First Hybrid Fuel-Cell/Turbine Power Plant for Natural-Gas Pipeline Applications

7 November 2006

FuelCell Energy and Enbridge are beginning production of their first multi-megawatt hybrid power product, which generates clean electricity while recovering energy normally lost during natural-gas pipeline operations.

The Direct FuelCell-Energy Recovery Generation (DFC-ERG) system combines a 1.2 MW Direct FuelCell (DFC) power plant with a 1 MW unfired gas expansion turbine. Operating at natural gas pipeline letdown stations, the system generates 2.2 megawatts MW of electricity.

To transport natural gas across the continent, natural gas pipelines operate at high pressures. Achieving the pressures required requires the application of considerable energy. The high pressure must be reduced when the gas enters lower-pressure systems that deliver gas to homes and businesses. Currently, there no commercial use is made of the energy that is lost at that stage.

Additionally, when pressure is reduced, the gas cools. To ensure reliable pipeline operations, the cooling is offset by burning some gas in boilers to reheat the supply to an acceptable temperature.

With the new DFC-ERG system, high-pressure gas passes through a turbine, capturing some of the energy that was otherwise lost, and turns it into usable electricity. The integrated fuel cell also electrochemically converts some of the gas into electricity. Finally, heat normally generated by the fuel cell warms the gas to its proper distribution temperature, thus eliminating the boiler (and its emissions). The combined system can achieve electrical efficiencies of more than 60%, with low noise and virtually zero smog emissions.

Engineering of the DFC-ERG system has been underway for more than a year. Enbridge has ordered FuelCell Energy’s new up-rated 1.2 megawatt DFC power plant to ensure product integration is complete in time to meet the needs in emerging markets like Ontario, Canada, and Connecticut, as well as other US states.

The first production unit includes the participation of other vendor partners including Cryostar SAS, a provider of radial in-flow turbines and low-carbon energy solutions, and SatCon Power Systems Canada, Ltd., provider of multi-megawatt, utility grade, power inverter solutions. Cryostar, a business unit of the BOC Group, recently was acquired by the Linde Group, a world leading industrial gases and engineering company with a presence in 70 countries and gas and engineering sales of approximately €12 billion.

The companies expect the hybrid power plant to be available in the third calendar quarter of 2007. Enbridge’s research has identified 40-60 MW of opportunities for the DFC-ERG system in just one of its operating areas.

The North American market represents another 200-300 MW, consisting of the half dozen US states currently seeking to add fuel cells’ environmental attributes to their Renewable Portfolio Standards (RPS).

Enbridge is a Canadian company and a transporter and distributor of energy in North America and internationally. Enbridge operates, in Canada and the United States, the world’s longest crude oil and liquids pipeline system. As a distributor of energy, Enbridge owns and operates Canada’s largest natural gas distribution company, and provides distribution services in Ontario, Quebec, New Brunswick and New York State.