The larger wind turbines run into a wall with scaling of volume ³ (=mass and cost) vs swept area ² with increasing rotor diameter, so that the economics probably start to get worse at sizes beyond those already in use (apart from perhaps reducing maintenance costs). Makani http://www.makanipower.com/ and other kite power companies have a small chance of beating the cost problems by eliminating big expensive generators and towers as well as getting up into much stronger wind - they might bring costs down to <$0.05/kWh, but it will take another 10 years to see if their technology pans out from a maintenance point of view.
So I don't think conventional wind has much of a future near term given incredibly low cost and massive availability of shale gas, and it is that low gas price that is also driving the western move away from nuclear due to lower cost. US wellhead gas prices are now about $0.007 kWh (yes less than $0.01!), though Europe is several times more expensive. It is also noticeable that throughout Europe renewables like wind and solar are rapidly falling out of favour with the public due to very high cost. Japan is ramping up gas imports to compensate for less nuclear power (electricity from LNG imports costs about $0.10/kWh), and that may actually turn out to be cheaper for them in medium term than nuclear (even if it has dire consequences for their balance of trade figures) But the west is in many ways irrelevant now anyway, with shrinking population and industrial capacity. Almost all new capacity in the world is going into developing Asian countries and they are definitely choosing Nuclear and gas ahead of wind and solar: China is building reactors at a huge rate (25 currently under construction, many more to start soon) to ensure their energy security. And these are being built for $1000-1500/kW - 2 or 3 times cheaper than what the West seems to be able to do. At that price their electricity costs are only $0.03-0.04/kWh which is roughly cost competitive with gas (electricity distribution costs amount to an additional $0.05-.10 anyway). With their high build rate China is also on a learning curve that will see those costs drop significantly. India is also currently building about 1.5 reactors a year, and aiming to ramp that up significantly in very near future. So for Asia new nuclear beats any foreseeable renewable technology (other than hydro). Still hoping for economically competitive LENR to change the equation. On 19 April 2012 18:32, Jed Rothwell <jedrothw...@gmail.com> wrote: > See: > > > http://www.renewableenergyworld.com/rea/news/article/2012/04/wind-turbine-blades-keep-growing > > It does not say how long they are, but only that they are 20% longer than > they were a few years ago. Anyway, the longer the blade, the larger the > cross-section it sweeps, and the more power you get. QUOTE: > > "The industry as a whole continues to focus its onshore efforts in the 1.6 > MW-3.5 MW segment, while the offshore segment has moved away from 5 MW > systems and is graduating to 6 MW-7 MW offerings to cope with larger > offshore farms at greater water depths and greater distances from shore. > The interplay between onshore and offshore wind turbine portfolios has left > a noticeable gap in the 3.5 MW-5 MW segment." > > The ratio of actual to nameplate is much better offshore than onshore. > Typically, they find places where it is about 40%. Offshore wind is > immensely powerful and surprisingly predictable. It powered all of world > oceanic trade until 1850, moving millions of tons across oceans and seas. > > 6 MW nameplate is approximately 2.4 MW actual, so it would take roughly > 420 of these to replace one Japanese nuke plant. At present there are 53 > nukes sitting there, turned off. One is running. Given the now robust local > opposition to nuclear power I doubt that most will ever be turned on again. > There is no chance additional ones will be built. Nuclear power in Japan is > dead, dead, dead & gone. It turns out Japan has a great deal more offshore > wind than people though a few years ago. In other words, you could replace > those nuke plants with 22,000 wind turbines. That's not an impossible > number. It would be cheaper than the cleanup cost for the Fukushima > accident. Of course there are many difficult technical problems such as how > to store energy, but installing 20 thousand turbines in Japan would take 30 > years and over that time I think the problems could be solved. > > In real life you would want to use a lot of solar power, because people in > Japan need electricity the most when the sun is shining brightly, for > air-conditioning. Especially in southern Japan. > > Worldwide, wind power increases by around 20 GW nameplate. That's the > increase, above replacements. That is the equivalent of building ~6 nukes, > which is probably more than nuclear power increased in its heyday back in > the 1970s. Certainly the sustained growth in wind power is greater than > nukes were. > > - Jed > >
