Heat pump trial with Sero, National Grid and other partners concludes

How were the trials conducted?

Sero customers provided a total of 630 hours of flexibility to National Grid Electricity Distribution by turning off their heat pumps. Heat pumps were turned off remotely by the Sero BEE, with Sero reacting to signals from National Grid Electricity Distribution. Customers were kept informed of events by email and SMS, with the option to opt out at any time. Sero had an impressive 100% participation rate, with no opt outs – at either event, or trial level. Customers were rewarded for their participation by an advanced monthly payment, or a payment per event.

The coldest trial event day occurred on 13th December 2022 with an average outdoor temperature during the 2-hour event window of 0.4°C, data collected from the Sero BEE observed an indoor average reduction in temperature of just 0.56°C. The mildest event day also occurred in December, on 19th when it was on average 12.65°C outside. On this event day there was no change in indoor temperature observed. The average outdoor temperature during the 2-hour event window, across all events, was 6.3°C and the average drop of temperature in home, across all events, is a 0.23°C temperature decrease.

What did these results tell us?

The results confirm that homes with heat pumps can provide flexibility with minimal impact on comfort levels – even in extremely cold weather conditions. The homes included in the trial are EPC A zero carbon ready homes with batteries, solar panels and ground source heat pumps.

Sero participants were surveyed following each trial event, across all trial events 72% of the time residents reported no change to comfort levels. Residents reported moderate discomfort 8% of the time and mild discomfort 17% of the time. While residents reported they were uncomfortable only 3% of the time. Typically, as expected larger changes to comfort were reported during colder spells.

Ryan Huxtable – Innovation Engineer – ‘We are pleased to see that the flexibility events during our first winter trial had minimal impact on customers participating in Sero homes, and that although they were able to opt out at any point, no customers felt the need to. The results from this trial will help us understand how we can use this service in the future to provide best value for customers”.

What next following the trials?

The EQUINOX project partners are now considering the trial design and billing methods for Winter 2023/24. Sero will open recruitment to eligible homes in late Summer/early Autumn for participation in Winter 2023/24. Visit the National Grid EQUINOX webpage to find out more about the trials.

Sero’s mission is to accelerate the adoption of sustainable lifestyles and make the journey to net zero homes simple and affordable to all. It’s vital energy suppliers, aggregators and the grid collaborate to support decarbonisation as uptake of low carbon technology increases in UK homes. Sero are delighted to be involved in EQUINOX and trialling how domestic homes can provide flexibility through heat. Projects like EQUINOX will help to develop and deliver a scalable long-term solution that supports both the grid and customer.

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