Image copyright TLP Image caption The lagoon is privately financed and £35m has already been spent on project development

A publicly-owned energy company should be set up in Wales, Plaid Cymru has said.

It believes it could help keep the £1.3bn Swansea tidal lagoon project alive.

Party energy spokesman Simon Thomas said: "If the UK government does decide to betray Wales, then we need to think of ways in which we can deliver it without them".

The Welsh Government has offered £200m in a stake or loan to get it built.

Plaid Cymru led a debate in the Senedd and Mr Thomas called for the Welsh Government to look again at setting up an energy company for Wales.

This would take several months but if the UK government delayed a final decision on Swansea it could "buy time" for a solution.

It is set against a background of reports that the UK government is on the point of throwing the lagoon plans out.

The project, with turbines set along a 9.5km breakwater in Swansea Bay, would be a first.

The developers Tidal Lagoon Power (TLP) have the support of an independent review into the technology but need the UK government to agree on a price for future electricity it would generate.

But there is concern in Westminster about the cost, compared to nuclear power.

Plaid has had a long-held proposal for a publicly-owned energy company, Ynni Cymru, which would use profit from Welsh resources to cut energy costs to consumers.

Wales' largest onshore wind farm, Pen-y-Cymoedd, is run by a Swedish state-owned company Vattenfall, and the profits made when the turbines turn return to taxpayers in Scandinavia.

The argument for a Welsh energy company is that profits could pay towards our public services.

Wales also has a history of different models for delivering utilities - with Dwr Cymru being run as a not-for-profit water company since 2000.

Meanwhile, the new operators of the all-Wales rail franchise and South Wales Metro from October are being brought under the arms-length Transport for Wales and asked to deliver services with a cap on profits.

Image caption Simon Thomas believes community energy projects could also benefit

Mr Thomas said the national energy company "could be the vehicle for the Welsh Government to invest and be part of that significant new industry".

He added: "We here will either take the decision to invest in the tidal lagoon and be part of that or we will find ourselves supplicants again, when in 10 years time, perhaps, a Chinese company comes in and says 'I love your tidal range, let's have a lagoon.'"

Ahead of the debate, Mr Thomas said: "Wales has the potential to become self-sufficient in electricity from renewables and powering ahead with world-leading tidal energy technology.

"Managing our own natural resources would reap vast environmental and economic benefits for the people of Wales."

"Following the rumours that Westminster may reject plans for a Swansea Bay Tidal Lagoon, the Welsh Government needs to show how committed it is to delivering this scheme."

He said Welsh ministers could bring the project alive themselves and said Labour's own Welsh manifesto in 2017 supported publicly-owned, locally accountable energy companies and co-operatives to rival existing private energy suppliers.

"What better time than now to implement this manifesto pledge and ensure that Wales invests in renewable energy including the Swansea Bay Tidal Lagoon project?"

He also believes that community renewable projects could also benefit from having a larger organisation behind them, which could negotiate with the main electricity buyers.

David Melding, Conservative AM, told AMs he was in favour of reform but not a nationalised model.

'Interesting and creative ideas'

Environment minister Hannah Blythyn said a Wales-wide electricity supply company had been ruled out, as a strong case had not been made for it and companies they had studied still relied on public subsidy and were not making money.

On the debate, she added: "This raises many interesting, innovative and creative ideas and it's up to all of us to take that debate forward and see how Wales can lead the way in how we approach renewable energy and energy sources in the future."

First Minister Carwyn Jones wrote to UK Business Secretary Greg Clark offering a substantial investment.

He wrote: "As I have repeatedly made clear to the UK government, I am prepared to consider a substantial equity and/or loan investment by the Welsh Government in the Swansea Bay tidal lagoon if that would enable the project to move forward."

TLP called it a "timely initiative".

A Department for Business, Energy and Industrial Strategy said on Tuesday: "The government is considering the findings of Hendry review into tidal lagoons and an announcement will be made in due course."