Premium solar PV and battery storage install at Harbour Farm

Premium solar PV and battery storage install at Harbour Farm

Overview

Harbour Farm was the site for a premium residential solar and battery storage project completed by DW Energy for a residential customer near Chichester.

The property is a large rural home with a substantial roof area, high quality external finishes and an open surrounding landscape. The customer wanted a system that could reduce reliance on grid electricity, make better use of solar generation throughout the day and maintain the appearance of the home.

DW Energy designed and installed a 6.3 kW solar PV system with 13.5 kWh of battery storage, using 14 black 450 W SOLARWATT panels and a Tesla Powerwall 3. The system was designed to sit neatly within the roofline while giving the customer more control over how and when electricity is used at the property.

The challenge

Harbour Farm had strong potential for solar generation, but the installation needed to be handled carefully.

The property’s roof design meant the system had to be positioned with precision, both for performance and visual finish. This was not a project where panels could simply be added without considering the wider look of the building. The customer needed a clean result that suited the home’s architecture, particularly given the prominent roofline and open views around the property.

The system also needed to support a household with significant electricity demand. Before solar, annual usage was assumed at 9,157 kWh, so the installation had to be designed around more than just daytime generation. Without storage, a large share of the solar output could have been exported when the home did not need it, reducing the value retained on site.

The solution

DW Energy designed a 6.3 kW solar PV system using 14 black 450 W SOLARWATT Panel vision modules, paired with a Tesla Powerwall 3 battery with 13.5 kWh of usable storage.

The panels were installed using an in roof mounting system, giving the array a more integrated finish against the tiled roof. This helped preserve the character of the property while still delivering a high performing solar system.

The Tesla Powerwall 3 provides both battery storage and inverter capability, supported by Tesla Gateway 3 for metering and backup power. DW Energy also included an Eddi by myenergi hot water diverter, allowing surplus solar energy to be directed towards hot water when available.

The system was forecast to generate 7,655 kWh per year, with a 97% system efficiency and a strong shading factor of 0.99. With the battery included, expected solar self consumption increased to 5,923 kWh, helping lift forecast grid independence to 66%.

The result

Harbour Farm now has a solar and storage system designed around both performance and presentation.

The black panels sit cleanly on the roof, giving the customer a more discreet finish than a standard above roof array. The completed installation complements the property rather than dominating it, which was especially important for a home of this size and setting.

From an energy perspective, the system gives the customer a much stronger route to using their own electricity on site. Solar generation can support daytime demand, while the Tesla Powerwall 3 stores surplus electricity for later use in the evening, overnight or during periods of lower generation.

The proposal forecast estimated annual savings of £2,984.85, with a discounted payback period of 5 to 6 years and a 25 year net present value of £58,047.52. The system was also forecast to deliver environmental benefits equivalent to 139 trees planted per year, 2,312 litres of avoided fuel per year and 2,627 kg of avoided coal burnt per year.

Closing summary

Harbour Farm shows how residential solar can be delivered without compromising the appearance of a high quality property.

By combining in roof SOLARWATT panels, Tesla Powerwall 3 storage and smart hot water diversion, DW Energy created a system that helps the customer reduce grid reliance, retain more value from their solar generation and improve long term energy resilience.

For a residential customer with a large home and high electricity usage, the project provides a practical example of how solar PV and battery storage can work together as a complete home energy system.