With zero congressional wrangling, President Obama sent down an executive order in March – dubbed “planning for federal sustainability in the next decade” – that mandates that federal agencies get at least 30 percent of their electricity from renewable sources by the year 2025.
Engineers at the National Renewable Energy Laboratory in Golden have the task of guiding building supervisors toward that goal. Andy Walker, principal engineer with NREL’s Integrated Applications Center, joined “First Take with Lando and Chavis” on KUVO this week to talk about the massive fast-track program.
Even the Lincoln Memorial has been considered for solar power, Walker said.
Planning solar retrofits for 35,000 federal buildings (a lot of them overseas) is a one at a time proposition, with each presenting unique obstacles and possibilities.
“The energy hogs – the worst users (of energy) – were built in the 1970s and 80s,” said Walker. He estimates that a quarter of all federal buildings are in historic districts or are themselves historic buildings, which presents another set of issues about what is appropriate change for a historic structure.
“Any building that was built before 1940 was probably built with daylighting and natural ventilation,” Walker said on KUVO. “Over the years those features have been compromised by dividing space up into private offices. One strategy is to restore the historic features of a building.”
Other challenges face solar retrofits, he said.
“The structure might be very strong, and likely to have strength beyond what is needed, but a lot of times the roof condition itself is poor. We might have to replace the roof as part of a solar project. Also, electrical service is small and needs to be upgraded.”
Engineers are even looking at America’s iconic memorials and monuments.
“Solar has been looked at on the part of the Lincoln Memorial which people can’t see from the street,” the NREL engineer said. “But in a place like Washington D.C., that’s the other challenge with doing any kind of project on a historical building. There are a large number of stakeholders (who) are going to have an opinion about whether (solar panels) are acceptable in a historic district or not.
“What we’ve found acceptable is that if it’s on a part of the roof, surrounded by a parapet wall and not visible from the street, there’s a good chance it might get approved.”
One example: Solar panels were installed atop the White House last year.
The Thoreau Center for Sustainability in the old Letterman Hospital in San Francisco’s Presidio, now a national park and historic landmark, represents a different approach.
“They built a new entry canopy with solar overhead. There the strategy is to make it (the solar addition) look modern, so there’s no confusion about what is historic fabric and what’s not.”
Just three years ago, a solar retrofit was completed on Alcatraz Island, generating 307 kilowatts from photovoltaic collectors on the cellblock roof. The infamous island prison in the middle of San Francisco Bay is a tourist attraction these days, hosting one million visitors a year. With a diesel backup generator, it’s entirely off the grid.
“First we look across the country and see what the markets for solar are, what the drivers in those markets are – whether it’s high utility rates or public incentives – and then what the plays in those markets are. Should an agency purchase a system outright, or use one of the more sophisticated financing alternatives (e.g. a lease arrangement)?”
NREL also has a high-tech system for plotting out where the sun shines.
“We use our geo-spatial mapping tools,” Walker said. “We have data on the solar resource on a pretty fine resolution across the United States.
“I can’t say it’s just because of the current administration, but the growth in solar (energy) has been tremendous due to technology and the economy of scale. The cost has really come down in recent years,” Walker said.
One sprawling federal jurisdiction where NREL’s assistance has paid off is the Department of the Interior, parent to the National Park Service. DOI has managed to reduce the amount of energy it uses by about 34 percent from 10 years earlier, while increasing its use of renewable energy sources by 10.1 percent since 2008, NREL said in a separate release.
“The Park Service has many remote locations that are burning diesel fuel for power,” said Scott Haase, NREL’s lab program manager for DOI. “It’s obviously not ideal when you’re in a pristine environment to have diesel running in the background. We’re trying to identify ways to mix more solar into those systems.”
The Department of Defense, meanwhile, uses far more energy than any other federal agency and also relies on renewables the most. About 1.5 million megawatt-hours of the DOD’s energy came from renewables in fiscal year 2013, the NREL statement said. But that accounted for 6.2 percent of the 30 million megawatt-hours the agency used that year.