Also missing in the release are details of the power rating of the storage system. Only the storage capacity has been mentioned. Does the electrical power input and output of the installed electrolyser and fuel cell match a Tesla PowerWall 2, IE 5kW/5kVA ?
We don’t really know, but based on the current conversion technologies. The 40kWh Electrical equivalent hydrogen storage option planned for 2021 might need to be coupled to at least a 10kW electrolyser and PV system to deliver 20kW of stored energy per day. (Assumes a 80% electrolyser efficiency and 60% fuel cell efficiency for 48% trip efficiency. Losses in DC/AC Inverter and panel DC/DC converter not considered as these also occur with a Powerwall.)
Fuel cells perform best with stable loads. Hydrogen powered vehicles include a battery/super capacitor to manage peak and variable load demand.
Most homes use electricity in short high powered bursts. Solar PV also comes in a short burst over 4-8hrs daily.
It will be useful to know more assuming more complete specifications and performance data will be available for preorder customers to consider.
It might be a great way to go off grid with a smaller battery storage meeting peak demands, and the hydrogen to provide long term security over several days or longer.
