24th August 2026
There is a remarkable change taking place in the world's electricity system, and it is easy to miss because it is happening in several different technologies at once.
Solar power is expanding at record speed. Wind power is still growing strongly. Electric vehicles are spreading. Data centres are creating new electricity demand. And at the same time, countries around the world are investing heavily in something that, until relatively recently, played only a minor role in the electricity system: battery storage.
This is not a coincidence.
The world is discovering that producing renewable electricity is one problem. Making sure that electricity is available at the right time is another.
The scale of the battery expansion is remarkable. The International Energy Agency says that 108 gigawatts of new battery storage capacity was deployed globally during 2025, around 40% more than in 2024. Battery storage is now the fastest-growing power technology, with installed capacity around eleven times higher than it was in 2021. About 80% of the new capacity installed in 2025 was utility-scale rather than household storage.
That is happening alongside an extraordinary expansion of renewable generation. Global renewable capacity additions reached a record 800GW in 2025, with solar accounting for more than three-quarters of it and wind contributing another 20%.
Put the two figures together and the direction of travel becomes much clearer.
The world isn't simply building more wind turbines and solar panels.
It is simultaneously building the storage needed to make all that intermittent electricity more useful.
Why batteries have suddenly become so important
A gas or coal power station can increase production when electricity demand rises. A nuclear plant can provide a steady supply. A hydroelectric station can often be adjusted to meet changing demand.
Solar and wind are different.
Solar produces heavily during daylight hours and nothing at night. Wind can produce huge quantities of electricity when the weather is favourable and considerably less when it isn't.
That isn't necessarily a problem when renewable generation represents a relatively small part of the electricity system.
It becomes much more important when renewables dominate.
If a country has enormous amounts of solar generation at midday, it can eventually reach the point where there is more electricity being produced than consumers need.
Without somewhere to put the surplus, some generation has to be switched off or curtailed.
A battery provides another option.
It can charge when electricity is plentiful and relatively cheap, then discharge when electricity is scarce and more valuable.
This creates a new relationship between renewable generation and storage.
More solar and wind create a greater need for storage. Cheaper batteries make it easier to build more solar and wind.
It becomes a feedback loop.
China is leading the race
China is particularly striking.
It is already the world's largest battery-storage market and added around 42GW of new-type energy storage capacity during 2024. By 2025, global deployment had accelerated still further.
China is also the dominant manufacturing centre for batteries.
That is important because the battery story isn't simply about electricity.
It is becoming an industrial and geopolitical story as well.
The IEA estimates that the global lithium-ion battery market exceeded $150 billion in 2025, increasing by more than 20% in a single year. Batteries are now important not just for electric cars and electricity storage but also as backup power for digital infrastructure and data centres.
The United States and Europe are also investing heavily, although the scale varies considerably between markets.
The result is something approaching a global battery race.
And the cost is falling
One of the reasons this is happening now rather than a decade ago is simple economics.
Battery costs have fallen dramatically.
The IEA reports that average lithium-ion battery pack prices fell by around 20% in 2024 and another 8% in 2025.
The dominant chemistry for stationary storage is increasingly lithium iron phosphate, or LFP. It is less energy-dense than some alternatives but is relatively inexpensive, durable and well suited to being charged and discharged repeatedly. The IEA estimates that LFP batteries accounted for around 90% of battery-storage deployments in 2025.
That matters because stationary batteries don't need to be light enough to carry a car.
They simply need to store electricity safely and cheaply.
The renewable revolution is therefore becoming an electricity-system revolution
This is perhaps the most important point.
For years the discussion about renewable energy concentrated on generation.
How many wind turbines?
How many solar panels?
How many gigawatts?
Increasingly, the question is changing.
How do you operate an electricity system when the cheapest electricity may be produced at exactly the time you don't need it?
Storage is one answer.
But it isn't the only one.
Interconnectors can move electricity between countries. Pumped-storage hydro can store enormous quantities of energy. Demand can be shifted to times when electricity is plentiful. Better forecasting can help grid operators. Electric vehicles could eventually provide additional flexibility.
The future electricity system is therefore likely to be much more complicated than the old model of large power stations simply producing electricity whenever required.
There is another unexpected driver: AI
The rapid expansion of artificial intelligence is adding another dimension.
Data centres require enormous amounts of electricity and their numbers are growing rapidly. The IEA says data centres accounted for around half of US electricity-demand growth in 2025.
That creates demand for reliable electricity supplies.
Batteries can provide backup power, help smooth demand and provide flexibility to the grid.
So the battery industry is increasingly sitting at the intersection of several major technological changes: renewable electricity, electric vehicles, artificial intelligence, data centres and grid modernisation.
And then there is Scotland
This global trend has a very local relevance.
Scotland has enormous renewable-energy resources, particularly wind.
The difficulty has increasingly been not whether Scotland can produce electricity, but how much electricity the grid can accommodate and where that electricity can be sent.
That is why battery storage is beginning to appear in Highland planning applications.
A recent Highland Council report on the proposed Dalchork Battery Energy Storage System near Lairg describes a facility with an export capacity of up to 249.9MW.
Another proposed battery development at Mey has received Scottish Ministers' support, with the planning decision explicitly recognising that grid-scale storage can help alleviate grid constraints, reduce curtailment and increase the productivity of renewable generation.
This is significant for Caithness.
A battery installation doesn't generate electricity.
But it can make electricity generated by wind farms more useful.
If a windy night produces more electricity than the grid can immediately accommodate, some of that electricity could potentially be stored rather than curtailed. Later, when demand rises or generation falls, the battery can release it.
That doesn't remove the need for new transmission infrastructure.
But it provides another tool for dealing with the problem.
The irony is that the battery boom is partly a consequence of renewable success
There is an interesting irony here.
The more successful solar and wind become, the more valuable storage becomes.
The IEA estimates that global energy storage capacity needs to increase sixfold to around 1,500GW by 2030 in order to support the rapid expansion of renewable generation envisaged under its net-zero scenario. Batteries would provide the vast majority of that increase.
We therefore shouldn't think of batteries as a competitor to wind and solar.
They are increasingly becoming partners.
And that may eventually change the way we think about Scotland's renewable-energy resources.
The question may no longer simply be whether Caithness can generate huge quantities of electricity from the wind.
It could become whether Caithness can become part of a much larger renewable-energy, storage and transmission system, with electricity generated here being stored, balanced and moved around the country when it is actually needed.
That is a very different energy landscape from the one Scotland had only a few years ago.
And it suggests that the next phase of the renewable revolution may not be dominated by the number of turbines we can build.
It may be about what we do with all the electricity when the turbines are turning.