Best Renewables

Before any proposed government legislation can become approved, there are a number of stages and checkpoints designed to ensure that all relevant factors have been considered. This is to protect the nation against poor quality or erroneous decisions adversely affecting the interests of the electorate, and at least to gather valid criticisms of that legislation.

The Climate Change Act of 2008 did not follow that path, with only five MP’s voting against it. One such MP who opposed the legislation gives his reasons here . It was carried forward without proper scrutiny, without public input, and with barely any dissenting voice being allowed to be heard. Its stipulation to ensure that the net UK ‘carbon account’ for all six Kyoto ‘greenhouse gases’ for the year 2050 were to be at least 80% lower than the 1990 baseline, prompted the move away from conventional power sources to renewables.

The renewables so optimistically touted as the means to achieve the CO2 reductions required by the the Climate Change Act are windturbines and solar power, but they have major drawbacks for the UK. The presence or the lack of wind is not predictable, and in the UK we have cloudy skies on about two thirds of our days. Winter is the time when most electricity is consumed and the coldest periods coincide with high pressure anti-cyclones possessing very low wind speeds. In mid winter even on clear days there may be less than eight hours of low sun available for solar power. The variability of renewables also requires the frequent ramping up and down of mainly gas conventional power sources on standby, to match the additional variability in supply. There may be nights when the wind is not blowing and there will be no significant renewable power at all.

The deficiencies of such renewables are therefore:

  • unpredictably intermittent
  • likely failure to provide peak output under conditions of most demand
  • inefficiencies of having to track variable renewable output with gas powered stations
  • inability to provide base load power

If the intention of the CC Act was to provide renewable energy which would eventually supersede reliable carbon or nuclear based sources, then from the above, it will never succeed. Wind and solar will always need backup from conventionals, and unless there is some breakthrough in energy storage, periods where electricity demand is high may not be matched by renewable capacity. Wind and solar renewables, as conceived by the CC Act, therefore do not reduce the need for conventional electricity generators.

If the original proposition of the CC Act had been subject to a measured analysis and proper scientific scrutiny, the more obvious defects of the UK’s renewables schemes would have been apparent. There would have been a chance to put forward renewables schemes best suited to the UK. Instead in 2008 such was the level of hubris to do something about the supposed climate problems, no politician would have dared to question the automatic assumption that it was right to gamble on the future of the entire UK electricity grid. It is further surprising that none of the MP’s of the three main parties, with only a few exceptions, seemed bothered to ask if there were alternative renewable schemes to the offered windturbine and solar solutions. Such a question would not have been politically dangerous as it was still going with the flow in lauding the praises of renewables.

There were few such penetrating questions, yet it is obvious to anyone having lived in the UK that solar power would be ineffective in winter, and regularly weak in other seasons in the frequently cloudy weather. With a little extra thought, the deficiencies inherent in windpower in regard to its incompatibility with conventional sources might also have been teased out.

In Germany, they have already experienced such deficiencies in winter conditions, in early December 2013:

…wind and solar power production was consistently near to non-existent. More than 23,000 German wind turbines stood still for days. One million photovoltaic systems, subsidized by consumers to the tune of with 108 billion euros, stopped work nearly complete and delivered a few kilowatt hours only very briefly during lunch. For the whole week unloved coal, nuclear and gas power plants had to generate an estimated 95 percent of Germany’s electricity supply…

…it will not add anything to the German power supply if the green power expansion continues and when in the future 40,000 instead of the current 23,000 wind turbines stand still in the doldrums – or when two million instead of one million solar panels do not generate any electricity during the long winter darkness. “

The scale of the gamble taking place in the CC Act was never made apparent. Due to the rush to commit to renewables, any kind of renewables, the opportunity was lost to include considered opinion outside of the self-congratulatory carnival of environmental righteousness taking place in Westminster.

The other practical renewables in the frame for the UK are hydro, tidal, including barrages, coffer dams and tidal streams, tidal flow, and biomass schemes. Although biomass is ‘carbon neutral’ it requires substantial fuel inputs themselves energy intensive and it is not significant on a national scale. Hydro has been long established in the UK and has little scope for further exploitation. The UK is well positioned to take advantage of tidal power. The ideal geographic locations are long narrow islands with irregular coasts, on a continental shelf, looking out into an ocean.

Tidal is inherently predictable in strength, duration, and timing, which makes it more compatible with conventional sources, with less need for standby systems. It can be scaled for maximum annual demand. The peak tidal flows around an undulating or irregular coast do not occur at the same times, which brings in the possibility of using tidal flow for base load generation, replacing some conventional capacity.

tides_2Peak tidal flows in a region

Comparing the properties:

Wind and Solar

Tidal Flow

Unpredictably intermittent

Variable, but highly predictable
High failure probability to provide peak output under conditions of most demand Can be scaled accurately for peak demand
Inefficiencies of standby generators to cover for intermittent renewable output Known output patterns can be pre-matched to conventional generator cycles
Inability to provide base load power Base load generation capability due to overlapping tidal flows

Tidal flow has advantageous fundamental properties not possessed by wind or solar, placing it ahead of them in the preference order of candidate renewable technologies. Yet, apart from a few examples, it has been either ignored or dismissed as unworthy of the hundreds of billions being pumped into wind and solar. If there had originally been a rational and inclusive approach to the use of renewables in the UK, there would have been no reckless haste to grasp at ultimately inappropriate systems, and there would have been space for consideration of alternative types such as tidal flows. Further, the renewable systems under trial would have been validated on a small scale before being universally rolled out, if successful.

This is not to say that the tidal flow renewables outlined here are ultimately the way forward, but they are at least a logical starting choice for considered evaluation and should have been properly included in the original debates. However, this is asking too much of a closed political system driven by its own hubris. The need to make grand gestures, to gratify powerful lobbyists, and to pursue big ticket dreams, all triumph over the rules which prevail in the everyday but coherent world outside. We require rationality and structure in this debate if we are to see any successful use of renewables for the UK.


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