GE Energy and energy developer ECOS are to demonstrate an innovative industrial waste heat recovery system that will increase both the efficiency and output of a 7.2 MW biogas power plant in the eastern Slovenia town of Lendava, near the border with Hungary. GE’s new pilot Organic Rankine Cycle (ORC) waste heat recovery system for gas engines is designed to make on-site power plants that use natural gas, landfill gas and other waste gases more cost-attractive to build.

The new system will allow ECOS to capture more waste heat created by its Bioplinarna Lendava biogas plant. The extra thermal power will be used to produce steam, which in turn will help generate enough electricity to support 300 European homes without using additional fuel, says GE.

The pilot ORC system will be installed on one of the three GE ecomagination-certified Jenbacher J420 biogas engines that have powered ECOS’ Bioplinarna Lendava plant since June 2008. The ORC technology will boost the Jenbacher unit’s electrical efficiency by an estimated five percentage points.

Executives from the two companies signed the new project agreement at a celebration of the fifth anniversary of GE’s European Global Research facility in Munich, a leader in industrial energy efficiency research.

Landfill gas and other renewable biogas projects are among the prime candidates for ORC systems, especially in countries – including those in Europe – that offer high electricity feed-in tariffs. ‘Countries around the world want to increase the use of renewable biofuels to meet their energy security and environmental requirements,’ said Prady Iyyanki, CEO of GE’s Jenbacher gas engine business. ‘Pairing GE’s ORC technology with gas engines represents an important innovation in energy efficiency, allowing existing and future on-site power plants around the world to generate extra electricity without consuming additional fuel or creating more emissions.’

ORC systems generally offer enhanced energy efficiency by utilizing organic fluids that have lower boiling points than water to create steam for electricity generation. However, due to technical waste-heat recovery constraints, there had been few gas engine-based ORC applications to date.