Home & Office Solar Sizing Calculator

Powering a home office with solar

A home office is one of the most rewarding loads to put on solar, for a simple reason: it runs almost entirely during daylight hours. Where a household's biggest demands often fall in the evening, office equipment — computers, monitors, lighting, networking — draws power precisely when your panels are generating most. That overlap means a high share of self-consumption, which (as solar economics now reward) makes the savings unusually strong even where export rates are poor. If you work from home, your roof can cover your working day with very little waste.

The rise of remote and hybrid work has quietly created an ideal solar use-case that didn’t exist at scale a decade ago: a household that consumes a steady, predictable chunk of electricity in the middle of the day, every working day. That pattern is almost tailor-made for rooftop solar, because it lets you consume your own generation as it happens rather than exporting it for a pittance and buying it back after dark. For anyone weighing whether solar "makes sense" for them, working from home tips the scales noticeably in solar’s favour. The calculation below helps you see how much of your working-day energy a given array would cover, and where the line falls between the light electronic loads that solar handles effortlessly and the heavier climate-control loads that need more thought.

What a home office actually draws

Office loads are modest compared with heating or cooking. A laptop draws perhaps 30–65 W, a desktop with a monitor 100–300 W, networking gear 10–30 W, and lighting a few tens of watts with LEDs. The big variable is whether your "office" also runs climate control — a space heater or air-conditioner can dwarf all the electronics combined. For an accurate estimate, separate the steady electronics load (which solar covers beautifully) from any heating or cooling (which is larger and more seasonal). Multiply each device's wattage by its daily hours to get watt-hours, as in any load calculation.

Why daytime use makes the economics work

Because a home office consumes power during peak generation, most of the solar it uses is self-consumed at full retail value rather than exported cheaply. In a world where export rates have fallen well below retail — California's NEM 3.0, the UK, Pakistan, and increasingly elsewhere — that daytime alignment is exactly what maximises savings. A relatively small array dedicated to office loads can offset them almost entirely without needing a battery, because you're using the power as it's made. This is the opposite of, say, evening cooking loads, which need storage to be solar-powered.

Backup matters for work

For many remote workers, keeping the office running through a grid outage is as valuable as the savings. A modest battery can keep a laptop, monitor, router and lights going for hours — office loads are light, so a small bank gives long runtime — and it switches over instantly, unlike a generator. If your livelihood depends on staying online, pairing a small solar-plus-battery setup sized to your office loads is an affordable resilience measure. Our battery runtime calculator can estimate how long a given battery would keep your office powered.

Tax and the home office

If you run a business or work for yourself, the electricity your home office uses — and in some places a portion of a solar system that powers it — may have tax implications, such as deductible business-use-of-home expenses. The rules vary widely by country and situation, and we're not tax advisers, so treat this only as a prompt to ask a qualified professional. The energy side is what this tool addresses: knowing how much electricity your office consumes is the starting point for both sizing solar and, if relevant, documenting business energy use accurately.

Frequently asked questions

Often just one to three panels cover typical office electronics, since laptops, monitors and networking draw little. The number rises sharply only if you include space heating or air-conditioning. Enter your equipment above for a tailored estimate.

Yes — unusually so. Because it runs during daylight, most of the solar it uses is consumed on-site at full value rather than exported cheaply, which maximises savings under modern tariffs without needing a battery.

Not for savings, if you work during daylight — you use the solar as it's generated. A battery is worth it mainly for backup, to keep you online through outages. Office loads are light, so even a small battery gives useful runtime.

Climate control. The electronics are small, but a space heater or air-conditioner can use more than everything else combined and is seasonal. Size for it separately if your office is heated or cooled.

It can tip a borderline case into a clear yes, because it raises your daytime self-consumption — the most valuable kind of solar use under today's tariffs. If much of your household's electricity is now used during working hours at home, more of your generation is consumed at full retail value instead of exported cheaply, which shortens payback.