ᐅ Fuel cell or operating costs, photovoltaic systems and solar thermal energy?
Created on: 5 Jun 2019 08:51
J
Jupiter1234
Greetings,
I am currently working on the heating system.
We are taking over the house and property of my grandparents, built in 1948.
I don’t need to describe the current condition here, as we are planning a complete renovation anyway.
A gas heating system is installed.
The plan includes roof refurbishment, exterior insulation, new windows with triple glazing, underfloor heating in the bathroom, and a new heating system in general.
I am weighing my options.
I have come across fuel cell heating systems from manufacturers like Buderus and Viessmann and find the technology really impressive. However, I wonder if it is wise to remain dependent on natural gas. In the end, it is a great technology but still based on natural gas. My electricity would also come from fossil fuels, and I’m not really comfortable with that idea.
As an alternative, I have considered simply replacing the old gas heating system with a condensing boiler and installing a sizeable solar thermal system and photovoltaic panels on the roof. Combined with a large buffer tank and a battery in the basement, I should be able to cover the emission-free heating demand during the sunny months. In winter, the fuel cell system would probably still trigger the boiler to handle peak heating demand.
However, the roof slopes face east-northeast and west-southwest, which is not ideal.
The property is quite large, though, so there is the possibility to place the modules somewhere in the garden.
I really like the idea of combined heat and power (CHP), but in the end, the power would still go out if the gas supply is cut off.
Does anyone have an opinion for me?
Thank you
I am currently working on the heating system.
We are taking over the house and property of my grandparents, built in 1948.
I don’t need to describe the current condition here, as we are planning a complete renovation anyway.
A gas heating system is installed.
The plan includes roof refurbishment, exterior insulation, new windows with triple glazing, underfloor heating in the bathroom, and a new heating system in general.
I am weighing my options.
I have come across fuel cell heating systems from manufacturers like Buderus and Viessmann and find the technology really impressive. However, I wonder if it is wise to remain dependent on natural gas. In the end, it is a great technology but still based on natural gas. My electricity would also come from fossil fuels, and I’m not really comfortable with that idea.
As an alternative, I have considered simply replacing the old gas heating system with a condensing boiler and installing a sizeable solar thermal system and photovoltaic panels on the roof. Combined with a large buffer tank and a battery in the basement, I should be able to cover the emission-free heating demand during the sunny months. In winter, the fuel cell system would probably still trigger the boiler to handle peak heating demand.
However, the roof slopes face east-northeast and west-southwest, which is not ideal.
The property is quite large, though, so there is the possibility to place the modules somewhere in the garden.
I really like the idea of combined heat and power (CHP), but in the end, the power would still go out if the gas supply is cut off.
Does anyone have an opinion for me?
Thank you
There are also stoves that are room air-independent, with a fresh air supply from outside and airtight doors. Or stoves with a water connection to heat the central heating water. However, you need to critically assess whether this is cost-effective, depending on how often you are at home to use them extensively, and whether you actually need the energy released into the living space.
Since the system temperatures are similar, the following combination would work: gas boiler + solar thermal (ST) + water-bearing masonry stove.
A good match would also be a heat pump combined with photovoltaic panels, but that does not fit your setup without underfloor heating.
I just looked up the data for the Viessmann fuel cell. It only produces about 1.1 kW thermal and 0.75 kW electric output. That’s very low. Calling it a fuel cell heating system is quite an exaggeration.
Since the system temperatures are similar, the following combination would work: gas boiler + solar thermal (ST) + water-bearing masonry stove.
A good match would also be a heat pump combined with photovoltaic panels, but that does not fit your setup without underfloor heating.
I just looked up the data for the Viessmann fuel cell. It only produces about 1.1 kW thermal and 0.75 kW electric output. That’s very low. Calling it a fuel cell heating system is quite an exaggeration.
J
Jupiter12345 Jun 2019 13:31Well, by gas valve I meant that socially, heating with gas is becoming less acceptable, or that economically it might no longer make sense in about 20 years, because gas prices have become extremely high.
Otherwise, the statement about natural gas is only partially true. That may be the case today, but there are already systems that convert excess eco-friendly wind power into hydrogen for storage instead of wasting it. However, this is not yet done on a large scale, which is why industries currently produce hydrogen from natural gas – but that will likely change in the future.
When it comes to technology, I am very optimistic and always expect the best.
Regarding durability, your point was definitely a good prompt:
"According to the manufacturer, maintenance is only necessary every five years. The fuel cell stack is designed for a lifespan of 12 years, but the device itself can operate for up to 20 years."
I had completely wrong assumptions there. I initially assumed the unit would just sit unused in the basement for at least 20 years anyway.
If it were a new build, I would agree with just installing a heat pump plus photovoltaic panels and that would be sufficient. But since this is an older building with ceiling heights of only 2.45 meters (8 feet), I didn’t want to install underfloor heating everywhere, as that would reduce ceiling height even more.
Otherwise, the statement about natural gas is only partially true. That may be the case today, but there are already systems that convert excess eco-friendly wind power into hydrogen for storage instead of wasting it. However, this is not yet done on a large scale, which is why industries currently produce hydrogen from natural gas – but that will likely change in the future.
When it comes to technology, I am very optimistic and always expect the best.
Regarding durability, your point was definitely a good prompt:
"According to the manufacturer, maintenance is only necessary every five years. The fuel cell stack is designed for a lifespan of 12 years, but the device itself can operate for up to 20 years."
I had completely wrong assumptions there. I initially assumed the unit would just sit unused in the basement for at least 20 years anyway.
If it were a new build, I would agree with just installing a heat pump plus photovoltaic panels and that would be sufficient. But since this is an older building with ceiling heights of only 2.45 meters (8 feet), I didn’t want to install underfloor heating everywhere, as that would reduce ceiling height even more.
J
Jupiter12345 Jun 2019 13:34fragg schrieb:
I just looked at the data for the Viessmann fuel cell. It only has 1.1 kW thermal and 0.75 kW electrical output. That's not much at all. Calling it a fuel cell heating system seems like a stretch. Right?
“The fuel cell heating system is suitable for an annual heat demand of up to 32,000 kWh per year and an electricity demand of up to 6,200 kWh. The Vitovalor PT2 can produce a maximum of 18 kWh of electricity per day.”
That sounded okay to me as a layperson. The two of us currently use only about 1,500 kWh in our 90 m² (970 sq ft) apartment, even though I work from home. And my grandparents, in that very same house with the old gas boiler, used 30,000 kWh of gas last year.
So I expected that this would be sufficient. Of course, it should be noted that there is always a condensing boiler alongside the fuel cell system in case the fuel cell’s output is not enough during the winter. So it definitely doesn’t work entirely on its own here either.
B
boxandroof5 Jun 2019 14:42Jupiter1234 schrieb:
I’m going back and forth on this.Proper insulation, carefully planned surface heating (underfloor heating, wall, ceiling, or high-capacity radiators). Then a compact, affordable, and easy-to-install or replace heat pump (not a split system) together with as much photovoltaic as possible—that would be my approach. Make sure to take advantage of any subsidies for the heat pump.It will never work without electricity, and you won’t need more than that. The car will soon run on electricity too.
If cost-effectiveness is less important than being “green,” install a battery storage system right away; otherwise, do it later.
Jupiter1234 schrieb:
in maybe 20 years it won’t make sense anymore because gas has become brutally expensive.1. You would have heated for 20 years with one of the most economical systems available. 2. Why should gas become “brutally” expensive by then? Nord Stream 2 adds another 55 billion m³/year (cubic meters per year), MONACO can provide about 17 billion m³/year. The supply is increasing faster than demand, which is driven primarily by the base-load combined cycle power plants (CCPPs) to be built that will replace coal and nuclear power. As long as the tax burden per cubic meter of gas doesn’t rise excessively, I currently see few indications that would justify a disproportionate increase in gas prices.
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