New study suggests renewables susceptible to ‘energy droughts’

With wind and solar potential varying widely year-on-year, backup power sources will be needed as the world moves to greener, emission-free networks. 

Research conducted by Upmanu Lall, a professor at Columbia Engineering and the Columbia Climate School, New York, shows that fluctuations in the elements involved in renewable energy systems could leave nations vulnerable to ‘energy droughts’. 

Simply put, no two years on the planet are the same, and this includes the number of sunshine hours, wind (and therefore tidal) strength – key factors that dictate the efficiency and effectiveness of renewable power. As such, the new study, published in Patterns, suggests that alternative power sources will be needed to avoid ‘dry spells’ in energy supply. 

‘Designers of renewable energy systems will need to pay attention to changing wind and solar patterns over weeks, months, and years, the way water managers do,’ Lall said. ‘You won’t be able to manage variability like this with batteries. You’ll need more capacity.’

Focusing on Texas, the US leader in wind and the country’s fifth-largest solar power producer, work drew on 70 years of historic wind and solar-power data, with the team building AI to predict the probability of a network scale ‘drought’ – when renewable production falls below a target threshold. Setting this at the 30th percentile, when roughly one third of all days in a year are categorised as low-production, in that situation Texas would be vulnerable to ‘energy droughts’ lasting up to four months. 

In related news, researchers at Southampton University published research earlier this year showing that renewable projects do not need to harm biodiversity. 

Image credit: Nuno Marques