Backup power and solar for a small business or shop
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For a small business, a power cut isn’t just inconvenient: it means lost sales, spoiled stock and idle staff. The good news is that many businesses are open in daylight, which makes solar a natural fit. Here is how to plan.
Step 1: separate what must run from what would be nice
List every electrical item, then sort it into:
- Must run: what stops you trading. Card terminals, the till or laptop, Wi-Fi, lights, security cameras, a drinks fridge or freezer holding stock, the tools of your trade (clippers and dryers in a salon, a sewing machine, a printer).
- Nice to have: comfort and extras, such as air conditioning, a TV or a kettle.
- Leave on the grid or generator: heavy machines such as welders, grinders, large compressors and ovens. These are usually far too big for an affordable battery system.
Size the backup system for the first list. Each item you move off it can cut the cost substantially.
Step 2: count hours the way the business uses them
For each must-run item, note its watts and how many hours a day it runs during opening hours. A drinks fridge runs on and off all day; a card terminal sits mostly idle; lights may be on all day. See how to find your appliances’ watts.
Step 3: match solar to your opening hours
If you trade mainly in daylight, solar can power the business directly while the sun shines, and a smaller battery only has to cover cloudy spells, early mornings and evenings. In the calculator, choose “Power everything, every day” for solar and set the hours without grid power to match your outages during opening hours.
Businesses that trade late into the evening need more battery, since solar has stopped producing.
Step 4: think about peaks, not just totals
Several things starting at once can overload an inverter: a freezer compressor, a hair dryer and a printer warming up together, for example. Plan which heavy items can run together, and size the inverter for that. See kVA vs kW.
Example: a small shop
- LED lights: 10 × 10 W, 10 hours
- Drinks fridge: 200 W, cycling about 12 hours a day
- Card terminal, router and phone charging: about 40 W, 10 hours
- Laptop: 60 W, 8 hours
- Security cameras: 40 W, 24 hours
That’s roughly 5.2 kWh a day, with a running load under 500 W. A modest inverter covers it, and the battery and panels depend on outage hours and local sunshine. Run the numbers for your own shop in the calculator.
Practical points for businesses
- Protect stock first. A fridge or freezer of stock is often worth more than the rest of the system. See fridges on backup power.
- Put must-run items on their own circuit, so heavy equipment can’t drain the battery by accident.
- Security matters. Panels, batteries and inverters are valuable. Mount panels securely and keep batteries in a locked, ventilated space.
- Ask about warranties and service response times, since downtime costs money. See questions for installers.
- Compare against your generator costs. For many businesses the fuel saved is what pays for the system. See inverter vs generator.