Fuel cell or operating costs, photovoltaics and solar thermal?

Well, by gas valve to I meant that it is no longer socially desired to heat with gas or that it might not make economic sense in maybe 20 years because gas has become brutally expensive.

In 20 years, every current system will be at the end of its service life. Then you can switch again to whatever the current state of technology is.

Fuel cell module: 0.75 kWel

The system delivers 750W. You need expensive electricity storage to store the daily demand in between. That also costs money, and I strongly doubt that an electricity storage will last 20 years. Asked differently: Can you afford these gimmicks budget-wise? None of the options makes sense from a purely economic point of view. Everywhere you pay extra to ease your environmental conscience.

In 20 years, every current system will have reached the end of its lifespan. Then you can switch again, to whatever the current state of technology is.

Put differently: Can you afford these gimmicks from a budget perspective? None of the options make sense purely from an economic point of view. You pay extra everywhere just to ease your environmental conscience

1. Then you have heated for 20 years with one of the most economical systems there is.
2. Why should gas become "brutally" expensive by then? [...]

Of course, these are both good arguments. Why not use what is available now as efficiently as possible and then switch to whatever in the future.

Apart from that, the argument about economic viability just made me realize that a combined heat and power plant might actually be questionable in our case.
Certainly, electricity consumption will be higher in a house than in an apartment, but in the end, it only becomes economical if you consume as much of the electricity yourself as possible. And if I look at the fact that the payback in our case basically only happens through the electricity costs, then the calculation suddenly looks quite different. I might only just manage to recoup that within the lifetime of the fuel cell, if at all, and then you really have to ask yourself whether it's all that sensible.

Green is always welcome, but putting a big financial burden on yourself ... hm.

In these nice model calculations, I overlooked that households sometimes have extremely high electricity consumption. That our consumption rises from 1500kWh at 90m² to 4000kWh just because we live in a house with a few more square meters is unrealistic.

Too bad, now the whole project is in jeopardy again. I really should have done the math properly beforehand,

Put the money into insulation and well-planned surface heating, that is a prerequisite for efficient heating. Photovoltaics pays off on its own. A good heat pump does not have to be expensive. If better affordable technology is available, you can always switch.

If there is money left over, buy a power storage or rainforest certificates. It doesn't get much greener than that.

The electricity consumption in the house does not have to be higher than in the apartment.

May I ask what the OP has decided on now?

Since this is almost the only thread on the topic of fuel cell heating, I am interested in the topic and I am reviving this few-months-old thread.

Basically, a fuel cell heating system sounds great: electricity + heat from a heater powered by gas. As wrote, I also don’t think that gas prices will explode in the near future.

The question is also whether electricity will still be as "expensive" in 5 years as it is now? My future property would have a gas connection, so I am considering whether to get a cheaper gas heating system (only for heat) or to invest a bit more money in the fuel cell heating to offset the (rising?) electricity prices right away.

With photovoltaics, the main problem is that you are not at home at midday/during the day, when most electricity is generated, and therefore cannot use it yourself. Unless you buy an electricity storage, of course. But with fuel cell heating, can’t it be set so that it primarily converts gas into electricity + heat in the evening/night/early morning, and thus, unlike photovoltaics, you can use almost all the electricity yourself?

Greetings

Caution: Fuel cells and a small home combined heat and power unit are two different types of power generation!

With photovoltaics, the main problem is that you are not at home at noon/daytime when most of the electricity is generated, so you cannot use it yourself

That is not a problem. Others use this electricity just as you use "other" electricity. From an ecological and economic perspective, it currently makes the most sense not to strive for high autonomy at any cost for its own sake.