This story originally aired July, 2 2012. Updated June, 23 2014.

Akron test run

Steam from the city’s heating plant is normally used to heat buildings in downtown Akron.  But today the excess steam is piped into a crisp white box the size of a moving van parked next to the plant.  The box is Echogen’s new 250 kW waste-heat engine, on its first real test run outside the lab. The engine takes any type of waste heat, like what goes up a factory smoke stack and turns it into electricity. 

A few blocks away at Echogen’s headquarters, CEO and founder Phil Brennan believes his new waste-heat engine may even overturn the coal industry’s centuries-old reliance on steam to spin turbines. 

“Our goal ultimately is to displace steam as the power-generation fluid of choice.”

It’s an ambitious goal for technology barely off the drawing board.

Brennan started Echogen in 2007, licensing the original design from a NASA prototype. 

Super critical CO2

His new technology works through the innovative use of a common material -  CO_{2 .}  Except in Echogen’s engine, the CO2 is pressurized and heated to the point where the gas becomes a stable liquid called super critical carbon dioxide. 

Carbon dioxide has been used in other applications.  In Europe it’s been used in refrigeration, and in air conditioning systems for cars in Europe because it’s a safe refrigerant.  It’s used very successfully as a heat pump in Japan.  But Brennan says his company is the first to use super critical carbon dioxide to generate electricity.

In just five years Brennan and his team took their waste heat engine from the concept phase to field testing.  But it hasn't been easy.  He says there is a bridge between theory and practice and it’s been a painful and repeated lesson for Echogen.

The engine works by flowing the super critical CO2 through a waste-heat exchanger that sits inside a smoke stack.  The CO2 heats up inside the engine, spins a turbine, and cranks out electricity.

Brennan is anxious to get his product to market - 

“We’ve been living in what the venture capitalists call the ‘Valley of Death’ for a while. The sun has been beating on us but someone has been giving us water and with just a couple of successes, the financial picture looks very different.”

One revitalizing bucket of water came this month in the form of loan from the Ohio Third Frontier Commercial Acceleration Fund.

Echogen was awarded $1.5 million to develop the latest version of their heat recovery system for use in new markets.

Echogen last year signed a deal with GE marine division to tailor their units to capture waste-heat energy from shipboard diesel engines.

Waste-heat energy is also produced from heavy industry’s smoke stacks, steel smelters and brick kilns.

But CEO Brennan is under no illusions of guaranteed success.

With the renewable energy industry under fire in Ohio - recent legislation has put a freeze on green energy mandates for utilities - a technology made and nurtured in Ohio will for the near future likely serve far flung markets.

I’m Jeff St.Clair with this week’s Exploradio.