Portable power stations are battery boxes with a built-in inverter, sold by brands such as EcoFlow and Jackery and often called “solar generators”. They are popular for brownouts and evacuations. They are useful tools, but they don’t replace a solar system on your roof. This guide explains how to tell which one you need.
Two numbers to understand
- Capacity (Wh) is how much energy the battery stores. A 1,000 Wh unit can in theory run a 100 W load for about 10 hours, and somewhat less in practice because of conversion losses.
- Output (W) is the most power it can deliver at once, and it decides which appliances will start at all. Motors, compressors and pumps can draw more than their rated power for a moment when they start.
Good uses
- Lights, fans, phones, wifi and laptops during short brownouts
- Evacuation and emergency kits
- Market stalls, events, boats and camping
- Quiet backup for medical devices (check with your doctor and the device maker first)
Limits
- Their capacity is small compared with a household’s daily use. Aircon and electric cooking drain them quickly.
- A folding solar panel recharges them slowly.
- Batteries wear out with use. Check the rated cycle life before you buy.
Solar water pumps
For farms and gardens, a solar water pump can run directly from panels during the day and fill a storage tank for use at any time. A pump is sized by how much water you need each day and how high the water has to be lifted, from the water level in the well to the top of the tank. Ask for a design based on your own well and tank, not a generic kit.
When a rooftop system is the better buy
If you find yourself adding up power stations to cover a whole home, a hybrid rooftop system is usually the better long-term investment. Send us your list of appliances and we will tell you which approach fits.