Sixth Jenbacher completes Risley 4 contract

The recent installation and commissioning of a sixth and final Jenbacher containerised landfill gas engine generator at UK Waste Management`s Risley 4 landfill site in Warrington, Cheshire, UK, fulfils the 1997 NFFO 4 contract to supply a power capacity of just over 6 MW.

The contract was carried out by Clarke Energy, the sole UK distributor of Jenbacher engines. The project was executed in three stages, going back to last October, during which Clarke Energy supplied six model JGC 320 GS – L.L containerised engines, each delivering 1 MW.

These purpose-designed engines are particularly adept at handling significant variations in landfill gas methane levels. They have consistently proved themselves in these type of constant duty baseload operations.

The environmental responsibility to select the most fuel-efficient engines, operating to the highest European standards led to the selection of the Jenbacher engines. The first engine units commissioned are said to be achieving availabilities of more than 97 per cent.

Risley 4, UK Waste Management`s latest north-west England landfill gas generation scheme, covers a plant area in excess of 60 hectares and is currently taking waste at a rate of 700 000 tonnes each year.

The total amount of gas currently being extracted from 50 permanent and 170 temporary shallow wells is 3200 m3/hr, but predictions indicate that up to 6000 m3/hr could be produced.

In terms of the engines, additional performance assurance is provided by the state-of-the-art DIA.NE computer control system. This is fitted to the Jenbacher models and operates, monitors and protects the entire system.

The remote monitoring control facility allows Clarke Energy to monitor the Risley 4 operations back at its Knowsley headquarters and implement round-the-clock preventative maintenance whenever necessary.

Estimates suggest that Risley 4 will take 8 million tonnes of waste when full. The initial landfill gas contract is for 15 years, but UK Waste Management intends to carry on generating from the site for as long as it is economically viable.