Update: the German manufacturer of hydrogen equipment mentioned in this article filed for bankruptcy on april 1, 2025. See: https://www.pv-magazine.de/2025/04/07/insolvenzverfahren-von-hps-eroeffnet-geschaeftsbetrieb-eingestellt/
Batteries: practical but not for long periods of time
Storing excess solar power for use later in the day, we all know how that works by now. Zonnefabriek has been installing storage systems with lithium-ion batteries from SMA and other manufacturers for a few years already. In these batteries you can temporarily store excess solar power that you don't need immediately in the home. In the evening when the sun goes down, you can draw on this stored surplus to power consumer appliances in the home. This is a very practical solution, but only for short periods of storage. Batteries are expensive and you only get economic benefit from them if they are charged and discharged frequently. Storing solar energy in a battery in the summer and not using it again until winter doesn't work. You'd have to buy a whole mountain of batteries and not be able to use them for several months until winter comes, and hope they haven't drained too much in the meantime: not practical, in other words.
The solution: hydrogen
A German company now says they have a solution to that: storage in the form of hydrogen. We have our doubts about its usability but it is nice to see exactly what they have come up with.
The product in question it the “Picea” from Home Power Solutions: This is a device that uses excess solar power from solar panels to split water into hydrogen and oxygen. The hydrogen (H2) produced is stored in tanks for the long term. In winter, the hydrogen is converted back into electricity using a fuel cell: this solves the problem of long-term storage!
De Picea from HPS (source: HPS)
The hydrogen produced is stored in these tanks (source: HPS)
Storage tanks
The product will initially be sold only in Germany. But even if it were already for sale in the Netherlands, it's not a product we would jump on without hesitation. According to the manufacturer, the storage tanks must be placed outside the home, which is probably a good idea in view of all that highly flammable gas, but of course you have to have enough space for that.
We also don't know anything about the price or efficiency of the system at this time. According to the presentation on the website, 1 system would be able to store about 1500 kWh of solar power from summer to winter, which would be fine for an average home. Therefore, we will wait and see how this product will do in the market, but we wanted to inform you about what is possible. For now, Zonnefabriek will only continue to offer “regular” battery storage; should we start doing hydrogen, you will of course be the first to hear about it!
In winter, a fuel cell converts the stored hydrogen back into electricity (source: HPS)
