Posted in Energy, Places of Interest, tagged cruachan, dinorwig, electricity, energy, ffestiniog, foyers, ofgem, peak demand, pumped storage, reservoir on 3 July 2013|
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The UK’s capacity to produce electricity is in the news. The energy regulator, Ofgem, has warned that spare capacity in power production could fall to 2% by 2015, increasing the risk of blackouts. The closure of ageing power stations, as well as tough emissions targets and the UK’s increasing dependency on gas imports, are all contributing to this heightened risk of shortages. But behind the scenes the matching of electricity supply to demand – electricity cannot be stored on a large-scale – remains a considerable challenge every day.
Most of our power is generated by fossil fuel power stations, which take half an hour or so to crank up to full power; nuclear power stations take much longer. If a cold spell is forecast there’s enough time to respond, and the same goes for the predictable increase in demand in the mornings and in the late afternoon. But when a popular TV programme finishes , many people go and put the kettle on, causing a sudden peak in demand for electricity that conventional power stations can’t meet instantly. How can electricity be produced immediately?
Pumped Storage Reservoirs
To meet sudden peaks in demand for electricity, water is released from an upper reservoir to a low level reservoir on the way driving turbines and the generators that produce electricity. At night, the water is pumped back up to the top reservoir using cheaper electricity.
The solution is provided by pumped storage reservoirs. A pumped storage plant has two separate reservoirs, an upper and a lower one. When electricity is in low demand, usually at night, water is pumped into the upper reservoir. When there is a sudden demand for power, giant taps known as the headgates are opened allowing water from the upper reservoir to flow down through pipes to turbines which produce electricity, and back into the lower reservoir ready to be pumped back up later. To maximise the fall of the water, the four pumped storage plants are all in mountainous areas. The Cruachan and Foyers schemes are in Scotland, and Ffestiniog and Dinorwig are in North Wales. (more…)
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Posted in Global Warming & Climate Change, Globalisation, tagged co2 emissions, duncan clark, energy, financial markets, fossil fuel, j k galbraith, mike berners-lee, photosynthesis, renewable energy, shale gas & oil, sustainability on 4 June 2013|
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Financial markets are gambling trillions of dollars on a bet that governments will never seriously curb carbon emissions say Mike Berners-Lee and Duncan Clark in The Burning Question: We can’t burn half the world’s oil, coal, and gas, so how do we quit? published by Profile. Why do they claim this? Because to address climate change would mean leaving most of the remaining fossil fuels in the ground. But that would mean the future value of the fossil-fuel energy companies falling to a fraction of their current market valuation. In any event, sudden action forced on governments by a period of catastrophic climate change and food shortages would cause the collapse of the energy industry, far greater than the banking crash of 2008. Something will have to give.
The authors explain the maths very well. CO2 in the atmosphere has now reached 400 parts per million from 280 ppm in pre-industrial times. The switch to renewable energy has so far had no impact upon global carbon emissions (since this book’s publication, figures released for carbon emissions show that in the UK, emissions went up by 3% in 2012, the highest in Europe). What is the amount of fossil fuels we can safely burn to stay within the agreed 2 degree C rise in average surface temperatures above which the lives of millions of people are a risk. The answer is 565 gigatonnes of CO2 by 2050. But established reserves of fossil fuel are 2,795 gigatonnes, and the 565 gigatonne emission limit will be hit by 2030.
Areas of the UK with potential shale gas
And this does not allow for the dramatic increase in potential shale gas fields world-wide. In the UK, estimates of reserves of shale gas are continually being revised upwards, with claims that just the fields in the north of Englad could meet UK energy needs for five years. In the USA, the extraction of shale gas is welcomed, it is cheaper and it is the solution to their dependency on imported oil from dictatorial regimes. So it’s carry on as normal. (more…)
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