Monitored case study · Five-bedroom family home

An off-grid home designed for comfort through winter.

A rural barn conversion approximately 500 metres from the grid faced a connection quotation exceeding £100,000. The alternative was a fully off-grid system capable of supporting a substantial family home and air-source heating throughout the year.

The challenge

A home taking shape, with no affordable power connection.

Bruce and Vanessa were already well into their barn conversion when the electricity connection became a serious obstacle. Nearby power lines had made a connection seem straightforward, but the routes and quotations told a different story.

They met Ian at a housebuilding event. He then worked through the electrical demand with their electricians, plumbers and heating engineer, including whether the air-source heat pump could be supported off-grid.

The design brought generation, battery storage, heating demand and backup together so the family could use their home normally.

“We live almost exactly as we'd live if we were on the grid.”
Homeowners, Fields View BarnFrom the Victron Energy project film
Interior of the completed five-bedroom off-grid barn conversion

The engineering decision

The house and energy system had to be designed together.

The challenge was not simply producing enough annual energy. Winter heating demand, simultaneous electrical loads, battery reserve and generator support all had to work as one operating system.

Electrical capacity was coordinated with the heating engineer, while monitoring and automatic controls made the system practical for normal family life rather than dependent on constant owner intervention.

“After an hour of talking to Ian, I remember Ian left and they looked at me and said, ‘He can do this.’”
Homeowner, Fields View BarnFrom the Victron Energy project film

System architecture

Capacity where it matters.

Solar PV80 × 335 W modules: 26.8 kWp ground-mounted array
BatteryThree 13.8 kWh lithium iron phosphate batteries: 41.4 kWh nominal
Power conversion15 kVA inverter and 200 A charger at approximately 55 V DC
Solar controlFour 100 A MPPT solar charge controllers
Backup20 kVA automatic LPG generator
HeatingAir-source heat pump coordinated with the electrical design

Recorded operation · Calendar year 2025

Evidence after commissioning.

In 2025, the monitoring record shows 11,035 kWh supplied to household loads. Of that delivered energy, 36% came directly from solar, 56% from the battery and 8% directly from the generator. No grid import or export was recorded.

The solar array routed 9,970 kWh to the home and batteries during the year. The generator also sent 1,764 kWh into the battery, so battery-delivered energy cannot be described as wholly renewable. Generator-to-battery charging is part of the intended bulk-charge strategy, not energy consumed twice.

Source: VRM 15-minute energy export, 1 January–31 December 2025. Figures are rounded. Missing channels were not estimated. Recorded solar is energy routed to loads or batteries and may exclude generation curtailed when storage was full.

How energy reached the loadsFields View Barn · 2025
36%Direct solar
56%From battery
8%Direct generator

Delivery route, not renewable share: battery output can include energy previously supplied by the generator.

“We've got what we wanted by a rather strange route, but we could not be happier with it.”
Homeowners, Fields View BarnFrom the Victron Energy project film
11,035 kWhsupply to household loads
9,970 kWhsolar routed to loads and batteries
92%delivered directly by solar or battery
0 kWhgrid import or export

Victron Energy project film

Visit Fields View Barn.

Bruce and Vanessa explain the connection problem and what living off-grid is like. Ian walks through the system design.

Watch on YouTube

Role and attribution

Designed by Ian Hewson.

Ian designed this system while a co-founder and director of Off Grid Engineering Ltd. It forms part of his personal engineering record and monitored evidence base.

Planning a rural home?

Resolve the winter strategy before the architecture is fixed.

Early decisions about fabric, heating, roof area, plant space, wind potential and backup can determine whether the finished system is resilient or compromised.

Discuss your project