Renewables have always painted a pretty picture, with heroic turbines and solar panels harnessing the power of Mother Nature, providing us with the refreshingly clean electricity we all deserve – especially when pitted against the gluttonous, fossil-fuel devouring, smoke-splurging coal stations of old. But this dream has become a reality, and this article attempts to show why.
What are the problems with renewables?
The foremost criticism levelled at our heroine is intermittency – “we will only have energy when the sun is shining and the wind blowing.” But we are fast approaching an age where this will simply no longer be the case; all manner of storage systems are being developed to hoard the excess power that these plants will produce – it is an area of fervent research. Science cannot be ignored: in the US there have been huge leaps made with flywheel technology (Beacon Power in the US have developed systems with a storage capacity of 10% of the USA’s electricity), fuel cells and flow batteries. We are living through the energy storage revolution, and this technology will allow renewable energy to take centre stage in all future energy production.
And let me lay waste to doubts that renewable energy simply doesn’t have bottle to meet our energy needs. On Sunday 7 August this year, Scottish wind turbines alone generated more electricity than Scotland used that day. Recent studies have also shown that China is on track to produce over a quarter of its electricity using wind power by 2030, and in 2015, low-carbon sources supplied 46% of the UK’s electricity. It is a really exciting time for green energy.
To further sweeten the pill, the cost of renewable energy is decreasing all the time. It is no longer a question of paying more to go green: the price of electricity generated by on-land wind turbines in the UK has fallen to £66/MWh, compared with the current price of coal-fired power in the UK, which is £89/MWh. This is the levelised cost of electricity, which factors in building the plants or farms. For comparison, the electricity that will be produced by the infamous Hinkley Point C will be locked in at a minimum strike price of £92.5/MWh – which has already risen to £97/MWh with inflation.
Another, better-grounded argument against renewables is their potential incompatibility with the current grid system. The power grid is designed with large, controllable generators in mind, with very little storage capacity on the grid. Being able to control the amount of electricity that flows into the grid is very important – the grid operator is in constant communication with power plants, to ensure that the power injected into the grid is equal to the power drawn out of it. The innate variability of renewables at first makes the two seem incompatible, for the demand for electricity is changing day-by-day, hour-by-hour, minute-by-minute and must be met more or less exactly.
But this issue can be overcome, ironically, by increasing the number of renewable energy contributions to the electricity grid. By the law of large numbers, the greater the number of renewable power sources that contribute to the grid, the less variable their combined output, making these energy calculations far simpler… and once efficient electricity storage systems have caught up with the times, this will cease to be an issue.
It appears that another area of investment would be the electricity grid itself – a more extensive, efficient grid would further diminish the impact of intermittency. If all parts of a continent or country are better connected, energy could be moved around to the areas that need it most, and the chances of a “lull” in the green energy source, be it wind or solar, would be proportionally diminished.
And so where does this leave us?
Until renewables can go the whole way, there will always be a reliance on coal/nuclear to make up that excess. Herein lies a subtle short-term problem: once built, the price of renewable energy is very cheap. The price of non-renewable energy will increasingly be undercut by solar/wind, forcing traditional power companies to increase the price of their electricity to make ends meet and/or demand subsidies from government. But until renewables can fully take over the reins, non-renewable energy cannot just be ignored, for it is still an absolute necessity.
With imminent advances in energy storage, and financial backing from government, renewables can go all the way. Ernest Moniz, the US Energy Secretary, is confident that the US electricity grid and power system will be decarbonised by the middle of the century. Hurdle after hurdle has been cleared by renewable energy, and it is surely but a few hurdles more before we enter the Age of Renewables.