The UK is facing a potential energy gap as older power stations close and North Sea gas reserves dwindle. To ensure our electricity supply is not interrupted, we need to build new generating capacity, taking into account the limitations of various energy sources and their generating technologies.

Capacity vs. demand

Existing UK power stations have an estimated combined capacity of around 90 gigawatts (GW) – sufficient to fulfil our current electricity needs, which typically peak at around 60 GW.

Since 2010, 26 power stations (19GW) have closed, that’s 20% of the UK’s electricity generation capacity. By the end of 2030, a further 35% (over 30 GW) of that 2010 capacity will close down, including all but one of our current nuclear power stations.

Meanwhile, peak demand is expected to rise as electricity is increasingly used to power transport and heating.

Closing the energy gap

To help close the potential energy gap, we need to reduce demand through energy efficiency measures, and new power stations must be brought online. But the options for building new power stations are constrained by the limitations of the different fuel sources.

For example, by 2050 the UK must reduce its carbon emissions to levels 80% below those of 1990 – giving strong motivation for any new generating capacity to be low-carbon.

Many power stations built in 2020 are likely to be still generating electricity in 2050, so we must make the right decisions about what type of generating plants to build now. At the same time, UK fossil fuel reserves are diminishing, so any new fossil fuel power stations might increase our long-term reliance on imports. Their security of supply and affordability can be uncertain due to increasing global demand.

The impact of electrification

Over the next two decades the UK is likely to undertake significant electrification of its transport network. As low-carbon sources of energy, such as wind and nuclear power, are increasingly used to generate electricity, electrification will benefit us in two ways.

It will help to further reduce greenhouse gas emissions and to reduce our reliance on dwindling fossil-fuel reserves. But it will also increase demand for electricity, which means bridging the energy gap will be even more important.

The best solution

No one fuel source provides all the answers – each has its limitations. Fossil fuels release too much carbon dioxide into the atmosphere and will eventually run out. Nuclear energy creates radioactive waste while renewables such as wind and solar are intermittent and expensive. Many generating technologies suffer from a lack of suitable sites, lengthy approval procedures or insufficient industrial capacity.

Used together, however, the different generating technologies have individual strengths that help to compensate for each other’s weaknesses.

Sustained action on energy efficiency, demand management, a smart grid and a diverse energy mix encompassing renewables, fossil fuel generation fitted with carbon capture and storage and nuclear power should help to ensure low-carbon, secure, affordable electricity supplies for the UK for decades to come.


Renewable energy sources like wind, sunlight, tides and flowing water are theoretically inexhaustible, but the quantity of this energy that can be converted into electricity is limited by the efficiency of current technology. 


Countries that rely on imported fossil fuels to power their electricity supply can potentially be exposed to security of supply issues, including fluctuating fuel prices and disruptions to fuel supplies due to political or geographical instability.


An electricity supply that includes variable energy sources can still be reliable overall, provided there is sufficient diversity in the generating mix. Flexible energy sources can be called on when the less predictable intermittent energy sources fail to supply.

Climate change

More than two thirds of the world's carbon dioxide emissions come from the way energy is produced and used. To meet its carbon-reduction commitments, the UK has to phase out the use of carbon-rich fuels and to replace them with low-carbon equivalents.


When estimating the affordability of different energy sources, it is important to take into account all the costs – including planning, construction, operation, decommissioning and environmental costs – as well as factors like the typical lifetime of the equipment.

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Go behind the scenes

We've prepared a number of interesting videos that show you around one of our nuclear power stations and introduce you some of the people who power our energy.