Solar Panels for Garden Offices, Sheds and Outbuildings in Ireland

Solar panels for a garden office in Ireland can cut an electricity bill that otherwise runs through your home supply, and a shed or outbuilding is no different. A garden room is usually powered by an extension cable from the house, which is fine until you add heating and the running costs climb. You can either extend your home system to the outbuilding or fit a small stand-alone array on its roof. This guide explains how much power a garden office actually uses, how to size solar for it, what it costs at the time of writing (October 2026), and how the SEAI grant applies.

How Much Electricity Does a Garden Office Use?

It depends almost entirely on how you heat it. A laptop, monitor, router and LED lights together draw only around 150 to 250 watts, so a full working day of computing uses roughly 1 to 1.5 kWh. Add an electric heater, though, and the picture changes, because a single 2 kW heater can use 6 to 8 kWh across a working day.

*Figures are typical for an Irish garden office and vary with insulation, heater type and working hours.

At a daytime rate of roughly €0.35 to €0.42 per kWh, heating a garden office electrically can add €500 to €900 a year to your bill. That is the cost solar is competing against.

Can You Power a Garden Office with Solar Panels?

Yes, and there are two sensible ways to do it. The first is to extend your existing or planned home solar system to the outbuilding with a buried cable and a small consumer unit, so the office runs on the same solar and battery as the house. The second is a stand-alone solar and battery system mounted on the outbuilding itself, which suits a garden room far from the house or a property with no home solar.

• Extending the home system is usually the cheapest option if you already have solar or plan to add it, because one inverter and one battery serve everything.
• A stand-alone array on the garden office roof is self-contained and works even if the office sits well away from the house.
• Both options can include a battery, so power generated at midday is available for evening use.

Rooftop solar on houses is exempt from planning permission across Ireland, and the 2022 regulations extended exemptions to many other buildings, though larger or ground-mounted systems and certain locations have their own rules. The Government's solar planning exemptions set out the detail.

How Big a Solar System Does a Garden Office Need?

Size the array around the office's daytime load, not its total energy use. Because a garden office is used mostly during daylight, solar matches its demand well.

• A 1 kWp array generates roughly 900 to 1,000 kWh a year in Ireland, enough to cover computing, lighting and a small fridge.
• A 2 kWp array covers those loads with room to spare, and can send surplus power back to the house.
• If you heat the office electrically, size the system to offset the heater or accept that some winter heating will come from the grid.
• A battery of 5 kWh lets you shift surplus daytime power into the evening, when the office is often still in use.
• Roof space, orientation and shading decide what is realistic, so a survey matters more than a rule of thumb.

What Do the Grants Cover?

The SEAI solar PV grant is tied to your home, not to a separate outbuilding, so the smartest route is usually to extend the home system rather than build a stand-alone one. At the time of writing (October 2026), the grant pays up to €1,800 for solar PV, and a battery of 5 kWh or larger now attracts a separate €600 grant, which brings the maximum combined support to €2,400. Eligibility has also been widened to homes built and lived in before 2025.

• The solar PV grant is a once-off payment per home, claimed before any work begins.
• The €600 battery grant applies to systems of 5 kWh or larger.
• A stand-alone system on a detached outbuilding is generally not covered, which is another reason to extend the home installation.
• Our SEAI grant guide explains the current amounts and the application steps.

Is Solar for a Garden Office Worth It?

For a home office that is heated electrically, yes, in most cases. You are replacing power bought at retail rates with power you generate yourself, and the office's daytime demand lines up neatly with when solar produces most. The case is strongest when the solar is part of a wider home installation, because the grant, the 0% VAT on solar, and a single battery all do more work across the whole property.

The case is weaker for a lightly used, unheated shed, where the electricity bill is small to begin with. If your garden room runs a heater through the winter, solar plus a battery is one of the better ways to bring that cost down.

Final Thoughts

A garden office is a small building with a real electricity bill, and solar is a natural fit because its demand peaks in daylight. Extending your home solar system to the outbuilding is usually the cheapest and best-supported route, and a battery lets you keep the power for the evening. For anyone who works from home in Ireland, it turns a running cost into an asset.

Ready to Power Your Garden Office with Solar?

WattCharger designs and installs solar panel and battery storage systems for Irish homes, and can size an array that covers your garden office as well as the house. Get in touch for a free consultation and a customised quote that takes your outbuilding into account.