Chief News and Features Editor, Nature; Author, Mapping Mars

Sunshine State

I am not, by default, optimistic; it is an attribute that I take on as a duty more than out of temperament. Left to myself I do not look out at the world and see a hopeful place—and did not do so even when the geopolitical state we are in was not so dreadful. But I have been convinced over the years that an outlook that gives play to hopefulness is by and large a better tool with which to help improve the future than the alternatives. You are more likely to find solutions if you believe they are there than not. The trick for those of us without the sunny state of mind naturally suited to such an outlook is to find objects for our optimism that make the duty feel less dutiful.

My current optimism is for solar energy. The simple facts of the matter are that the sun provides more energy to the earth in an hour than humanity makes use of in a year. Of the non-fossil-fuel energy sources, all the big players that are not nuclear—biomass, hydroelectric, wind—are ultimately driven by the sun. I am optimistic that direct solar conversion—photovoltaic cells and their future analogues—will come to take its place among and then surpass these more established technologies a lot more quickly than most people outside the area currently imagine. I'am hoping for at least a terawatt of solar by 2025, two if we're lucky, and dramatic cuts in carbon dioxide emissions as a result.

The locus for this optimism is California. A history of generous and far-sighted subsidy has built up the silicon-based Japanese and German solar industries over the past decades. Something similar now looks to be happening on the West Coast, where newer technologies are poised to benefit. There couldn't be a better suited place: California, and in particular the Bay area, boasts a near-unique concentration of world class research universities and national laboratories and a large number of people well versed in the solid-state trades who are ready and able to move from semiconductors that deal with information to those that deal with energy. It is also very well endowed with business angels and venture capitalists, many of whom combine their desire to make money with an urge to change the world. They largely share a network-first, build-from-the-periphery, revolutionise-the-whole-shebang mindset well suited to (and shaped by) the development of the Internet, an attitude which ports itself easily to the idea of decentralised solar power generation. The optimism to which I need to psych myself up seems to come naturally to such people in such places.

New materials and new material-processing techniques should allow the cost of installed photovoltaic capacity to be halved in the next few years, and there is room for considerable further improvement after that: while wind power, nuclear power and dams are not going to become radically cheaper to install, solar power capacity is. It is also going to become more flexible, both physically and metaphorically, with new applications on new surfaces, from windows to clothing. Some of these applications may well be gimmicky and unsustainable, but one of the great advantages of the coming solar power boom is that it offers the possibility for a wide range of technologies both to compete for the main prize—cheap domestic and light industrial electricity in developed and developing countries alike—and also to find and to create new niches.

The boom will not just be a matter of lower cost manufacture or better efficiency. System-wide solutions need to be found—new ways of accommodating solar materials architecturally, new technologies for storing energy, smart approaches to the electric grid, new financial arrangements and instruments that will allow people to get the benefits of solar electricity without necessarily taking on the capital costs of installation themselves. The sort of imagination that gets such things happening is far from unique to California—but it is abundant there, and can be put to use.

California is not essential to an acceleration in the already exponential growth of installed solar capacity. The big breakthroughs may come in Germany or Texas or China, and they will certainly have to be used in China and India if they are to have the dramatic effect on carbon emissions they could have. But it is in California that we see the most striking collocation of public interest, political support, research capacity, technological exuberance, entrepreneurial flair, a supportive business ethos, smart capital—and, crucially, sunshine.