CrankyOne

We're getting another few inches this morning. Heavy wet stuff. My bike will stay put until the paths are plowed.

I keep wondering if there're not better options than plowing/blowing the stuff. It'd seem like running geothermal under paths would work. Too expensive? Could geothermal also keep it melted long enough to drain down to storm sewers? Anywhere near enough savings from not having to plow to cover much of the cost?

prathmann

Where are you? It takes a lot of energy to melt snow and ice - only a few places have cheap geothermal energy available. And clearly the temperature plays a role as well. One thing if it's mainly water already at 0C, another if it's at -30C.

RaleighSport

Wondering why my fellow bay area citizen knows about snow melting at -30c....

CrankyOne

I'm in Minnesota, but I'd not keep this very geographically specific. It'd be interesting to see this or something else experimented with here or elsewhere.

BTW, increasing numbers of individuals and businesses here are using geothermal to help keep sidewalks clear.

fietsbob

Iceland is a volcanic Island.. its part of the Mid Atlantic Ridge , tectonically.

prathmann

Not melting it, but certainly about shoveling it. Grew up in Fargo, ND.

The economics is very different for heating a small sidewalk space in front of a building that already has a geo heat exchange system for improving the efficiency of the buildings H/AC systems compared with a dedicated system to heat a pathway that extends for miles.

trike_guy

Oslo apparently uses the sewer system to warm some expressways. But no I don't there is any magical way to melt snow. Everything has a cost, pollution of one kind or another.

Brushes, incidentally, are a lot better for bike paths than plows or blowers.

ItsJustMe

I think that physically moving the snow a few feet is going to be significantly less energy intensive than melting and then evaporating it. Just melting isn't good enough, re-frozen ice is worse than snow.

Packing it down to a uniform hard pack is actually not bad either, if you don't want to move it.

CrankyOne

Great thoughts. Roller brooms do work well, but generally require 2 passes instead of just 1 with a plow or blower. They also don't work when there's more than about a foot of snow on either side and many of our paths have over 3' on each side. The latter could likely be fixed once or twice per year when needed by running a blower a few inches off the ground beside the path to clear the build up, which is something they do along many roadways already (there were 11 dump trucks lined up behind a blower on my way in on Friday).

Using the sewer is a good idea. Not sure how well it would work here with 4' of frost, but maybe it would and seems like it would work elsewhere with less frost depth. I wonder if there's a good way to pipe the heat from the sewer up (similar to geo-thermal or heat pipes in computers?).

With the melt idea (geo or sewer) I'd think you'd also have to use geo/sewer heat to keep drainage happening down to the storm sewer. Generally the top of all of our storm sewers is at least 7' below ground level so what makes it there doesn't freeze. Interestingly, many storm sewer grates along streets remain open from heat from below so there must be some significant heat even in storm sewers (and these are not sanitary sewers which I know do have considerable heat generated).

Jseis 

A covered path might pencil out when amortized over 25 or so years as compared to fighting thermodynamics. Just make sure its got a steep roof. Then there's wind. Good snow boots?