Waltham Forest Power to Success with Longfield House Solar PV Project



Longfield House Solar PV and Energy Storage

Project Aim

242 JA Solar 340W modules
12 SolarEdge P370 Optimiser
1 Growatt MAX60 Inverter
1 Alpha ESS Storion T30 storage system
12 Alpha ESS 5.7kWh Lithium-Ion battery

Project Details

Reduce Site Energy Consumption
Reduce Site Carbon Footprint
Respond to Climate Change

Project Performance

Annual Yield – 72,134kWh
Annual CO2 reduction – 18,466kgs


Project Portfolio

As a forward-thinking local Authority, Waltham Forest Council had already installed more than 1,000 solar PV panels onto council properties and reduced carbon emissions by almost 35% in the last decade.

Following the declaration, by the Council, of a climate emergency in April 2019 they set up London’s first independent Climate Emergency Commission to explore, examine and interrogate the Council’s existing climate change plans and their new ideas about how Waltham Forest could become a net zero-carbon borough.

Through the Council’s long-standing partnership with leading facilities management company, Aston Group, a plan was forged to deliver sustainable renewable energy projects to more council owned properties within the borough.

Aston Group, established in 1964 as Aston Heating, have worked with the borough since 2012 delivering efficient facilities management to the Council’s portfolio of properties. Aston Group have excelled achieving over 98% resident satisfaction in recent surveys.

The plan was to install solar PV systems to council owned properties, together with battery storage systems, to not only provide clean renewable energy to the property but to actively export low carbon electricity into the surrounding borough.

Three trial sites were identified to pilot the ambitious programme, Longfield house in Walthamstow, Plaxton Court and Clifton House, both in Leytonstone.

Built in 1986, Longfield House offers sheltered retirement living to residents aged 55 years and older. With 36 flats, there is on site management staff and communal facilities.

The project was to provide solar PV power to the communal areas of the building, reducing running costs and carbon emissions.

In November 2020, Aston Group commissioned Spartek ECS to deliver the first project at Longfield House with them.

With roof elevations facing in every direction, the challenge facing the Spartek team was to design an efficient solar PV system that could match and even exceed the energy demand of the building, leaving surplus power to charge an on-site storage battery.

Commencing in December 2020, a total of 242 solar PV panels were installed to the roof. JA Solar panels were selected for the project due to their longstanding presence in the solar PV industry and global Tier 1 status. Each panel is capable of delivering 340 Watts of power, giving a total system size of 82.28kW. To overcome issues with different orientations, angles and minor shade, SolarEdge optimisers were installed to affected panels allowing each solar panel to perform at its optimum.

A Growatt MAX60K inverter was installed to convert all of the energy harvested into usable power that could be distributed throughout the building. Rated at over 99% efficient the Growatt inverter provides seamless integration into the buildings energy supply and can be monitored remotely through the internet.

Capable of delivering 72,134kWh of electricity to the building each year and reducing carbon emissions by over 18,466kgs per year the system is designed not only to support consumption within the building itself, but also to export clean energy into the local community.

To further support on-site consumption of the power an Alpha ESS AC coupled battery store was installed. With a full complement of 12 lithium-ion batteries giving total storage capacity of 68.4kWh, the Alpha ESS can deliver up to 30kW of power output through its own onboard inverter.

The system was energised and commissioned by the Spartek team on 3rd February 2021 and is already exceeding expectation.

Constantly monitored through the online portal the performance can be followed in 5-minute intervals, with only a 5-minute delay in data transmission. A display in the reception area of the building shows live data from the system to residents and visitors interested in how their local authority are acting to stop climate change.
Since being energised, the system is already having a huge impact generating over 1,834kWh of energy from the solar PV panels, reducing import from the grid by almost 41% and exporting over 277kWh back into the local grid, saving over 469kgs of carbon emissions.

Peaking on the 23rd February, the building consumed 184kWh of electricity but purchased less than 54kWh from the grid, giving a reduction of almost 71% of energy purchased. With over 228kWh generated by the PV array and more than 98kWh exported, the system saved over 58kgs of carbon emissions in a single day.
Following the immediate success of the project, the second project is already progressing with details to be given after installation.

If you would like to learn more about this project, or investigate having a similar project added to your home or business then contact …………….