REM talked to Charlotte Johnson, General Manager of Generation Flex at Kraken, concerning a range of topics, including flexibility, storage, how AI is transforming energy systems and the costs and benefits of making the UK grid more flexible.
Can you give me a bit of background about yourself and Kraken and what it does?
I’m Charlotte Johnson, the general manager of Generation Flex at Kraken. Kraken is the world’s only proven, end-to-end platform for utilities’ digitalisation and transformation, trusted by global energy giants like EDF Energy, E.ON Next, Engie, Uniper, Octopus Energy, Origin and Tokyo Gas. We manage more than 70 million accounts, over 40 GW of power – from off-shore wind to grid-scale batteries – and more than 500,000 consumer devices such as electric cars and heat pumps.
How flexible is the UK grid at the moment?
The UK currently has over 5 GW of grid scale storage and a few GW of consumer devices; this equates to just under 20 percent of peak demand.
However, the system requires more flexibility than other European countries for two key reasons. Firstly, nearly 50 percent of our generation mix is renewable – much of it intermittent. Secondly, the UK is an island. The level of interconnection is significantly lower than that of continental European countries. NESO projects that by 2050, the UK will need up to 200 GW of flexibility - nearly triple the 70 GW we have today – over 80 percent of which currently comes from thermal power.”
What kinds of measures can be implemented to make it more flexible and over what timescale?
Flexibility needs to be adopted and deployed at scale. There are two key things needed to do this: the ability to connect to the grid in a timely manner and the ability to participate in the market and monetise the asset.
The measures needed to adopt flexibility across the grid largely depend on the scale of the asset. Smaller assets often struggle just to get into energy markets – they may be clean and flexible, but if they don’t have enough volume to be aggregated and if they can’t adhere to strict grid requirements for balancing markets, they’re effectively locked out and when they can enter, they are not always dispatched.
On the other end, the large assets we work with are already in the market, but the issue is they’re not always used – even when they’re the cheapest option. System operators like the National Energy System Operator (NESO) consistently default to more expensive gas assets simply because they’re familiar and perceived as more reliable. In fact, we see cheaper assets being passed over about 80 percent of the time: 12 months ago, this was 95 percent.
That’s why we’re working closely with grid operators – not just to upgrade their technology, but also to shift control room culture – so they can start relying more on clean, cost-effective alternatives that can deliver just as reliably.”
What are the costs and benefits that go along with that?
Rising costs from inflexible grid infrastructure.
Globally, around $2 trillion is being invested in renewable energy projects, yet only $400 billion is allocated to grid infrastructure. This imbalance has significant implications. One of the most pressing consequences is the rising rate of curtailment, where renewable energy generation is forcibly reduced due to grid limitations. Curtailment has reached around 10 percent in several countries, translating into massive costs.
In the UK alone, over £1 billion was spent on constraint costs last year, costs that are ultimately passed on to consumers. Up to 70 percent of curtailment costs stem from ramping up gas elsewhere – a cost that could be avoided with enhanced grid flexibility.
This is not a local issue. Spain curtailed solar energy for the first time last year, and Texas and Australia curtailed 9 percent and 8 percent of their solar generation, respectively. The European Union has responded by targeting 200 GW of energy storage by 2030 to mitigate this. However, location matters. Storage must be strategically placed to be effective. A study from Imperial College suggests that more targeted storage could save the UK up to £3.5 billion per year.
Benefits: A more stable and resilient grid
One of the less visible but equally critical benefits of a flexible grid is enhanced resilience. Power plants and interconnectors can trip unexpectedly, a common issue in the UK, especially with European interconnectors. Fortunately, sub-second response services are now capable of reacting to these events to prevent outages.
Batteries are the only assets currently capable of delivering this rapid, precise response. The UK has successfully employed them numerous times. Other nations need to follow suit. For example, Spain has no grid-scale storage, contributing to vulnerabilities like the recent Iberian blackout. Similarly, a 2016 blackout in South Australia, which left 850,000 customers without power, spurred major investments in grid-scale storage, including the development of the Hornsdale battery.
Projects like Blackhillock, Europe’s largest battery installation, exemplify the economic and technical value of grid flexibility. It is a world-first for offering grid stability services, projected to save UK customers £170 million annually and cut 3.4 million tonnes of emissions over the next 15 years.
How is the UK doing at the moment with regard to installing, improving and innovating energy storage to support the grid?
The GB battery fleet has grown rapidly - from just a few megawatts in 2015 to approximately 5 GW by 2025. This expansion has been underpinned by three key waves of business models.
The first wave was driven by long-term frequency response contracts, which provided a stable revenue foundation. However, in 2021 these transitioned to shorter-term, day-ahead procurement, prompting a shift in market dynamics.
The second wave saw the emergence of merchant revenue streams from wholesale power and increasing participation in the Balancing Mechanism, enabling batteries to capture more volatile price spreads.
The third wave is now being shaped by grid stability services, with batteries like Blackhillock now playing a growing role in inertia, voltage support, and fast frequency response. This shows how batteries are continually expanding their capabilities to replace conventional generators even more quickly than anticipated, contributing to a development pipeline that now exceeds 120 GW.
Kraken now manages half of Great Britain’s battery sites, with more on the way. Quietly and quickly, batteries are becoming the heart of a cleaner, cheaper, and more reliable energy system.
How does the UK compare with other nations with regard to energy storage?
The UK leads with sophistication, but the US leads with volume. The UK has more than 5 gigawatts of storage in place. Meanwhile, the US has over 20 GW of storage, mainly in Texas and California, and is growing rapidly. In Europe, countries like Italy, Germany and Poland are expanding; the full impact of battery storage is still ramping up across the continent. But for now, the UK remains the leader.
How is AI revolutionising the energy sector and the transition away from fossil fuels?
AI enables us to optimise assets in real time for market prices, carbon intensity, and availability in ways that simply weren’t possible before.
Kraken delivers large-scale grid flexibility, managing renewable generation and battery sites to charge when energy is cheap (or when prices are even negative – so you are paid to charge a battery) and abundant, and supporting the grid at peak times to bring down bills for everyone and stabilise the electricity system.
The market is also incredibly sophisticated now and needs AI to navigate it. Today's portfolios – batteries, EVs, solar, wind, data centres – are far too complex to be run by a few lines in Excel. Our platform is designed to optimise these assets across 20+ markets for physical constraints, grid rules, prices, carbon intensity, compliances, and technical asset capability. AI means we can test thousands of scenarios every minute to get the best solution.
How important is AI for demand response and making the grid more intelligent and smarter?
Kraken’s flexible device management relies on advanced machine learning to balance supply and demand across the power grid – making a decentralised, abundant, clean energy system a reality.
Our platform continuously analyses thousands of different scenarios every hour, rating them in real time so customers can make the best choices for their goals – whether that’s financial performance, carbon reduction, or grid stability. It’s not about us running things for businesses; it’s about empowering them with the tools to take control and make smarter decisions, faster.
Looking ahead, I'm most excited about the large-scale use of intelligent demand from industries and commercial entities to transform how we balance the grid. In five years, I believe we’ll see breakthrough innovations in how these assets can support our energy transition at scale.
What kind of pressure is being inflicted on the grid at the moment by the growth in data centres, and how can this be addressed?
Data centres are a big focus right now, specifically in the US where load growth is rapid – places like Texas are seeing load growing over 5 percent a year, far above the average historical load growth of 1 percent a year. Europe is facing a different set of challenges, with deindustrialisation combined with high energy costs.
What makes data centres particularly interesting is not just the demand – they also present unique challenges around how to get them connected to the grid quickly and reliably. This isn’t just a US issue, but the scale and speed of deployment in the US makes it especially pressing. It’s pushing us to innovate around grid integration, grid stability, and automation – more customers want to be connected to the grid and are not willing to wait up to a decade for a connection.
Anything else you would like to add here?
We’ve developed a truly integrated platform that’s asset agnostic, which means we can work with any asset – whether it's storage, solar, wind, or data centres. This gives us the flexibility to serve a wide range of customers.
Our platform also covers the entire lifecycle – from contract management, connecting assets to the grid, controlling, optimising, and settling them – everything in one place. This end-to-end capability makes us unique, especially for large utilities operating across multiple markets. In contrast, other solutions break up these processes, leaving customers to juggle data across multiple platforms.
Our solution streamlines this, delivering efficiency and innovation, which is why we’re the partner of choice for utilities across Europe.
For additional information:
