A house that already had solar, but not a plan.

Project intro

A house that already had solar, but not a plan

The property is a ten-year-old villa with a small existing array, installed before the household added a pool and, more recently, an electric vehicle.

The brief was to work out whether the existing array, the roof and the consumer unit could support a battery and a charge point, or whether more than a battery needed to change.

Operational context

Evening use that the original system was never sized for

Consumption data showed the load had shifted since the original installation: pool equipment through the afternoon, and a clear evening peak once the household is home.

The existing array covered the daytime load reasonably well. The gap was almost entirely in the evening, which is the condition a battery is actually for.

Roof and electrical assessment

The board, not the roof, was the constraint

The roof had enough remaining usable surface for a modest array extension. The consumer unit did not: it was already full, with no spare ways for a battery, let alone a future charge point.

A full rewire was not needed, but the consumer unit itself had reached the end of what it could reasonably accommodate.

System design

Sized against the evening gap, not the roof

The battery was sized against measured evening and overnight consumption on an ordinary day, not against the array size or a standard package.

A consumer unit upgrade was included in the scope specifically to create the spare capacity the original installation never had, with an additional way reserved for EV charging.

• Battery sized on measured evening consumption, not on array size
• Consumer unit upgraded to create genuine spare capacity
• A way reserved in the new board for EV charging
• Existing array inspected and retained rather than replaced

Installation planning

Two visits, not one

The consumer unit upgrade required a supply interruption, agreed in advance for a weekday morning when the household was out.

Battery installation and commissioning followed as a second, shorter visit, once the new board was live and tested.

Monitoring

One dashboard for the whole system

Generation, battery state and consumption are shown together, so the household can see whether the battery is actually covering the evening gap it was sized for.

Monitoring access was set up directly in the household's name, not left tied to an installer login.

Result

A ten-year-old system brought up to what the house now needs

The retrofit did not replace a working array. It addressed the actual constraint, which was electrical capacity, and sized storage against how the household uses electricity today rather than when the original system was installed.

A charge point can now be added without a second board upgrade, because the capacity for it already exists.

• Evening consumption largely covered by stored generation
• Consumer unit with genuine spare capacity for the first time since installation
• EV charging prepared for, not yet installed
• Monitoring in the household's own name