What we have witnessed in Texas was a cascade failure of energy infrastructure.
The storms tripped an increased demand while power plants were undergoing routine maintenance, which was made worse by insufficient regulatory oversight meaning Texan authorities didn’t require energy assets to be resilient enough for winter.
Suddenly, there were issues with water, food, heat and health for millions of people. It isn’t just Texas. Places around the world, including the UK and California, have seen unusual grid instability.
Blame has been foisted onto Texas’ renewables, but the primary driver of the crisis was the loss of nearly 30 gigawatt-hours of gas, coal and nuclear generation in the state. The global push towards renewable energy has highlighted problems with ageing grid networks, but it also offers a solution.
Reducing greenhouse gas emissions requires widespread use of renewable sources, mainly wind and solar. But these cannot be controlled like so-called dispatchable sources such as natural gas and nuclear power.
After all, we aren’t in charge of when the sun shines or the wind blows. The result is that renewable energy produces more energy than is needed sometimes and not enough at others. For example, during 2020 over 1,500 gigawatt-hours – enough to power 250,000 homes for a year – of renewable electricity production went unused in California. In the UK, there was more wind energy available than could be used on 75 per cent of days last year.
As we saw in Texas, grid instability, combined with extreme weather events, can have a shocking knock-on effect.
So how can renewables help? One part of that answer is large-scale energy storage. Industrial size batteries can store electricity when it is abundant and make it available when it is needed, creating a more stable source of energy for the grid. Simply put, energy storage unlocks renewables as a low-cost, low-carbon alternative to conventional power sources.
This story has been playing out in Oxford, where a consortium of partners, including Invinity, are supporting the development of the Energy Superhub Oxford. It’s an ambitious project aiming to decarbonise transport and residential heating, which means a large-scale transition from fuel to electricity.
Storage comes in to play to address the inevitable stress on the electric network when everyone charges their car at the same time or turns up the heating on a cold morning, or, as in the case of Texas, when temperatures unexpectedly plummet. It effectively creates a fail-safe for the grid, to ensure there is always a constant supply of energy.
The Energy Superhub Oxford Project is home to the largest hybrid energy storage system of its kind. It combines lithium-ion batteries, which we are all familiar with, and “flow” batteries. Both are connected to the national grid.
Lithium-ion batteries work well with the grid when they are not used heavily, day in and day out. Think of old cell phones, you run the battery down all day and then charge it up all night, this sort of heavy use eventually degrades the capacity to a point where it is unusable.
Flow batteries don’t degrade with use, and are more suitable to respond constantly as electricity needs change at the Superhub. The lithium-ion batteries work in tandem, and are called on less frequently, therefore preserving their life.
A decarbonised global energy system will rely on a plethora of energy storage. The Texas crisis made that abundantly clear. Lithium-ion, hydrogen and flow will all have a part to play, applied where each is best suited.
It was recently estimated that the UK will require up to 30 gigawatt hours (30,000 MWh) of energy storage to meet net-zero targets. This is the equivalent of over 500 Energy Superhub Oxford projects and can only be addressed with the entire spectrum of storage technologies working in concert or independently as the use demands.
Addressing the climate crisis is an unprecedented opportunity for energy storage. But even more important is the opportunity to build a net-zero energy structure that is robust and resilient. That is a goal we can all work toward.