We face an energy crisis if the warnings are ignored

We face an energy crisis if the warnings are ignored

by Paul Spare
article from Monday 8, October, 2018

AS HAS been widely reported, it is ten years since the collapse of Lehman Brothers bank and the ensuing financial crisis in the banking system. Many commentators issued warnings preceding the crisis that too few boardroom personnel understood the novel financial instruments that were being authorised by their companies.  Since in the short term, however, the financial tools appeared to be generating large annual profits, the operations were permitted without adequate scrutiny and controls.

A similar scenario is developing in electricity supply with ultimately a similar inevitable catastrophic day of reckoning.  This will happen when the present unbalanced system that is being distorted by political dogma rather than sound engineering, can no longer cope as the backup plants falter or are retired.  Unfavourable circumstances will combine to force renewables supporters to face up to the realities of physics and engineering.

This time, the implicated parties include the EU, political parties and environmental campaigners.  However these groups could educate themselves in a few hours, since the technical evidence about the developing problem is freely available on public websites that record electricity generation. The issue is not as esoteric as the banks’ algorithms dealing in “futures” and “hedging”.

Renewable technologies are seen as the panacea that will solve a spectrum of problems in the energy sector whilst having no drawbacks or adverse effects. In the short term, subsidies have supported their steady growth, but their weaknesses are apparent to the prescient observer.  Any engineering system must be tested in real time or by analysis, against various predictable faults and stresses.  Wind and solar power are not being examined seriously as we plunge forward with misplaced confidence in the new technologies.

The Achilles heel of renewable technologies remains their vulnerability to common-mode failure; ie one event affecting several power sources. Maximum electricity demand occurs during winter evenings with freezing fog – times when both wind and sun have little power and wave energy would also be negligible.   Data from a few sample days over the past year illustrates the level of risk that even the most committed renewables supporter should be able to comprehend.

A typical autumn day – 2 November 2017.  Electricity demand 43,000 MW… of which wind power was producing only 1 per cent;  gas 56 per cent, coal 11 per cent and nuclear 20 per cent. 

An average winter day – 10th or 11th of January 2018. Wind power declined to less than 300 MW – 0.6 per cent.   To prevent power cuts it was necessary to have maximum output from our coal stations  – 9000 MW, ie generating over 20 per cent of peak demand.  These coal stations will be retired in only a few years if we comply with EU Directives.  

Highly variable renewables output also occurs in the summer.  June 14th 2018 was a particularly favourable day for wind power.  The aggregate output was in excess of 9000 MW between 0650 and 1250 hrs - producing 35 per cent of our electricity, but the situation changed dramatically only a few days later. Over the ten days from 4th July to 13th:

  •  Output was less than 2 per cent for about one third of the time ie three days;   
  •   For many hours wind power from 10,000 turbines declined to only 100 MW – 0.3 per cent of electricity demand.  That is about the same as the engines in the largest super-tanker.

 

There are three essential messages from this sample data.

  •      Wind power can collapse to only 1 per cent of our electricity quite frequently.
  •      These unfavourable days can occur at any time of the year
  •      Periods of low wind power can last for many days – way beyond any feasible storage option.

 

It also has to be factored in that electricity demand in the summer is only about half the winter maximum.  It would be impossible to maintain our essential services, communications, financial systems, water and food supplies if electricity generation dropped to 2 per cent for three days.  Fossil fuel backup is not a frivolous option, it must be maintained up to the full capacity of wind power installations to cover for windless days. The announcement at the recent Labour Party conference that more wind turbines should be built, ignored these inconvenient facts.

There are fanciful claims that the batteries in electric cars will store surplus renewable electricity and help us to survive on days with low wind output.  A few relevant calculations shows that this is a fantasy.  Average daily electricity use in the UK is about 1TWh.  That will mean little to most non-scientists but in more recognisable units it is one thousand million kWh.   

The propulsion battery in a Nissan Leaf has a rating of 30 kWh.  It would therefore require 35 million Leaf batteries to store the electricity that we use in a single day.  On a favourable day, our 10,000 wind turbines can provide about 20 per cent or our electricity… to produce all of our electricity would require about 50,000 turbines.  However to generate double the usual quantity so that a surplus could be stored for the following day, the number of turbines would have to be doubled to 100,000.

However, to store the 1TWh of electricity would require all the cars to be connected to recharging points, rather than used for transport. Similarly, on the day of low renewables output, they would have to remain connected so that their stored electricity could be fed back into the grid – a truly impracticable requirement. It is also very unlikely that the meteorological conditions would conveniently arrange for a day with very high wind speeds (and hence surplus output) to precede a day with negligible output.  

The government proposes to force the change from liquid-fuelled vehicles to electric but, even with favourable economics, it took fifty years for vehicles to replace the horse.  Even if half the car population had batteries of 70kWh, the stored electricity would last only a day and a half, whilst there is still the impracticality of the vehicle population being effectively out of action.

The planned closure of the remaining coal plants must be rejected as a policy.  The oldest nuclear plants are now reaching 43 years when their design life was 30 years and after exit from the EU, French nuclear electricity may not be readily available.  Very few gas-fired plants are being built because of uncertainties.  After the disasters in the banking system, it would be scandalous if an equivalent crisis was permitted in electricity supply, but the warning signs are being dismissed and so many heads are being buried in the sand. 

Paul Spare CEng FEI FIMechE

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