Revision as of 21:02, 27 February 2016 by ***** (***** | *****)
Small wind energy devices (wind turbines) with no external rotating parts are environment-friendly and easy to install and maintain.
For example, if wind energy devices with effective height 2,5 m and width 2 m were deployed in a number equal to the number of motor vehicles in the world, the electricity production from these devices in fresh breeze (8,5 m/s) would constitute about 56% of the world electricity production.
This is calculated as follows:
According to ref. 1 the number of vehicles in service worldwide has surpassed 1 billion. Using data from 2013 the world electricity production was 23,322 TWh. This is equal to 23,322 billion kWh. A small wind energy device shown at ref. 4 is assumed to produce 1,5 kW in 8,5 m/s wind.
If the annual average electricity from each device was 1,5 kW the amount of electricity produced per year from 1 billion devices would be 1,5 (kW) x 24 x 365 (number of hours per year) x 1 billion = 13,140 billion kWh.
This constitute about 56 % of the world electricity production.
1,5 kW from a device with effective area 2,5 x 2 m and overall efficiency 0,75 requires a wind energy density of 400 W/m^2.
At ref. 4 you can find information about the average wind energy density in your area. Please note that the available energy depends on the altitude of the energy converter components in relation to the ground.
The terrain around the wind energy device may both decrease and increase the wind energy density. In some cases a building wall can locally increase the wind energy density.
Before deciding to buy a wind energy device the wind speed at the site should be measured by means of a Wind Speed Meter. For examples of such meters see ref. 5.