“Hello David, it's me again. The article below on solar power appeared in today's City A.M. paper (London). The author draws a graphic analogy of panels installed to date with the Ford Model-T which was produced from 1908-1927. Look at the sophistication, reliability and affordability of modern cars by comparison and we get some idea of how amazing solar power is likely to become in coming decades. It will transform the world, in my humble opinion.”

Ed: Here is a section:

First, grid parity – when electricity generation is competitive with grid-electricity rates without subsidies – is edging closer. In 2012, Bloomberg reported that Germany, Denmark, Italy, Spain, Portugal, Australia, and Brazil could already expect to achieve at least a 6 per cent return on PV investments. Many of these countries still offer indirect subsidies, so the market isn’t competitive quite yet. But the direction is clear. The average US PV market will likely reach proper grid parity around 2020, and states like California should reach that point sooner. Within a few years, arguments about feed-in tariffs will become irrelevant in many countries, because the solar industry won’t need subsidies.

Second, large companies are flocking to solar. Thanks in part to cheap PV modules, non-energy businesses are becoming mini power generators. The retail giant Walmart already has a solar-energy capacity of almost 90 megawatts (MW) in the US. If the retailer installed panels on every US store, it could generate 1.5 to 2 gigawatts – or about twice the output of my local nuclear power station. If other big-box retailers follow – and many are already doing so – we could see collective generation capacity skyrocket, making solar increasingly viable as part of the energy mix.

Its potential goes beyond retail. Solar is well-suited to industrial and processing applications: in Saudi Arabia, the Al-Khafji solar-powered seawater desalination plant is set to produce 30,000 cubic metres of salt-free water per day. And entrepreneurs are honing new applications. The US startup WaterFX, for example, is developing solar “troughs” that remove salt from water by distillation to deal with drought.

But these innovations are only possible because solar technology is developing rapidly. Today’s domestic PV modules are the Ford Model-Ts of solar: cheap, mass-produced, commercial pioneers. But they are poor at converting sunlight into electricity (efficiencies of around 10 to 15 per cent are common). These figures, however, could easily double.

Scientists from the California Institute of Technology and partners are developing a new multi-junction cell with a target efficiency of over 50 per cent. Building-integrated PV – glazing that generates power – could further popularise solar power. And PV is not the only form of solar energy. Improvements in other approaches, such as concentrated solar power (CSP), are possible. CSP uses mirrors to concentrate a large amount of sunlight onto a small area, driving a turbine. Just look at Spain’s 50MW Solnova Solar power station.

David Fuller's view

Many thanks for the article, as informative emails are most welcome, not least in the field of technology.  Solar farms can be understandably contentious if they are anywhere near recreational areas and sights of natural beauty, although they are considerably less menacing than noisy windmills. 

 Today, virtually every business can now lower its long-term energy costs by utilising solar power on its buildings, as we read with Walmart above.  Similarly, many homes will also benefit from the addition of solar panels, ideally when the target efficiency is above 50% with the help of graphene and other rapidly developing technological advancements.  Additionally, I do not see why California and other cities prone to drought cannot benefit from solar-powered seawater desalination plants as Saudi Arabia is doing.  My thanks to Eoin for pointing out this Carlsbad desalination plant, near the San Diego region of California.  The state will need more of these plants.