---
title: "Is a home battery worth it? A simple way to decide"
description: "Evening usage, peak tariffs, and outages decide whether storage pays off. Here is how to check yours."
url: "https://ecozen-astro.pages.dev/blog/is-a-home-battery-worth-it/"
date: "2026-10-07"
author: "Clara Morel"
---

# Is a home battery worth it? A simple way to decide

> Evening usage, peak tariffs, and outages decide whether storage pays off. Here is how to check yours.

## What a battery actually does

Solar panels produce most of their energy around midday, while most homes use most of their power in the morning and evening. A battery stores the midday surplus and releases it later, so you buy less from the grid when prices are higher.

Whether that is worth paying for depends on three things: how much you export today, how big the gap is between the price you pay and the price you get for exports, and how much you value backup power.

## Step 1: Find your evening gap

Look at a typical day in your monitoring app or smart meter data. Note two numbers:

- **Daily export:** solar energy sent to the grid because nobody was using it
- **Evening import:** energy bought from the grid between sunset and bedtime

The smaller of the two is roughly what a battery can shift each day. If you export 8 kWh but only import 4 kWh in the evening, a battery of about 5 kWh usable capacity covers most of the benefit. A larger one would sit partly empty.

## Step 2: Put a price on each kilowatt-hour

Every kilowatt-hour a battery shifts saves the difference between your import price and your export credit.

| Import price | Export credit | Saving per kWh shifted | Yearly saving (4 kWh a day) |
| ------------ | ------------- | ---------------------- | --------------------------- |
| 0.30         | 0.05          | 0.25                   | about 365                   |
| 0.30         | 0.15          | 0.15                   | about 219                   |
| 0.40         | 0.08          | 0.32                   | about 467                   |

Figures are in your local currency and assume around 300 useful cycles a year. Winter months shift less because there is less surplus to store.

If export credits are close to the import price, a battery saves little. If export credits are low or zero, storage becomes much more attractive.

## Step 3: Check your tariff options

Time-of-use tariffs change the picture. Some homes charge the battery from the grid overnight at a cheap rate, then use that energy during the expensive evening peak. This works even in winter, when solar output is low. Ask your supplier which tariffs are available for homes with solar and storage before you decide on battery size.

## Step 4: Decide how much backup you want

Not every battery keeps the lights on during a power cut. Backup needs the right inverter and a switch that isolates the home from the grid. There are two common setups:

1. **Essential loads:** a separate circuit for the fridge, lights, router, and a few sockets. Cheaper and keeps the battery running longer.
2. **Whole home:** the full house runs from the battery. More convenient, but heavy loads such as ovens or heat pumps drain it quickly.

If outages are rare where you live, backup is a nice extra. If they are frequent, it may be the main reason to buy.

## Payback in plain terms

Divide the installed cost of the battery by the yearly saving from Step 2. Most home batteries carry a warranty of around ten years, so a payback under eight to ten years is usually a sound decision. A payback much longer than the warranty means you are paying for backup and independence rather than savings, which can still be a fair choice.

## Questions to ask an installer

- What is the usable capacity, not just the rated capacity?
- How many cycles or how much energy throughput does the warranty cover?
- Can the battery charge from the grid on a cheap overnight tariff?
- Does the system provide backup, and which circuits does it cover?
- Can more battery modules be added later?

A battery is rarely a bad idea, but it isn't always a good investment on day one. Run the numbers for your own usage, and you'll know which it is for your home.