Heat pump with photovoltaics vs gas and solar thermal

60 k € for a heat pump? Then it must be with gold leaf, right? :x *duck*

No, platinum.

Jokes aside, I have a heating load of 25 kW and that has to come from somewhere.

In 2012, when I bought the heating system, the costs would have been in that range. At the moment, I don’t know if anything has changed since then.

The brine water heat pump itself costs around 10K € (including accessories). The drilling is naturally variable - and it is correspondingly more expensive with a high heating load. Furthermore, you certainly cannot operate with a low flow temperature (unless it is 500 sqm of living space) - I would think I would also use gas there... or pellets - simply more robust. Alternatively, one could of course consider options for reducing the load.

If you have an 8400 kWh heating load, that corresponds to about 850 liters of heating oil (if gas is not available, there would be liquefied gas with an underground tank). At current prices, that would be €400/year.

Why should there be no ROI? I would have had to invest €60,000 for the heat pump solution versus €12,500 for the gas condensing boiler solution??? That would be €47,500 ADDITIONAL COSTS—when do I get that back => ROI??

If I now get the heat pump solution for €30,000 in 10 years, then I have the gas condensing boiler....

Where is my thinking error now???

I don’t pay 20 cents for it like you, but only 1.5 cents. Ok, I have to store the wood and I have to light the stove, but I would do that anyway because I like that warmth.

I don’t have a fireplace stove that ‘glows’; my stove is 2.5 m long and stands as a room divider between the living area and kitchen/dining area. It releases the stored heat slowly into the room. If I put wood on for the last time at 6 pm, then the next morning at around 30 degrees surface temperature. If I sit on the stove bench in the morning with my coffee, I have a nice warm back....

For me, the supplier = the grid operator (Bayernwerk AG formerly E.ON). I have to check whether it is actually possible to change the supplier. Although I don’t know what happens to the 10% non-refundable feed-in. So far, it was offset against my consumption.... We’re talking about approx. 3000 kW

I don’t have time right now, but your numbers don’t add up at all. Your stated 10 kg of wood costs, according to your own numbers, €1.45 (then 100 kg would be €14.5 and 550 kg your quoted price), and produces significantly less heat than the heat pump for €1. You want to compare and talk about numbers, but they are all wrong (including the heating oil number)? Take your time to calculate!

ROI denotes a return as the ratio of profit to capital, but a heating system doesn’t generate profit, it only costs money. This term fits at most your solar system.

And you haven’t said anything about solar thermal yet.

And the thinking error lies in the higher consumption of the gas boiler.

By the way, there are also heat pumps available easily for 50 kW load and higher.

your numbers don’t add up at all.

correct
1 rm wood costs €80 and weighs 550kg efficiency 80% = 440kg, 10 kilos then cost €1.81. 10 kg of wood have a heating energy of 10*4 = 40kwh. If I now divide 1.81 / 40 then I have the price for one kwh at 80% efficiency of 0.045 (no idea where I made the calculation error earlier).

If I now assume your electricity price of 20 cents (I currently pay 31 gross) and an AP of 6 then I don’t see any significant savings that would make the additional investment in a heat pump solution attractive to me.

Back then the heat pump was offered to me and it was far from what I was willing to invest. By the way, if I look at the investment from Sarrus with a heating demand of 8kw €20,000 and I only take the difference to my heating system, I am already at €7,500 additional costs.

For me, the ROI consideration is not the heating system itself but the ADDITIONAL COSTS the heat pump solution would have cost me.

People talk about how great the heat pump is and how economical etc...

BUT I DON’T SEE IT

Maybe someone can explain to me now where my thinking error is that I would be cheaper with a heat pump... Please bore a few holes into the board in front of my head because from the numbers discussed so far I see no significant savings that justify the additional costs.

Besides, you probably cannot work with low flow temperature (unless it is 500 sqm of living space.) - I would probably take gas there too... or pellets - simply more robust.

Areas:
Underfloor heating area 240 sqm apartment on the ground floor, and 340 sqm office on the upper floor,
without underfloor heating on the ground floor heating/technical room and garage 100 sqm.

The brine-water heat pump itself costs around €10,000 (including accessories). The drilling is of course variable - and much higher heating load is correspondingly more expensive

A wall-mounted gas condensing boiler costs around €2,000. Installed in the attic and a 50mm plastic pipe through the roof for the exhaust gases and that’s it... No need to build a chimney or boiler room.

You throw out completely unfounded claims and you expect me to research them for you now?

How about you make the effort to be able to justify wild claims?

Why unfounded? Just because you don't have the knowledge or what? If you know better, why don't you argue against it? Or instead make the effort to close your knowledge gaps. Since when is that the job of a third party? Do you do that at work too?

In this price range, you don’t have a boiler with 95% efficiency at 25kW output? Which chimney sweep approves this gas boiler according to your setup and allows me to operate it? It can’t get more blatant than that. With the previous example with the wood (with the buffer tank temperature), you didn’t reach 40kWh, but 23kWh with the 10kg. With my electricity price, the saving looks small (1 cent less), but percentage-wise it’s 25%. Apart from that, you haven’t said anything about the costs of the fireplace, water jacket, and the large buffer tank. I only have the heat pump with an integrated storage as a contrast. So don’t just compare the cost of the boiler. Additionally, I would have had to buy a gas/oil tank, which would have caused significant additional costs, running costs, and space requirements. So with me, I have slightly higher investment but lower operating costs. I don’t understand your problem with the heat pump. It may not be worthwhile for your circumstances, but for other situations, heat pumps are definitely a good and affordable alternative. You just don’t want to admit that. Furthermore: the higher the demand, the more important the operating costs become. Therefore, all heating technologies definitely have their justification.