ᐅ Electricity Costs for a KfW QNG 40 House

Currently, we pay 200 euros per year for heating costs in the apartment. A significantly higher expense is for hot water, where we currently pay around 600 euros per year.
Then there is the regular household electricity, which for us is about 3000 kWh per year (around 1300 euros).
Since we currently get heating and hot water from district heating, I am not quite sure how much the additional electricity costs for the heat pump will be per year if I move into a semi-detached house (4 people) of about 120 m² (1300 ft²), KfW 40 QNG standard.

You are familiar with the basic concepts, right?
KfW 40 has a maximum heating demand per square meter and year. If you know how many square meters you will have, you can roughly calculate the kWh as a reference value.
After that, it depends on the heat pump you use and your electricity tariff.

With heating costs of 200 euros per year, the question arises: is the house located in Germany or in the Mediterranean region? Does the house have a water-based underfloor heating system, or what type of heating is used?

dajotech schrieb:

My question is: roughly how much will I pay monthly for electricity?

You are asking the wrong question. The correct one would be: What are the heating costs for a 120sqm (1,290 sq ft) newly built house with a heat pump?

You already know your electricity costs for personal use. Those won’t change with a different property.
Heating costs = electricity consumption is the only unknown. This depends both on your behavior and the heating system design. If you keep the room temperature at 25°C (77°F) while windows are open at the same time—because "people" always want fresh air—consumption will differ significantly from 21°C (70°F) with controlled mechanical ventilation.
Expect the consumption to be around the already mentioned 1,500–2,000 kWh.

Then simply multiply by your electricity price to find out your maximum electricity cost. Maximum, because you still need to subtract photovoltaic (PV) generation. With my 10-panel system without battery storage, I have about 25% self-consumption, roughly 2,500 kWh (including an electric car, as noted). If you have storage, self-consumption can reach 45%, so you can subtract about 1,800 kWh of self-used electricity from your total consumption.

P.S. Please let go of the "40 QNG" term. It says absolutely nothing about actual consumption. Just say "newly built house" with photovoltaic and heat pump.

Nida35a schrieb:

With heating costs of 200€ per year, the question is,
is the house located in Germany or the Mediterranean region?
Does the house have a hydronic underfloor heating system, or how is it heated?

Hello Nida35a,
I currently live in an apartment within a multi-family building.
For 2022, I paid roughly 1200 euros for heating, hot water, and cold water.

Heating (underfloor heating): 230 euros per year (of which about 150 are fixed costs and 80 for consumption) – 880 kWh district heating.
Hot water: about 500 euros for 47 m³ (16.6 ft³)
Cold water: about 370 euros for 112 m³ (39.5 ft³)

KarstenausNRW schrieb:

You’re asking the wrong question. The correct one would be: What are my heating costs in a 120sqm (1300 sq ft) new build with a heat pump?

You already know your electricity costs for personal use. Those won’t change depending on the property.
Heating costs = electricity consumption is the only unknown. It depends both on your behavior and the heating system design. If you keep the room temperature at 25°C (77°F) while windows are open—because “fresh air” is always needed—your consumption will be significantly higher than at 21°C (70°F) with a controlled mechanical ventilation system.
Expect the already mentioned 1,500–2,000 kWh.

Then just multiply that by your electricity price and you’ll know your maximum electricity costs. Maximum, because you still need to subtract your photovoltaic (solar) generation. For my 10-panel system without battery storage, I have about 25% self-consumption, roughly 2,500 kWh (including the electric car as mentioned).
If you have a battery, you might get up to 45% self-consumption, so about 1,800 kWh you can subtract from your total consumption.

P.S. Please forget about “40 QNG.” That doesn’t say anything about actual consumption. Just say “new build” with photovoltaic and heat pump.

Hello Karsten,
Thank you very much.
Since we currently pay about 200 Euros for heating with an energy efficiency rating of B (I think somewhere around 80), I thought we would pay even less in a new build with KfW 40 standard. 🙂
My second unknown is hot water. At the moment, we use about 50m³ (1,765 cubic feet) per year. Do you have experience with a heat pump?
How much electricity does one need for 50m³ (1,765 cubic feet) per year?

Thank you all very much