Converting recovered exhaust heat to electricity

NRGreen gets power from “waste”

Case Study - Challenge

An increased demand for electricity, coupled with heightened environmental concern, have created a difficult environment for some businesses in the energy industry. But it is also an opportunity to contribute to the grid by developing alternative energy-generation technologies and facilities.

NRGreen Power Limited Partnership develops electrical-generation opportunities in association with Alliance Pipeline (a 2,311-mile mainline conduit for clean natural gas produced in Canada) by recovering and converting waste heat at compressor stations to generate electricity. The challenge was to do so without additional emissions, fuel, or water consumption.

Case Study - Solution

Each day, the pipeline delivers 1.6 billion ft3 of clean energy. It also produces exhaust heat, which is captured and converted into electricity using GE’s new ORegen™ technology, the largest organic Rankine cycle system available (which, unlike combined-cycle power plants, does not require water.

ORegen is designed to increase overall plant efficiency by 20-35% and deliver 40% more power with no additional fuel consumption. For NRGreen, GE developed a system in which one closed fluid loop captures heat energy from turbine exhaust, and a second loop transfers that energy to a high-speed, high-efficiency turboexpander generator.

Case Study - Results

The ORegen solution is expected to:
•    Generate 14 MW of cleaner electricity (sufficient to power about 14,000 homes)
•    Save 2,641,720 gallons of water annually (enough to fill four Olympic-sized swimming pools)
•    Eliminate 38,000 metric tons of CO2 per year (equivalent of taking 7,000+ cars off the road)
•    Generate $9 million/year in revenue (based on average price of electricity in Alberta, Canada)