After my previous post about Blue-NG’s plans to harness geopressure technology from the UK gas pipeline to generate renewable electricity, raised considerable interest, I have looked into some of the points of discussion and felt a further blog was necessary.

An architect's drawing of the planned site at Beckton, East London

The first of the eight schemes will install a highly efficient power station at a pressure reduction station (PRS) in Beckton, East London. It will utilize innovative Combined Heat and intelligent Power (CHiP) technology, with an expected energy potential of 19.5MWe – enough to power 50,000 homes. Click here to see the BBC’s report on this scheme.

Blue-NG has confirmed that there is no use of geopressure technology to generate ‘clean’ energy as detailed in the previous post, and other reports of the project. Blue-NG confirmed that despite early consideration of geo-pressure options for 2OC‘s agreement with the National Grid, this project is now only concerned with CHiP technology to capture heat, and not pressure.  Whilst 2OC campaigned for geopressure to be recognized in the Renewables Obligation, this will only benefit geopressure projects they may develop later; however this scheme will still benefit from ROCS for the use of fuel and heat.

Nevertheless, Blue-NG claim that the CHiP (click here for diagram) is the world’s most efficient generator, reaching a maximum efficiency of 96% and therefore boasts a number of environmental benefits.

It will produce electricity in three ways:

1.     A diesel engine will produce electricity from burning liquid biomass – locally grown and sustainable rapeseed oil sourced from within 50 miles of London. This will replace the gas boilers currently used to pre-heat the gas at PRSs to avoid unacceptable temperature drops (which may freeze pipes and valves) during the normal gas pressure reduction process.

2.     Surplus heat will be captured and used for local district heating

3.     The remaining surplus heat will be used to heat the natural gas in the National Grid’s PRS as part of its normal process operation, to ensure pipes and valves do not freeze as the pressure of the gas is reduced. 

Despite support from Greenpeace, the project has attracted criticism from some environmental organizations, including Biofuels Watch, who remain concerned about the health and sustainability issues relating to production of electricity from biofuels. They claim that the use of biofuels provokes a number of issues, including the displacement of food, human and animals, as well as leading to deforestation in developing countries from which they are imported.

However, Blue-NG highlight that the Section 106 agreement – a condition applied to the project by Newham council, requires them to source their fuel from sustainable sources, and prove that they have not displaced crops. This would allow the council to monitor the fuels used by the plant at any time, although some argue that this may still be difficult to police.

Richard Lyddon, from Blue-NG added that, the company’s sustainable procurement policy, developed with support from Greenpeace, commits them to sourcing rapeseed oil, (which will be processed) from credited farmers within 50 miles of the site.

Rapeseed is currently used as a break crop by farmers, and as a result of the EU abandoning the ‘set-aside’ policy for farmers, 10,000 hectares of land is expected to become available for growing rapeseed in the 50 mile radius from which Blue-NG will be procuring these crops. Lyddon confirmed that the project would only use rapeseed oil, and not palm oil, which was mentioned in an original tender. However, objectors of the project remain skeptical about whether the plan to source such a level of biofuels locally is realistic, and recognize the additional environmental costs of shipping the fuel to site.

Whilst Blue-NG plan to contribute to climate change mitigation through ongoing implementation of their CHiP technology after the 8 planned schemes and the government continues to incentivise biofuels through the Renewables Obligation (RO), many environmental organizations, including Biofuels Watch, remain unconvinced and argue that biofuels are simply unsustainable.

The UK National Grid has teamed up with 2OC, a company, which has developed “geo-pressure” technology to utilize the enormous pressure inside the UK gas pipelines, which supply UK homes.

(source: www.cryostar.com)

The first of several planned schemes will see the implementation of small turbines inside the gas network, to produce 20MW of clean energy by 2010 from the natural gas that is delivered at high pressures through the pipes.

The innovative technology will support the National Grid, which owns most of the UK’s gas pipeline, in meeting its targets of sourcing all of its internal energy use from renewable technology. It is estimated that on completion of the eight planned schemes across the UK, the combined renewable energy generation could be as much as 1GW – the equivalent a conventional coal or nuclear power station.

Andrew Mercer from 2OC explains that

“Natural gas is at far too high a pressure when it is drilled from underground reservoirs, so can’t be used safely in homes. It would just blow up your gas cooker.”

Instead, the pressure must be released at hundreds of sites across the supply network known as pressure reduction stations (PRSs). 2OC plans to build mini-power stations across these PRSs, to capture this energy, which is currently lost, to generate clean electricity.

Whilst the technology has in some form been in the spotlight before – the US considered it at some sites in the 80s – the huge associated costs have meant that it did not become more widespread. The British engineers expect to reduce costs by combining the technology with a Combined Heat and Power (CHP) unit at high efficiency. 

Mercer has also identified another use for the technology, which he calls “free cold“. Reducing the gas pressure also delivers significant temperature drops, from as much as 10C to -30C, presenting an opportunity as a potential replacement technology in refrigeration and air conditioning units. In addition there have been talks about using this technology for large scale cooling close to letdown stations, such as the EU’s proposed concentrated solar power project across Northern Africa (making the project planned for the blistering heat of the Sahara desert more feasible) and also to supply the huge cooling needs of large computer data centres.

The emergence and implementation of such innovative ideas is well received by environmentalists, particularly in light of the momentum we have built on the climate change agenda in the UK. Despite the technology being in its pilot stages in the UK, if implementation of the technology continues across the 2000+ potential sites in the UK, this would significantly reduce the UK’s dependence on foreign imports of fossil fuels to satisfy it’s ever-increasing energy consumption. Whilst enabling the UK to meet carbon reduction targets (to contribute to the mitigation of climate change) and increasing energy security, it should be noted that the technology uses the high pressure from deliveries of natural gas. If supplies are depleting, do we need to consider other ways of using this technology – assuming fewer deliveries gas? I think we do.

In terms of prices, I would expect that after initial investments to install geo-pressure technology at PRSs, the dual function (additional clean energy) which can be harnessed from deliveries of natural gas should reduce the prices of gas for end users, but whether this might be cancelled out by the increasing gas prices from overseas remains to be seem.