Will water become the world’s biggest battery?

Published on March 22nd, 2018

Insight from Christopher Gasson, Repost from GWI publisher

I spent this afternoon at the Louvre Abu Dhabi with Department of Energy chairman Awaidha Al Marar and Environment Agency boss Razan Al Mubarak. The location had nothing to do with the conversation, although the futuristic setting of the gallery reinforced the feeling that tomorrow has already started to happen in some parts of the world.

The specific future that Abu Dhabi has been grappling with concerns the implications of the transition to renewable energy for the water sector. In the past, when people talked about the water and energy nexus, they tended to refer to the fact that water needs energy to produce, and vice versa. In Abu Dhabi today, it is the growing independence of the two that creates the challenge. They used to go hand in hand: everyone needed more of both, and the two could be happily generated together. Renewable energy has changed that. Power supply becomes more dependent on the sun and the wind than what people actually need to use at any one moment, and either way, it doesn’t need much water.

Al Mubarak (who is incidentally one of the most dynamic women in the Middle Eastern water sector) saw this as an opportunity to turn the aquifer into a giant battery. It stores water produced from excess electricity in the winter months, and then releases it when power demand increases in the summertime, when it is necessary to switch power capacity away from water production. Although we have seen aquifer storage form part of an indirect potable reuse cycle in the past, I think it is the first time a utility has pumped pristine desalinated water into an aquifer to manage the mismatch between energy demand and supply.

That mismatch is a growing problem right across the world. In Germany last year, there was a windy weekend in October when the price of electricity dropped to minus $0.098/kWh. That is to say that anyone who could use a wholesale amount of electricity would have been paid to take it off the grid.

The great thing about water is that it can be stored in a way that electricity cannot. For example, in 20 years’ time you can imagine that California’s water systems could become part of its power storage system. It is often said that moving water consumes 20% of the state’s electricity: why not do all the pumping when power demand is low, and let the reservoirs run down when it is high?

From a desalination point of view, it very much changes the game. After leaving the Louvre, I visited Corrado Sommariva, who runs ILF’s desal business and advises on many of the desal projects across the Middle East. He thinks that desalination plant operators will need to confront this. It will no longer be possible to ignore the power demand risk and ask for a pass-through on the energy costs. Plants will have to be built to take it into account – and take advantage of it.

I can see where he is going. If you are going to get paid $0.098/kWh to use electricity one minute, only to find the flow of money reversing the next minute, it opens up a world of creative possibilities. Economic logic suggests that these should be beneficial. If the power sector is generating more volatility than it can handle, and the water sector is better able to manage that volatility, then there is a profitable trade to be made.