---
title: "A family home that covers most of its own power"
description: "A 7.2 kWp roof array and a 10 kWh battery for a four-person household with an electric car."
url: "https://ecozen-astro.pages.dev/projects/family-home-rooftop/"
date: "2026-06-12"
---

# A family home that covers most of its own power

> A 7.2 kWp roof array and a 10 kWh battery for a four-person household with an electric car.

A family of four had just bought an electric car and watched their electricity bill climb every month. They wanted to make more of their own power without filling the whole garden with equipment.

## The challenge [.h4]

The roof faces south-west and is shaded by a tall tree for part of the afternoon. Most of the household's use happens in the evening, when the car is plugged in and the kitchen is busy, so a panels-only system would have exported much of its output for very little return.

## The system we designed [.h4]

We mapped the shading over a full year and placed the panels where the roof sees the most sun. A battery in the garage stores the midday surplus for the evening peak.

- 18 panels, 7.2 kWp in total, with optimisers on the shaded rows
- A 10 kWh battery and a hybrid inverter in the garage
- Smart car charging that follows solar output during the day
- Monitoring app with live production and savings

## The result [.h4]

In the first year the system produced 7,900 kWh, and the household bought 71% less electricity from the grid. At current tariffs the system pays for itself in under seven years, and the battery keeps the lights and the fridge on during short power cuts.