HPS system - picea as a source of electricity and heat?

Hello dear ones,

I have been following along diligently for several weeks now. We are currently in the planning phase of our single-family house in the outskirts of Munich and are currently dealing with ... well... everything basically.

Among other things, we actually fell for the picea system from HPS Home Power Solutions very early in our planning process. This system is not cheap, but the concept convinced us. For everyone who has never heard of it: this is a power storage, heating support, and ventilation device all in one. Simply put, electricity is generated via a photovoltaic system, fed into a battery storage, and simultaneously (if enough electricity is generated by the sun) converted into hydrogen via an electrolyzer and stored in hydrogen tanks. The waste heat generated is used to support the hot water. In winter or when no solar power is generated, the hydrogen from the tanks is converted back into electricity, and the waste heat produced is fed into the ventilation system. This way, you can use the self-generated solar power throughout the entire year.

So far, so good. We have already done a lot of reading and today had a conversation with a representative from the company; however, he quickly put a damper on our hopes and said that we would still need an additional heating system. Since the picea system is already very expensive (just under €100,000 – 900 kWh hydrogen storage, ventilation device with heat exchanger, 25 kWh battery included; approx. €15,000 subsidy) and unfortunately we have not (yet ;-) ) won the lottery, despite all ecological benefits, we cannot push such a system to the extreme.

Has anyone of you by chance already installed a picea and can report on how you handled the hot water and warm air production?

We want to build a passive house if possible. About 220 sqm total area (including basement with granny flat), roof sheathing up to approx. 15 kWp facing south and also possible on our property to the north (about 60% capacity). We are still looking for a building partner (we have talks with construction companies, architects, planning offices, individual trades, etc.), so nothing is set in stone yet.

There are currently two of us, but it could become about 4 people and 2 dogs.

I would be very happy about experience reports or sensible alternative suggestions that are similarly ecological!

If you are concerned about ecology, I would steer clear of it. The conversion losses from photovoltaics->hydrogen->fuel cells->electricity alone are probably far too high. Aside from that, mass production probably only started at the end of last year, which would be way too uncertain for me given the amount. For that money, you can buy 10 batteries ...

I have no experience with the Picea system, know the concept and find it wonderful. If independence and climate awareness are more important to you than profitability, go for it. You can nitpick the efficiency of converting into hydrogen for long-term storage. But don't forget that the inefficiency is climate-neutral and therefore a financial factor – it remains environmentally friendly in any case. I am working with a customer on a project where electrolyzers produce hydrogen for public transport vehicles from photovoltaics. The technology is not new but proven. The efficiency is still being improved. Those who embrace new things always have to deal with doubters. Some bring good arguments, many just prejudices. Every time I mention our solar tiles here, the same people come and have to comment negatively.

The concept is good and will also work if it works. You are buying the 0-series, a new and complicated product. I am relaxed about the expected runtime of 10, 20, 30 years, we did not buy the system. Still too uncertain and too expensive for us.

Thanks already for your answers!

Thank you for your kind words! So far, we have been able to convince everyone we spoke to in person about the system, at least of its theoretical brilliance. Whether it’s feasible for us is still up in the air and depends heavily on whether we need to install an additional heating system. I hadn’t heard of solar tiles until your post, but they somehow look really appealing :)

The efficiency of the picea system is actually quite decent. Unfortunately, 10 batteries won’t get us through the winter :( I agree with you that series production has only just started and it’s pretty expensive!

Which system did you decide on?

The Picea system was too expensive for us. The idea of storing the self-generated electricity so that it is available 365 days a year and also bridges the winter is good. However, you see, it is not enough for heating. Our heating system is an air heat pump, so we heat with electricity. The consumption costs are somewhat higher than with gas; we omitted the gas connection. We could generate electricity ourselves with a photovoltaic system, but not gas. Our electricity consumption is 6000 kWh, half for the heat pump and half for the household. If we install a photovoltaic system generating 10,000 kWh, we feel morally positive that we produce more than we consume. At the moment, we lack the finances for the photovoltaic system, but it will come.