How to Remove Snow

We had our first major snowstorm of the season last night, and as I was shoveling the driveway I was thinking about different ways to remove snow.

Okay, I'll be honest--I was trying to figure out how to justify installing a snow-melting system when we have to replace our driveway in a few years. I still shovel the drive by hand, but I can foresee a time when I won't want to do that any more or will be traveling enough so I can't.

There are four basic ways to remove snow and ice from a driveway: shovel it by hand, clear it with a snowblower, melt it with a heated driveway, or hire a snowplow service. (You could look at a fifth possibility, melt it with chemicals, but that would require so much chemicals as to have serious environmental consequences. Chemicals are best used for stubborn patches of ice which are hard to remove mechanically.)

The Physics Perspective

The most obvious way to look at the problem of How to Remove Snow is to compare the energy required to melt snow vs. move it.  I measured our driveway and found that it is about 1,200 square feet (I'm going to use English rather than metric units because they're probably more familiar to my readers).

If we get a heavy snowfall of a foot, which translates to an inch of equivalent rainfall (Minnesota's snow tends to have one inch of rainfall equivalent for every 8-15 inches of snow), that's about 6,000 pounds of ice on the driveway which needs to be melted (which will yield about 750 gallons of water, if you're keeping track).  It takes 144 BTU to melt a pound of ice, so it will take about 850,000 BTU to melt all the snow.

In addition to melting the snow, you also have to heat the driveway itself. If there's three inches of brick over the 1,200 square foot driveway, that's about 40,000 pounds of brick. In the worst-case scenario, that brick needs to be warmed by about 100 degrees F, which will take about another 900,000 BTU. Normally a snow-melting installation includes a layer of insulation underneath the driveway, so we don't need to heat the ground underneath the driveway. In total, then, we need about 1.75 million BTU to melt a foot of snow from the driveway on a very cold day.

Calculating the energy it takes to move the snow isn't quite as straightforward since it depends on whether you push the snow (with a plow), lift the snow (with a shovel), or launch the snow (with a snowblower). Hard-to-measure factors like friction and ice adhering to the surface can matter a lot. The simplest case is the snowblower, which essentially fires the snow out a chute. If we assume that the snowblower shoots the snow out fast enough to launch it about 30 feet straight up, then it will take about 300 BTU to clear all the snow.

This is a rather lopsided result: it takes about 5,800 times as much energy to melt the snow as to clear it with a snowblower. This is not a helpful result in my quest to justify a snow melting system. It's not the end of the story, though: a snowblower turns out to be much less efficient.

It turns out to be fairly easy to convert chemical energy from natural gas into heat. Our on-demand hot water heater (which would likely be pressed into service to drive any snow-melting system) claims to be 98% efficient, and the required plumbing would have only minimal loss, so over 90% of the energy of the natural gas would be available to heat the driveway. Delivering our 1.75 million BTU to the driveway will require just a little over 1.75 million BTU of natural gas.

Small gasoline engines, like the ones used to drive snowblowers, are not very efficient. Only about 10% of the energy content of the gasoline is actually converted into mechanical energy in the driveshaft of the engine. What's more, the snowblower has a lot of internal friction, idle time, and other losses. It's probably reasonable to assume that only 10% of the output of the engine actually gets converted into flying snow. Realistically, then, it probably takes about 30,000 BTU of gasoline (or about 1/8 of a gallon) to clear the driveway.

Even accounting for the relative efficiency of melting vs. moving snow, it still takes 58 times more energy to melt the snow. This is still not a helpful result, but there's one more wrinkle: a foot of snow on a very cold day is a worst-case scenario for the snow melting system, and melting less snow on a warmer day leads to a direct reduction in the energy required. The snowblower, on the other hand, is likely to use about the same two cups of gasoline no matter how little snow fell or how warm the weather, because most of the energy is going into friction and the important factor is how long it takes to walk the machine across the entire driveway. With only an inch of snow on a warmish sunny day, the snow-melt system might require only 2-3 times as much energy as the snowblower.

The Fuel Perspective

Another way to look at the problem is to estimate the amount of fuel consumed by the different ways to remove snow. For our foot of snow, the snow-melt system will consume about 18 therms of natural gas, or about $13 of gas at recent prices from our gas company. The two cups of gasoline the snowblower consumes is about $0.30 of fuel these days.

The amount of gasoline consumed by the snowplowing service is harder to estimate because they likely burn more gas getting to and from our driveway than they use in actually clearing the snow. Plow services tend to drive big four-wheel-drive trucks which get poor mileage (especially with a giant plow rig attached to the front), so it seems reasonable to assume they burn about 1/2 gallon (or $1.20) getting to and from each client on the route.

Finally, when I shovel the driveway by hand, it takes me about an hour and burns 720 calories according to government exercise tables. That's about three candy bars, which cost about a dollar each at the convenience store, so about $3 worth of "fuel" is required.

Here, too, there's a slight wrinkle. Our geothermal system uses waste heat to warm a storage tank for hot water, and this heat could be available for use in a snow-melt system. This could give us the first 25,000 BTU or so for free each time we run the heated driveway--not very helpful for the foot of snow on a subzero day, but a significant factor in the case where we're trying to remove a small amount of snow or ice on a warmer day. This low-use scenario could wind up costing $0.50 or less.

The Time and Money Perspective

Finally, we can look at the problem from the perspective of how much time and money it takes to clean the driveway. Right now I spend about an hour shoveling the driveway every time we have a significant snowfall, and for bigger storms this sometimes needs to be done twice or more. As already established, this costs about $3 worth of candy bars.

Clearing the driveway with a snowblower takes about a half-hour, and about $0.30 worth of fuel each time. This may seem like a no-brainer (replacing $3 of Snickers with $0.30 of unleaded and taking half the time), but the snowblower itself will cost about $500 and last perhaps five years. If I have to clear the driveway ten times a season, it's clear that buying the snowblower is the most important expense, adding about $10 to the cost of each snowfall.

Hiring a snowplow service is the most expensive option, but it takes me zero time to clear the driveway. We used to hire a service until about 10 years ago, and back then they charged a minimum of $30 every time it snowed with a surcharge for more than three inches of snow. Today it would probably cost $40-$50 for every snowfall, and our foot of snow could cost as much as $75 with surcharges.

The snow-melt system actually starts to look compelling from a time and money perspective. Like the snowplow service, it requires zero effort for snow removal, but the deep snow on a cold day will only cost about $13 in natural gas. I haven't priced the cost of installing the system, but my guess is that it would add between $2,000 and $5,000 to the cost of replacing the driveway (which will have to be done anyway in a few years). Considering that we already have a water heater capable of driving the system, we could well come in at the low end of the range.

The installation price of a snow-melt system is steep, but it should last for the life of the driveway or longer. Over 25 years, the $5,000 spent on the system will cost only $200/year, or $20 for each snowfall if we need it ten times per season. So (rounding off a little), a heavy snowfall will cost about $35 in fuel plus capital expense to melt the snow, as compared to $50-$75 for a plowing service. A light snowfall would cost only about $20 to melt (essentially just the amortized cost of installation), but $40-$50 for a service.

Concluding Thoughts

There's no question that moving snow takes much less energy than trying to melt it, and the cheapest, most efficient way to clean up after a snowstorm is to shovel by hand. I'm happy to keep doing this, but She Who Puts Up With Me has zero interest in hand-clearing our driveway.

At some point, I might not want to keep shoveling, or my business travel schedule may make it likely that I won't be in town when the snow flies. When that time comes, we can hire a service, buy a snowblower, or install a snow-melt system.

Buying a snowblower is the cheapest option, but also the least convenient--it will still require someone to spend a half-hour in the cold and blowing snow. I don't think She Who Puts Up With Me will be too excited about this, though it's still better than hand-shoveling.

That leaves hiring a service or going with the heated driveway.

If we have to choose between those options, the snow-melt system is substantially cheaper, as long as we anticipate using the service for a number of years. If we expect to need a service for only a few years (maybe we expect my travel schedule to change, or move to a different house), then the capital expense of the snow-melt system makes it more expensive.

All this is still dreaming at this point: the time to make a decision about a heated driveway is when we replace the driveway. Our current driveway is 25 years old and in poor shape, so it could be replaced at any time. On the other hand, after the geothermal system this year we're not eager to embark on another major home-improvement project for a couple years.


ditch the shovel

looks like you put a lot of thought into this. you had some good points. but as a Wisconsinite myself i share your snow removal woes.
Anyone one interested may want to check out this article.


Very interesting thred of dialogue.... My husband and I are considering buying a property North of Duluth. It has a wonderful Lake Superior view, but a drastically steep driveway. We have hesitated about making an offer with the fear of not being able to get up to the house in the winter. This would be our second home and only visited on weekends and vacations until we retire in 25 years. The driveway is currently asphalt and we are considering some sort of heating system. As you were investigating your options, did you find any firms in Minnesota who sell and install electric driveway heating systems? My online seach has only yielded a few options.

I didn't research contractors

I didn't research contractors yet. One thing to consider is that you probably have a South-facing driveway. A blacktop South-facing driveway will get a lot of solar heat if you can get enough snow off to get down to pavement.

So unlike me, you probably don't need to worry about ice buildup during the winter, just snow removal.

If you're thinking of moving there permanently in 25 years, you've got a lot of time to work on this problem. Good luck!

Physics Numbers????

Where did you get your Physics numbers?

To melt snow/Ice, you only have to have a temperature of 33F or higher. The higher the temp, the faster the melt. Other items can cause snow to melt faster, such as friction (wind) and sunlight. What makes you think you have to heat the brick to 100 degrees? Are you going to cook on the driveway also? You aren’t going to evaporate the snow, just melt it. Also snow is a form of ice, but snow melts much faster than an ice cube or a sheet of ice, due to the small size of the snowflake. Give the local College a call and ask for the Mechanical Engineering dept. Heat transfer, gain and the formulas to figure these answers fall under their curriculum. Maybe some professor can assign it as homework to some 18 year old.

Heat radiates upward, from the ground. If you heat the ground (or stone) just under the driveway, concrete, asphalt or brick, it will increase in temp, slowly, and radiate some of that heat up into the air, slowly.

North of the Mason Dixon line the frost line is 48 inches down. A hole dug deeper than 4 ft will have a soil temp of 58 degrees, weather it’s a 6 ft hole or a 10 ft hole. Take a length of tubing, like a super durable garden hose (but NOT a garden hose), bury it 6ft underground, run a section of the hose to just below the surface of the driveway, across the driveway and back, then back to 6ft deep. Continue this until you have covered the driveway with hose spaced 10 inches apart. You will have to have a water pump to circulate the fluid inside the hose, and don’t use straight water, mix with windshield wiper fluid. The circulating water will heat the rocks used as a base to your new driveway to roughly 56 degrees. Those rocks will radiate heat to the driveway to a temp of 54 degrees. The driveway will heat the air just above it to 50 degrees. This will not only melt the snow on your driveway, it will also melt any snow on a car sitting in the driveway. Actually the snow will melt before it hits the driveway. Water droplets, not snow or ice will be on your driveway. When you have a new driveway installed, tell them to grade the drive towards the yard away from the buried hose, if possible to the street.

Geo-thermal heating of a driveway is a great way to go. The Earth temp is constant at 58 degrees, so the heat is always there. You have to pay for the power to run a pump, which could be offset with a few solar panels. Geo-thermal heating is also a cooling source. In the summer when the driveway is 98-105 degrees, turn the pump on and cool the driveway down a few degrees. This will keep the driveway from cracking, meaning it will keep the new look longer and will help the driveway last longer.

Replacing a driveway, with a driveway, will not increase the value of your house. But a heated driveway will return all money invested in the heating system. Ask any Real Estate agent about that.

Go Geo!

Using a heater to mellt a pile of snow

Perhaps you can weigh in on this. What if after plowing the snow in a parking lot I wind up with a pile that is 15ft x 15ft and 10ft high ( or higher and wider) and it is over a Catch Basin. I was thinking that I could use a 200,000 btu propane heated to melt it or higher 1,000,000 btu, run a tube or number of metal tubes with holes, thru the base of the pile and melt the snow. What are your thoughts? The manufacture is Flargo Usa.
Each Flagro Model F-1500T at a sale rate of $3,912.00 plus tax

Each Flagro Model F-1000T at a sale rate of $3,498.00 plus tax

Each Flagro Model F-400T at a sale rate of $1,704.00 plus tax
Note: The rate include the heater and the 2nd stage regulator.


I used a 100-degree increase in the temperature in an attempt to be conservative and make sure I was calculating enough energy to melt the snow. After a snowstorm in Minnesota, it's not uncommon for the temperature to get below zero, and the bricks of the driveway have to be warm enough to allow fast enough heat transfer to the snow and ice on top. Maybe heating them to 100F is overkill, but better that than a system which is undersized. This also gives a fudge factor since there are heat losses which I didn't account for (such as to the air).

It doesn't matter whether you're melting snow or ice, what matters is the total mass of frozen water. Snow is fluffier than ice, so a given volume of snow weighs less, but you can get a lot more volume of snow in a single storm. I based all the calculations on an equivalent water depth of one inch (which is 10" to 20" of snow, or an inch of ice--either way a big but not record storm).

As it happens, after I wrote this article I did some more research and found that the engineering recommendation for heated driveways in Minnesota is to provide 150 BTU/hour per square foot--which isn't that different from what I came up with.

Your idea for just circulating fluid through buried pipes is interesting, but not practical in Minnesota. I actually looked into this when we were designing our geothermal system, and it turns out that if you aren't going to use a heat pump (just circulate fluid), a system sized to handle the worst-case Minnesota winter will have to circulate fluid through about 3,000 cubic yards of dirt--that's a heck of a lot of excavation or well digging. Worse, though, the heat transfer properties of dirt aren't that great, and to extract the heat fast enough to melt the snow in a reasonable amount of time would take literally miles of buried pipe. If you use a heat pump you don't need as big a loop field, but then the heat pump winds up being huge--it turns out that the heat pump to heat the driveway would be bigger than the combined capacity of the heat pumps used to heat the entire house. The installation cost of this is absurdly expensive, which is why I didn't consider it in my original post.


I also live in a winter wonderland, upstate NY, where we get just as much snow, ice and sub zero days as you. I'm looking into a geothermal heated driveway, I have to replace my driveway, and why not do it right. The tubing I'm looking at is the new stuff plumbers are using. It is rubber with a thick coat of plastic on the outside. You can find it any hardware store, Home Depot or Lowes, and it is suitable for outdoor use. It is said to be good for 200 years. I'll settle for 20 underground. Using the tubing means I don't have to dig a huge or long trench, I can dig a 10 feet deep trench right next to my driveway, same length and about 6 ft wide. I'll lay the tubing in the trench and keep it loosely coiled and overlapping. I saw someplace, and I have to get this verified, that the heat lose to heat gain thru ground temp is an 8:1 ratio. In other words, if you run a piece of tubing 1 foot at the surface of the ground, or just under the driveway asphalt, you have to have 8 feet of the tubing underground to reheat back to underground temperature. The pump will be in my basement, closest to the driveway. I have to find a pump that can move that much fluid. One of the downfalls to heating a driveway this way is the time factor. It is estimated that it would take 24 hours to heat the driveway up to a melting temperature, and to keep the driveway warm, the pump would run all the time. For this reason I want to put up solar panels first.

I'm having a hard time finding a company that does this type of work, and am now thinking maybe I found a part time job to earn some good extra cash, working with a paving company and putting in geothermal heated driveways.


If you did melt the snow, where would the runoff go? Your driveway slopes down toward your house, and it seems to me that the melted snow would pool at the base of your driveway until spring.

Drainage needs to be fixed anyway

The drainage is a problem whether or not we install a heated driveway, though it's likely to be more of a problem with heat than without. Our driveway has a low point in the middle where water collects before running down the hill behind the house.

Right now we get a small skating rink at the bottom of the driveway every winter, because meltwater has no place to go until the snowbanks on either side of the driveway melt. When we rebuild the drive, we will have to address this somehow--possibly with a drain and underground pipe, or possibly by significantly regrading along the side of the house to provide more of a slope to move the water away faster.

Geo-Heating & Cooling

What diameter of plastic pipe are talking about anyway, 1inch?

Geothermal Heating

The coils in the ground are referred to as a 'ground array', and an arrangement called a slinky seems to be the most cost efficient way of doing it. Have a look at:

These are normally used to supply low grade energy to heat pumps, but I can see that a sufficient length of ground array piping would also keep a drive snow-free.

Ian in the (frozen) Netherlands