Villa Solar + Battery System

Project intro

An occupied villa, retrofitted without rewiring the house

The property is a detached villa in Altea, occupied year round, with an electrical installation that had been extended piecemeal over time.

The owners wanted solar, expected to add a battery, and were clear that they did not want the house opened up twice to achieve it.

Client requirement

Cover the evening, and leave room to grow

The stated priority was to use more of the property's own generation rather than to build the largest possible array.

A second requirement was that an electric vehicle would be added within a few years, and the electrical design had to allow for it without further disruption.

• Increase the share of generation used on site
• Fit storage now rather than retrofit it later
• Reserve capacity and a route for a future charge point
• Keep documentation good enough for another electrician to work from

Property conditions

What the survey found

The main roof offered a usable surface on two orientations, with afternoon shading from a mature tree on one section and a chimney interrupting another.

The consumer unit had limited spare capacity and no obvious position for additional protection, which turned out to be the constraint that shaped the whole project.

Design approach

The board first, the array second

Because the existing board could not carry the additional circuits, the design started with a new sub-distribution arrangement sized for the solar, the battery and a future charge point together.

Only once that was settled was the array laid out, avoiding the shaded section rather than filling the roof and accepting the losses.

Solar layout

Two orientations, one inverter

The array was split across the two usable orientations, which spreads generation across a longer part of the day instead of concentrating it at midday.

A hybrid inverter was selected so that storage could be connected directly, and the shaded roof section was left clear and noted in the handover drawings as available if the tree is ever removed.

Battery integration

Sized on the evening, not on the roof

Storage capacity was set against the energy the household draws between the end of generation and the following morning on an ordinary day, rather than against the peak output of the array.

The battery position was chosen for ventilation, temperature and access, and the cable route was kept short and separate from the living areas.

Installation

Planned around an occupied house

Roof work, cabling and board work were sequenced so that the property was without power only during agreed windows, each confirmed the day before.

Mounting was selected for the roof covering, and every penetration was recorded in the handover documentation.

Monitoring

Readable by the people who live there

Monitoring was configured at commissioning to show generation, household consumption and battery state together, rather than generation alone.

The owners were shown what a normal day looks like on the display, so that an abnormal one is recognisable without a technical background.

Result

An integrated system, documented and ready to extend

The finished installation works as one system: generation, storage and the house electrics are configured together and reported in one place.

The electrical design carries reserved capacity and a prepared route for the charge point the owners expect to add, so that work will not reopen anything done here.

• An integrated system rather than three separate installations
• Monitoring the household can actually read
• Battery functionality configured and demonstrated at handover
• A future-ready electrical design with capacity held in reserve