Myatt’s Fields Estate South National Net Zero Accelerator (NNZA) Project

South National Net Zero Accelerator (NNZA) Project

Lambeth Council is undertaking whole house energy efficiency retrofit works at 24 homes on the Myatt’s Field Estate, South. The main objective of this project is to dramatically improve the energy efficiency of each home, reduce carbon emissions and attain a 70% reduction in energy use.  The goal is to achieve homes that are Net Zero ready and to create a warmer and healthier living environment for households. The project also helps to improve energy security. Air Source heat pumps don’t rely on imported natural gas and lower energy use helps to shield households from fluctuating energy prices.

Lambeth received funding from the Social Housing Decarbonisation Fund Demonstrator towards this project The measures that were retrofitted to the homes were:

• Solar panels on the roofs with battery storage to store the electricity generated
• external wall insulation to keep more heat in the home
• replacing the gas boilers with air source heat pumps that extract heat from the air outside, even at low temperatures, and use this heat to warm the home
• energy efficient doors and windows that keep the heat in
• mechanical ventilation with a heat recovery system that consistently draws in fresh air to ventilate the home and expels the old air extracting any heat from it to be used in the home.

The measures installed mean the homes should now be able to maintain a comfortable temperature of 21oC in the main rooms and 18oC in the bedrooms, all year round, meaning that they will be warmer in the winter and cooler in the summer. The new air source heat pumps will also provide 140 litres of hot water per day to each home and a continuous supply of fresh filtered air will keep the internal atmosphere healthy and remove the risk of damp and mould. The energy consumption of the homes is expected to drop by 70% from 143 kWh per m2 per year to 40kWh per m2 per year; which will drastically reduce household energy bills.

To ensure the measures are performing correctly and maintaining a comfortable temperature for households, monitoring equipment known as “Comfort Systems” were installed. These systems constantly monitor the  temperature, humidity and carbon dioxide levels of the home as well as the performance of the Air Source Heat Pump.  The monitoring equipment will also measure how much of the electricity used in the home is generated from the solar panels on the roof and how much electricity is drawn from the grid. This allows the Council to see whether the homes are performing as expected. Households will be able to control the temperature and other settings via an app which can be accessed via a smartphone.  If there is a problem with any of the equipment,  this will be picked up remotely by the monitoring system and arrangements will be made to proactively rectify it.

The system uses the energy generated by the solar panels first, before using electricity from the grid. The solar panels help to power the homes, but if significant additional energy use occurs - for example thermostats are turned up well beyond designed temperatures - any energy from the grid would then be paid for by the resident via their energy suppliers bills.

The measures installed in these homes include: solar photovoltaic panels on the roof with battery storage of generated electricity, external wall insulation - the existing slate wall coverings were carefully removed and refitted over the new insulation - the gas boilers were removed and replaced with Air Source Heat Pumps, windows and doors were replaced with high performance equivalents.  The homes are ventilated using a Mechanical Ventilation with Heat Recovery system (MVHR).  Fresh air is drawn into the home though a system which uses the heat from the exhaust stale to warm it.