Is insulation worth it beyond the new construction standard?

Interesting topic. What I did not understand, however, are the following terms:

Share of Windgas
and Biogas.

I would be particularly interested at first in the production of wind gas and its usability for homeowners. I am quite unfamiliar with this and have never (really) read anything about it.

With biogas, however, I am quite sure that it primarily (besides a huge pile of substrate residues) still produces electricity via a generator in the plant, which is sold to the local energy suppliers through fixed purchase agreements. It is possible that no gas is left over for the homeowner here.

But I may be mistaken and am happy to educate myself further.

Biogas can be fed into the regular gas grid (under certain conditions) and used, for example, for gas condensing boilers or even for mini combined heat and power plants.

I have already heard of "Mini-Biogasanlagen" for "Hausgebrauch," also that biogas can power combined heat and power plants. In practice, in my opinion, it does not occur very often.

Windgas is, however, not even familiar to me by name and represents my primary interest. It brought a broad smile to my face very, very early on and was therefore valuable. That is how one should always start the day.

I did not know the term either, but Wiki knows everything:

Power-to-Gas (abbreviated PtG or P2G) refers to a chemical process in which a fuel gas is produced by water electrolysis with partially subsequent methanation using electricity from renewable energies (RE). The gas produced this way is also called RE gas. Depending on the type of renewable energy used, the gas is also called wind gas, solar gas, or similar; depending on the chemical composition of the gas, the term "methane" or "hydrogen" is also used instead of "gas." The fuel gas produced in this way can either be fed into the public gas grid, seasonally stored in cavern storage, or used in transportation. In addition, there are also concepts for integrated storage power plants based on reversible fuel cells, a technology now introduced to the market that promises higher efficiencies than the aforementioned uses.

Windgas is not familiar to me - not even by name - and represents my primary interest. It put a broad smile on my face very, very early on and was valuable for that reason. That's how one should always start the day.

Windgas is more commonly known as "Power to Gas," as Musketier already wrote. For example, Audi has put a first plant into operation in Werlte. In terms of price, the gas produced this way is not yet competitive, but it is a good method to temporarily store surplus electricity from wind and solar plants in our gas network.

Just as a note - also offTopic: Modern heat pumps are "Smartgrid ready", so that with a manageable expansion of the infrastructure (Internet is available in almost every modern house), excess energy can be stored in the hot water tank or possibly in a buffer. With a sufficiently high number of centrally controlled HPs, this allows a relief of the power grid and a higher coverage by renewable energy - and no further loss-laden conversion into hydrogen or "wind gas" is needed. Furthermore, modern batteries are (allegedly) able to deliver up to 90% of the energy used for charging again - (again allegedly) over many years. What is the actual output of Power2Gas? 30% or even less?