Exelon plans clean-energy test plant

The power system Exelon Corp. is incorporating into its latest natural gas development. Courtesy of Net Power LLC website.
The power system Exelon Corp. is incorporating into its natural gas test plant. Courtesy of Net Power LLC website.

By Melissa “Missy” Enaje

Chicago-based energy provider Exelon Corp. has joined with two partners to build a demonstration power plant that will generate electricity from natural gas while eliminating all air emissions, including carbon dioxide.

In conventional power plants, fuel is burned to create steam that spins turbines. It’s not a very efficient operation, as much of the heat is lost into steam. It also produces carbon dioxide gas as a waste product, which enters the air and contributes to global warming.

The system Exelon and its partners are planning will rely on a semi-closed-loop ”non-carbon capture system,” in which carbon dioxide under high pressure serves as the working fluid, instead of steam.

In theory, the new system should be more efficient, and it will also create almost-pure carbon dioxide as a byproduct. The CO2 is re-used to continue the process. That’s a big change from current systems, where CO2 comes out the smokestack as an unwanted gas emission.

The $140 million project, under Exelon Generation, the company’s power generation division, is slated for construction at a site in Texas. It will operate using what’s known as “Allam Cycle Technology,” developed by NET Power LLC. of Durham, N.C.

“It’s interesting economically and commercially,” said Nishit Mehta, board member in Chicago’s Young Professionals in Energy organization,.. “For the first time you could generate power using the abundant supply of carbon dioxide, natural gas” while creating“zero emissions.”

While renewable sources such as solar and wind have claimed much of the attention, Mehta said, they aren’t adequate to fill the future energy needs. “The world will look to other forms of energy generation that could also be clean, or as close to clean as solar and wind,” he noted, “and if this works commercially, then this would be a part of that solution.”

For existing steam-power plants, capturing carbon dioxide emissions is a costly burden.

“This technology is a potential game changer in reducing carbon emissions from power generation,” Exelon president and CEO Chris Crane said in a statement. The collaboration with NET Power’s system “is another step towards Exelon’s vision of a clean, innovate energy future.”

The power cycle system aims to match or lower the current cost of electricity from natural gas.

Exelon Generation’s partners in the venture are energy-infrastructure provider CB&I, and the technology-commercialization firm 8 Rivers Capital.