Metal hydride hydrogen storage canisters developed and manufactured by Horizon Fuel Cell Technologies are designed with an aluminum alloy enclosure and a ReNi5 alloy for hydrogen absorption. After activation (canisters are shipped inactive), the ReNi5 alloy is capable of absorbing hydrogen, expanding and releasing heat until saturation. The internal pressure of the canister remains at 8 Bar at ambient temperatures of 20C-25C. Once the canister valve is opened and pressure is reduced, hydrogen will be continuously released from the alloy which will absorb heat. If the heat absorption rate decreases, so will the hydrogen release rate.

The canister enclosure materials are made of an aluminum alloy which has excellent heat conductivity properties facilitating heat conduction of the alloy during gas absorption and release processes. Gas absorption efficiency of the alloy can be significantly impacted by oxidization due to humidity, therefore dry hydrogen gas with a purity of no less than 99.99% is required for filling.