Holden Group

The Client

Holden Group is a family-owned network of car dealerships, looking after customers since 1928. They represent the Kia, Volvo, Honda, Renault, Dacia and MG brands in Norwich and surrounding Norfolk areas.

The company has a trusted reputation for being knowledgeable and offering an honest and enjoyable experience. It offers new, nearly new and approved used cars and vans for sale to private and business clients. It also provides affordable servicing, repairs and maintenance from its Norwich and Kings Lynn sites.

The showroom sites consume 586,768kWh of electricity annually in total and Holden Group aimed to make a significant investment for the business to demonstrate a commitment to sustainable energy use and reducing CO2 emissions.

The company was aware that all of the brands it represents were heavily invested in EV technology and that cutting carbon was also important to its customers. It wanted to ensure that it was investing in its facilities to match the expectations of franchise partners, colleagues and customers.

Working closely with SaveMoneyCutCarbon director and co-founder Charlie Farr, the Holden Group explored the potential solutions for carbon reductions and energy savings across its properties.

Holden Group invested more than £500,000 in a rooftop solar panel installation at its showroom sites.

Following desktop and detailed site surveys, the SaveMoneyCutCarbon team installed 992 panels in a roof-mounted system, optimised for greatest yield, maximum generation, monitoring and ROI, as opposed to a standard string system. All installed products and services are Microgeneration Certification Scheme (MCS) approved.

The selected monocrystalline PV modules offer the highest efficiency cells and lower degradation rates. They are made from a single piece of silicon, making it easier for electricity to flow through. They have a pyramid cell pattern which offers a larger surface area, enabling the panels to collect a greater amount of energy from the sun’s rays.

The system also benefits from Solar Edge inverters with optimisers behind each panel. All inverters are ready to be connected to batteries in the future in order to maximise on self-consumption during the night. They also have the capability to limit export to the grid to zero.

Optimisers give a minimum of a yield increase of on average 10%, provide added safety features, panel level monitoring showing generation data assisting maintenance and an extra two years on the inverter warranty. The optimisers allow the panels to perform independently so the strings are not brought down to the lowest performing panel as in a standard string inverter set up.

The system is classed as a Safe DC system. A standard string inverter set up cannot shut down the array so will typically have live cabling up to 750V at any point during daylight, the optimisers on the roof allow the SolarEdge system to shut down the panel output to 1 volt per optimiser, making each string circa 20 Volts making it the safest and most productive system on the market.

• Trina Solar 425W panels
• S440a Optimisers
• P850 Optimisers
• Renusol Metasole+ mounting system

• SolarEdge Manager 100k full unit inverter
• SolarEdge SE25K Full unit inverter
• SolarEdge SE12.5K inverter
• Metering and monitoring packs