By the end of this century, and perhaps much sooner, the world’s energy mix could be made up of some technologies already in play and others that are currently just gleams in researchers’ eyes, according to a presentation by Dan Lewis, chief executive of research and analysis firm Future Energy Strategies, at this week’s Energy Live event in London.

In the energy sector, especially if we work in renewables but increasingly across the technology spectrum, we’re constantly hearing about new technologies that could be the next disruptive thing if only someone would fund them, and we all know technologies that promised to actually be disruptive (RIP Solyndra) but, for one reason or another, didn’t live up to their promise – so safe predictions for the future tend to depend in large part on analysis of past and existing trends.

In his talk Unconventional & Deep Future Energy: Where Are We Going?, Lewis  proved to be a cautious predictor who backed up his future visions with hard data and the caveat that trends can bend or break – even, conceivably, the ever-upward trend of worldwide energy consumption. And while some technologies may seem far-fetched now, others that might have looked similar a mere 20 years ago are commonplace today. While, as Lewis quoted, permanence might be the illusion of every age, our current energy mix is changing and it is not such a shocking idea that the landscape could look very different in a relatively short amount of time. In recent years we’ve seen the opening of the world’s first commercial carbon capture and storage project, the deployment of tidal energy demonstration projects, the construction of massive offshore wind farms, the global spread of rooftop solar installations as well as numerous, perhaps less sexy technologies such as energy from waste and CHP that nonetheless have fundamentally changed the ways we power homes and businesses.

Lewis began his talk with a near-future technology, shale gas in the UK, about which he agrees with the widely held opinion that the nation should be further along in its development by now than it actually is. According to Lewis, while everyone looks to the US for a shale gas market development paradigm, the UK is actually very well-positioned to take it forward and even has some considerable advantages over the US, including gas prices up to three times higher. So why so little investment to date? At this early stage, investment is still widely seen as a big risk. According to Lewis, one issue is the need to develop a future supply chain, as the UK currently has little or no fracking equipment or personnel. However, it’s almost certain that this future energy source will be developed soon despite protests by a public alarmed at stories from the less well-regulated US.

Other technologies that are well on the way to development include underground coal gasification (there is a lot of underground coal in the UK, and this technology could open up 85 per cent of previously unobtainable reserves, said Lewis), small modular nuclear reactors (on which progress is demonstrably being made, and more expected by 2020), nuclear fusion (a demonstration project is now expected in 2033), ocean thermal energy conversion (cf Lockheed Martin’s plan for a 10 MW plant off the Chinese coast) and very deep, super-enhanced geothermal energy, which isn’t that much of a stretch from today’s geothermal power but, Lewis warned, will cost more given the increased drilling depths.

Since all of these technologies sound reasonable to us today, why should the slightly further-out (in Lewis’s words, the “black swan” technologies) seem any less so? For an example from Lewis, take space-based solar power (SBSP), which could solve a number of problems with ground-based solar (notably weather-based variability and land use) but is currently unfeasibly expensive. That is, until commercial space companies grow into their own – something that could be set to happen within the next 50 years despite this decade’s initial setbacks – and start bringing down the costs involved in transporting things into low-earth orbit. That this will eventually happen is plausible enough that Japan has outlined plans for a 1 GW SBSP plant; Russia’s space agency has developed a working 100 kW prototype and China has said it plans to launch a 100 kW SBSP into orbit by 2025.

Lewis says these are all “good reasons to be optimistic” about our future energy scenario, in which power will be “plentiful, clean and largely free”. Of these three predictions, the only one I might question is the last, and I wish I’d thought to ask him to clarify it. A utopian vision of free future energy is the only part of Lewis’s conclusion that I don’t think was particularly justified by his presentation.