Welcome to the future. You know, the future. The “Back to the Future II”-future. In the sequel to “Back to the future” Michael J. Fox travels to the year 2015, in case you had forgotten or have never seen the film. Yes, I know, by the time I am writing this post in mid-January, I am hopelessly late onto the BTTF2 bandwagon and you have probably already read loads of articles about the future imagined in this 1980s classic, watched YouTube comparisons between the “future” and our present, as well as skimmed through Buzzfeed’s „Top 30 things BTTF2 got wrong about 2015”.

Turns out, they got quite a lot wrong. Some of it –omnipresent fax machines vomiting out “You’re fired” notices in an apocalyptic telecom dance routine, or even more end-of-days stuff, such as the double tie – thankfully never made it past the film set. Turns out humans might still be killing each other and being generally horrible, but we’re not that horrible.

Other inventions, which would have made our lives easier or at least more exciting, sadly never made it into mass production. One of these inventions, the hovering skateboard, has now become the new universal symbol for not only unfulfilled childhood dreams, and “It’s 2015, where is my hoverboard?” has now replaced “Where is my jetpack?” as the rhetorical question to illustrate un-kept scientific promises.

Jetpacks, and now hoverboards, have become symbols for inventions, which had been presented in visions of the future but subsequently failed to feature in everyday life. Or rather, it is not that they don’t exist; it’s just that they don’t exist in any form that would make them widely available. Every industry has its own hoverboard. For the auto industry it is the self-driving car (KITT says hi) or the flying car. Both exist, but are restricted to science labs or secluded airfields in the Nevada desert. In the renewable energy sector our hoverboards are not even as sophisticated as flying cars or levitating skateboards. Our hoverboards are batteries. Or rather affordable energy storage solutions, to be precise.

Let me take you back: Remember those other visions of the future from our childhood? The paintings of futuristic cities in children’s textbooks? The future, when we saved the environment by switching to renewable energy? The solar panels covering every rooftop and the solar cars? So why did those visions not come true? While renewable energy certainly has become a major part of our energy mix (renewables were the biggest contributor to Germany’s electricity supply last year), we have gone down a different path. Vast solar power plants and wind farms produce green energy on an unprecedented scale and in some regions of Germany almost every rural rooftop is covered in solar panels. But the energy produced by these rooftop power plants is however generally not consumed on site, but sold into the power grid at a state-guaranteed “Feed in tariff”. This is largely down to the fact that renewable power plants do not necessarily produce electricity exactly when needed. In the case of solar power either during low-light winter months or at night. When you sit down to watch TV in the evening, the sun usually shines on somebody else a few thousand kilometres to the West.

The missing link between our energy reality and the childhood visions of the future is the possibility to store renewable energy to be used later, when it is needed. Solar batteries and other storage solutions exist and are used in many projects, but are not available as financially viable storage solutions for the general public. Unless you want to invest large sums on solar batteries which will take up an entire room in your basement, you are currently still better off buying energy from the power grid in the evening. Sure, Smart Houses can automatically turn on your dishwasher and other household appliances during the day to run on the solar power produced on your rooftop but when the sun goes down and you need to charge your phone overnight, you’re still stuck. One particularly promising development in energy storage uses a kind of side step. Instead of feeding energy directly into batteries, you can use any electricity to produce Hydrogen from normal water through electrolysis. Then, with the help of Hydrogen power cells you can use that energy to either fill up your hydrogen car (the first of which are already commercially available in some countries) or you use a stationary fuel cell in your home. The space needed is relatively small. The electrolyser and the fuel cell are both about as big as washing machines, but – as you might guess – extremely expensive at the moment.

But as with all technology, a significant price drop is expected over the next few years, and hydrogen production from solar energy might in the end very well be one of the game changers. Within the renewable energy sector the arrival of affordable storage solutions is as eagerly anticipated as the arrival of the half time whistle for Brazil in the 2014 World Cup Semifinal. It will be a game changer. Imagine Brazil substituting David Luiz for Paolo Maldini at half time and taking of Hulk and replacing him with the actual Hulk.

Readily available energy solutions could not only stabilise the production of less predictable energy sources, such as wind farms, but bring us a giant step closer to “grid parity”: the moment when renewable energy can economically compete with conventional forms of energy without subsidies. The need for subsidies has until now been a major issue for renewables in Europe. This is particularly true in countries such as the Czech Republic, where a political omnishambles has led to the near failure of a sustainable and sensible solar support scheme. The feed-in-tariff has been used as a key argument in a smear campaign against solar energy and has turned public opinion against renewables as a whole. For renewable energy companies, relying on fragile governments to do the right thing and support green energy, is a risk many companies no longer want to take. With solar storage households and businesses will be able to use self-produced energy without the need for subsidies and at a lower cost than energy from the grid. This, in turn, will be a major factor in winning over the population again and rallying public and in turn political support for renewables. And maybe, by turning ordinary people into power producers, we will see increasing power savings, as people might not want to waste their own energy to avoid purchasing extra energy from the grid. But most important, it could lead to decentralisation of energy production on an enormous scale. With family homes and commercial rooftops (warehouses, supermarkets, etc.) transformed into power plants, we will at least partially have made those visions of the future from our childhood a reality.

Upfront investment costs will still be a drawback, but innovative financing solutions, such as solar leasing or Power Purchase Agreements (where the power plant on your roof is owned by a power company and you just buy energy from it), should help overcome this hurdle.2 For now though, batteries remain the hoverboards of the renewable energy sector. Articles about scientific breakthroughs are published every week, real-life solar storage systems (like the project built by Photon Energy in Australia, which powers a large radio antenna with solar energy 24/73) generate buzz and solar batteries are being manufactured every day. But in the end, we are still waiting. Let’s just hope that solar batteries turn from the “Back to the Future 2 – hoverboards” into the “Back to the Future 2 flat screen TVs”. Because they did actually get that one right in the film. PS: If you want to know, why you don’t own a jetpack.