Sand battery

[bladerunnerpv]

I guess this is slightly off-topic but seems most closely related to this forum, so posted it here

I found this to be a fascinating read, thought some here might be interested.

https://www.bbc.com/future/article/20221102-how-a-sand-battery-could-transform-clean-energy

 

[johnb2713]

Not dissimilar to the Tepeo boiler https://tepeo.com

 

[Joules]

I guess this is slightly off-topic but seems most closely related to this forum, so posted it here

I found this to be a fascinating read, thought some here might be interested.

https://www.bbc.com/future/article/20221102-how-a-sand-battery-could-transform-clean-energy

The linked article describes the eureka moment.

In 2016, while doing research for his engineering Master's degree, Eronen was looking into water-based storage systems for renewable energy. But while reading an article about traditional Finnish fireplaces, made from stone and sand, Eronen had a lightbulb moment. "It got me thinking: would a solid material, rather than water, be more suitable for storing solar and wind energy?"

Coincidentally, a page on Engineering Toolbox called Storing Thermal Heat in Materials: energy stored as sensible heat compares heat stored in granite and in water with the specific heat of granite being near enough to that of sand for a sensible comparison.

The Physics MC has some fun with the Specific Heat of Sand on YouTube.

The Finnish engineering is sound but because sand can store heat to a higher temperature than water the trick is to make sure that heat recovered using flowing water does not boil off or cause an explosion of super-heated steam.

Dave of EEBlog describes a cautionary tale of judging a book by its cover. All of that hot sand can make you thirsty but would you buy a Fontus Self Filling Water Bottle to quench that thirst?

 

[bagpiperuler]

While the thread is a bit off-topic, can anyone comment on the reason no electric vehicles are fitted with solar panels on roof and bonnet?

 

[Richard-the-Ninth]

Toyota make a car such as you describe Click me (I am not saying I like it or that it is any good, but they are experimenting with it.)

 

[bagpiperuler]

That's more like it. I suppose its naive to think that that kind of development could be done here. Absolute no-brainer. Thanks for the info

 

[johnb2713]

While the thread is a bit off-topic, can anyone comment on the reason no electric vehicles are fitted with solar panels on roof and bonnet?

Considering the area of panels needed to provide a meaningful amount of power and the area available on a car for those panels there would seem to be little point. I would guess an average of around 3.5 miles per kWh assuming you could generate say 600w from small area panels not aligned at the sun, you would be generating at a rate of 2.1 miles per hour. I doubt that even 600w would be possible but even at that, the additional cost and weight IMHO makes it not viable.

 

[binky]

Considering the area of panels needed to provide a meaningful amount of power and the area available on a car for those panels there would seem to be little point. I would guess an average of around 3.5 miles per kWh assuming you could generate say 600w from small area panels not aligned at the sun, you would be generating at a rate of 2.1 miles per hour. I doubt that even 600w would be possible but even at that, the additional cost and weight IMHO makes it not viable.

33% efficiency of the solar cells is an interesting claim, with 30miles extra milage a day - makes you wonder what country and time of year?

 

[johnb2713]

33% efficiency of the solar cells is an interesting claim, with 30miles extra milage a day - makes you wonder what country and time of year?

Toyota not unknown for it's outlandish claims, flogging another dead horse like Hydrogen.