ᐅ Methanol as a Long-Term Energy Storage Solution for Fuel Cells in Residential Buildings

Thank you – that sounds very plausible, and please excuse my unspecific statement, which, as you rightly pointed out, was based on my lack of information. I will do some more research to see if my accusation of greenwashing is still justified. 🙂

I just hope that the combination of battery and fuel cell is further developed. :-D

For clean batteries (and for a small-scale system), I recommend researching SALD batteries. Fraunhofer was involved in their development, and a factory is currently being built in Eindhoven. Unfortunately, at the moment, private individuals cannot yet purchase shares in typical small-scale quantities.

hampshire schrieb:

I came across a really coherent concept that could make my house independent from the power grid even in winter – it’s called methanology. The idea is simple and logical: in summer, you produce methanol from excess photovoltaic energy, which is then stored as a long-term energy carrier...

This is roughly equivalent to the SynFuel concept intended for aircraft engines.

The major drawback is the efficiency:

Methanol fuel cells have an efficiency of less than 50% (lower heating value to electricity),
meaning that from 1 kWh of chemical heating energy in methanol, less than 500 Wh of electrical energy come out, plus CO2 emissions and the like.

If you want to reverse the process, you first have to input significantly more energy:
CO2 plus air components (to obtain hydrogen), to then produce liquid CH3OH (methanol).
Additional energy is required to extract the CO2 from the air beforehand. Across the entire production chain, the overall efficiency is roughly under 25%.
That means from 1 kWh of electrical input, only about 0.25 kWh of usable energy remains after the fuel cell for propulsion.

This is always subtly "forgotten" in presentations.
I couldn’t find any information about this from the developer MY-Technology either.

The vision that solar power has no additional environmental burden doesn’t help as long as there isn’t enough surplus photovoltaic (or wind) electricity available.
But even if there were sufficient surplus electricity, the additional CO2 costs from producing extra solar panels remain.

In my opinion, this sounds too good to be true.

konibar schrieb:

The idea that electricity from solar panels causes no additional environmental impact is not helpful as long as there is not yet a sufficient surplus of photovoltaic or wind power.

This discussion concerns local solutions where enough electricity from solar panels can be supplied, not a universal patent for saving the world. It is a functional component. When the solar power yield is sufficiently large, efficiency becomes less important from a climate protection perspective. An efficiency of 25% from nearly carbon-neutral energy is definitely better than an efficiency of 80% from fossil fuels. Efficiency can no longer be the sole benchmark when it comes to reducing CO2; instead, CO2 emissions per kWh should be the focus.

konibar schrieb:

But even if there were enough surplus electricity, the additional CO2 upfront costs in the production chain of the extra solar panels remain.

It is well documented that the CO2 balance of photovoltaic energy, including production emissions, is very favorable. There is no need to buy the cheapest modules from China, which are manufactured using coal-based power. There are plenty of alternatives available.