By 2020 the three renewable technologies could each be providing around twenty times as much electric power as Hinkley Point is meant to produce in 2023.
Photovoltaic and wind power installations have expanded exponentially in the UK since 2006 when it was decided that new nuclear reactors were necessary.
But now the European Commission has agreed to allow the UK government to spend an estimated £15-20 billion subsidising a nuclear reactor to be built for, and by, two French government-owned companies.
So it's opportune to ask: does the UK even need this new reactor, scheduled for completion in 2023?
Taxpayers and investors should also be aware that a large renewable electricity contribution will mean a lower wholesale electricity price - and an even higher subsidy for nuclear.
The amazing expansion of renewable electricity generation
The renewables have dramatically changed the UK electricity generation scene since 2006 when the then Labour government took the decision that new nuclear reactors were necessary.
Department of Energy and Climate Change (DECC) figures show that in 2013 the UK had over 14 GW of solar photovoltaic (PV) and wind power connected to the grid. This is already nine times the power of the first 1.6 GW reactor proposed for Hinkley Point, which is not expected to contribute electricity until 2023 at the earliest.
Even more significantly, over the past seven years, installations of PV, onshore wind and offshore wind power in the UK have all been increasing exponentially.
If these rates of expansion continue, by 2020 the three renewable technologies could each be providing around twenty times as much electric power as the proposed Hinkley C nuclear plant (assuming no construction delays) is to produce in 2023.
The PV prediction is based on a rate of increase that Germany has already achieved. A re-assessment of our need for new nuclear power by government and investors is clearly overdue.
Renewables reduce the wholesale price of electricity
The government's newly developed 'contracts for difference' commit the taxpayer to pay the difference between expensive nuclear electricity and the wholesale price of electrical energy at the time that nuclear contributes.
Nuclear electricity is expected to be about twice as expensive as the current wholesale price. But a large amount of renewable power on the grid in 2023 will mean that the wholesale price will be far lower than now.
Under the 'contracts for difference' system this means that we are going to have to provide an even higher subsidy for Hinkley C than most observers have realised.
So if the cost is levied directly on consumers, as planned, new nuclear will mean far higher electricity bills - the very opposite of what the government is claiming today.
The evidence that the renewables reduce the wholesale price of electricity comes from Germany. For example, as the contribution of PV power on the German grid has increased, the peak wholesale price of electricity has fallen.
The cheap PV power is at its maximum around noon, the time of greatest daytime demand and previously the time of highest wholesale electricity cost.
Energy or Power? The difference is important for PV and wind power
DECC is not in a good position to make a re-assessment of the need for nuclear power. Its computer programme, 'Pathways to 2050', was designed to justify the decision to go for new nuclear power, after the decision had already had been taken.
It is therefore based on aggregated energy flows, rather than the need to balance instantaneous electrical power demand with power supply moment by moment, as happens on the grid.
A nuclear reactor of a certain power 'capacity' should produce around seven times as much electrical energy in a year as a PV system of the same capacity. Therefore accounting in terms of the energy produced over a year, rather than power favours nuclear over solar by a large factor.
But such calculations ignore the importance of timing which is crucial where power is concerned. For example the DECC programme would be unable to explain why in 2011 - when PV provided only 3% of the electrical energy on the German grid - the peak wholesale price of electricity had fallen by 20%.
The fall was due to large amounts of cheap PV power arriving when daytime demand is at its highest, thereby pushing prices down for the huge volumes of electricity being consumed at these times.
Matching electrical power demand with power supply
Power is also more important than energy because electrical demand and electrical supply are measured in terms of power. A far better approach than 'Pathways to 2050' to assess whether nuclear power is necessary was demonstrated in Germany in 2006.
I describe the Kombikraftwerk project (German for 'combined power plant') in my book The Burning Answer: a User's Guide to the Solar Revolution. A computer program matched 1/10,000 of the actual, real-time electrical power demand on the German grid using the actual real-time power output of a number of wind, PV and biogas electricity generators.
The Kombikraftwerk project showed that electrical power demand matched the electrical power supply throughout every day and over the entire year. The results showed that wind and PV generators are complementary. Together they supplied a very impressive 78% of the power.
The main backup was provided by the biogas generators, which only had to supply 17% of the power. One important feature of biogas electricity generators is that they can vary their output in a matter of minutes and they are therefore able to cope with the short-term variations of the wind supply.
Kombikraftwerk conclusively demonstrated that nuclear power was not needed to back up large amounts of wind and PV power. It was no surprise when Germany decided, following the Fukushima disaster, to confirm its intention not to replace ageing nuclear reactors.
The daily and yearly variation in electricity demand in Britain is similar to that in Germany. The main difference is relatively higher evening peak demands in the UK in winter. This is compensated by the fact that the wind supply variation between winter and summer is larger in the UK than in Germany.
In both countries nuclear power is a completely inappropriate back-up to large amounts of PV and wind power. Once it is running, a nuclear power station cannot change its output, certainly not in minutes, or even day to night or summer to winter.
Are renewable subsidies being cut to ensure room for new nuclear?
One important question to consider is whether present and future government policies will allow the renewables to continue to expand exponentially. There is a real fear in the renewable energy industry of the way the coalition government is cutting renewable subsidies.
The popular and successful feed-in-tariff for domestic roof-top systems is being cut month on month. The equally successful subsidy for solar farms is to be removed. It will be replaced by the untried 'contracts for difference' that were designed to subsidize very large and expensive new nuclear power systems.
The renewable industry fears that nuclear power will swallow the major share of the subsidies leaving the renewables to compete against each other for the leftovers.
The government argument that the successful renewables subsidies were costing too much does not hold water. The high-carbon, well established and wealthy natural gas industry is currently subsidised to a greater extent than all the renewable industries taken together.
What next? New nuclear still has hurdles to surmount
The best hope for renewables is that new nuclear will fall at one of the hurdles it still has to surmount. First there is likely to be an appeal against a decision which flies in the face of the doubts the commission raised about the subsidy in 2013.
Then, will investors wish to fund this massive project given the fear a future government might default on the subsidy when the renewables bring down the wholesale price?
Finally, prudent investors would do well to wait until one of the two EPR (European Pressurised Reactor) prototypes for the Hinkley C - at Olkiluoto in Finland and at Flamanville in France - actually works before signing on the dotted line.
The Flamanville EPR was due to be completed by 2012 at a cost of €3.3 billion, but is now projected for completion in 2016 at a cost of €8.5 billion. No one will be surprised if the timeline is subject to further slippages.
The Olkiluoto EPR is doing even worse. Construction began in 2005 and was originally due for completion in 2009. It now has a projected completion date of 2018, almost a decade behind schedule.
Furthermore, design modifications are always necessary in the light of prototype performance, whether an engineering project is large or small. And a third generation nuclear reactor is a very large and very complex engineering project.
The modifications will surely take the cost of the nuclear electricity even higher. This could be the rather hefty last straw that finally breaks the camel's back.
Event today: Keith Barnham is speaking on 'The Solar Alternative' at Victoria Park Community Centre, Victoria Rd, Bridgwater, Somerset TA6 7AS. Wednesday October 15th at 7.30 pm. All welcome. Free admission. Event organised by Bridgwater & West Somerset Green Party (01278 425451).
Keith Barnham is Emeritus Professor of Physics at Imperial College London, where he founded the Quantum Photovoltaic group. The group developed a third generation solar cell with three times the efficiency of current rooftop PV.
The book: 'The Burning Answer: a User's Guide to the Solar Revolution', by Keith Barnham, is published by Weidenfeld and Nicolson. ISBN 9780297869634.