One of the biggest – and most legitimate – criticisms of renewable energy is that it simply isn’t reliable enough. In the space of just a decade, the costs of offshore wind, in particular, has tumbled (but that’s probably best left for a more detailed article to come). And although NIMBYs might complain that wind turbines or solar farms are unsightly, everyone who’s serious about climate change agrees that renewables are going to play a pivotal role in greening our energy mix.
The problem with them, of course, is that the sun doesn’t always shine and the wind doesn’t always blow. Some renewables, like geothermal and tidal, are more dependable for “baseload” generation capacity, but these technologies are either not universally viable (geothermal depends on nearby tectonic boundaries) or underdeveloped (tidal energy has exorbitant capital costs set against wind).
Texas’ recent deep freeze, with temperatures falling to a chilly -18 C, has brought this issue into focus once again. Scenes you might usually associate with a developing country after a typhoon or hurricane have been playing out across America’s second-biggest state: homes lit up with flickering tealights as rolling blackouts dragged on, hospitals forced to rely on paraffin-powered emergency generators, and people ordered to boil water before drinking after treatment plants failed. Many hard-right conservatives have blamed Texas’ heavy use of wind for this problem and claimed that this is evidence that we should rely more on tried-and-tested, CO2 producing energy sources like coal and gas. But setting aside the denial of global warming that often goes with such arguments, do they have a point?
Not really. It’s true that Texas gets slightly more energy from renewables than average for the US (25% vs 17%, whilst the UK is 40% renewable), but this isn’t the fundamental reason for their grid’s catastrophic and spectacular failure. The vast majority of countries and US states link their electricity systems to one another’s with huge interconnectors, to help balance out temporary fluctuations in demand by buying or selling power to neighbours. Texas, going its own way, is the sole state whose power network isn’t connected to any others (it’s to help them avoid federal-level regulation). In ordinary times, this isn’t usually a problem – so great is their generation capacity that Texas’ electricity prices sometimes even go negative, with suppliers paying people to take their energy.
But with climate change increasing the frequency of extreme weather events, our new “normal” will soon be anything but. All grid designers know that (surprise, surprise) we can’t always rely on favourable winds and sunshine to power our cities, and that’s why they build in some level of excess capacity. This usually comes in the form of conventional thermal power stations. They burn carbon-spewing fossil fuels, releasing heat (hence the “thermal”) which boils water into steam, which then drives a generator to produce electricity. Since these are overseen by operators in control room rather than the whims of Mother Nature, these stations can be switched on or off at a moment’s notice, vital for their role in balancing the grid’s demand and supply.
Or at least that’s how it’s meant to work. When the cold weather started to spread across Texas, 15 GW of wind power was lost due to turbines freezing up, around one-fifth of their peak load. That might seem like a lot, but this wasn’t the real problem – the grid operator only banked on using wind for 7% of their energy needs in an “extreme winter” scenario, about a third of the usual proportion. The problems emerged when their gas and coal plants failed to switch on because they hadn’t been suitably cold-proofed, resulting in a generation gap of 30 GW, twice that caused by wind. Talk about unreliability – the electricity source of last resort wasn’t set up to work in cold temperatures! As we shift away from fossil fuels, much more resilience needs to be built into our grids. We can do that in any number of ways: building more interconnectors so the pains of regional shocks can be softened; adding in cleaner biomass plants to replace the aging stock of coal-burning ones; developing hydrogen, battery, and other novel forms of energy storage. However we choose do it, the process needs to start soon – legal wrangling, coupled with the lengthy lead times associated with any infrastructure project mean that indecision now will lead to even more otherwise avoidable disasters like the one we’re seeing in Texas today.
If their response to the pandemic has taught Western governments anything, it’s that preparedness pays. And if their response to the pandemic has taught us citizens anything, it’s that foresight is regrettably lacking more often than not.
Better start stocking up on candles, kettles, and kerosene, then.
1. BBC News, “US cold snap: Why is Texas seeing Arctic temperatures?”, https://www.bbc.co.uk/news/world-us-canada-56058372, Feb. 15 2021
2 The Guardian, “Why the cold weather caused huge Texas blackouts – a visual explainer” https://www.theguardian.com/us-news/2021/feb/20/texas-power-grid-explainer-winter-weather, Feb. 20 2021
3 ERCOT Grid Info, http://www.ercot.com/gridinfo/, Accessed March 1 2021
4. Texas Tribune, “Texas largely relies on natural gas for power. It wasn’t ready for the extreme cold” https://www.texastribune.org/2021/02/16/natural-gas-power-storm/, Feb. 16 2021