Glasgow solar study: 'We could put oil back in ground'
The sun gives its energy away for free. We can harvest it with solar cells and wind turbines to make electricity. That's the good news.
The bad? It's electricity. It's difficult stuff to store and sometimes, just when you need some, it's dark or the wind's stopped blowing.
That's why Glasgow University's Solar Fuels Group want us to make the leap from solar power to solar fuel. It's a multidisciplinary, multi-million pound effort which aims to convert renewable energy into fuel that's simple to store.
It might look a lot like diesel - and we could use it in much the same way we use fossil fuels now.
Professor Richard Cogdell is a botanist whose inspiration for converting solar power into fuel comes from plants.
He said: "When you make electricity you essentially have to use it straight away.
"What fuel gives you is stored energy that you can access whenever you want to."
It's easy enough to make electricity into fuel - of a sort - right now. It's an old experiment: you stick two electrodes into some water, apply a voltage - and hydrogen and oxygen bubble up. The trouble with hydrogen? Like electricity, it doesn't store well in large quantities, as anyone who's seen footage of the Hindenburg disaster will testify.
So in Prof Lee Cronin's chemistry lab they're working on the next step. He shows me a variation on the electrodes-in-water experiment in which an added chemical acts like a battery.
Instead of hydrogen rising from an electrode there's a plume of deep blue liquid. Energy from the electricity is being stored to create a precursor to fuel.
Turning something like that into something like diesel is the next big step. Photosynthesis may be an inspiration, but the process will have to be many times more efficient than plants can manage.
The potential benefits are huge. At the moment we take fossil fuels out of the ground, burn them, and release carbon dioxide - CO2 - into the atmosphere. The Glasgow University research envisages taking renewable energy and combining it with carbon to create the new fuel. When burned, it too would create CO2.
But the carbon from that could be used again to store more solar energy. We could have a closed carbon cycle.
Prof Cronin sees the research leading ever further.
"We could ... fix all the extra CO2 in the atmosphere and put it back in the ground.
"And that way we could safely store oil back in the oil wells that we wouldn't need to burn, and therefore lower the carbon dioxide concentration and prevent the disaster of global warming."
This is not science fiction. But it's not yet science fact. To perfect it will probably take tens of years and billions of pounds.
The effort required is being likened to a new Apollo programme. But the Glasgow team say Scotland has the resources and the infrastructure to make it happen.