One Year On: Continued savings for Havebury Housing Resident
It’s been a full year since Ann and her husband had their Mixergy cylinder installed as part of Havebury Housing’s retrofit project and the results speak for themselves.
From April 2024 to April 2025, their hot water has mostly been powered by solar. Just 35% of the energy used to heat their water came from oil. The rest, over 837 kWh, came from excess solar PV generation that would’ve otherwise gone unused. That’s an average of 2.29 kWh of free, low-carbon energy going into the cylinder every day.
Because the cylinder only topped up when it needed to, and prioritised solar wherever possible, the oil boiler didn’t need to fire up at all for 185 days. And when it did, it only heated the cylinder to around 56% on average, saving even more oil.
Over the year, using oil for hot water led to around 113 kg of CO₂ emissions. If the cylinder had used oil alone, that figure would’ve been closer to 373 kg. So by switching to a Mixergy system, Ann and her husband cut their hot water emissions by about 70%, while still having the hot water they needed, when they needed it.
