Thought following Paul Wheaton's recent YouTubes on RMHs

Noob here; please be gentle... I tried to look up 'mirrors' on the search function to check whether I was repeating old ground.

Wife & I would like to build a strawbale home with a rocket-mass heater. Paul & Uncle Mud discussed how a potential big drawback is when you have to be away for a while during cold weather--the potential for freezing pipes, etc. Therefore, they recommend getting an additional heat-pump system on a thermostat.

I've been watching this Ukrainian YouTuber called Sergiy Yurko:

https://www.youtube.com/@sergiyyurko8668

He has dozens of (honestly sometimes kinda repetitive) videos about his efforts to create a cheap, low-tech solar energy generator that outperforms the existing high-tech generators.

The gist is: a curved mirror that focuses sunlight onto a piped liquid that heats up, circulates and drives a turbine. The guy has demonstrated good results with prototypes even in the winter, and he's working on low-tech ways to track sun's path and get even more energy in a day with no manual faff.

What if... instead of driving a turbine, the liquid was piped through the thermal mass of a RMH?

No heat pump, no problem..?

Gordon Blair wrote:Noob here; please be gentle... I tried to look up 'mirrors' on the search function to check whether I was repeating old ground.

Wife & I would like to build a strawbale home with a rocket-mass heater. Paul & Uncle Mud discussed how a potential big drawback is when you have to be away for a while during cold weather--the potential for freezing pipes, etc. Therefore, they recommend getting an additional heat-pump system on a thermostat.

I've been watching this Ukrainian YouTuber called Sergiy Yurko:

https://www.youtube.com/@sergiyyurko8668

He has dozens of (honestly sometimes kinda repetitive) videos about his efforts to create a cheap, low-tech solar energy generator that outperforms the existing high-tech generators.

The gist is: a curved mirror that focuses sunlight onto a piped liquid that heats up, circulates and drives a turbine. The guy has demonstrated good results with prototypes even in the winter, and he's working on low-tech ways to track sun's path and get even more energy in a day with no manual faff.

What if... instead of driving a turbine, the liquid was piped through the thermal mass of a RMH?


No heat pump, no problem..?

Solar thermal is a great technology. The problem you get though is you cannot guarantee the sun will be out when you need it. You would have to add enough solar generation and storage to match your solar availability in the winter which is significantly lower then the summer.  

I understand about the sun being unreliable & variable, but unless I am dealing with a nuclear winter, there will be *some* sun while I'm away for a fortnight in winter, and my concept here is that the thermal mass will store and radiate enough of that energy just to keep my pipes from freezing..?

Gordon, welcome to the forum!

Great idea about mirrors.

Here is a good one:

Paul said, So there is a town that sits in a valley and gets zero direct sun for 84 days of the year. And now they have installed a 25 foot mirror to mend this problem.

https://permies.com/t/12973/mirror-bring-sunshine#117346

I really like the newest video about using an inground heat pump.  I had heard of heat pumps though not inground ones.

Gordon said, the liquid was piped through the thermal mass of a RMH?

I always liked this idea and there are threads about an RMH water heater and running water to heat under the floor.

I am not sure what liquid he is using?  Water turns to steam so it is not good to run through a RMH.

11 year ago! You've got some memory, Anne.

I think that using focused/redirected sunlight to heat liquids (or black surfaces) is a criminally underexplored renewable-energy approach. Probably because there's no expensive tech and profits involved. The GREENPOWERSCIENCE channel do loads of interesting stuff:

https://www.youtube.com/@GREENPOWERSCIENCE

The best way to keep your house's pipes from freezing is to build and insulate it in a way that keeps the interior from getting that cold. My house is "superinsulated" (but with fiberglass which is now full of rodent tunnels and some sections completely packed down to the floor), and my life has evolved so that I am away from it for several days at a time every week year round. My propane Polaris water heater is out of commission due to probably a malfunctioning gas valve which no professional will work on, so the house is unheated except by solar gain when I am gone. It can stay above freezing when the air gets down to 10F outside. When I finish the addition in progress and repair the rest of the failed fiberglass, I expect better than that.

I mean, passive rodent-heat does sound kinda cute in theory...

Ideas…

1) Turn off the water and drain the pipes.

2) Find a house-sitter

3) non-tracking solar thermal is plenty warm, efficient, less expensive, and more reliable.