Fossil-fuel energy is in its final act, but what alternative is waiting in the wings? Nuclear power is unpopular and costly to set up. Wind farms are on the rise, already providing 2% of the world’s electricity and doubling in capacity every year. The star of the show, however, is solar energy, currently only generating a quarter of a percent of the planet’s electricity supply, but with 86% growth last year, it has the potential to disrupt the electricity market completely.
Solar supporters are calling the phenomenon ‘Swanson’s Law’ (in reference to Moore’s law). Swanson’s law, named after Richard Swanson, the founder of American solar-cell manufacturer, SunPower, suggests that “the cost of the photovoltaic cells needed to generate solar power falls by 20% with each doubling of global manufacturing capacity.” The modules used to make solar-power plants now cost less than a dollar per watt of capacity. Power-station construction costs can add $4 (USD) to that, but these, too, are falling as builders work out how to do the job better. And running a solar power station is cheap because the fuel is free. Even the most affordable energy giants can’t compete with that. The final obstacle currently being invested in is how to make an unreliable source of energy (the wind doesn’t always blow and the sun doesn’t always shine) reliable, or rather, how to store it. Scientists are devising ‘flow batteries’: hybrids between traditional batteries and fuel cells, using liquid electrolytes, often made from cheap materials such as iron, that squirrel away huge amounts of energy in chemical form. ‘Grid-scale’ storage is the second way, after Swanson’s law, that the economics of renewable energy will be transformed.
Germany has recently committed to an extreme energy transformation, or what they are calling an ‘Energiewende’ (‘wende’ being a 90 degree tack in sailing), aiming to cut overall energy consumption in half by 2050 and electricity consumption by 25%. The UK on the other hand, which uses half the energy, is aiming for an increase in electricity use between 33% and 66%. Germany also aims to produce 80% of electricity from renewables by the same date. The people are already on board (for the most part) in shifting from the current grid to a renewable one. In fact, some haven’t waited for government to catch up. In Germany 65% of renewables are owned by individuals or communities. Again, to compare, in the UK the figure is less than 10%. “When leasing of the local grid that connects the village [of Feldheim]'s squat, steep-roofed homes was made prohibitively expensive, Werner Frohwitter built his own [with his renewable energy company Energiequelle]. The 128 inhabitants now get all their power by tapping into some of the 43 turbines dotting the fields around, some solar panels and a plant that turns farmyard manure into gas-powered electricity.” Frohwitter showed that transitioning to renewable energy is something that can be tackled locally, as initiatives in rural communities that wish to take an active role in their future. In 2011, 20% of electricity in Germany was generated from renewables, the majority from home solar panels, wind turbines in farmer's fields and biogas plants fed by local farms.