On Solarcentury’s 21st birthday, an interesting question occurs to me. How many Solarcenturys would it take to stave off the climate crisis, at least where energy is concerned. The answer I arrive at might really surprise you.

First the background. As concern spreads in the world about the implications should humankind fail to cut carbon emissions, realisation that the threat of global heating is existential has become increasingly commonplace. Perhaps most notably of late, it is expressed in the name of one of the most impactful protest groups yet to emerge, Extinction Rebellion.

The good news is that the route to surviving the threat is clear. As set out by international expert groups including the Intergovernmental Panel on Climate Change, it is to restructure the global economy for net zero carbon emissions before 2050. The even better news, as set out by expert groups including the Global Commission on the Economy and Climate, is that this can be done at far lower cost than business-as-usual, saving literally trillions of dollars over the course of the transition: trillions that can be spent improving society in many ways. It seems almost counter-intuitive, if one listens to the many fossil-fuel diehard naysayers, but it is true.

In early May the International Energy Agency (IEA) summarised progress in the energy sector. To hit the survival trajectory, as expressed in Paris Agreement targets, the agency calculates that the world needs to be adding over 300 gigawatts (GW) of renewable energy capacity per year on average through 2030. How much did we install in 2018? 180 GW, 60% of what we need. Well over half of that was solar.

Far from hopeless, you might say. But that would ignore the fact that the total renewable capacity installed was the same in 2017. Last year was the first stall in two decades of strong annual renewables expansion.

In another recent IEA report, the setback can be seen in energy-investment trends. Renewables investment was down for the second year running in 2018, to $304bn. Meanwhile fossil-fuel investment was up – despite everything we know about the fueling by coal, oil and gas of climate chaos and killer air pollution – to $1.2 trillion.

Viewing this, a justifiable reaction might be to wonder if we are collectively mad. Our citizens are now protesting their anguish over climate chaos on the streets in their millions. Our schoolchildren are going on strike in multiple countries. Our learned bodies are telling us the very survival of our species is at stake, not to mention countless other species. Yet we invest four times more in fossil fuels than we do in survival technologies. We permit our pension funds, banks and other financial institutions essentially to bankroll collective suicide and ecocide.

All true, I would argue, but that is a glass-half-empty way to view it. There is a glass-half-full view of the same situation, and it strikes me like this. I have exactly the same feeling today that I had in Berlin in October 1989, looking at the Berlin Wall from a hundred yards away. I remember thinking that in the context of those times – glasnost rampant in Moscow and east-west arms-control negotiations in the news every day – “this is crazy. It cannot last. The pressure in society is just too great.”

I have not always been right in my big-picture thinking, over the years. But I was on that occasion. The Berlin Wall fell a few weeks later.

I believe the survival-investment gap, where energy is concerned, will close in similar vein during the next few years. It is impossible to identify a specific trigger or triggers that will topple this particular metaphorical wall. But it is easy to see the buildup of pressure across society, just as it was at the end of the Cold War. And given the propensity of investors to act as a crowd, once their collective sentiment tips, we may well find that the investment-gap wall can fall almost as quickly as the Berlin Wall did.

So to the birthday thought. For me, Solarcentury embodies the hope that the gap can close, and quickly. We are a very international team of 210, busy riding the survival-pressure that I have described in society. Indeed, we capture it in our DNA. Our mission is to make as big a difference as we can in fighting climate chaos. And we are well positioned for a useful contribution: an international pipeline of solar projects now in excess of 5 GW. Those projects will be delivered over perhaps 5 years, so let us think in round numbers and assume we deliver an average of 1 GW a year. (That figure is conservative: it can easily be higher as the team finds more projects). How many Solarcenturys would the world need, on this basis, to be on a survival trajectory?

There are caveats to this back-of-envelope calculation, which I explore in a longer version of this note on my website. But let us go with the IEA’s numbers for now, as so many do. The answer on that basis is somewhere not far from 300.

How difficult is it to imagine 300 or so Solarcenturys around the world?

Not very difficult at all, from where I sit, watching the 210 current Solarcenturians hard at work today. On top of this there are the 670 Solarcentury alumni, many of whom now work on fellow solar- and other clean-energy companies. Knowing many of these people and their companies as I do, the vision becomes even easier to conjure up.

On our birthday, I want to extend a grateful founder’s heartfelt thanks to every member of the current Solarcentury team, all our alumni, and all our partners and customers present and past. Together, may we be granted the chance to keep riding the extinction rebellion now underway in global society, all the way to the tantalisingly tangible point of success.

I have updated the summary of our history, in pictures and charts, that I compiled with the help of colleagues a year ago. You can view it on my website here.