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17. How can the need for electricity be met?
"You oppose wind power - so propose an alternative."
A dishonest diversionary tactic, this is repeatedly used by politicians and green campaigners when wind power is criticised in debate.
The honest questions which should be asked are: - "How shall we provide ourselves with electricity when fossil fuel runs out?” and "Should we reduce CO2 emission now as a precautionary measure and if so, how?"
Neither questions nor answers are black and white - more a dirty shade of grey and certainly not ‘green’!
Our technological civilisation is entirely dependent on an uninterrupted supply of electricity, free from significant deviations of frequency or voltage. That we are provided with this near-miracle is a tribute to the generating industry and a triumph for the National Grid which is now almost 70 years old.
It was expressed political opinion after WW2 that the UK would not have survived without the safety-net of the grid which insures against localised failure of generating plant or transmission. It is the height of folly for influential organisations to persuade government that the grid system should be dismantled in favour of localised distribution and 'micro-generation (Greenpeace, 2005). The fate of the de-nationalised railways is an ever-present warning.
The world is centuries from exhausting fossil fuel reserves, in particular coal (e.g. British Coal’s annual report for 1991/1992), so any urgency about replacing coal-fired generation with emission-free electricity has to hinge on the need to reduce or stabilise atmospheric CO2. The writer's view is that Earth has but one atmosphere of which one parameter, CO2 concentration, has already been modified by one third of its pre-industrial value. We should stop.
There are several possibilities.
1. Continue to use fossil fuel and sequester the CO2 (burial seems to be the only practicable scheme). Fossil fuel at present supplies 74 % of all electricity.
2. Replace fossil fuel with renewables. In order of present supply these are: -
i. Biomass combustion; ii. Hydro-electricity; iii. Wind; iv. Wave; v. Photovoltaic and other direct solar energy; vii. Tidal. Renewables in total, at present supply 3.6% of all electricity (with bio-fuels, mostly waste materials contributing over ¾ of renewable electricity and hydroelectricity a tenth of this)
3. Replace fossil fuel with nuclear. This is already proven technology as 25% of UK electricity was drawn from nuclear for many years and even now it is 20%. Despite the hysterical opposition even to mentioning nuclear power in 'green' quarters, it is essential that we discuss this option (SDC 2006). Nuclear power at present supplies 19 % of all UK electricity (and in France, our immediate neighbour and only internationally linked electricity source, nuclear supplies well over 70%.
1. CO2 sequestration
The only practicable scheme is injection of CO2 into porous geological strata, most easily accessed in worked-out oil wells where the overlying formations are by definition gas-tight and assumedly will prevent leakage of CO2.
Small scale experiments in the US and Norway indicate that geological sequestration is feasible, but in the UK we have a serious problem that the only suitable strata are under-sea, in the North Sea oilfield. Some years ago the DTI (pers. comm.) pointed out that such disposal was constrained by our obligations under the London and Ospar Conventions which govern dumping at sea. More recently the IPCC (2005) has reported: -
“No formal interpretations so far have been agreed regarding whether… CO2 injection into the geological sub-seabed or the ocean is compatible with certain provisions of international law… Currently, there are several treaties (notably the London and OSPAR Conventions) that potentially apply to the injection of CO2 into the geological sub-seabed or the ocean.”
Alternative and probably ill-conceived proposals for disposal of liquefied CO2 into deep ocean water appear to have been abandoned on environmental grounds.
2. Renewables
Most renewable energy sources are derivatives of solar energy – either harnessed directly via solar heating or conversion to electricity using solar cells - or indirectly by biomass combustion, hydroelectricity, windpower and wave energy. The latter all rely on secondary access to the sun's energy through the biochemical process of photosynthesis or solar heat-driven evaporation of water or atmospheric convection.
The only exceptions are geothermal heat derived from deep earth processes and tidal energy related to harnessing of the sun's and moon's gravitational energy by global water movement.
As will be shown, none of the renewable means of electricity generation produce significant amounts of power because the energy density of solar radiation is very low even when concentrated by a 'real time' trapping process. The reason why 'fossil' solar energy in coal, oil and gas can produce so much more instantaneous energy is that it has been concentrated over enormous periods of geological time - hence the fact that it is definitely not renewable.
2.i. Biomass combustion at present is largely of waste materials and is nearly at its maximum potential unless it is significantly increased by growing dedicated fuel-crops. This is both impracticable (RAE 2002) and would displace land from food production in a starving world. Its current promotion by government seems to be irresponsible and yet another symbolic gesture, as is wind power.
2. ii. Hydroelectricity in the UK is close to its maximum capacity as geologically acceptable sites have mostly been used, and small scale run-of-river schemes can provide only a very small additional yield.
2. iii. It was shown in Section 5 that wind power is unable to make more than a small contribution to total generation and could not measurably alter atmospheric CO2 concentration sufficiently to influence climate.
2. iv. Wave power, like many other 'techno breaks' is always just around the corner. In the writer's opinion the problem of wave damage and winter storms will prove insuperable. Shore installations will suffer repeated damage (just as do coastal defences) and all moored offshore devices seem to be little more than madness. Reviewed in ICE (2005a)
2.v. Photovoltaic (PV) and other solar energy. Solar energy as a source of low grade heat is old - predating technological culture. The cultivation of plants such as vines on sunward, heat-trapping slopes and the Roman construction of primitive plant shelters was the beginning, but it was not until glass became available in quantity that the 'greenhouse'(15th-16th C) and solar heating was on its way. Despite our cloudy climate, solar heating panels providing hot water are a cost-effective addition to any domestic building.
Photovoltaic silicon cells have been available for some years but so far expense has been a serious limiting factor and even today it seems that without enormous subsidy the pay-off period may be between 45 and 70 years, which is two or three times the predicted life of the cells (ICE 2005b). However in future, solar PV coupled to hydrogen production in low latitude deserts may come to replace our present reliance on fossil fuels though Hayden (2004) gives another view.
2. vi Tidal. The only significant tidal generator in the world is the Rance estuary, a 240 MW impoundment scheme in Brittany. The only worthwhile UK site is the Severn Estuary which could provide in excess of 5% of UK generation from a major impoundment with 8640 MW capacity. The Severn barrage is at present in abeyance for reasons of environmental impact and high cost of electricity. All remaining potential for impoundments or for tidal current generators (still technologically undeveloped) is so small as to have little realistic impact in reducing total CO2-emitting generation. See review in ICE (2005a). At the moment tidal energy effectively provides no electricity in the UK.
3. The nuclear option. Until very recently it has not been possible to discuss nuclear power without a hysterical outcry from the ‘green’ organisations and individuals (Etherington 2003b). However, though the writer has for half a lifetime been convinced that it would be a safer future if the world could dispense with nuclear power it must be discussed in open forum.
The decision about nuclear also has to be taken in the context of risk from climatic change and the precautionary assumption that it is anthropogenic. The proponents of anthropogenic global warming assure us that thousands are already dying, for example the US charity, the Natural Resources Defense Council says: -
“Warning signs today: In 2003, extreme heat waves caused more than 20,000 deaths in Europe and more than 1500 deaths in India.” http://www.nrdc.org/globalWarming/fcons.asp
Even more extremely, James Lovelock of Gaia fame, wrote: -
“… before this century is over billions of us will die and the few breeding pairs of people that survive will be in the Arctic.” (Independent 16 January 2006). Lovelock has also said that the only hope is rapid deployment of more nuclear power.
Promotion of nuclear power has always provoked heated exchanges to the extent that the words ‘Chernobyl’ and ‘Three Mile Island’ are now synonymous with global doom. However, a recent UN analysis shows that the direct death toll from the Chernobyl accident was less than 50 (The Chernobyl Forum, 2003–2005). This is the only accident worldwide which has caused significant radiation deaths. The second most serious nuclear power accident at Three Mile Island, Pennsylvania, was held in check by safety measures and caused no deaths or exposure of the public to radiation.
We cannot discuss the nuclear option unless opponents and proponents are willing to have open debate based upon facts. Do we want nuclear power and is it a 'green' energy source - or do we tolerate climate change (if indeed we can do anything about it)?
The climate is changing – of opinion as well as weather. In early 2006, the Sustainable Development Commission, chaired by Sir Jonathon Porritt (former chair, FoE), hedged its dislike for nuclear power by saying that: -
“Nuclear power may be able to make a useful contribution to the UK’s economy, by providing low carbon electricity at a competitive price.”
However the SDC also raised many pertinent questions about relative cost and future safety but closed on the note of open debate: -
“Nonetheless, the majority of the Commission also believes it is right for the Government to continue to assess the potential contribution of new nuclear technologies for the future, as well as pursuing answers to our nuclear waste problems as actively as possible.”
More recently the Financial Times (March 30 2006) reported that Government Chief Scientific Adviser, Sir David King “believes 40 per cent of Britain’s electricity should come from nuclear generation.”
However, Sir David has missed a trick. We could have a lot more than 40% nuclear, as does France, thus meeting the 2050 target of 60% carbon-free as early as 2015-20. It is patently obvious that no renewable technology, least of all wind power, could approach such a saving. The reason for setting a 40% limit is the risk of over-generation because nuclear plant cannot easily be 'turned-down'. However with the surplus nuclear generation harnessed to hydrogen production, the gas could be used to fuel electricity generation at peak times, or the hydrogen could be diverted into transport fuel. The technology for all this exists at the moment, as proponents of wind power often tell us (Section 4. The problem of intermittency and need for backup).
Nuclear generation is most suited to providing base-load electricity supply as it runs continuously at peak output with infrequent interruption for maintenance.
Relevant articles, news items, papers, reports
“ It would be unrealistic to assume that wind energy would displace any nuclear capacity”
Sustainable Development Commission, chaired by Jonathan Porritt, May 2005
Wind Energy - Saint or Sinner
Dr Mike Hall, Submission to Whinash Public Inquiry, 2005
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The Case against Windfarms