emerging sustainable energy technologies

Ferrybridge Power Station (Eric De Mare)

 Oil, coal and natural gas dominate the world’s primary energy market and will continue to do so for the foreseeable future.  Barely 10% of global fossil fuel reserves have already been consumed.  Coal is perceived as environmentally unfriendly, producing relatively large amounts of CO 2 and SO 2 when burnt.

 For coal to continue to drive power generation across the globe, technology must continue to be developed to reduce coal plant emissions to near zero.

 Trends in employment in UK energy industries (1980 – 2009).

 UK production of primary fuels (1980 – 2009).

 UK import dependency of fossil fuels (1980 – 2009).

 UK import dependency of coal (1980 – 2009).

 UK coal consumption (1980 – 2009).

 UK electricity supplied by fuel type (1980 – 2009).

 While the demand for the coal across Europe is falling, elsewhere – notably USA, India and China – the demand for coal is increasing.  Coal is the cheapest fossil fuel, the easiest to extract and by far the most abundant.  Coal will continue to be a primary energy source for decades, possibly for centuries.  Implementing clean coal burning technologies is essential to maintain CO 2 reduction targets.

 Three strategies for reducing emissions from fossil fuel power generation:- (a) increase energy efficiency of thermal cycle (b) use a less carbon intensive source (c) capture and storage of CO 2

Increasing the energy efficiency of the thermal cycle

 Rankine cycle + Brayton cycle = Combined cycle  Combined cycle fed with superheated high pressure air and gasified coal = IGCC  Use pulverised coal in an IGCC plant

 pre combustion capture  oxy-fuel combustion  post combustion capture Capture and storage of CO 2

Pre combustion capture coal gasification + combined cycle power generation = IGCC

Pre combustion capture underground coal gasification

Oxy-fuel combustion Coal combustion occurs in an O 2 enriched environment, producing a flue gas comprised mainly of CO 2 and water. The water is easily separated by condensation and the CO 2 is ready for sequestration.

Post combustion capture Carbon capture and storage, also known as CCS or carbon sequestration, describes a family of technologies designed to tackle global warming by capturing CO 2 – from coal-fired power stations in this case – and permanently storing it underground.

Post combustion capture source:

Conclusions  Experts have divergent views on the economic and technical feasibility of commercial-scale CCS.  Up to 40% of a power station's energy could end up being used to run the CCS scrubbing and transport systems.  Estimates for retro-fitting Britain's ageing power stations are as high as £1bn each.

Conclusions  Critics argue that CCS cannot reduce global CO 2 emissions in time to avoid a 2 o C increase in global temperature.  Over the next 20 years, only 7Gt CO 2 will be sequestrated.  CCS has no place in a sustainable energy future because it relies on continued use of fossil fuels and has a negative interaction with the elements of a renewable low energy system.

Conclusions  CCS technologies are being developed at Hatfield colliery near Doncaster where plans for a 900MW clean coal power station, run on hydrogen extracted from coal are currently being allied to CCS technologies to capture 90% of the CO 2 emissions and pipe them to the North Sea for geological storage.  Legislative and financial support for clean coal allied with CCS would ensure that the UK has an environmentally friendly, secure and indigenous supply of energy for decades to come.  In addition, jobs created within a nascent clean coal industry would give a lifeline to mining communities that have seen a quarter of a century of economic and social decline.

Conclusions  Will ‘peak coal’ ever be a concern? “I don't think we'll ever experience peak coal... The Dakotas, Mississippi, Alabama, Louisiana, Texas all have large, large amounts of lignite. Or in China[‘s] Xinjiang province... there's a trillion tonnes of resources [that] will be the new Middle East. Anyone who has the notion that we're going to move away from fossil fuels just isn't paying attention.” Fred Palmer, Peabody Energy