Thick rammed earth or tyre walls, deep thermal mass and careful orientation mean these houses need little heating. What they still need is power for water pumps, greywater systems, fridges, lighting and the occasional tool. Off-grid ones often have generous generation on good days and nothing for a week when the weather sits still. Batteries alone struggle to bridge that, and owners are often reluctant to fall back on a petrol generator.
Hydrogen held at 30 bar or less keeps for weeks without losing charge, which suits a house that wants to bank surplus from a windy spell or a wet week on a micro-hydro creek. The electrolyser runs on surplus power, the fuel cell gives it back when needed, and the water it makes returns to the loop. Round-trip efficiency is 30% or less, so the source must be sized generously for the loss.
How it works →
A 15 kW system is designed for an average home, and many earthship-style houses use far less than that. It suits a larger household, a site with workshops and pumps as well as the house, or a small cluster of dwellings sharing one system. Where a single small house uses very little, the pilot would say so plainly rather than sell more than is needed. The rainwater the house already collects can feed the electrolyser after filtering and de-ionising.
It can be. It is designed for an average home. A small earthship-style house may use far less, so the system suits larger households, shared sites or properties with other loads. The pilot would be honest about it.
It needs filtered, de-ionised water, about 9 litres per kilogram of hydrogen, and the system includes treatment. Rainwater can be the source, and the fuel cell returns most of the water to the loop.
No. It is designed to charge from a wind turbine or micro-hydro off the grid, as well as from off-peak grid power where a connection exists. Many earthship-style builders choose sites with no line at all, which is the case the system is designed around.
Pilot installs go to people on this list first. Rural homes, farms and remote sites especially. No spam, no payment.