Why Plaid and the Greens need a nuclear rethink before they take power

Nic Conner

If the polls are correct, we are days away from a Plaid Cymru government, potentially supported by the Wales Green Party in coalition.

If this is the case, I urge both Plaid Cymru and the Greens to reconsider their stance on nuclear power.

Neither Plaid Cymru nor the Wales Greens place nuclear anywhere in their 2026 manifestos, which, in policy terms, appears deliberate rather than accidental.

Both set out energy strategies centred on renewables, local ownership and system decentralisation, talking extensively about wind, solar and community energy models, alongside job creation through green investment and infrastructure.

The absence of nuclear sits alongside a wider, established position. The Greens are explicitly opposed to nuclear, while Plaid Cymru’s 2024 general election manifesto opposed new nuclear projects and small modular reactors (SMR’s), citing concerns around cost and delivery timelines relative to renewables.

For those in the nuclear sector, the implications are concerning. The current status quo of either party does not see nuclear as part of Wales’ future energy mix.

As of 29 April 2026, the United Kingdom is importing around 4 to 5 gigawatts of power, including roughly 3 gigawatts from France, predominantly nuclear derived, and over 1 gigawatt from Norway, largely hydro.

We are currently reliant on our neighbours for firm and flexible generation. This is a concern. The United Kingdom needs to strengthen its energy security.

Renewable energy systems require reliable back up or firm power to maintain supply when wind and solar output is low.

In the United Kingdom, that role is currently provided largely by gas fired generation, which exposes the system to price volatility and geopolitical risk given its link to international gas markets.

Nuclear power offers an alternative source of low carbon, dispatchable electricity, and countries such as France have used a nuclear led system to provide a high degree of energy security and relatively stable power prices.

Expanding nuclear within the United Kingdom’s energy mix will support system reliability and price stability, although costs, delivery timelines and financing structures remain key considerations.

The United Kingdom’s nuclear roadmap is intended to strengthen energy security and reduce exposure to volatile gas prices. However, this progress could be at risk.

Plaid Cymru and the Greens’ opposition, if translated into government, could mean blocking projects such as the Wylfa power station, which has recently been approved as a SMR manufacturing site.

This could bring around 8,000 new jobs to Ynys Môn and North Wales.

Uncertainty

By not stating support for nuclear in their manifestos or speeches, they risk creating uncertainty at precisely the moment confidence is most needed.

Investor confidence is everything. Capital is mobile. If Wales cannot offer policy certainty, investors will deploy that capital elsewhere, whether in England, Europe or beyond.

Major infrastructure projects like Wylfa depend on long term political stability. Investors will not commit billions where the policy environment is unclear or hostile. Any arrangement that undermines confidence risks sending the wrong signal.

Under a Plaid Cymru and Green arrangement, Wales could follow Scottish Government policy in opposing new nuclear, using devolved planning powers to effectively block projects. If that were to happen, the consequences would extend beyond energy security to jobs, livelihoods and our communities.

Renewables will play a vital role, but they cannot deliver a stable system on their own. Nuclear provides the firm power that complements them.

Skilled jobs

Wylfa could deliver thousands of skilled jobs, billions in investment and long term economic stability, supporting apprenticeships, strengthening supply chains and giving young people a reason to stay and build their futures in Wales.

Virginia Crosbie, the former MP for Ynys Môn, tells the story of visiting Hinkley Point C in Somerset, where she met young Welsh speakers from Anglesey who had moved away for work. They told her how they wanted to see Wylfa developed so they could return home.

For Wales, the case for nuclear is not only economic but cultural. Protecting the Welsh language depends on thriving communities where people can live and work.

The average age in parts of North Wales is well above the UK average. On Anglesey and in Conwy it is around 49, while in Gwynedd it is around 45.

By comparison, in London it is around 35. The population is ageing, and quickly. We need jobs and opportunities to sustain communities and culture.

Too often, young people are forced to leave in search of opportunity elsewhere. Long term investment and quality jobs are essential if Welsh speaking communities are to survive and flourish.

Energy security

From France to the United States, governments are backing nuclear as a cornerstone of energy security and industrial strategy.

Under Plaid Cymru and the Greens, the question is whether Wales will do the same, because even uncertainty could be damaging for the nation.

Nic Conner is the Honorary Secretary of Supporters of Nuclear Energy (SONE), an independent grassroots group advocating for new UK nuclear power to deliver affordable, reliable, low-carbon energy. He is a partner at Parisi Consulting and lives in the Conwy Valley with his young family.