Wind power with 'windgas' is cheaper and greener than Hinkley Point C nuclear plant

| 17th February 2016
More wind farms like this, combined with 'wind to gas' plants, gas storage and CCGT power stations, and you could have the same electricity production profile as the Hinkley C nuclear power station - more quickly and at lower cost and with lower financial
More wind farms like this, combined with 'wind to gas' plants, gas storage and CCGT power stations, and you could have the same electricity production profile as the Hinkley C nuclear power station - more quickly and at lower cost and with lower financial and safety risk. Photo: Jeff Kubina via Flickr (CC BY-SA).
If the UK really wants 3.2GW of 'baseload' power in Somerset, then the Hinkley C nuclear power station is not the only way, write Marie-Louise Heddrich, Thorsten Lenck and Carlos Perez Linkenheil. Wind power with 'wind to gas' plant and CCGT gas power stations could do the same - faster, cheaper, more flexibily, and at much lower technical and financial risk.
The cost of the wind power and windgas alternative amounts to €101.4 billion: €7.2 billion lower than the subsidy cost of €108.6 billion that would accrue during the 35 years following the start of operations at Hinkley Point C in 2023.

We have carried out a study comparing the cost of the UK's planned Hinkley Point C (HPC) nuclear power station with a 100% renewable system capable of delivering precisely the same power intended supply profile of a flat 3.2GW (gigawatts).

We chose a very simple system in which all the electricity is generated by wind turbines. Wind power that is surplus to the HPC's 3.2GW is used to produce 'windgas' by electrolysing water to produce hydrogen, and then using that to produce methane.

Natural fluctuations in wind power generationare balanced by windgas (also known as power-to-gas) so that, overall, the same volume of electricity is generated as would be by HPC (see Illustration 1).

We performed a simulatation of electricity production during August 2025, a month well-suited to depicting strong fluctuations in wind yield due to ambient weather conditions. Illustration 2 shows how steady power production by can be replaced by wind power and windgas.

The illustration shows that surplus wind power above HPC's 3.2GW is used in windgas facilities first to produce hydrogen (H2), then convert it to methane (CH4). This is then fed into the conventional gas distribution system or stored in already existing gas storage facilities and later reconverted into electricity in combined-cycle gas turbine (CCGT) power plants when the need arises (B in green).

The installed capacities of windgas facilities and CCGT plants needed to balance fluctuations were calculated at their optimal cost based on an annual quantitative balance. Hydrogen produced by electrolysis can often often be used directly without needing methanation. However, the study took a conservative approach and based calculations on a complete methanation of surplus stocks because windgas can then be fed into the existing gas network.

HPC is due to receive a guaranteed price of 2012 €120.30 / MWh for a period of 35 years. Our major finding is that our wind-powered alternative can deliver power at a substantially lower cost of 2012 €110.51 / MWh.

A detailed cost comparison

For this process, the study calculated the cost of the windgas alternative using the Power2Sim energy market model, based on hourly simulation, and compared this with the subsidies that Hinkley Point C is expected to receive for the 35 years following the start of its operation.

The result: In a comparison using the figures from HPC's current subsidy programme and the present degression defined in Germany's Renewable Energies Act (EEG), wind power and windgas facilities can replace the Hinkley Point C nuclear power plant at a lower cost.

Illustration 3 shows the results of the cost analysis of the windgas alternative compared to the planned subsidy costs of €108.6 billion (nominal) for HPC. Cost developments for windgas are based on assumptions calculated by the Technical University of Regensburg's Research Centre for Energy Networks and Energy Storage (FENES) / Energy Brainpool in 2015.

The cost of the wind power and windgas alternative amounts to €101.4 billion: €7.2 billion lower than the subsidy cost of €108.6 billion that would accrue during the 35 years following the start of operations at Hinkley Point C in 2023.

The cost of the wind power and windgas alternative amounts to €101.4 billion; this figure is €7.2 billion lower than the subsidy cost of €108.6 billion that would accrue during the 35 years following the start of operations at Hinkley Point C in 2023.

The cost calculation for the wind power and windgas alternative includes the construction and operation of all wind turbines as well as all electrolysers and CCGT (combined cycle) power plants.


Basic principles

  • To guarantee the UK's future supply of electricity, the British government is planning the new build of a nuclear power plant (NPP) at the site of the already existing Hinkley Point NPP. Construction of this plant is to be subsidised with State Aid reflecting the strike price of 2012 €120.30/MWh.

  • This adds up to a total subsidy volume of 2012 €55.18 billion over the subsidy's 35-year period of validity. Taking into consideration the figure used for the subsidy calculation, an annual inflation rate of 2.43%, the total subsidy costs amount to €108.6 billion (nominal).

  • Accordingly, Hinkley Point C will generate electricity steadily except during annual periods of maintenance (presumably in September each year). This is due mainly to its high level of subsidisation, which is based on the volume of electricity it feeds into the grid. For this reason, Hinkley Point C will tend to force other power plants out of the market rather than shut itself down and relinquish these subsidies.

  • Modelling was done with the Power2Sim energy market model software based on hourly simulation.


Because the processes of electrolysis and methanation as well as the reconversion of windgas to electricity in combined-cycle gas turbine (CCGT) power plants have losses, there must be correspondingly more surplus electricity available to compensate for these shortages.

Surplus electricity constitutes the amount of wind power that is generated above the 3.2GW level foreseen for HPC. Shortages constitute the amount of wind power that is lacking below this level. Calculations for the power production of wind turbines are based on wind data for the UK published on the ELEXON portal.

The efficiency factor for electrolysis and methanation was calculated together at 71% and for CCGT power plants at 60%, with the resulting formula:

Surplus energy x 60 % x 71 % = shortage

Therefore, when conversion losses are taken into account, 33.3 TWh of wind power must be generated each year.

Assuming that sufficient gas storage capacity is available, the combination of wind power and windgas technologies can provide the same power output as Hinkley Point C at any time.

Basic assumptions


Hinkley Point C

Land-based wind power

CCGT plants

Windgas facilities

Installed capacity in GW





Power production per year in TWh





Annual full-load hours





Level of subsidies (based on real 2012 figures) in EUR/MWh





Costs (based on real 2014 figures) in EUR/kW





Average annualized cost
(nominal) EUR/kW





Subsidy period in years





Lifetime in years





Inflation rate in %





These basic assumptions were used for calculations in this study.

Subsidy for HPC: £92.5 / MWh.

HPC will be subsidised by the same Contracts for Difference (CfD) mechanism used for wind turbines. However, in contrast to wind turbine subsidies, the strike price for HPC subsidies will remain constant at £92.5 / MWh and also be adjusted for inflation.

This means that HPC will always receive the difference between the market price for electricity and the strike price. The subsidy costs for HPC have been calculated using this principle (strike price minus the market price for power).

Subsidy for wind turbines: The CfD strike price at the last auction (£79.23 / MW) formed the basis of calculations for 2023 and 2048, using the quarterly degression rate (0.04%) laid out in Germany's Renewable Energies Act (EEG). This resulted in a new average subsidy price of €74.41 /MWh.

This approach proved to be the most likely regarding the cost calculation of wind turbines in the UK. The Contract for Difference (CfD) mechanism is meant to replace the current subsidy mechanism for wind power in the UK by 2018.

The first CfD auction was held in January 2015. Subsidy prices for the years from 2023 to 2058 were determined on the basis of this price multiplied by the EEG degression. The inflation rate of 2.43% was used in these calculations as well.

The duration of CfD subsidisation for wind turbines is 15 years, after which time the turbines continue to operate for 10 years without funding.

Subsidisation with the CfD mechanism provides a funding period of 15 years. Considering that the average life span of a land-based wind turbine is 25 years, a period of 10 years remains during which the turbine is not subsidised.

The electricity prices used for the revenue accounting of Hinkley Point C and of wind turbines were determined on a precise hourly basis with the Power2Sim energy market simulation programme.

The method used for the revenue accounting of wind turbines was the same as for Hinkley Point C since both technologies are subsidised through the CfD mechanism. Calculations took into account that wind turbines usually generate lower revenue than base-load power plants do because at times of high wind power feed-in, prices fall due to the merit order principle.

Wind data for the UK was based on information posted on the ELEXON portal.

The ELEXON portal posts wind data for the UK; this information was used to extrapolate the amount of installed wind turbine capacity needed (11.2 GW) for the renewable alternative.

Wind power generation per year is 33.28 TWh.

This sum is the outcome of a cost-optimised quantitative balance calculation based on the assumption that enough surplus electricity or windgas is provided at any time to sustain power output at 3.2 GW.

Shortages are balanced during the entire period by means of electrolysis and methanation processes that consume surplus electricity and generate windgas which is later reconverted to electricity in combined-cycle gas turbine (CCGT) power plants. Taking conversion losses into account, 33.28 TWh of wind power must be generated each year. In comparison, the annual power production of Hinkley Point C is 25.7 TWh.

It was assumed that the efficiency factor for converting electricity to methane was 71% on average (64% in 2023, up to 78% by 2043).

These figures, together with the efficiency factor for the CCGT plants (60%), formed the basis for calculating the quantitative balance because surplus electricity, multiplied by the efficiency factors, must equal the shortages.

The inflation rate was taken from the information provided by the European Commission regarding the subsidisation of Hinkley Point C.

But in the real world, it gets even better

If we also take into consideration that Hinkley Point C will not begin operating in 2023 but later due to delays in construction, we can assume that cost savings from using the windgas alternative will be even greater due to improved efficiency and lower costs in windgas technology, and possibly due to gas-fired power plants becoming less expensive. Operations are currently expected to begin in 2025 and not in 2017 as originally planned.

In assessing these results, we must also take into account that the two variants in this study were compared with each other in ideal and typical settings (same volume of power production, same power production structure). In the renewable alternative, the installed capacity of gas-fired power plants is therefore calculated in dimensions large enough to ensure that these plants produce as much electricity as Hinkley Point C would even during a complete lull in wind.

If there is wind supply, the gas-fired power plants are not used in the direct comparison with Hinkley Point C. If these plants are nevertheless kept in operation, additional revenue from their power generation would contribute further to the cost advantages of the renewable alternative.

In a real situation, each technology would be integrated into the UK's overall electricity market. This would allow electricity surpluses and shortages, already taken into account in the windgas alternative, to be balanced more efficiently with other flexible options throughout the entire power market, thereby further reducing the cost of the renewable alternative.

With the help of windgas, the wind power and windgas alternative is able to generate the same amount of electricity at the same level of availability as HPC would, even if wind power were not available. In addition to windgas facilities, there are other technical flexibility options for balancing wind power such as photovoltaic facilities, hydropower plants, highly efficient cogeneration (CHP) plants, storage batteries, pumped storage hydropower plants, and shifts in demand or consumption.

Although these options generally have a lower balancing effect than windgas does, they can be utilised more efficiently and cheaply in most cases. As an alternative to HPC, a renewable energy system that makes use of flexibility options therefore has further cost-cutting potential.



Energy Brainpool is an independent market specialist for the energy sector that focuses on electricity and energy trading in Europe. Their expertise encompasses the analysis, forecasting and simulation of electricity prices, individual consulting, the preparation of studies, and expert training in the energy sector. They combine knowledge and reliability with practical experience in conventional and renewable energy systems. See their website.

This article is an edited version of a 'Wind power as an alternative to nuclear power from Hinkley Point C: A cost comparison', a report by Marie-Louise Heddrich, Thorsten Lenck and Carlos Perez Linkenheil, all of Energy Brainpool, commissioned by Greenpeace Energy. The evidence it furnishes is expected to be used as part of the legal case against HPC forthcoming in the European Court of Justice.


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