Experts say the technology is available to switch to a low-carbon economy within years. So what's the hold up?

The latest dire warnings from the UN's intergovernmental panel on climate change again conclude that if the world is going to avoid meltdown then we need to move to renewable energy sources pretty sharpish.

Here in the UK, with less than 5% of our energy needs met by renewables, we're still a long way from the official target of producing even 15% of our energy from renewable sources by 2020. The good news is that there's an increasing number of reports, roadmaps and studies which all share the vision that the UK can obtain the majority of its energy from renewables.

WWF-UK, for example, concludes that by 2030 up to 90% of our electricity could come from a combination of solar, tidal, wind and other sustainable sources, with the rest supplied via an international supergrid and gas power stations.

It's not just the UK that could look forward to a low-carbon future; Europe could meet at least 80% of its energy needs from renewables by 2050 without paying more for electricity than it would under the current fossil-fuel based infrastructure, according to the European Climate Foundation. But just how realistic are these targets and, crucially, will they ever attract the support of both government and industry?

"These goals are most definitely achievable," concludes Paul Ekins, a member of the energy systems team at the UK Energy Research Centre. "The technologies are there, and enough of them have already been rolled out at scale in different countries for us to be clear that they work and that they can generate the power that we need."

Alistair Cameron, renewable energy campaigner at Friends Of the Earth, agrees: "We can definitely do this. We're on the verge of a massive technological transformation in the renewable energy sector, and the costs of solar and other renewable technologies are already rapidly falling."

Despite the positive attitudes, a voice of caution comes from an unexpected corner. "Although future scoping is helpful for showing what's technically possible," says Nina Skorupska, chief executive of the Renewable Energy Association, the trade body for the UK's renewables industry, "100% renewables by 2050 is not something we are calling for. Expanding renewable energy is very important, but calling for too much, too soon, when governments have so many other priorities, will not get you very far. The key thing is to keep the momentum going and the industry growing."

So though a low carbon future looks technically possible, could it ever receive the necessary political support to make it a reality? With senior Tories muttering about a possible moratorium on onshore windfarms, it looks unlikely. "The single biggest block to rolling out renewables is a lack of political will. The renewable industry needs a strong signal that we're serious about a low-carbon future," says Professor Ekins.

According to Cameron, we have neither the necessary ambition nor vision as a nation to make renewable technologies mainstream. "We need to make a strong case for a renewable future in terms of clean air, carbon reduction and green jobs to people, communities and the UK as a whole," he says.

But reading the government's support for renewables can be a tricky business. Skorupska describes the "renewable heat incentive" – a world first – as a "terrific work", but warns that the same administration is also undermining its own work. "It [the coalition] has also taken regressive steps, such as limiting support for biomass power, failing to set out a plan for renewable transport and taking an often negative approach to onshore wind. Its reluctance to support the EU's 2030 renewables targets is telling, too."

The energy industry is itself divided over the transition to a low carbon economy. Diversification of the energy market, and the providers that supply it, is clearly a pressure point for the main players. "If we move to a renewable world, then this will have a mix of large- and small-scale projects. This means that more companies will be able to enter the market creating more competition from the likes of renewable energy companies such as Ecotricity and Good Energy – which is clearly a threat to the big six," says Nick Molho, head of energy policy at WWF-UK.

Skorupska believes that our big energy companies have yet to step up to the challenges of a low-carbon future: "Despite some impressive investments in renewables, especially in wind and biomass, renewables are still very much periphery activities for most of the major utilities," she adds. "Renewables should be at the heart of any plans for low-carbon energy generation because they are the only proven low-carbon technologies that are actually getting cheaper.

"A lot of future investment will come from new market entrants, such as farmers, businesses, and communities investing in on-site and local renewable energy generation, [but] we need to take the utilities with us as well."

This article is part of the Guardian's #bigenergydebate series. Click here to find out more about this project and our partners.