Honestly, it’s not a great take from low-tech magazine.

This does not replace what solar panels do, which is to be an almost entirely passive way to collect/generate clean energy. It requires a fuel source, produces dirty emissions, requires actively monitoring while in use, and generates very little energy relative to what it is exposed to.

It’s potentially good for reusing waste heat as a small amount of electricity but it’s very little compared to other methods of reclamation like a hot water heater or an actual steam engine.

A 2015 prototype, in which a wood stove used for cooking and space and water heating was equipped with 21 thermoelectric modules cooled by a pumped water system, showed a power production from 25W (burning 1 kg of pine wood per hour) over 70W (4 kg wood/hour) to 166W (9 kg wood/hour).

So, it takes burning 1kg of wood to generate 25 Wh, or 90kJ. One kilo of wood contains, roughly, 20.000kJ of energy. That’s about 0.5%.

It’s fine if you want heat at that time, but quite a bit power demand is when you don’t need any heat.

It also creates huge problems with particulate pollution that are tied with all fossil fuel heating systems.

An interesting article (big fan of Lowtech mag), but I have some gripes.

1. The title mentions it’s lower cost than solar panels, but no where in the article does it mention the cost of the experimental thermometric peltier generators discussed, which seems odd to leave out. Based on bulk orders from alibaba, it appears they cost somewhere between $4 to $11 per module for ones that can withstand woodstove temperatures (not including a heatsink, which will add some additional cost. The Water cooled ones that use a pump, tubing, and mounting hardware will add a lot of extra cost).
2. These devices are only really practical in areas that require a home to be heated for a good portion of the year. In warmer climates, they would only be truly viable to use for a handful of months out of the year, outside of short cooking sessions in the warmer months.
3. In higher density areas, wood/coal burning causes immense air pollution to the point of making the air dangerous to breathe (Poland’s smog issue from coal/wood burning home heating is a good example). It doesn’t seem like a great idea to add incentives to keep using those sources of heat instead of a heat pump (though for the people where these generators may be appealing, they likely cannot afford a heat pump without some form of government assistance).

I don’t think the idea is entirely meritless, it could probably be useful in low-density impoverished areas without access to an electric grid, especially in colder climates, but it’s not something that can scale up beyond those very specific situations without the negatives of burning dirty fossil fuels drastically outweighing the potential benefits.

I think something like Solar Microgrids would be a better long-term solution that can slowly scale up in impoverished areas without those negative side-effects (though I’d prefer to see collective ownership of a microgrid, as opposed to the way it’s presented in that video as a way for neighbors to control and sell electricity to each other).