Special To EnergyBulletin.Net

LAS VEGAS–A groundbreaking took place Monday at Nellis Air Force Base, just north of Las Vegas, Nevada, in the desolate, arid, windswept Mojave Desert. The ceremony will initiate construction on what will be the largest solar photovoltaic (PV) array in the United States, capable of producing 15-18 megawatts of power.

At least for a year or so, say Air Force officials, the plant will also constitute the largest such facility in the world, encompassing an investment of $100 million on 140 acres. The land will largely be covered by silicon wafers that will rotate each day to doggedly follow the sun across the sky.

The facility represents one of the U.S. Department of Defense’s (DOD’s) largest forward leaps in developing renewable energy. It is symbolic of the DOD’s efforts to reduce the high cost of fossil-fuel generated electricity that will increasingly, in the years ahead, characterize life in Southern Nevada.

Expecting to eventually save $1 million a year on their electric bill, thanks to the new solar plant, base officials expressed pride at being able to demonstrate leadership in developing a significant on-base alternative. They said they expect the new plant to go online by the end of the year.

Yet, in many ways, the new facility is a reminder that PV energy remains largely on the sidelines in the larger scheme of energy production in the area. It turns out, for example, that the Air Force is more a host than a progenitor of the new plant.

The owner-customer will be neither the U.S. Air Force nor the DOD, according to sources close to the project’s civilian collaborators. Who, then, is the underwriter and force motrice behind this salient development?

A set of investors headed up by an entity known as MMA Renewable Ventures, San Francisco. They, along with commercial entities such as SunPower, the builder and systems specialist, and Nevada Power, have been propounding the deal for years, but it has came into being only as the civilian entities got their act together. For example, NP’s board voted to approve its participation in the project in early April.

Depending on time of day and usage, a small amount of the power generated by the facility may go off base to surrounding communities. However, the Nellis plant will produce electricity during the day–not after sundown. Lacking battery storage capacity, its power will constitute a useful supplement, not an impressive primary generating source, for the base’s own needs.

Some estimates suggest the plant may supply only 25 percent of the base’s needs. That figure has been listed elsewhere as 30 percent. Both figures are still impressive, considering 12,000 people work on the base and 7,215 live there.

But those percentages hardly inspire confidence that the plant will produce any spare solar-generated power for Southern Nevada’s high-growth communities-notably Las Vegas, directly south, and Mesquite, about 40 miles to the north-traditionally dependent on cheap, abundant electricity, not to mention adequate water supplies from adjacent Lake Mead (currently down 100 feet from normal).

So the new venture actually points up the foreboding limitations on solar electric power development-even in places that engineers deem “highly insolated” like the Mojave, whose clear, blue skies pretty much make it an optimal setting in which to undertake a larger PV project.

As much as the Air Force may now be demonstrating meritable leadership in this area, PV technology has been under fairly intense development for more than three decades. Solar generation remains expensive, relying on large amounts of wide open space and taxpayer support, while producing negligible usable power for many localities on nights and overcast days.

As many residents now appreciate, PV arrays in the U.S. are used mainly on a small scale-e.g., as rooftop panels on homes and commercial buildings, to provide light for roadside signs (including billboards) or to provide power for freeway call boxes. Some European countries, have certainly built large-scale PV arrays, providing utility-scale power-notably, Germany.

But, as at Nellis, these have required aggressive subsidies to keep them economically viable. The partners, according to base PR director Michael Estrada, will be able to build the plant, recover costs and produce electricity at a savings, only because of the fairly complex financing structure arranged among MMA, its investors, Nevada Power, and Nellis–in addition to the blessing of multimillion-dollar government incentives.

The Air Force never wanted to pay construction costs. That didn’t deter MMA’s private investors, who anticipated a steady flow of Air Force revenue once the project powered up. SunPower Corp., PowerLight’s owner, joined in, wanting visibility as well as, nominally, the work.

MMA, out of San Francisco, is counting on attracting institutional investors. It will own and operate the plant on land leased, not owned, by the Air Force, which has committed only to paying below market rates for its solar electricity.

For its part, NP will make possible those low rates by making payments to MMA Renewable Ventures for solar energy credits (SECs). Like other renewable energy credits (RECs), such as those recently purchased in large quantities by forward-looking concerns such as Whole Foods Markets and Vail Resorts, the utility plans to use the SECs to meet the State of Nevada’s requirements that it obtain 20% of its power renewably by 2015, say sources at NP.

In addition, the investors will be able to utilize a 30% federal tax credit. Congress passed the credit, which expires this year, in 2005. The solar industry is asking for a 10-year extension, crucial to keeping solar-electric rates low and the industry viable. The investors in the Nellis facility will also avail themselves of an additional tax break-accelerated depreciation rates.

So, at this point, the new facility represents more of a silver lining on the dark cloud of energy depletion than a burst of sun amidst the the gathering darkness. Of course, the hope of at least the commercial players involved is that ever-larger U.S. projects, adapting the Nellis format, will be developed, particularly if Congress extends tax subsidies and more states compel power companies to include a significant percentage–i.e., 10%-20%–of renewable sources in their energy production.

Alas, Southern Nevada residents will just have to stay exquisitely tuned in to find out–on their electrically powered IPods, cellphones, picture viewers, and IPhones-to discover ultimately how feasible the Nellis format is, as the hotly expanding area hurtles toward its water- and energy-challenged future.