Nellis Solar Power Plant

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Nellis Solar Power Plant
Nellis AFB Solar panels.jpg
Nellis Solar Power Plant, the second largest photovoltaic power plant in North America
Nellis Solar Power Plant is located in Nevada
Nellis Solar Power Plant
Location of the Nellis Solar Power Plant in Nevada
Country United States
Location Nellis Air Force Base, Nevada
Coordinates 36°15′30″N 115°03′10″W / 36.25833°N 115.05278°W / 36.25833; -115.05278Coordinates: 36°15′30″N 115°03′10″W / 36.25833°N 115.05278°W / 36.25833; -115.05278
Commission date December 17, 2007
Owner(s) MEMC
Solar farm
Type Flat-panel PV
Site area 140 acres (0.6 km2)
Power generation
Units operational 72,416
Nameplate capacity 14.2
Annual generation 30

The Nellis Solar Power Plant is located within Nellis Air Force Base in Clark County, Nevada, northeast of Las Vegas. The Nellis solar energy system will generate in excess of 25 gigawatt-hours (90 TJ) of electricity annually and supply more than 25% of the power used at the base.1 The system was inaugurated in a ceremony on December 17, 2007, with Nevada Governor Jim Gibbons activating full operation of the 14 megawatt (MW) array.23

Occupying 140 acres (57 ha) of land leased from the Air Force at the northeastern corner of the base, this ground-mounted solar system employs an advanced sun tracking system, designed and deployed by SunPower. The system contains approximately 70,000 solar panels, and the peak power generation capacity of the plant is approximately 13 MW AC.1 This means the ratio of average to peak output, or capacity factor, of this plant is around 22%.

The energy generated will support more than 12,000 military and civilians at Nellis who are responsible for Air Force advanced combat training, tactics development and operational testing. Construction began on April 23, 2007,1 and operation of the first 5 MW began on October 12, 2007.45

Economics

Under the terms of the Power Purchase Agreement, MMA Renewable Ventures, who own the panels, is leasing the land at no cost and Nellis is agreeing to buy the power for 20 years at about 2.2 cents/kW·h, instead of the 9 cents they are paying to Nevada Power, saving the Air Force $1 million each year. None of the $100 million cost came from the Air Force, but instead from subsidizing taxpayers and Nevada Power customers who are paying for the RPS credits.6

The partners were able to build the plant, recover costs and produce electricity at a savings, because of the fairly complex financing structure arranged among MMA, its investors, Nevada Power, and Nellis — in addition to multimillion-dollar government incentives.7

The plant was expected to produce 30 GWh per year but actually produced about 32 GWh the first year, 8% more than expected,8 saving the Air Force $1.2 million in the first year of operation.9

There is no provision for operation during a power failure, when the base reverts to generator power. This would require limiting the output to less than or equal to what the generators can provide. Otherwise a cloud could pass over and cause the sudden drop in output to overload the generators, causing them to trip off. If a pumped-hydro facility was added in the nearby hills, that would allow the base to operate during power failures under solar power, although batteries would also be needed to allow time for the hydro-electric plant to adjust to the load requirements.10

Design

Nellis consists of 5,821 tilted axis, T20 single axis trackers made by Sunpower, and uses 72,416 200 watt solar panels,11 and 54 Xantrex (Schneider Electric) GT 250 inverters,12 each rated 250 kW. The maximum output is therefore inverter limited to 13.5 Megawatts (AC). At full output, the inverters are 96% efficient. Approximately 10% of the panels are mounted on North-South oriented horizontal single axis trackers. About one third of the solar panels were made by Suntech Power, the lead supplier.13

Renewable portfolio standard

A section of the Nellis Solar Power Plant

In 1999, Nevada passed a renewable portfolio standard (RPS) as part of their 1997 Electric Restructuring Legislation (AB 366). It required any electric providers in the state to acquire actual renewable electric generation or purchase renewable energy credits so that each utility had 1 percent of total consumption in renewables. However, on June 8, 2001, Nevada Governor Kenny Guinn signed SB 372, at the time the country's most aggressive renewable portfolio standard. The law requires that 15 percent of all electricity generated in Nevada be derived from new renewables by the year 2013.14

The 2001, revision to the RPS keeps in place Nevada's commitment to expand solar energy resources by requiring that at least 5 percent of the renewable energy projects must generate electricity from solar energy.14

In June 2005, the Nevada legislature passed a bill during a special legislative session that modified the Nevada RPS (Assembly Bill 03). The bill extends the deadline and raised the requirements of the RPS to 20 percent of sales by 2015.14

Expansion

An extension of the plant, which could generate another 18 megawatts of power, has been proposed. The Air Force has not yet decided whether to have the extension built, and its potential cost and size have not been determined, but the military sees considerable operational advantages in solar power.15

Presidential visit

President Barack Obama addressed an audience of more than 450 people at the Nellis Solar Power Plant on May 27, 2009.

President Barack Obama visited the facility on May 27, 2009.1617

Production

Generation (GWh)18
Year January February March April May June July August September October November December Total
2007 1.497 0.859 0.398 2.754
2008 0.535 1.284 3.143 3.923 3.995 5.120 3.630 3.386 3.338 2.382 1.136 0.627 32.499
2009 0.624 1.073 3.155 3.651 4.230 3.106 3.672 4.258 3.525 2.323 1.571 0.821 31.999
2010 0.443 0.819 2.023 2.585 3.662 4.322 3.339 4.211 3.925 2.377 2.264 1.330 31.300
2011 1.447 1.940 2.432 3.392 3.745 4.286 3.135 3.681 2.632 2.535 1.553 1.347 32.125
Total 130.677

See also

References

External links








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