ᐅ Cold district heating with ground source heat pump

Created on: 25 Feb 2021 21:16
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DaniMartinez
Hello everyone,

I hope you can help me. In our development area, there will be a cold local heating network, where the energy provider supplies the heat pump in the house through deep drilling and a connected ring main network.

We have been considering integrating a photovoltaic system to use the self-generated electricity to power the heat pump. So far, so good! Today we received a letter from the energy provider stating that, for billing reasons, it is not possible to use the self-generated electricity for the heat pump.

Here is the original wording:
“As you have correctly understood, for billing reasons it is not feasible to register self-generated electricity from a photovoltaic system. By feeding it into the system through us, there would additionally be the disadvantage that the full Renewable Energy Act surcharge would apply to all electricity, so the benefit of self-generated electricity would no longer be fully realized.”

Has anyone heard of something similar? Is it really not possible?

If that is the case, a photovoltaic system almost doesn’t make sense anymore. The contract conditions do not state anywhere that self-generated electricity cannot be used for the heat pump.

Thank you very much in advance!
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DaniMartinez
26 Feb 2021 09:02
MayrCh schrieb:

The setup as I understand it:
Heat pump owned by the utility company. The network is not a closed loop but has supply and return lines, so it’s a tree topology. The supply line carries a "higher" temperature, the heat pump extracts energy and sends the lower temperature return back to the primary side generator. If the operator then receives photovoltaic electricity from the customer, in my layman’s understanding, the Renewable Energy Act applies.

This is how the principle works here... I’m also a layperson and don’t really understand it, but somehow I feel like we’re being taken advantage of!

Infographic of geothermal heating with ground probes, heaters, and piping.
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MayrCh
26 Feb 2021 09:03
DaniMartinez schrieb:

How do you especially understand the last part? ‍
That the property boundary starts at the heat meter. This is usually the case.
DaniMartinez schrieb:

In that case, it might almost be more cost-effective to drill on my own property...
Typically, in areas with district heating, there is an obligation to connect. So it’s not that easy to avoid.
DaniMartinez schrieb:

Somehow I feel like we are getting screwed over!
Did anyone force or pressure you when choosing your plot?
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DaniMartinez
26 Feb 2021 09:05
superzapp schrieb:

Heat sold to third parties from self-generated electricity is simply not subject to the Renewable Energy Act!
It’s heat, not electricity. That’s just how energy producers are. Of course, I’m not a lawyer, but if it’s not in the contract? How do they want to technically prevent it? Have they only just realized that electricity from homeowners’ solar panels is bad for their business?

Thanks for your reply!! I’m currently researching this, but apparently, there should be a heat meter installed behind the heat pump to handle the billing! Unfortunately, I have no idea if or how it can be technically prevented that I supply the heat pump with my own electricity ‍♂️
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DaniMartinez
26 Feb 2021 09:07
MayrCh schrieb:

The property boundary usually starts at the heat meter. That is common practice.

In general, in residential developments with district heating, there is an obligation to connect. So you can't easily avoid it.

That's true, but interestingly, no one in the municipality knew that you cannot use self-generated electricity to power the heat pump! They apparently forgot to inform about the energy consumption, and the energy supplier even promoted at their information event that you could use self-generated electricity for the heat pump!
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DaniMartinez
26 Feb 2021 09:11
MayrCh schrieb:

The property boundary usually starts at the heat meter. This is the standard practice.

Typically, in residential areas with district heating systems, there is a mandatory connection requirement. So it’s not that easy to avoid it.

Did anyone pressure or force you when choosing the plot?

Sorry, I missed the last question... so the municipality first sent the offers for the plots but then subtly implied that you can only keep a plot if you participate! I would say that is mandatory.
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DaniMartinez
26 Feb 2021 09:14
T_im_Norden schrieb:

Is your supplier providing the water for the heat pump, and is the heat pump powered through your electrical grid?
This is how the system works here... a heat meter is installed behind the heat pump...! We can also get household electricity from any company, so it seems the heat pump runs separately in that case?!

Infographic: geothermal system with ground probes, pipes to houses, heating/hot water.