8.4kW solar panel and battery installation in Marshfield, near Cardiff

Marshfield, near CardiffCardiff showroomInstalled March 2026

Drone view of the house in Marshfield with 18 AIKO panels on the roof

8.4kWp

solar system size

AIKO 465W panels

20kWh

GoodWe battery

8kW

hybrid inverter

£3,512

estimated yearly saving

Photos

The finished roof from above, looking over the garden and pool

The house and solar roof seen from the far end of the garden

The four-battery GoodWe stack on the side wall of the house

The story of this install

A family home that uses a lot

Claire's household gets through around 12,000kWh of electricity a year, three times a typical home. Their house sits in an open spot in Marshfield, between Cardiff and Newport, with a big slate roof rising above a timber balcony. She came to our Cardiff team wanting solar and enough storage to really use it.

When the grid says 4kW

One roof face, 30° off due south at a 30° pitch, takes 18 AIKO 465W panels (8.4kWp) and a GoodWe 8kW hybrid inverter. When we applied to National Grid, the network operator, it approved the connection but limited exports to 4kW.

That shaped the design. On a bright day the panels can produce more than the home uses and more than it's allowed to export, so we fitted four GoodWe batteries, stacked on the side wall, for 20kWh of storage. The surplus goes into the batteries instead of being wasted.

Built for the coast

The house is less than two kilometres from the sea, so the mounting was designed for the higher wind loads you get on the coast. That's part of the structural check we do on every roof before anything goes up.

Living with it

The system was switched on in March 2026, just in time for the longer days. With usage this high, most of what the roof makes is used in the house. Whatever's left after the batteries are full is exported, within the 4kW limit.

Claire can see all of this in the GoodWe app: what the roof is making, what the house is using, how full the batteries are and when exports reach the limit. The MCS estimate for the system is around 7,700kWh a year.

Yearly generation is the MCS estimate made for this home before installation, using the standard MCS method. Real output varies from year to year with the weather.

Full kit list

Panels: 18 × AIKO 465W (8.4kWp)
Inverter: GoodWe 8kW hybrid inverter
Battery: GoodWe batteries, 20kWh
Paperwork: MCS certificates (solar and battery), DNO approval and handover pack