As technology, financial incentives and consumer demand push renewable energy sources like solar and wind power into the mainstream, brownfields are in an ideal position to benefit from the growing green convergence.

"Right now, there are significant tax advantages and tax credits for installing renewable energy under the stimulus package," —Kevin Matthews, vice president, energy and environment at NSI, based in Washington, D.C.

"More and more people understand that it's not just about cleaning up a brownfield and putting it back into productive use," says Kevin Matthews, vice president, energy and environment at NSI, a business-to-government consulting firm based in Washington, D.C. "It's putting it back in a way that doesn't impact the environment more harmfully. Commercial buildings use 40 percent of the energy consumed in the United States, so how you provide that energy is critical to the overall dynamic of our energy needs."

The U.S. Department of Energy projects that clean and renewable energy production will jump by more than 70 percent between 2006 and 2030, and President Obama's New Energy for America plan calls for 10 percent of all electricity to come from renewable sources by 2012 and 25 percent by 2025. In addition, a number of states are also setting goals for renewable energy usage.

Couple that with some brownfield properties' natural advantages for renewable energy projects, and you've got a perfect match, say observers. In fact, the Environmental Protection Agency and the National Renewable Energy Laboratory have identified almost 4,100 contaminated sites nationwide that have the potential to be developed with renewable energy generation. Solar energy has taken an early lead in brownfield projects, but wind and geothermal power are also generating interest, while biomass is still in the early stages of development.

The brownfield advantage
Brownfields can be especially suited for renewable energy developments because they usually have transmission capacity, infrastructure and appropriate zoning already in place. And for a brownfield where commercial development doesn't make economic sense because of high cleanup costs or low demand for the finished property, a stand-alone renewable energy facility can sometimes make the numbers work.

"It allows some brownfields that might have been marginal . . . to back away from the power grid a little bit, and makes a few more of these sites viable [for development]," says David Koch, national sector leader for brownfield services at Terracon Consultants Inc. in Kansas City, Mo.

"It allows some brownfields that might have been marginal . . . to back away from the power grid a little bit, and makes a few more of these sites viable [for development]." —David Koch, national sector leader for brownfield services at Terracon Consultants Inc. in Kansas City.   "Solar panels or a wind farm won't disturb the soil, but still allows the property to be viable and put to a really good use." — Jenny Redline, principal with Partner Energy in El Segundo, Calif.

In some cases, a brownfield whose use is limited by extensive contamination can support a renewable energy source because less cleanup is needed, says Jenny Redline, principal with Partner Energy in El Segundo, Calif. "Solar panels or a wind farm won't disturb the soil, but still allows the property to be viable and put to a really good use," she says.

"The brownfield opportunity for renewable energy is a potent one," agrees Matt Cheney, chief executive officer of San Francisco-based Renewable Ventures, which develops, owns and operates U.S. solar power plants. "There's a huge opportunity here to align what we're doing as a nation with what we're trying to do with renewable energy," he adds. "On one side, we're trying to stimulate the economy, and [on the other side] we're making investments in renewable energy. Our economy needs the jobs related to renewable energy, which is often constrained because land . . . is not available."

And when the only available land is a greenfield, it can cancel out the environmental benefits of a renewable energy source such as solar power, says Cheney. "With greenfields, you're often looking at taking agricultural land out of production to do [a solar project]," he says. "And there's some concern in Washington with respect to how many permits have been taken out on greenfields and BLM [Bureau of Land Management] territories for solar [projects]. What we're seeing is more work being done where land is being repurposed."

Show me the money
New financial incentives from both state and national sources are also helping to foster joint brownfield/renewable energy development. In addition to a $100 million boost for brownfield activities, the American Recovery and Reinvestment Act of 2009 extended some of the existing solar and renewable energy credits, and also created a new set of production and installation tax credits for 2009 and 2010.

The production tax credit (PTC) for wind energy is now in effect through 2012, while the PTC for biomass and geothermal energy facilities will extend through 2013. Because fewer companies are taking advantage of the tax credit in the current economic slump, though, owners of non-solar renewable energy facilities can now make an irrevocable election to earn a 30 percent investment credit rather than the PTC, throughout the period of the PTC.

Grants equal to 30 percent of the tax basis for a facility are also available for renewable energy facilities that would normally earn a business energy credit of 10 to 30 percent, as long as they are placed in service in 2009 or 2010, or construction begins in 2009 or 2010 and is completed before the PTC terminates. These grants apply to systems using fuel cells, solar energy, small wind turbines, geothermal energy, microturbines, and combined heat and power technologies.

"Right now, there are significant tax advantages and tax credits for installing renewable energy under the stimulus package," says NSI's Matthews. "We'll see the financial incentives continue to a point, making renewable energy competitive with existing forms of energy, and at some point we'll reach a tipping point where we no longer need those incentives."

Even the Small Business Administration has gotten into the act: Its SB 504 loan program has doubled the maximum allowable amount of a real estate loan, up to $4 million, for borrowers who reduce energy consumption by 10 percent or install a renewable energy source.

Stateside incentives
Beyond the federal energy incentives for renewable energy, "states and local governments have some very attractive programs too," says Matthews. "California clearly leads in anything related to the environment, and Arizona has some interesting programs. Oregon has also been aggressive in this area. Lots of other states have pieces here and there to make it [renewable energy generation] attractive."

Michigan, in fact, is poised to be one of the leaders in targeting renewable energy developments on brownfields as a way to help a state progress economically, says Charles McKeown, renewable energy program manager for the Land Policy Institute at Michigan State University and a co-author of a recent study on the subject. The state's 44,000 acres of brownfield sites have the potential to generate 5,855 megawatts and more than $15 billion in investments through renewable energy projects, according to the study.

"There's strong support for renewable energy and brownfields from the governor's office," McKeown explains. "We've had a couple of early adopters, and a whole lot of people who think this might be a good idea," he adds, citing a proposed wind project in Wyandotte and the Lansing Board of Water & Light, which owns and operates the state's largest solar array for generating electricity.

(The EPA maintains a list of Web sites detailing each state's incentives for renewable energy development on contaminated lands at http://www.epa.gov/oswer/ocpa/maps_incentives.htm ).

Here comes the sun
Right now, solar power seems to be the most popular renewable energy choice for brownfields, either on a small scale for site-specific needs or on a large scale for commercial energy production, says David Lloyd, director of the Office of Brownfields and Land Revitalization for the EPA.

"Solar is one of the most viable options because it doesn't require the amount of space that a large wind project would." —Steve Giles, director-energy market for Hull & Associates Inc. in Dublin, Ohio.

"Solar is one of the most viable options because it doesn't require the amount of space that a large wind project would," explains Steve Giles, director-energy market for Hull & Associates Inc. in Dublin, Ohio. "Solar [also] doesn't require the penetration of soils the way a wind project would. You can build a nice-sized solar facility on five to eight acres, and that is [a fairly common size] on a brownfield. A large wind developer is typically going to be looking for hundreds of acres."

Landfills in particular show a lot of promise for solar production, says Lloyd. In fact, the largest solar photovoltaic system in the U.S. sits partly atop a capped landfill at Nellis Air Force Base just outside of Las Vegas. The solar array, which went online in December 2007, served as a backdrop for President Obama in late May 2009 when he gave a speech highlighting the 100 th day after passage of the stimulus plan, and he lauded the green energy that generates nearly 25 percent of the electricity used at the base.

Using approximately 70,000 solar panels on 140 acres of land, the Nellis solar energy system is owned and operated by Renewable Ventures, which sells the power to the base under the terms of a Power Purchase Agreement (PPA).

Another military project, a solar power array constructed on a 12-acre former construction debris landfill at Fort Carson, Colo., began operation in early 2008. It will provide about 3,200 megawatt hours of power each year, a little more than 2 percent of the army installation's energy consumption. A group of utilities investors leased the land from Fort Carson and built the system, and Fort Carson has a 17-year contract to purchase the electricity at a fixed rate.

While sunny California and the Southwest have led the charge on brownfield solar developments, "we're seeing a lot of solar [projects] pop up in other parts of the country because of state incentives," says Pam Swingle, pollution prevention and innovation program manager for the EPA's Office of Solid Waste and Emergency Response. "For example, Pennsylvania, because of incentives and [state renewable] energy portfolio [standards], has a lot of solar going on at Superfund sites."

The country's largest "brightfield"—a remediated brownfield transformed into a solar energy-generating station—is located on a 3.7-acre site in Brockton, Mass. Formerly part of the Brockton Gas Light Co.'s gas works, the capped land now holds a 425-kilowatt photovoltaic solar energy system that opened in late 2006. A partnership of government agencies, nonprofit organizations and businesses got the $3 million Brockton Brightfield project off the ground, and the city hopes to eventually expand it to an associated brownfield across the street to boost capacity to 1 megawatt.

In Dayton, Ohio, a $3.5 million solar farm and geothermal heating system is in the works for the city's new Tech Town office development, whose first building was scheduled to open in July 2009. The development's 400,000 square feet of office and research space is located on a former General Motors industrial site.

Giles at Hull & Associates, which is working on the Tech Town development, says the solar farm will sit atop a three-acre contaminated site that had been sealed and capped. "The cost of remediating it would be expensive, because it has very thick concrete over it," he explains. "So we're designing a 500-kilowatt solar project to go essentially over the top of this area."

Blowin' in the wind
Because the giant turbines that convert wind power into energy need lots of land—not to mention a good stiff breeze—geography plays a large role in where wind developments can be sited.

"Wind [power] is a totally different animal [than solar power]," says EPA's Swingle. "There are a lot of great West, Southwest, and North and South Dakota areas [for wind]. And there may be a site that's not great for wind potential, but one corner of it on a ridge would produce great winds. You have to really do the studies to see the wind potential, and there's a lot of variability."

Wind potential is weakest in the Southeast, says Terracon's Koch, because of the many areas with trees and valleys. "You need a pretty tall wind turbine to get to a consistent wind resource [there]," he says.

Steel Winds wind farm in Lackawanna, N.Y., on the shores of Lake Erie near Buffalo, sits on 30 acres of former Bethlehem Steel industrial land that was used as a slag dumping site for decades. BQ Energy in Pawling, N.Y., and First Wind (formerly UPC Wind) in Newton, Mass., partnered to develop the $40 million project, with construction completed in March 2007. Today, the eight wind turbines at Steel Winds generate more than 50 million kilowatt hours of electric energy annually.

Geothermal tests waters
The recently decommissioned Mohave Generating Station in Laughlin, Nev., is a perfect example of a brownfield with good potential for geothermal energy development, says Mark Taylor, a senior associate at New Energy Finance Ltd. in Alexandria, Va. Nevada is already one of the largest geothermal states in the West, he says, and there are most likely geothermal resources in the area. The site's existing electrical switchyard, which is being maintained, could readily support another power plant run on renewable energy rather than the coal energy that helped doom the generating station after years of environmental controversy.

"Geothermal is very resource-specific from the get-go," says Taylor. "So you're kind of limited in where you can do brownfield applications. These decommissioned plants in Nevada and California are good opportunities."

The EPA's Swingle said her agency is planning to have maps highlighting contaminated sites with geothermal potential up on its Web site by the end of August 2009. "When you're looking at areas in the West that seem to have potential for solar, many of those have geothermal potential as well because of the tectonic activity in the desert Southwest and the West," she says.

But new technology being developed to create electricity from lower-temperature geothermal fluids may one day expand the reach of geothermal energy across the country. UTC Power is in the forefront of the move to generate geothermal energy at lower temperatures, says Taylor, with small-scale technology currently being used at a commercial power plant in Beaver County, Utah, that was opened in November 2008 by Raser Technologies Inc.

"This market [geothermal] has yet to really start—it's just on the cusp of starting," says Taylor.

Biomass on deck
Biomass energy development is still getting off the ground in the U.S., say experts. "For bio-digesters, biomass small power plants, the technology is there but it's not economically feasible right now, even with renewable energy credits," says Terracon's Koch.

At the second annual Waste-to-Fuels Conference in May 2009, speakers pointed out that the public's resistance to having waste-to-fuel plants in their area is a significant challenge, and encouraged situating biomass plants on brownfields as one possible solution to encourage community support.

As biomass energy gains ground, though, brownfield sites that are situated near usable waste streams "might present opportunities" for biomass power developments, says Hull & Associates' Giles.

Turning brown to green energy
No matter what kind of renewable energy a project incorporates, though, the key to success is "trying to think ahead so that you converge green sustainability with brownfield technical applications," says Koch. "You need to get all parties at the table early . . . to avoid the collision of brown and green. Historically, the architects have not been there early on."

That means adding green energy elements to the initial site contaminant map, in addition to cleanup information, he adds. "We'll say, 'You could put solar panels here,' or 'You could put deep foundations for a turbine in this area.' When the architects and developers have this map early on, they'll say, 'I can design around this activity and get a sustainable and green building, and not have to come in and take all the contaminants out later on," says Koch. "You can take it from brown to green and break the brownfield cycle."

High Potential Renewable Energy Site Requirements for Brownfields
Wind	Solar-PV (photovoltaic)	Solar—CSP (Concentrating Solar Power)	Biomass: Dry mill corn ethanol plant	Biomass: Biopower plant
— Class 4 or greater wind resource — Greater than 50 acres — Less than 20 percent slope — Within 25 miles of transmission and road	— Depends on site power requirements	— At least 40 acres — Less than 1 percent slope —Within 25 miles of existing transmission and roads	— At least 50 acres — Crop residues at least 100,000 tonnes/year — Within 50 miles of road —Within 10 miles of transmission	— At least 50 acres — All residues at least 150,000 tonnes/year — Within 50 miles of road — Within 10 miles of transmission
Source: National Renewable Energy Laboratory