Comment on We should rename Solar to Patriot Power to make it palatable to the right
skillissuer@discuss.tchncs.de 9 months agoAdditionally, I’d put the heated sand to work heating a large concrete driveway, a sidewalk in the winter months
please invest in good winter shoes and shovel. first, you need massive amount of heat to warm up all that concrete and then melt ice, but it’s not enough. you also have to get rid of liquid water entirely because otherwise it’ll just freeze again but now it’s glossy and flat surface of ice
square-cube law
when making sand battery, what you’re actually interested in is mass of sand. however you can’t conjure perfectly spherical globe of dirt suspended in vacuum, you have to put it somewhere. you need a tank, and one with hefty insulation. now: mass is proportional to volume, which is proportional to r^3 - cube. price of tank and amount of insulation needed is proportional to its surface - r^2 - square. the bigger you make it, the more sand you get per square meter of tank surface, meaning that storage costs go down with scale. that example from finland serves entire community for example
square-cube law provides some hard limitations on what is practical and what is not, for example it explains why big animals move slower than smaller ones. en.wikipedia.org/wiki/Square–cube_law
CoffeeJunkie@lemmy.world 9 months ago
I have plenty of boots & shovels. 😂 Again, it’s not a matter of “luxury”…I am concerned about both personal health & the snow being gone in a timely fashion after a snowfall.
Men who shovel snow are at an increased risk for heart attacks. And that’s just heart trouble; let’s not forget general sprains, strains, & aches. Possible slip-and-falls, I can’t imagine having a bad fall when I’m in my 70s, 80s+.We often see a few significant snow events per year, and to have a surefire way to automatically melt it would be great.
To be fully transparent about my situation…I have a big-ass tractor, too. I can clear the snow without physical exertion. But it’s over at another property, and after a fresh snowfall, I sometimes have to “schedule” time with the tractor jockeying against my parents & my sister, BIL. Annoying.
…but that’s not all, with the tractor method. Extremely, dangerously cold situations can even become too cold for tractors to operate. The diesel will gel unless more questionable additives, methods are used. Operating a tractor is not free, either, and puts more hours on an expensive piece of machinery. There have also been maybe 4 times where I’m clearing the snow, and some kid is on the road in his $2K car, and gets way too close to my $90K tractor when we’re all slogging in terrible, soggy/cold/poor visibility conditions. I’m always polite, of course, but then they leave & I audibly bellow to myself I don’t fucking need this. I don’t!! Why should I haggle with family, operate this good equipment, around the general public if I could avoid that entirely with a heated concrete driveway?
So the only real concern with the square-cube law is physical space occupied, and/or cost. Space isn’t an issue on the farm. 🤠 And sand by the ton is cheap. I was personally thinking about digging a big-ass hole to hold the sand. Line it with junk bricks and/or more concrete, only put money into an insulated “cap”.
The water left on the driveway is an interesting thought, but the driveway won’t be perfectly flat. It’ll have a downward slant, towards the road. If you think it’s enough of an issue, I could maybe put some designs in the concrete that route snow melt run-off off the concrete & into some grass on either side. I know people that heat driveways & they’re fine/dry; it can be done, I’ll ask around. I know it’s marketed as a luxury, but I want heated driveways normalized.
I DO need a lot of heat for this heated driveway, I know it’s ambitious, but I have plenty of reasons for wanting it. Outlined above. Heart attacks/hospital visits? Expensive, waste of time. Tractors, “sharing” operation costs, risk of accidents…expensive. Waste of time. I’m going to pay any way you look at it. Why not pay for a recirculating heat pump, its operation & watch my problems literally melt away??
skillissuer@discuss.tchncs.de 8 months ago
you need a lot of insulation on all sides. putting it all above ground would be easier because of no risk of groundwater ingress. structural steel container, fire-resistant brick and lots and lots of mineral wool around (we’re talking about insulating red-hot (600C) sand so that it stays hot for months). we’re talking about several tons of dirt suspended above ground and insulated on all sides, including bottom. you could put that heat to better use if it stays contained within another insulated container, that is as a hot water source or for space heating. these things are not free, and this comes before any heaters, pumps, piping, automation needed for it to work
if you want to go for a solution, then all good, but for it to be practical you also need to make sure it’s better than alternatives. i think that getting another tractor would be cheaper and more practical in your situation