The Future of Energy: Wind Power


Today’s guest post by Whaleoil reader Bruce Alan Forbes is part of an article he wrote called The Future of Energy with predictions for 2040. As it is an in-depth analysis I divided it into six posts so that we could discuss each part separately.

62 Siemens wind turbines of the type SWT-2.3-101 turn here in the wind park West Wind near Wellington in New Zealand.?

Wind Power,

Wind power has been around for thousands of years. 200 years ago, the Fens in the UK were drained using wind-driven pumps. Because they were expensive to build and operate, and the wind often did not blow when needed, these were soon replaced by low-pressure steam driven pumping engines that, by today?s standards, were very inefficient and extremely expensive. The drive for efficiency and low cost led to their being replaced with higher-pressure steam engines, diesel engines and finally, by electric pumps.

Wind power today suffers from the same problems it did hundreds of years ago – expensive machinery, low average output and the vagaries of the wind.

Wind farms do not generate much in light winds and they must be shut down in strong winds. Typically, they generate less than 10% of their rated output for 30% of the time, and more than 80% for only about 5% of the time. A wind farm provides expensive electricity at unpredictable times – often when it is not needed.

Despite these fundamental problems, wind power has expanded very rapidly, and worldwide there is now over 300 GW of total nominal capacity. This expansion has been driven by subsidies, not by economic or technical merit.

According to a study carried out by the International Renewable Energy Agency (IRENA) in 2012, the completed renewable generation cost in the US in 2009 and 2010 averaged $2,100/kW. Operation and maintenance costs are about 1 c/kWh, and these appear to increase over time. The IRENA study also calculated the long-term cost of power from a wind farm, based on a 10% discount rate and a 20-year life. For a capital cost of $2,100/kW, the cost was 13 c/kWh at a typical 25% capacity factor. These costs are well above the comparable costs of fossil fuel or nuclear generation.

A 2012 report by the American Tradition Institute entitled ?The Hidden Costs of Wind Electricity? shows a much worse picture for wind generation, because it takes account of the effects of subsidies and factors-in the costs of reserve plant, the fuel for these, and additional transmission costs. The result is that wind-derived electricity prices increase by an additional 6.9c/kWh. This additional, invariably hidden, cost is by itself more than the total cost of producing electricity from fossil fuels.

Wind power is expensive primarily because wind farms cost around $2,100/kW and their capacity factor is low. At first sight, $2,100/kW does not appear to be unreasonable, as this is about the same cost in $/kW terms as a coal-fired power station. However, because the capacity factor is much lower, it takes about 3 GW of wind farm capacity to generate the same amount of electricity as a 1 GW capacity coal-fired power station. This means that the equivalent cost of wind on an equal energy basis is a very expensive $6,300/kW. Operating and maintenance costs are between 1 and 2 c/kWh, which are close to those of many coal-fired power stations. The need for 3 GW of wind power instead of 1 GW of conventional generation means that 3 GW of associated transmission lines, transformers and the like are needed to transmit the power. Backup stations are also needed because wind power output during peak demand periods is often in the region of 2% to 10% of nominal design capacity.

Wind turbines will probably not last more than 20 years. There is also some evidence that as they get older, maintenance costs start to increase rapidly. In contrast, the normal life of a coal or gas-fired station is 30 to 40 years; nuclear 60 to 80 years and hydropower stations can last for hundreds of years.

Wind farms occupy large areas of land, are visually obtrusive and create low frequency noise. Major road projects are often required for construction and maintenance. The environmental costs of wind farms include those of the new roads, and the environmental effects of the backup stations, including their CO2 emissions. The development of wind power often requires that new transmission lines be built. Wind farm developers typically do not pay for them. While conventional power stations typically also get ?free? transmission, they generate about 3 times as much electricity per GW of nominal design capacity. This means that the transmission cost burden created by the wind farms is much higher than it is for conventional generation technologies.

Wind turbine blades kill many birds and bats. One estimate was that about 570,000 were killed in 2012 in the US. This number included 83,000 birds of prey, including some protected birds such as eagles. According to Spain?s Ornithological Society, between 6,000,000 and 18,000,000 birds and bats are killed annually by wind farms in that country.

Most wind farms avoid some CO2 emissions compared to the equivalent coal-fired stations, but not as much as claimed. The main reason is that the variable output of wind farms forces existing thermal power stations – which are designed for maximum efficiency while operating steadily at high outputs – to operate over a wide and rapidly fluctuating range of outputs. As a result, these existing stations emit more ash, carbon dioxide, sulphur dioxide and nitrous oxide per unit of electrical output than they would if they were running under the steady-state conditions they were designed for. Consequently, the quantities of CO2, particulates, SO2 and NOx emitted per kWh of overall output are all increased. The new OCGT stations needed to provide backup also add to the wind farm-associated CO2 emissions.

Future Developments in Wind Power

Since the technology is mature, there is little prospect of major advances that will lead to either higher outputs or lower costs. Although some contend that a change from the now standard 3-bladed, to 2-bladed turbines will reduce costs and increase reliability, there has been no sign that any major manufacturer will challenge the prevailing view that three blades are better. There have also been attempts to increase the height of wind towers to increase capacity factors, but success has been limited and capital costs significantly higher.