Land Area Requirements for Wind and Solar. Saskatchewan (& USA)

 

Wind turbines

Need to be spaced hundreds of meters apart so that the turbulent wake of one does not interfere with another. As a result just a few wind turbines can cover a very large area. The total area of a singe wind project is typically defined as the area within a perimeter surrounding all of the turbines within that project. This amount is highly variable depending on the wind farm configuration (see below) but is typically 35 hectares or 87 acres (± 60 percent) per megawatt. The average turbine size in the US today is 1.8 megawatts - in other words the total land area requirement per turbine is about 65 hectares or 155 acres.  However....

 
 

...although the total area of a wind farm can be quite large,only a very small proportion of this total is permanently impacted by the wind farm operations. Those direct effects are due to one or more of the turbine pad (i.e. the concrete foundation surrounding the wind turbine - see the picture below), roads, electrical substations or transmission.  Typically the permanently occupied land amounts to 0.4 hectares or 1 acre per megawatt. Using the same average turbine size of 1.8 megawatts, this equates to 0.7 hectares or 1.8 acres per turbine.

In order to generate 20 percent of Saskatchewan's electricity using wind energy and given Saskatchewan's world-class wind resource, 1,300 megawatts of wind turbines would be needed. This would require 520 hectares, 5.2 square kilometres, a parcel of land measuring 2.3 by 2.3 kilometres or 0.0008 percent of Saskatchewan's land area.

For more information check out this NREL paper.

The photo below was taken by David Ward, of the American Wind Energy Association, at the 20-turbine, 50 megawatt, Rippey Wind Farm in Iowa. The picture is included here as it neatly illustrates how crops can continue to be grown right up to the base of the turbine. It also shows the concrete foundation (known as the 'pad') on which the turbine sits.  By the way - the turbine shown is a 2.5 megawatt machine and this single turbine generates enough electricity to meet the needs of 1,000 average Saskatchewan houses.

 

Photo credit: David Ward @ the American Wind Energy Association.
Location: The 20-turbine, 50 megawatt, Rippey Wind Farm in Iowa.

 

Solar

The economics of large scale solar are not as attractive as those of wind energy; solar nonetheless has other extremely useful attributes and for these and other reasons, landowners, farmers and householders across Saskatchewan are giving increasing consideration to solar power. So here is a brief summary of land area requirements;

Roots Rock Renewables (a Sask. solar installer) advises that 4 hectares or 10 acres, of land are required per megawatt of solar capacity.  Given the solar resource in Saskatchewan, 3,000 megawatts of installed solar capacity would be needed in order to generate 20 percent of the province's electricity. This amount of solar would require 12,000 hectares, 120 square kilometres, a parcel of land measuring 11 by 11 kilometres or 0.02 percent of the total land area of Saskatchewan. 

Solar USA. It is interesting to consider this on a much larger scale. There is an excellent May 2015 analysis by the Massachusetts Institute of Technology 'The Future of Solar Energy' which considers the land area which would be required to power all of the US' 2050 electricity needs. The land required would be 33,000 square kilometres - while that may sound like quite a lot, it is not as the following graphic, from the study, shows. It is about the same as covering all US rooftops and golf courses with solar panels. 

But if one is talking about 'only' 20 percent of US electricity from solar (a more reasonable figure) then the land area requirement of 6,600 square kilometres (2,500 square miles) would  be just over half that which is currently covered with golf courses. Even more striking: it is only one third more than the 1,900 square miles of Louisiana wetland lost to sea-level rise and subsidence since 1930.

 

Source: Massachusetts Institute of Technology. 'The Future of Solar Energy'. May 2015