Greenfield Holdings was retained through RG Group Ltd, one of Sainsbury`s main contractors to source and deliver a solar system which was to be installed onto the roof at the Chingford Supermarket. The GHL team was made up of Active Technologies, who designed and manufactured the aluminum framing system for the arrays, Q Design Consultants that handled the electrical design and they also arranged the G59 submission to EDF and RoofTech which handled the installation of the frames and the photovoltaic panels. They also arranged the electrical engineers to wire the whole system together – Natural Watt and Energy ICT  – who provided the energy monitoring equipment. The energy metre was supplied by Elsevier while the solar panels were provided by Romag Holdings Plc and the inverters were supplied by Fronius.

Active Technologies Ltd

Active Technologies Limited (ATL) kicked of the project carrying out the loading calculations for the roof. This included maximum wind and snow loadings. The worst case loading for the wind uplift was determined to be 1Kn/m2 on the rear of the panels. Working in conjunction with the RG Group, Site Project Manager, and the building architect, a detailed structural support system was designed. This would enable the solar panel mounting frames to be fitted. ATL then produced a series of detailed site layout drawings for the solar panels in a due south at 30 degrees angle orientation, to achieve the most efficient solar collection. A full and comprehensive bill of materials for the 300 panel system was prepared, and with ATL’s in-house manufacturing the frames were assembled. These parts were delivered to site on time, for partners RoofTech to rollout the panel installation.

Q design consultants Ltd

‘Q Design Consultants’ were commissioned to prepare an energy strategy and PV cabling design for the Sainsbury’s Extension at Low Hall, Chingford. The original store first opened for trading during 1993 and has had a sub-sequent extension and refit in 2000. The most recent development comprised of an extension to the existing store, providing an additional floor area of 1721m2. This Energy Strategy identified the need for the new extension to satisfy the requirements of both the Target emission rate (TER) and the ‘On-Site’ renewable energy target, in meeting the improvement factor of 25% and LZC (Low to Zero Carbon) factor of 20%. This was achieved from installing 415m2 of Solar PV Panels, which provided approximately 57.356kW hours of electricity resulting in an estimated annual CO2 saving of 32.64 tonnes.

The second stage of our appointment included the design of the low voltage (ac) cabling, necessary for transferring the power from the Fronius PV Inverters back to Copyright 2010 Greenfield Holdings Ltd, Highlands House Basingstoke Road, Spencers Wood, Reading RG7 1NT the main incoming electrical switch panel. The G59 application was provided for sign-off by EDF for completion and hand-over of the system.


RoofTech handled the Project Management role and entire installation process from initial site discussions with the Main Contractor through to commissioning of the completed system and preparation of O&M Manuals – all in accordance with the

Construction (Design and Management) Regulations 2007 and their ISO 9002 Quality Management System.

All site operatives are CSCS and/or ECS/NIC EIC qualified to ensure the works are completed to meet current construction/electrical regulations and to the highest standards.

David Penfold from Sainsbury Supermarkets Limited commented:

“We met Tim Taylor and Clive Hall from Greenfield Holdings Ltd in October 2009, I was impressed with their can do attitude, the company promised that they would grant us an exclusivity and they would look to reduce the pricing of the PV panels if we were to try Greenfield Holdings, after a number of proposals set against kilowatt hours to be generated that we were looking for, we agreed to carry out a pilot scheme through one of our main contractors RG Group.

Tim prepared the proposal and RG Group checked all of the issues and signed the documentation with Rooftech who handled the invoicing, this was necessary because GHL was an early stage start up company.

We were impressed with the team and how well they worked together, they made sure that the team were up to speed very quickly with the structural calculations and the placing of the frames and arrays.

This installation has worked very well, we are thrilled at the quality of their work.”