ᐅ Natural Gas + Photovoltaics – Experiences with the Energy Saving Regulation (EnEV) from 2016

Hello everyone,

A quick note upfront: we are not required to meet KfW 70 or KfW 55 standards, but of course we must comply with the 2016 energy saving regulation.

We plan to use natural gas heating combined with a photovoltaic system on the roof. We will probably use a 36.5 cm (14 inches) BIMS thermal brick.

Does anyone have experience with combining photovoltaics and natural gas? Can this setup achieve the necessary energy values without relying on very high insulation levels?

There is a lot of information online about solar thermal (for hot water) and gas, but not much about photovoltaics and gas. From my perspective, we gain more energy from the sun with photovoltaics than with two solar panels extracting heat energy.

Thank you very much for your answers.

Good morning, KfW 70 no longer exists, so you can’t comply with it.

But photovoltaic and solar thermal are two completely different things. One generates electricity, the other heats water. And as far as I know, you won’t meet the requirements with a gas condensing boiler without solar thermal, but I’m not entirely sure.

The fact that you haven’t really found much about this online is already an indication that they are not really related.

Thank you for your reply. What does a gas condensing boiler mean?

Regarding compliance with the Energy Saving Ordinance from 2016, based on my research, you need to ensure that either as little energy as possible escapes from the house or that renewable energy is integrated.

If I generate energy from sunlight and use it for my own consumption or feed surplus energy back into the grid, my research suggests that this is taken into account to comply with the general Energy Saving Ordinance. However, I am not sure how much photovoltaic systems positively influence this.

Gas condensing boiler = Gas condensing boiler

For the other part, I am unsure. Since a gas condensing boiler does not require electricity, my understanding is that it initially has nothing to do with the primary energy demand needed for heating and hot water.

Next year we are building a single-family house according to the energy saving regulations (gas, controlled ventilation, solar), and we are currently considering replacing the solar thermal system with photovoltaic panels. As I understand it, the photovoltaic system must provide the same amount of renewable energy coverage as the solar thermal system.

This means the photovoltaic energy must be fed into the hot water storage tank via a heating element. Let’s say the solar thermal system delivers 2500 kWh (26910 BTU) annually, then the photovoltaic system must be designed to produce the same 2500 kWh (26910 BTU).

Sounds straightforward at first.

I’m still researching and need to do some calculations.

Our underfloor heating system is planned so that a heat pump can be used as well. If we switch to a heat pump in about 10 years, the appropriate photovoltaic system will already be in place. Adding a battery then...

cartau schrieb:
Our underfloor heating is designed to work with a heat pump. If we switch to a heat pump in about 10 years, the appropriate photovoltaic system will already be in place. Add a battery...

And why not just go with a heat pump right away? That way, you can avoid installing solar thermal and photovoltaic systems (and the gas connection) for now. Regarding batteries, photovoltaics, and heat pumps, there are plenty of threads here showing that it’s definitely possible, but it usually doesn’t offer a financial advantage.