The U.S. Could Get 20% of Power From Solar Sited Beneath Transmission Lines

by John Farrell

What if the U.S. could get 20 percent of its power from solar near transmission lines without covering virgin desert?

It could. Transmission right-of-way corridors, vast swaths of vegetation-free landscape to protect high-voltage power lines, could provide enough space for over 600,000 megawatts of solar PV.  These arrays could provide enough electricity to meet 20 percent of the country’s electric needs.  (Note: There may not be good interconnection opportunities for solar under these huge towers, so this should be read as a land use discussion rather than technical analysis of interconnection to the grid.)

It starts with the federal Government Accountability Office, which estimates there are 155,000 miles of high-voltage transmission lines in the United States (defined as lines 230 kilovolts and higher). According to at least two major utilities (Duke Energy and the Tennessee Valley Authority), such power lines require a minimum of 150 feet of right-of-way — land generally cleared of all significant vegetation that might come in contact with the power lines.

That’s 4,400 square miles of already developed (or denuded) land for solar power, right under existing grid infrastructure.

Of course, the power lines themselves cause some shading, as may nearby trees (although the New York Public Service Commission, and likely other PSCs, has height limits on nearby trees that would minimize shading on the actual right-of-way).  To be conservative, we’ll assume that half of transmission line right-of-way is unsuitable for solar.

That leaves 2,200 square miles of available land for solar. With approximately 275 megawatts (MW) able to be installed per square mile, over 600,000 MW of solar could occupy the available right-of-way, providing enough electricity (over 720 billion kilowatt-hours) to supply 20 percent of U.S. power demands (note: we used the average annual solar insolation in Cincinnati as a proxy for the U.S. as a whole).

Making big strides toward a renewable energy future doesn’t require massive, remote solar projects. We can use existing infrastructure or land to generate significant portions of our electricity demand. Transmission right-of-way, providing 20 percent of U.S. electricity from solar, is just one piece of the puzzle, with another 20 percent possible from using existing rooftops, and a solar potential of nearly 100 percent from solar installed on highway right-of-way.  Solar can help achieve a 100 percent clean — and local — energy future.

John Farrell is a researcher with the Institute for Local Self Reliance. This post originally appeared at Energy Self Reliant States, part of ILSF’s New Rules Project.



19 Responses to The U.S. Could Get 20% of Power From Solar Sited Beneath Transmission Lines

  1. Mark says:

    Then there’s RR ROWs, Freeway medians, and pipelines. Same concept.

  2. jduhls says:

    Why do that when we can just burn a non-renewable resource that poisons our air, land, and water? /sarc

  3. Larry Gilman says:

    Whoa there on the “vast swaths of vegetation-free landscape.” Don’t exist. In most of the country, there is no such thing as a vegetation-free powerline. At least in New England, powerlines are actually valuable habitat, and increasingly managed as such: please check out .

    Highway rights-of-way, powerlines, rooftops, etc. are of course critical to the future of distributed solar power. But just as there is no such thing as a “lifeless desert” that we can pave over with megahectares of solar panels without causing ecological damage, there is no such thing as a vegetation-free or ecologically null powerline corridor — at least, not in my neck of the woods.

  4. Jay A Turner says:

    In urban areas, the power generated from arrays on rights of way could be fed in to the local grid. My back yard ajoins the PG&E right of way for high voltage lines, and my PV array feeds into the local grid (the local power lines are only a few feet off of the right of way), so it’s a no-brainer that PG&E could hook in its own solar arrays too.

    We also have another vast urban resource: parking lots. Covering parking lots with solar arrays would deliver power where it’s needed and not take up any extra land.

  5. Alex C says:

    Then there’s the opportunity to position solar panels on the high-tension towers themselves. Panels in this location would not shade the ones below unless the sun is directly overhead. This could increase the usable area by as much as 5%. At the very least, such arrays could be coupled with battery storage to power the aircraft warning strobes on the towers.

  6. Theodore says:

    This is an issue that should not be resolved by people outside the energy industry thinking it might be a good idea. It needs to be resolved by analysis of the costs and benefits. If you were an engineer in the energy industry, would you like to be told by somebody with little or no experience in these matters that you have to implement this plan to save space? This is something that really should be left to the experts, who will consider the cost of land along with a thousand other details. I believe the vegetation under the power lines is keep down with herbicides. You would not want to spray solar panels. Alternative methods of clearing the land might be required. Maintenance of the panels might also be inefficient or difficult if they were under power lines and strung out across the landscape. In many areas, land is cheap, available, and a tiny part of the overall cost of producing solar power. Suggestions are fine, but we need input from people who actually build and maintain power lines and solar arrays.

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  8. Larry Gilman says:

    Herbicides are indeed generally used but need not be: alternatives have been developed and are already in profitable real-world use ( ). Perhaps panels could be rack-mounted in a way that does not shade the ground vegetation, which is ecologically valuable, into nonexistence; grazing has apparently been able to coexist with rack-mounted solar panels. But then, one would have to take care not to use 100% of the corridor footprint in one’s calculations of the available area.

  9. Anne Butterfield says:

    Theodore — what on earth made you think that this idea would be advanced without experts weighing in? A strange thing to say.

    Solar panels under trans lines would provide shade and inhibit the growth of some plants underneath; other plants would have to be controlled. The cost of such would have to be estimated and put on the business model of the solar installation; but conversely, have you considered the difficulty and expense of building new power lines? It’s extraordinary and puts much of our RE future on ice; Farrell’s suggestion is good enough to command attention and research. And that’s what FERC and regional trans authorities are for (as well as DOE, NREL, PNNL, Argonne, etc etc)

    Did you know that New Jersey has done a similar scheme by installing solar PV on local telephone poles? This is an idea whose time has more than come. see

  10. Anne Butterfield says:

    New England is more thickly settled than any other area of the US. And as such the trans corridors can in fact function as wildlife corridors. And good on em for that! Now consider all the big tran lines elsewhere around the nation, particularly crossing wilderness; it’s disturbed land to begin with and quite the opportunity in comparison with tearing up virgin land. And the big trans covering huge amounts of the mid west corn belt? Would seem to be perfect. Conversely, the big trans that climbs the Rocky Mountain range might not ought to be included in Farrell’s numbers. Terrain too rough for efficient installation? yeah. Solar installers like flat when they can get it….

  11. MaxUtil says:

    You have a fair point that there may be numerous reasons this would or wouldn’t be a viable concept. But I think you also have to admit that some of the reasons this kind of idea has not been pursued may simply be that it is a non-traditional use of land, there are regulatory complexities that developers would prefer not to deal with, financing may be easier to arrange with a traditional ‘lease a big open piece of land’ configuration, etc.

    I don’t think you can assume that just because an industry is not doing something means it is not a valid idea. There are lots of reasons industries follow traditional development paths. Many of these may just need some fresh thinking that could open up new ways of doing things. This isn’t a business plan, it is a suggestion and also a broader point about how there is a lot of available space that is being “used” already, but could be perfect for solar or other installations.

  12. PeterW says:

    Theordore, I would suggest Joe Romm is an expert in the energy industry and this is his blog, so maybe, there’s some credibility to this piece. Also since you’re not an expert, using your logic, should we put much weight in your criticisms?

  13. squidboy6 says:

    This can be done without a lot of regulation and the transmission is already available, I spent a lot of time out in the Anza-Borrego desert last year, near San Diego and this was an obvious solution.

    The land is already disturbed by the roads. Transmission is cheaper, the only negative is the panels would have to be serviced over a larger area so that would require more trucks, and more jobs so that’s not so bad.

    Placing them on rooftops and along right-of-ways is cheaper than building single sites. There would be some theft problems but that could be controlled as well.

    In towns like Santa Barbara solar panels were outlawed for esthetic reasons (???) for years but now they’ve been made legal. This would provide jobs.

  14. David B. Benson says:

    I’d want wildlife and ecological experts to weigh in first. Second, the power from the solar PV would require transmission as cannot just hook these up to the overhead high voltage lines. Altogether, this appears to me to be a nonstarter in most locations.

    I idea of using parking lots (along, of course, with roof tops) has much greater obvious appeal; pick the lower cost solutions first as integrating large amounts of solar power into existing grids is fraught with difficulties.

  15. Dr.A.Jagadeesh says:

    Excellent. Other countries can also follow this.

    Dr.A.Jagadeesh Nellore(AP),India
    Wind Energy Expert

  16. Larry Gilman says:

    Note, northern New England is not densely settled. Ranked by state population density, NH is 21st, Vermont 30th, and Maine 38th. Both VT and ME are below the national average. From:

  17. Theodore says:

    I realize now that my response to this idea was negative in large part because it reminded me of many of my father’s ideas about things of which he knew so little. He commonly would second guess the experts in matters of which he knew nothing. He sometimes commented that freeway median land was being wasted because it was “unused”. He wanted to raise cattle on it. I learned to regard his verbal ventures into engineering and business with monumental skepticism. It’s personal baggage and an instinctive negative response from many years of training.

  18. Tim says:

    Why not place vertical wind turbines and or solar on these transmission towers depending on the gain from either?

  19. Paul Revere says:

    If this is such an obvious and cost-effective idea then why isn’t it being done already by the profit-seeking capitalist energy companies?