efficiency so you're going to have to put a lot more power into the storage system than you get out.
As if that's not bad enough, it turns out that for some (many?) places peak power demand coincides with minimum wind power output. In the UK, for example, demand is greatest on cold, still nights when wind power output is basically zero. With a wide enough wind grid you could possibly transfer power from areas with better weather for power generation, but your transmission losses will be huge, and there's no guarantee other places do have better weather either.
So: To use wind power you need as much fossil generation capacity as you had anyway, but you use it less and have to pay to maintain it and your wind power generation. You have much lower emission of greenhouse gases (even after the emissions costs of wind farm construction, operation and maintenance) .... but your energy costs a lot more. Not just the premium you expect to pay for current renewable generation sources, but the added cost of paying for the often unused backup fossil generation capacity as well.
If you want wind power you have to live somewhere with insanely reliable wind and be prepared to accept brownouts, or you have to be prepared to pay like you've never paid before. Few people will accept either option.
My personal opinion is that we need to get used to the idea that power will be more available at some times than others - and not always predictably so. Industrial plant and processes already adapt to power availability to an extent (see, eg, Alcoa's refineries) but that needs to extend to things like home air-conditioning, refrigeration, water heating, etc, all of which need to become more aware of grid service levels and need to be more opportunistic about power use. We also need to dramatically cut regular household power use, especially idle use, and get used to the idea that non-critical services might just not work if generation capacity is overloaded.
(Yes, I know the above lacks external supporting references - if anyone takes issue to claims above please let me know and I'll follow-up with appropriate supporting refs. Right now I'm out of time).