Your Questions About Wind Turbine Cost

admin answers:

Wind power provides very little net energy. It is a non-starter. The use of plastics in wind turbines (as in ALL turbines) is a non-issue and completely misses the point.

Wind energy is a tempting IDEA but a disappointing reality. Wind power is so unreliable and variable that equivalent standby power has to be available all the time, wasting energy. Wind turbine construction is heavily subsidised and the electricity produced (even without allowing for the hidden cost of standby cover) is so expensive it is uneconomical. Power companies only buy wind generated power because they HAVE to by law and they cover the excessive cost by charging us more for ALL our electricity. If it wasn’t for the subsidies (direct grants plus subsidies through us paying more for conventional power) there would be no wind energy in the UK. It is an appalling waste of money that could be better spent on more productive, more economical, more reliable power generation using other technologies.

Tidal power is stronger and totally predictable but receives only a fraction of the subsidy of wind power. Ignoring ideology and looking for a realistic practical solution, we need to be building nuclear power capacity plus clean-burn coal fired power stations with tidal power as a longer term source.

admin answers:

The ability to generate electricity is measured in watts. Watts are very small units, so the terms kilowatt (kW, 1,000 watts), megawatt (MW, 1 million watts), and gigawatt (pronounced “jig-a-watt,” GW, 1 billion watts) are most commonly used to describe the capacity of generating units like wind turbines or other power plants.

Electricity production and consumption are most commonly measured in kilowatt-hours (kWh). A kilowatt-hour means one kilowatt (1,000 watts) of electricity produced or consumed for one hour. One 50-watt light bulb left on for 20 hours consumes one kilowatt-hour of electricity (50 watts x 20 hours = 1,000 watt-hours = 1 kilowatt-hour).

The output of a wind turbine depends on the turbine’s size and the wind’s speed through the rotor. Wind turbines being manufactured now have power ratings ranging from 250 watts to 5 megawatts (MW).

Example: A 10-kW wind turbine can generate about 10,000 kWh annually at a site with wind speeds averaging 12 miles per hour, or about enough to power a typical household. A 5-MW turbine can produce more than 15 million kWh in a year–enough to power more than 1, 400 households. The average U.S. Household consumes about 10,000 kWh of electricity each year.

Example: A 250-kW turbine installed at the elementary school in Spirit Lake, Iowa, provides an average of 350,000 kWh of electricity per year, more than is necessary for the 53,000-square-foot school. Excess electricity fed into the local utility system earned the school $25,000 in its first five years of operation. The school uses electricity from the utility at times when the wind does not blow. This project has been so successful that the Spirit Lake school district has since installed a second turbine with a capacity of 750 kW. (For further information on this project, see at the Web site of the International Council for Local Environmental Initiatives.)

Wind speed is a crucial element in projecting turbine performance, and a site’s wind speed is measured through wind resource assessment prior to a wind system’s construction. Generally, an annual average wind speed greater than four meters per second (m/s) (9 mph) is required for small wind electric turbines (less wind is required for water-pumping operations). Utility-scale wind power plants require minimum average wind speeds of 6 m/s (13 mph).

The power available in the wind is proportional to the cube of its speed, which means that doubling the wind speed increases the available power by a factor of eight. Thus, a turbine operating at a site with an average wind speed of 12 mph could in theory generate about 33% more electricity than one at an 11-mph site, because the cube of 12 (1,768) is 33% larger than the cube of 11 (1,331). (In the real world, the turbine will not produce quite that much more electricity, but it will still generate much more than the 9% difference in wind speed.) The important thing to understand is that what seems like a small difference in wind speed can mean a large difference in available energy and in electricity produced, and therefore, a large difference in the cost of the electricity generated. Also, there is little energy to be harvested at very low wind speeds (6-mph winds contain less than one-eighth the energy of 12-mph winds).