National Renewable Energy Laboratory: Solar Has The Most Potential Of Any Renewable Energy Source

Photo Courtesy of National Park Service

A recently released study by the National Renewable Energy Laboratory, estimates that the technical potential of photovoltaic cells and concentrated solar power (CSP) in the United States is as much as 200,000 Gigawatts, enough to generate about 400,000 TWh of energy annually.

The report dismisses economic and political impacts on the solar industry and focuses solely on the scientific and engineering limitations. The types of solar power studied in the report were Urban Utility-Scale Photovoltaics, Rural Utility-Scale Photovoltaics, Rooftop Photovoltaics, and Concentrated Solar Power, which is a utility-scale project “in which the solar heat energy is collected in a central location.”

The report broke down each type of solar array:

Urban Utility-Scale PV :

“The total estimated annual technical potential in the United States for urban utility-scale PV is 2,232 terawatt-hours (TWh). Texas and California have the highest estimated technical potential, a result of a combination of good solar resource and large population.”

Rural Utility Scale PV:

“Rural utility-scale PV leads all other technologies in technical potential. This is a result of relatively high power density, the absence of minimum resource threshold, and the availability of large swaths for development. Texas accounts for roughly 14% (38,993 TWh) of the entire estimated U.S. technical potential for utility-scale PV (280,613 TWh).”

Rooftop PV:

Total annual technical potential for rooftop PV is estimated at 818 TWh. States with the largest technical potential typically have the largest populations. California has the highest technical potential of 106 TWh due to its mix of high population and relatively good solar resource.


Technical potential for CSP exists predominately in the Southwest…. Texas has the highest estimated potential of 22,786 TWh, which accounts for roughly 20% of the entire estimated U.S. annual technical potential for CSP (116,146 TWh).

The report also conducted a state by state breakdown for potential energy from solar sources.

Due to their high populations, large land areas, and ample sunlight, California and Texas are the states best suited to harvest the most solar power, especially from utility-scale projects.

In fact, in California, the National Park Service and NREL, which is a division of the Department of Energy, have outfitted one of America’s most noteworthy locations with 1,300 solar panels as part of an on going effort.

Alcatraz, the notorious prison located on an island of the same name in the middle of San Francisco Bay, is now a tourist hotspot but was once home to infamous gangsters and murders such as Al Capone and “Machine Gun” Kelly. For decades, barges would bring shipments of oil and gasoline used to power the lights and other appliances on the island. Now, however,

“307-kilowatt photovoltaic (PV) array sits on the roof of the main Cellhouse building, attached to two 2,000-amp-hour battery strings and an inverter plant. The new 1,300-panel system produces close to 400,000 kilowatt-hours of electricity a year, reducing carbon dioxide (CO2) emissions by about 337,000 kilograms a year and reducing the time the generator runs from 100% to 40%.”

A major hurdle in installing the solar array was the concerns of historical conservationists that the modern solar panels would destroy the aesthetic of the old and venerated prison. Fortunately, the cells, and an enormous battery system to store power for cloudy days, have been completely hidden from view.

It should also be noted that the funding for this project, more than $3.5 million, came from the stimulus package, The American Investment and Recovery Act. Efforts to outfit Alcatraz with solar panels have existed, off and on, since 1995 and were finally acted upon when the stimulus funds became available.

Since the shipping of fossil fuels to Alcatraz slowed thanks to the photovoltaic cells, the price of electricity on the island has decreased by 5 cents a kilowatt hour.

Efforts like this one taken by NREL show the potential of persistence and creative thinking in installing innovating green ideas and limiting dependence on fossil fuels.

-Max Frankel

7 Responses to National Renewable Energy Laboratory: Solar Has The Most Potential Of Any Renewable Energy Source

  1. Leif says:

    So ~how much cash injected into the local economies does a TWh represent? And that amount in turn would not be from our pockets to the pockets of the Fossil Rich, would it not. What is not to likes here?

  2. Paul Klinkman says:

    This national laboratory’s idea of alternative energy “research” appears to be related to bean counting. Better than nothing whatsoever, I suppose, but hardly that useful. How about producing some merit-based innovation and product development instead?

  3. Solar Jim says:

    A reference in the post has this statement: “This would mean, photovoltaics could generate around 483,600 terawatt hours (TWh) of energy annually, and CSP, 116,100.”

    That would seem to be about 600,000 TWh.

    Also, what is the context as regards current capacity and generation? If memory serves correctly, we are talking a couple orders of magnitude more than what exists today, which implies that about one percent would be sufficient.

  4. squidboy6 says:

    I didn’t recognize the photo until after finishing the story, it is SF Bay! There was an old ranch on Santa Cruz Island, the Christie Ranch I think it was called, which would have been worth saving but the prison? It must be the tourist-trade people.

    Somebody should ask Romney what he thinks of the study and the development of the facility on Alcatraz. After all, they’ve been saying that the stimulus money went overseas. I’m sure Mitt will screw up his response. One comment I’ve seen called him the “lying sack of Mitt”. That’ being generous.

  5. Leif says:

    Could someone please check my math here. I suffered a minor stroke last year and math ability has suffered. By my numbers, one TWh of energy would have a market value of ~$100,000,000 at $0.10/kWh! That money could be helping the community, schools, health care, or what have you. Lowering the tax burden of the locals. Instead we buy from the already rich and pollute the commons as well. Go figure…

  6. turbofroggy says:

    “But a historic landmark group protested” who was funding this historic landmark group, the local fuel oil supplier? I still see LOTS of empty roof space on there. Hopefully they left room for expansion of the array. I think that combined with more energy saving measures (CFL/LED lighting, solar hot water and heating) and they could eliminate the diesel generator usage all together.

  7. Jan says:

    One small example. Our temple recently installed a 30kw system of PV panels. We are already $300/month cash positive, even as we pay for the system.

    Eventually, at the typical 7% annual increase in energy rates, we will help protect our commons (world’s weather) and save over $1 million in a 30 year period. Panels are guaranteed for 25 years.

    Why aren’t more organizations dying to get a system??????