More solar roadways B.S. - "Solar panels replaced tarmac on a motorway"

[Bassman59]

Still the ROI needs to be kept in mind. Saying $10k on a $500k house is insignificant is just fooling yourself. Worse if you take a mortgage because you likely pay more interest on the solar panels than they earn.

Interest rates on a first mortgage are still lower than a loan for a post-construction install. And the interest on $10k on a $500k mortgage isn't much of an adder. You can do the math. Especially when we know that a solar installation improves resale values. (My real-estate agent friends confirm this.)

A mortgage runs much longer than a consumer loan so in the end you really have crunch some numbers to make a good comparison.

A coworker made an observation yesterday about the extra $10k on the $500k property. "Wait a month and the value of the property will have increased more than the extra cost for the solar panels."

[nctnico]

But the $10k will still be lost. It is the little things which add up to the most. That is the danger on buying expensive items. Everything else suddenly looks cheap.

[PlainName]

Where there getting the energy to melt snow? From another power plant?

Does it matter? Suppose there were no solar panels but, instead, the company had proposed a road with built-in heating to melt ice and snow so hundreds of tons of salt wouldn't need to be spread over winter. Wouldn't that be a decent thing to do? Not only do you save the salt (and the manpower to spread it) you save the corrosion of vehicles and other stuff too. The big reason we don't see that kind of thing is because we can't do it, not because we wouldn't want to do it.

So here we have not just the ability to keep roads ice-free but also to do it with less power than would otherwise be required. I'd say that's a win, yet there is determination to paint it as a massive fail.

[Bassman59]

But the $10k will still be lost. It is the little things which add up to the most. That is the danger on buying expensive items. Everything else suddenly looks cheap.

Don't forget that the people buying these houses are blowing $25,000 on the kitchen accessories and furnishings. At least solar panels provide value -- and electricity!

[vk6zgo]

Where there getting the energy to melt snow? From another power plant?

Does it matter? Suppose there were no solar panels but, instead, the company had proposed a road with built-in heating to melt ice and snow so hundreds of tons of salt wouldn't need to be spread over winter. Wouldn't that be a decent thing to do? Not only do you save the salt (and the manpower to spread it) you save the corrosion of vehicles and other stuff too. The big reason we don't see that kind of thing is because we can't do it, not because we wouldn't want to do it.

So here we have not just the ability to keep roads ice-free but also to do it with less power than would otherwise be required. I'd say that's a win, yet there is determination to paint it as a massive fail.

In countries with snowy winters, the amount of sunlight arriving on the solar road is going to be reduced during snowstorms, so there will be less power available to remove the resultant ice & snow.

In Australia, it only snows in the mountainous areas in the SE of the country, so there is little advantage in "the ability to keep roads ice-free".
In this, & other countries with similar climates, the things must stand & fall on their electricity generation ability.

And why do you say "less power than would otherwise be required"?
The heating system is unlikely to be highly efficient, & heavy snowfalls will still have to be removed mechanically, so most of your perceived advantage is lost, before even factoring in the energy used installing the solar panels

[PlainName]

In countries with snowy winters, the amount of sunlight arriving on the solar road

Yes, yes. I think you missed the drift (sorry!) of my comment. Assume the panel get no light at all. Nothing. Nada. It's still a snow melter.

A bit like the airport around this way. They have heated runways to keep them clear in inclement weather, but periodically they get such a fall that they have to close. Doesn't negate the benefit those times it does work.

In regards roadways, there has to be some thinking involved at some point. You don't need to keep twenty zillion miles of it ice-free: you can concentrate just on junctions and still reap a benefit.

In Australia, it only snows in the mountainous areas

Hey, maybe you could use them just for generating electricity threre! A novel thought, but...

Sometimes a jack of many trades, master of none, can be more useful than a tightly focused genius. However, let me think a moment... tell you what, you could have panels aimed more at heating in icy locations and drop that bit in the sunny locations. I don't recall anywhere they said you had to use the exact same component regardless of where in the world it's going.

And why do you say "less power than would otherwise be required"?

Skip to the first para above: we assume there is no light at all. It's pure heating. We also assume that some heating is better than none (remember, doesn't have to be perfect, just usable). OK, not it might be a surprise but on some days it won't actually be night, and there will be a leetle bit of electricity generated. Not a lot, but some. Feed that back to the heaters and wouldn't you agree that you are suddenly using less external power than if you didn't?

The heating system is unlikely to be highly efficient

It's heating. The inefficient part of the energy is going to disappear as... well, I'm sure you don't need me to point it out. Feel free to correct me (yes, really) but ISTM the two questions are: 1. Is the heat going to go up or down, and 2. depending on insulating properties of the panel surface, how early do you need to turn it on to have the heat leak through in time to be useful?

Actually, that does raise another thing: could the heat from the daytime sun be used as well as light? being embedded in a  huge heatsink, I'm sure you could arrange for a temperature gradient across them (even if that meant, say, a borehole of an inch across and a few m deep under each). Maybe, if that worked, you could do the reverse for the snowy locations.