How flexibility can stop the UK’s green dream from blowing away

Posted: 24 Feb 2021

Valts Grintals

Flexibility Analyst

This blog explores how, through AI optimisation, the grid could generate a colossal 25TWh of flexibility annually - enough to manage a twelvefold increase in potential wind constraints (instances when wind turbines are turned off) - and could save the system up to £1bn in potential costs every year.

Your kettle, your washing machine, your cooker, your heating, your plug-in electric vehicle – the whole lot of them will get their juice cleanly and without guilt from the breezes that blow around these islands,” said Boris Johnson on pledging that the UK will become the ‘Saudi Arabia of wind’ and install enough wind capacity to power every home with renewable electricity by 2030. A great green vision, but how to make it happen?

Records were broken last year when the UK’s grid went fossil free for over 67 days (see the below Twitter post) and renewables accounted for 40.2% of generation between January and the end of September 2020



A large proportion of this renewable generation comes from on-shore and off-shore wind turbines and they are currently reaching their full capacity during high winds, producing 24GW. We are already seeing instances where the current electricity system is struggling to utilise this wind power, for example, during the first UK lockdown when system balancing costs skyrocketed and wind farms were paid ~£9.3m to ‘switch off’ to manage the system imbalance.

Over the last four years, at least £100m has been paid annually to switch off wind turbines at times when the grid is at optimal capacity. Currently this is equal to 3% or ~2 TWh of all annually generated electricity from the existing wind capacity and this is only expected to increase as the installed wind capacity grows from 24GW to 54GW by 2030.

As shown in Kaluza’s V2G whitepaper last year, increasing renewable generation is only part of the solution to creating a fully decarbonised grid. We must also create a system that uses it effectively and limits waste. This is where domestic flexibility comes in – storing green energy across smart devices in people’s homes when it’s in abundance.

Over the past two years, Kaluza’s AI has been shifting energy demand across domestic EVs, storage heaters, heat pumps and batteries to times when abundant renewable energy is available and cheap, whilst also keeping homes warm and EVs ready for their next journey. Our work in this space has shown how domestic flexibility can help effectively introduce more renewable energy onto the grid, help reduce grid stress at peak times while keeping end customers happy.

Optimising domestic heaters

Kaluza has been optimising fleets of smart storage heaters in homes across the UK for the last two years. Last winter, we saw that each storage heater offered our platform the flexibility to manage 5kWh of ‘storage heater charging’ per day, enabling us to capture the cheapest times in every Economy 7 tariff window. 

In fact, a subset of Kaluza’s optimised smart heaters have been operating in Orkney – one of the windiest locations in the UK – and capturing excess wind from the local wind turbines. Over the last five months alone, Kaluza-optimised storage heaters have responded to 467 wind turbine curtailment events, resulting in heaters reducing the ‘wasted’ wind energy by 10% with some heaters capturing 5-18 kWh of electricity directly from these turbines every month.

Smart charging electric vehicles

Kaluza’s work in EV flexibility includes the world’s largest domestic V2G project, one of the key DNO-led EV smart charging projects and the smart charging of a further 10,000 EVs throughout the UK.  Our data indicates that each smart charger could optimise 7kWh of EV charging per day to capture the most from times when intermittent renewable energy is available. Similarly, on an average day, each V2G device could give us the opportunity to capture 11.4 kWh of renewable energy while also enabling 6.7 kWh of this electricity to be returned back to the grid at times when additional capacity is needed to meet high demand. V2G further enhances the opportunities for EVs to play a major role in facilitating grid with high renewable generation in the mix. 

The big flex picture

Although the smart EV charging and smart heat market is still in its infancy, it is important that we project our current real-world learnings onto the future electricity system taking shape. By 2030, there will be circa 11 million EVs on the roads and at least 2 million homes with electrical heating, all of which have the flexibility and technical capabilities to deliver a cheaper and more effective energy system that will facilitate the additional 30GW of wind capacity (going from 24GW now, to 54GW by 2030).

Assuming all the necessary market drivers are in place and that we can create the right mix of solutions across heat and transport, 25 TWh of flexible charging capacity (equal to ~19% of the total annual wind generation capacity in 2030) could be produced by 2030. 

25 TWh would be enough to manage a twelvefold increase in potential wind constraints (instances when wind turbines are turned off) and could save the system up to £1bn in potential annual costs associated with managing increasing penetration of intermittent generators. Beyond this, if 50% of all EVs were V2G enabled, there would be an opportunity to use their export capacity to further power 3.6 million homes with cheaper and greener electricity whilst also delivering up to 77% of all system balancing needs, not to mention an ability to mobilise consumers in the transition by saving them money.

However, currently, most domestic customers don’t have any real incentives to shift their demand, leading to this type of flexibility remaining under-utilised.  

So, how do we make this flexible future a reality? 

While the government’s Energy White Paper includes a number of positive targets, and the new deadline for the banning of fossil fuelled cars is a helpful catalyst, there is still a way to go to completely decarbonise the UK’s heating systems and prepare the grid for the charging of 11 million EVs by 2030. The government and all key energy industry players must align to establish the right market incentives to facilitate the uptake of low carbon heat and transport solutions for consumers to make the most of renewables and save system costs.

Of course when these electric heating and transport systems do reach scale, ensuring system resilience is a major challenge, and that requires intelligent technology to manage the charging of millions of devices.

Kaluza sees three developments that are essential in unlocking these opportunities and helping the UK achieve a more cost-effective zero carbon grid:

  1. Progressing implementation of market wide half-hourly settlement (MWHHS) alongside further smart meter rollout. These are the foundations to the future energy system, incentivising customers to invest and utilise flexible assets in their home.
  2. Implementing more dynamic and cost reflective network charges at locational level. This will further enhance the incentive for customers to engage in flexibility and innovative solutions that are being developed alongside EVs and electrical heating. Data and digitalisation holds the key in making this reality.
  3. Establishing standardised flexibility markets that are as accessible to domestic flexibility as they are to grid-scale solutions. These markets are moving in the right direction, but further work is needed to ensure that these markets are ready to facilitate domestic flexibility once it reaches a more significant scale.   

With these measures in place we can allow for turbines to keep turning and reward customers for efficiently using the green energy around them, making the UK’s green dream a reality.

About the Author

Valts Grintals

Flexibility Analyst

Valts has over four years’ experience in the UK and European energy storage and flexibility space. Valts has a MSc in Renewable Energy and Distributed Generation from Heriot-Watt University. He began his career as a consultant, assisting a range of energy suppliers, OEMs, network operators and EnTech start-ups in navigating the emerging flexibility markets. Valts joined Kaluza as a Flexibility Analyst in 2018. As Flexibility Analyst, Valts works with Energy Traders, Energy Suppliers and Network Operators to understand and resolve grid challenges with domestic flexibility, helping to shape the future of energy.

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