On both sides of I-15 all one can see is scrub, weeds, debris, and power lines. Highway departments must keep their right of way clear of invasive weeds such as Russian thistle(tumbleweed), cheat grass, etc. Mowing or pesticide spaying operations are the most common methods. Instead of spending all those tax payer dollars trying to control photosynthesis, why don’t we use photosynthesis to create electricity along these highways?
By designing the proper alignment of solar systems along highways, land managers could also funnel wildlife away from dangerous highway crossings and into safe wildlife corridors. In the desert Southwest, miles of small fences are built along highways to protect the desert tortoise from getting killed by cars. Larger structural solar systems could also protect larger animals such as cattle, deer, and antelope. These larger animals also cause many serious accidents and human deaths on our highways.
How much acreage are we talking about? The first estimate to consider is the amount of land that highway departments currently manage. This is a small subset of all right of way highway acreage. Road Ecology: Science and Solutions written by Richard T. Forman in 2002 is a good source of information on managed right of way land along our nations highways.
Forman’s book states that California manages 230,000 acres of right of way on 15,000 miles of highway—about 15 acres per mile of highway. In the US we have about 4 million miles of roads, or 60 million acres of right of way to manage. On many sections of highways in the western US, the highway right of way is contiguous to federal land like the BLM (Bureau of Land Management). By using a small amount of this BLM land, we could easily double the amount of land available for highway solar energy.
Depending on the particular solar technology, one needs 2-4 acres of land to place a 1 megawatt solar power system. So a conservative estimate for US highway solar would be 20 million megawatts of total capacity.
In 2006 the existing US capacity for electricity was about 1 million megawatts. For example, in just the disturbed land along our nation highways, we could have almost 20 times more capacity then currently installed. Here are some energy figures from 2007:
The U.S. electric power industry’s total installed generating capacity was 1,089,807 megawatts (MW) as of December 31, 2007.
Total U.S. electricity generation was 4,159,514 gigawatt-hours (GWh).
The capacity of different power plants will produce different amounts of total electric generation. A coal or natural gas fired plant can run almost all the time. A solar power plant may only average 8 hours a day of energy generation. So the real effective electric generation for the 20 million megawatts of highway solar capacity would be about 7 million megawatts of full generation capacity. This is 7 times the electricity we currently consume in the US.
In summary, right of way highway solar could be a solution to our nation’s energy needs and could also reduce costs to manage these right of ways. Another benefit would be to help wildlife managers create wildlife corridors for both human and wildlife safety. Let’s preserve our undisturbed public lands by implementing solar technologies on these existing managed lands.