Solar Stirling engine: Saves sun power for night use

[Logic]

So; Evacuated Tube water heating and Solar.

Use the Solar power during the day and store Hot water in an insulated tank for the Stirling Engine use to make electricity once the sun sets.
(And for home use any time)

I NB that the Stirling Engine relies on the delta T between its hot and cold sides.
The water is losing temperature at night, but the air cooled cold side of the engine will be cooler too as temperatures drop, so there should be no slowdown in the rate of electrical (and mechanical) energy generation.

Also NB that when you cut the heat to a Stirling Engine and turn it with say an electric motor, it becomes a 'Cooling Engine'.
That means that during the day you can use solar to turn a motor, to turn the Stirling, to aircon your house.

Also nice is that biogas from food waste and/or poop can be stored and used untreated to heat the Stirling Engine on cloudy days or to suppliment power at night.
You get around 100L of Methane from 1kg of waste biomas. (food leftovers)
IIRC there's around another 50 liters of gas from 1kg of (antibiotic free) poop if one chooses to add that to your bio-digester.
Most importantly is that you do get maintenance free biodigesters!!


It's all very clever and interesting, which I like.
But with the exception of the biomass thing; the system does nothing one cant do with Solar and batteries.
A small battery bank will still be required to handle electric spikes and peak loads.

The question is then:
How does it compare in price to an equivalent large Solar and Battery bank..?
Or a good CCHP system??

https://www.youtube.com/watch?v=HReCEHFQthk

[freebeard]

IIRC there was a sand battery that stored up to 400F degrees.

I'd say one drawback is the audio signature. You'd want it in an outbuilding.

[Logic]

Originally Posted by freebeard

IIRC there was a sand battery that stored up to 400F degrees.

I'd say one drawback is the audio signature. You'd want it in an outbuilding.

I quiets down dramatically once started up.
Looks like you stopped the vid a little too soon.

Ye the sand batteries are interesting.
They can be heated to much higher temperatures and thus hold more energy per liter, but much lower specific heat.
So each has its uses.

You have me thinking:
Perhaps a sand battery heated with/around the exhaust is a more space efficient DIY heat battery solution in cars... Hmmm..!?

[freebeard]

I watched the whole thing. There's a steady state operation toward the end. Quieter but not quiet.

[freebeard]

Perhaps a sand battery heated with/around the exhaust ... in cars...

A phase change material would have less weight, but for a stationary situation it might show a better ROI.

en.wikipedia.org/wiki/Russian_stove

The Russian stove[1] (Russian: русская печь) is a type of masonry stove that first appeared in the 15th century or earlier.[2] These stoves combine the functions of a traditional stove, oven, and fireplace into a single unit, and serve a broad range of purposes, including cooking (boiling, baking, and smoking), drying plants and mushrooms, providing interior heating and ventilation, bathing, and providing a warm place to sleep (many units include a sleeping berth atop the stove).[3] They can be found in traditional Russian, Ukrainian, Romanian, and Belarusian households.[3] Such stoves burn only firewood.

The only thing they're missing is a[n] hot tub kludged onto the side.