solar array at White Sands Missile Range.jpg

The solar array planned for Redstone Arsenal could look similar to this 4 MW solar array at White Sands Missile Range in New Mexico. (Photo courtesy of Solaria)

HUNTSVILLE, Alabama -- The April 27, 2011, tornado outbreak left thousands of north Alabama businesses and institutions without power for days on end. Redstone Arsenal was no exception.

The prolonged power outage from that series of storms focused attention on the energy vulnerability of the arsenal and its tenants.

Since then, the Army has sought ways to ensure that Redstone -- and all its bases -- will never again fall vulnerable to loss of vital electric power. As part of the effort to secure what the Army terms "energy surety" Redstone Arsenal will become the site of Alabama's largest solar array within two years, according to the Huntsville Engineering Center of the Army Corps of Engineers.

Today, the Huntsville Corps of Engineers office accepted proposals from a dozen or more companies on what could become the largest renewable energy project in Alabama.

Redstone Arsenal will have the first in a series of large solar projects to result from the Army's $7 billion Multiple Award Task Order Contract. The Army released its request for proposals for the MATOC in August 2012.

Late July saw the selection of 49 firms to win MATOC contracts, which allows them to submit proposals on specific task orders. Twenty three of those firms attended an August pre-proposal meeting for the Redstone solar project.

Earl Johnson, Contracting officer for the project at the U.S. Army Corps of Engineers, Engineering and Support Center in Huntsville, said the Huntsville Corps expects a large number of proposals, but Corps protocols will prohibit the immediate release of the actual number.

None of those prime contractors are Huntsville-based, but Johnson said some of those firms will likely seek out Huntsville partners.

At stake: the contract to build what will be the Army's largest solar electric project thus far: a huge solar array that will generate some 18,000 megawatt hours (MWH) of solar-generated electricity annually for the arsenal.

Quick facts on the project:

At an estimated 10 to 14 megawatts in size, the array could have as many as 50,000 solar panels.

The solar array will be developed and owned by private sources, but Redstone Arsenal will buy the electricity under a 25-year Power Purchase Agreement. The Army will pay $.08 per KWH for power generated, with an escalation rate of no more than 2.5 percent annually.

The successful bidder will own the solar array and be responsible for project design, construction and operation. Redstone Arsenal will only buy the electric power produced via a 25-year Power Purchase Agreement.

Proposers can choose between a large site at the intersection of Redstone Road and Patton Road, and a smaller site located off Neal Road near Toftoy.

The Corps of Engineers expects to announce a winner by spring of 2015 with contract award to be before the end of 2015.

The Army has set a goal to have 25 percent of its energy produced by renewable sources by the year 2025. It's Energy Initiatives Task Force (EITF) will work with the Huntsville Corps of Engineers to oversee the project.

Amanda Simpson, EITF executive director, says the tornadoes had a major impact on the decision to make Redstone Arsenal one of the initial locations. "I think when the tornadoes hit in 2011 it alerted the leadership of our dependence on the grid."

At the August pre-proposal conference, Richard Kidd, Deputy Assistant Secretary of the Army for Energy and Sustainability, said the cost of solar installations has dropped so dramatically over the past few years – from more than $3 to now just over $1.50 per watt – that it now makes sense financially for the Army.

"We look at renewable energy as a means to secure energy for our installations," Kidd said at that time, "but we are not doing these projects for politically motivated reasons or because of the mandate (energy goal of 25 percent production of energy from renewable sources by 2025). We are doing them for mission effectiveness."

Simpson said the solar array – easily the largest in Alabama when complete – could be one of three types:

A ground-mounted system with panels permanently fixed to immovable frames

A "single-tracker" system with panels mounted to shafts that point the panels to the east in the morning and slowly rotate them to the west by afternoon to maximize power output.

A "dual-tracker" system where panels not only follow the sun through the day but also the sun's angle as it changes through the seasons.

Simpson stressed that the solar power produced will only be used by the arsenal and none will go back to the TVA grid. "None will feed back across the Redstone Arsenal fence line," she says.