Tapping into geopressure

The Sunday Times
April 12, 2009
Green pioneers: Andrew Mercer plans to harness the pressure of natural gas to generate electricity
Andrew Stone

BRITAIN’s gas network contains an untapped source of clean energy that Andrew Mercer, a former IT entrepreneur, plans to harness.
Mercer’s scheme is to tap the high pressure at which gas emerges from underground to drive turbines and generate electricity. Late next year Mercer’s “geopressure” company, called 2OC, will generate its first power at a gasworks in Becton, east London.
The plant will be the first project of Blue-Ng, a £300m joint venture between 2OC and National Grid. It will generate 19.5MW, enough to power 50,000 homes.
The Becton site will generate more power from an adjoining combined heat and power (CHP) plant that will burn oilseed-rape fuel supplied by nearby farms.
Blue-Ng has planning permission for a site in Southall, west London, and has an eye on five other London locations.
Generating power from geopressure is efficient as well as clean, according to Mercer. While a coal-fired power station will typically be 35% efficient and the best gas-turbine power station is about 50% efficient, 2OC claims it can achievce electricity-generation efficiencies of 70%-80%.
If biomass is burnt at the same time in a CHP plant, more than 90% of the heat produced can be recovered and used – in the case of Becton to reheat the gas that gets very cold when it loses pressure.
Mercer said his technology produces better results than wind or wave power. “Power generated by natural gas pressure is available round the clock. It does not require wasteful base-load power to be standing by and it is responsive to demand.”
The mini power plants will use existing brownfield sites so it should be easy to secure planning permission, said Mercer. “Many of these sites will be in industrial areas so you won’t really notice them.”
As Britain’s gas grid has 12,000 pressure-reduction stations, all of which in theory could be turned into mini power generators, the Blue-Ng venture could help plug the gap emerging in the country’s ageing power generation network, said Mercer.
“We expect to generate 1GW within five years but we also have a big hairy ambition to reach 10GW by 2020.”
By adding 1GW of clean electricity generating capacity to the UK’s power supply, 2OC claims it could remove 1m tonnes of carbon from the Earth’s atmosphere, equivalent to the National Health Service’s carbon footprint.
Mercer has global ambitions, too, and is establishing operations in America, Germany and the Middle East. If exploited worldwide, geopressure technology could add generating capacity of between 100GW and 400GW, reducing carbon emissions by between 100m and 400m tonnes. “The technology can be used anywhere there is a gas grid,” he said.