From humble hot water tank… to virtual power plant

November 2021

Thanks to a partnership between Centrica and Mixergy, over 1,000 water tanks installed in homes across the UK are now delivering 1MW of flexible power to the National Grid.

The Mixergy hot water tanks are connected using Centrica DSR’s platform which intelligently manages their collective storage capacity to create a ‘virtual power plant’ that stores excess energy when the grid is quiet, then releases it when demand is high.

About Centrica DSR

Centrica’s patented DSR tech platform for managing virtual power plants is capable of intelligently controlling a range of different electrical loads, from heavy industry through to domestic energy systems.

By providing new ‘energy flexibility’ to the grid, Centrica DSR is helping to facilitate the shift to renewables – and also helping the electricity system to work more reliably.

Why renewables need a more flexible grid

On windy or sunny days, there are now occasions when there is more power generated by the electricity system than we need in our homes and businesses.

At the same time, there are increasing numbers of new energy storage technologies available, such as home batteries and electric vehicles.

They can store the excess electricity and release it when demand is high – or when weather conditions mean there isn’t much renewable energy being generated.

Managed by smart tech like the Centrica DSR platform, all these devices have the potential to deliver substantial ‘energy flexibility’ to the grid.

The future of energy

Centrica’s partnership with Mixergy follows the publication of National Grid’s Future Energy Scenarios, which suggests that more than 23 million homes will need to install new low-carbon heating solutions by 2050.

Grid operators have suggested that as many as 23 million homes will need to install new low-carbon heating solutions by 2050.

If a quarter of those included smart hot water solutions, such as Mixergy, we’d be in a position to utilise as much as 15GW of flexible power which is more than the currently installed offshore wind capacity in the UK.

In order to hit Net Zero, we are exploring both the demand and supply side of the transition to renewable energy with equal importance – and leveraging the growth in IoT-connected devices to complement the rise in renewables so we can use our electricity infrastructure as efficiently as possible.

The Mixergy partnership is just one example of how Centrica are working with global manufacturers of residential appliances to bring flexible energy services to the electricity grid using the Centrica DSR platform.

About Mixergy

Oxford University spin-out Mixergy offers customers the opportunity to upgrade their hot water systems with a new intelligent hot water tank.

Heating hot water is the second most intensive use of energy in the home. In fact, hot water tanks consume as much energy as running a small car, but they have received little innovation to date.

The Mixergy tank system combines sensory and IoT technologies to keep track of hot water levels in the tank, learning the usage habits of the household so water volumes are personalised to heat just what is needed at the right time.

This can reduce heat losses and water energy usage by up to 40% a year, saving over 10% on hot water bills each year.

We are collaborating with Mixergy to show that intelligently connecting more traditional devices in the home, such as electric hot water tanks, can unlock energy flexibility and help the low-carbon energy transition.

We are very excited to be at the heart of Centrica’s mission to bring about additional flexibility to the energy system whilst delivering customer benefits through the deployment of solutions like the Mixergy tank.

Together with Centrica, we are paving the way for smart tariffs which will reduce energy consumption and carbon emissions by storing excess renewable energy on the grid. At the same time, we can reduce bills for householders by only heating the amount of hot water they require.

If you'd like to find out more about this project – or about how Centrica DSR can help you – get in touch to speak with one of our experts.

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In a nutshell

We recently connected over 1,000 Mixergy hot water tanks to our DSR platform, thus enabling us to intelligently manage their collective storage capacity to create a ‘virtual power plant’ that stores excess energy when the grid is quiet, then releases it when demand is high.


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The Company

Centrica plc is an international energy services and solutions business.

Centrica plc registered office:
Millstream, Maidenhead Road, Windsor, Berkshire, SL4 5GD, UK
Tel: +44 (0)1753 494000

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