*

Offline rooster

  • *
  • Posts: 4139
    • View Profile
Re: Solar Roadways
« Reply #140 on: June 03, 2014, 01:25:16 AM »
I think you'd potentially be missing out on one of the major upsides of this technology if you did this, the defrosting.  Northern latitudes and mountains terrain are particularly susceptible to snow and ice accumulation and leads to list business during the winter.  This would help keep the roads clear of snow and ice and would probably keep businesses and across open 90% of the time.

The problem with this is energy usage. While it sounds great, the amount of energy necessary to heat the panels enough to melt snow is tremendous. In winter months the panels would burn more energy than they create.
How much is required?
It doesn't have to get to any great temperature, just enough to keep snow from collecting.

The energy required to convert a volume of solid water at 0oC to liquid water at 0oC is about the same amount of energy required to get that liquid water 3/4 of the way to boiling. This is not a trivial amount of energy.
It doesn't have to convert solid ice to water, it only has to be warm enough to keep the ice from forming.

*

Offline Pete Svarrior

  • e
  • Planar Moderator
  • *****
  • Posts: 16073
  • (◕˽ ◕ ✿)
    • View Profile
Re: Solar Roadways
« Reply #141 on: June 03, 2014, 02:50:49 AM »
It doesn't have to convert solid ice to water, it only has to be warm enough to keep the ice from forming.
Snow forms long before it touches the ground. It does have to be able to melt it.
Read the FAQ before asking your question - chances are we already addressed it.
Follow the Flat Earth Society on Twitter and Facebook!

If we are not speculating then we must assume

*

Offline rooster

  • *
  • Posts: 4139
    • View Profile
Re: Solar Roadways
« Reply #142 on: June 03, 2014, 10:53:09 AM »
I don't understand how keeping the panels slightly warmer than freezing is using the same amount of energy to get water 3/4 of the way to boiling.

*

Offline markjo

  • *
  • Posts: 7849
  • Zetetic Council runner-up
    • View Profile
Re: Solar Roadways
« Reply #143 on: June 03, 2014, 12:32:09 PM »
I don't understand how keeping the panels slightly warmer than freezing is using the same amount of energy to get water 3/4 of the way to boiling.
It takes 1 calorie of heat energy to raise the temperature of 1 gram of water by 1 degree C, but it takes 80 calories of heat energy to convert 1 gram of ice at 0 degrees C to water at 0 degrees C.  Where do you suppose that heat energy has to come from when snow, sleet or freezing rain lands on the solar tile, especially on short, gloomy days or at night?
« Last Edit: June 03, 2014, 12:34:33 PM by markjo »
Abandon hope all ye who press enter here.

Science is what happens when preconception meets verification.

Ignorance more frequently begets confidence than does knowledge. -- Charles Darwin

If you can't demonstrate it, then you shouldn't believe it.

*

Offline Lord Dave

  • *
  • Posts: 7653
  • Grumpy old man.
    • View Profile
Re: Solar Roadways
« Reply #144 on: June 03, 2014, 05:26:24 PM »
They're right rooster.
When snow hits the ground but doesn't stick (ie it melts) the ground is giving up energy to the snowflake.  If enough snow flakes fall, the ground could get cold enough to not be able to melt the snow anymore and it begins to stick.


Anyway...

You guys are looking at the cost and comparing it to road construction.  And it's significantly cheaper.  Even with liberal estimates repaving all the roads in the US wouldn't cost even close to the national budget.  (which makes me wonder where all the transportation money goes...)

Anyway the problem is that this road has 4 functions, not just 1.
1. Road. (paint, cat eyes, etc...)
2. Utility channel.
3. Storm Drainage
4. Power generation.

Start adding all that together and it starts looking like the cost of the solar roadways.

But I realized something, the solar roadways could destroy our economy.

Consider:
Right now, you can sell back power to power companies.  So if the government (local, state, federal depending on road) were to have a bunch of solar panels, where does the power go?  Why to the local power company.  It's sold back.  This means money for the government.  But the power company just lost a ton of money.  How much money can they lose and still stay in business?

We can apply this to home solar.  How much money can the power companies lose by having to "buy back" energy before they have to close up shop?  How high would the per kwh have to be to make ends meet when everyone has solar panels?  So the government would have to either take over OR offer subsidies.  Energy excess is a very serious problem.

If the government had to offer subsides, the subsidies would definitely be larger than the actual cost and it would cost governments MORE to have the same service.

If you are going to DebOOonK an expert then you have to at least provide a source with credentials of equal or greater relevance. Even then, it merely shows that some experts disagree with each other.

*

Offline rooster

  • *
  • Posts: 4139
    • View Profile
Re: Solar Roadways
« Reply #145 on: June 03, 2014, 05:35:19 PM »
Where do you suppose that heat energy has to come from when snow, sleet or freezing rain lands on the solar tile, especially on short, gloomy days or at night?
I've already said something about this. They've conceded that it would require a lot of energy but they said they hadn't tested enough for all the conditions nor temperatures.

But some communities may decide that it is worth it to keep their roads clear and businesses open for the winter season anyway.

Yes, Lord Dave, I know how accumulation actually works. And I know energy is required to heat the panels and melt snowflakes, but the question is how much is really required at a bare minimum. The equation from a solid > liquid > gas is what went over my head.

*

Offline markjo

  • *
  • Posts: 7849
  • Zetetic Council runner-up
    • View Profile
Re: Solar Roadways
« Reply #146 on: June 03, 2014, 06:28:37 PM »
Consider:
Right now, you can sell back power to power companies.  So if the government (local, state, federal depending on road) were to have a bunch of solar panels, where does the power go?  Why to the local power company.  It's sold back.  This means money for the government.  But the power company just lost a ton of money.  How much money can they lose and still stay in business?
Are you saying that the power company wouldn't resell the energy that they bought from the solar roadway at a profit?  As it is, the power companies own the transmission lines, substations, etc.  When you buy your electricity from an alternative energy company, the power company still charges you for using their distribution infrastructure (delivery charge).  So don't worry Dave, the power companies won't be going broke any time soon.
Abandon hope all ye who press enter here.

Science is what happens when preconception meets verification.

Ignorance more frequently begets confidence than does knowledge. -- Charles Darwin

If you can't demonstrate it, then you shouldn't believe it.

Re: Solar Roadways
« Reply #147 on: June 03, 2014, 07:21:11 PM »
Where do you suppose that heat energy has to come from when snow, sleet or freezing rain lands on the solar tile, especially on short, gloomy days or at night?
I've already said something about this. They've conceded that it would require a lot of energy but they said they hadn't tested enough for all the conditions nor temperatures.

But some communities may decide that it is worth it to keep their roads clear and businesses open for the winter season anyway.

Yes, Lord Dave, I know how accumulation actually works. And I know energy is required to heat the panels and melt snowflakes, but the question is how much is really required at a bare minimum. The equation from a solid > liquid > gas is what went over my head.

It looks like 1 cubic foot of snow would typically make about 3ml of liquid water. So it would take 240 calories to melt a cubic foot of snow, or about 1kj, or roughly .3Wh of power. At ideal conditions, a 1 square foot solar panel can output about 31Wh of power every hour. If it's snowing, it will be overcast, so that will greatly reduce the power output. Also, since it's winter, the sun will be at a shallower angle, which reduces power further, and there is reduced daylight, reducing the amount of power it can make per day. I found a site that shows that early in the morning (sun at low angle) on an overcast day, their panel was producing 3% of it's capacity, or ~1Wh. If we assume 6 hours of sunlight, that's 6Wh per day, or .25Wh per hour, which if it's snowing at a rate of 1ft/day, then the solar panel doesn't produce enough energy to melt the snow. This is assuming no heating losses to the ground, or to the air. Of course this is a hugely rough estimate, I could make any number of different assumptions and come to vastly different conclusions.
Quote from: Saddam Hussein
I don't know what you're implying, but you're probably wrong.

Re: Solar Roadways
« Reply #148 on: June 03, 2014, 07:27:21 PM »
Your'e forgetting that solar energy generated in Florida will be pumped up to the northern states.

/trololol

*

Offline Pete Svarrior

  • e
  • Planar Moderator
  • *****
  • Posts: 16073
  • (◕˽ ◕ ✿)
    • View Profile
Re: Solar Roadways
« Reply #149 on: June 03, 2014, 07:46:00 PM »
Start adding all that together and it starts looking like the cost of the solar roadways.
Yeah, no.
Read the FAQ before asking your question - chances are we already addressed it.
Follow the Flat Earth Society on Twitter and Facebook!

If we are not speculating then we must assume

*

Offline markjo

  • *
  • Posts: 7849
  • Zetetic Council runner-up
    • View Profile
Re: Solar Roadways
« Reply #150 on: June 03, 2014, 08:14:14 PM »
It looks like 1 cubic foot of snow would typically make about 3ml of liquid water.
Ummm....  No.
Abandon hope all ye who press enter here.

Science is what happens when preconception meets verification.

Ignorance more frequently begets confidence than does knowledge. -- Charles Darwin

If you can't demonstrate it, then you shouldn't believe it.

Re: Solar Roadways
« Reply #151 on: June 03, 2014, 08:31:00 PM »
yeah that doesn't sound like a lot. internet says different.

Re: Solar Roadways
« Reply #152 on: June 03, 2014, 09:01:07 PM »
It looks like 1 cubic foot of snow would typically make about 3ml of liquid water.
Ummm....  No.

I used that 1 foot of snow is about 1 inch of rain. so a cubic foot of snow, would melt to 1ft by 1ft by 1in of rain. Oh, I may be off by a factor of 1000. It'd be about 3l of water. So it'd be 1MJ of energy, which would be 300Wh of power, or 10x the power generated by a 1sq ft solar panel under ideal conditions.
Quote from: Saddam Hussein
I don't know what you're implying, but you're probably wrong.

*

Offline Rushy

  • Planar Moderator
  • *****
  • Posts: 8569
    • View Profile
Re: Solar Roadways
« Reply #153 on: June 05, 2014, 02:20:47 AM »
I'm glad we could all agree that solar roads are an awful, awful idea.

Re: Solar Roadways
« Reply #154 on: June 08, 2014, 02:41:08 AM »
Couldn't we just like.. Put solar panels everywhere else first? Why does it have to be roads?

*

Offline Rushy

  • Planar Moderator
  • *****
  • Posts: 8569
    • View Profile
Re: Solar Roadways
« Reply #155 on: June 08, 2014, 02:58:03 AM »
Couldn't we just like.. Put solar panels everywhere else first? Why does it have to be roads?

See earlier in the thread where I put forth this very thing and a few people genuinely thought there is no room left for solar panels and they simply must be placed on the roads.

http://forum.tfes.org/index.php?topic=1564.msg29588#msg29588

*

Offline Pete Svarrior

  • e
  • Planar Moderator
  • *****
  • Posts: 16073
  • (◕˽ ◕ ✿)
    • View Profile
Re: Solar Roadways
« Reply #156 on: June 08, 2014, 03:40:09 AM »
Couldn't we just like.. Put solar panels everywhere else first? Why does it have to be roads?
Because a loud and obnoxious video says we should, and it would be like freakin' TRON.

Do not underestimate the power of dumb hype.
Read the FAQ before asking your question - chances are we already addressed it.
Follow the Flat Earth Society on Twitter and Facebook!

If we are not speculating then we must assume

*

Offline rooster

  • *
  • Posts: 4139
    • View Profile
Re: Solar Roadways
« Reply #157 on: June 08, 2014, 04:06:20 AM »
PUT THEM EVERY WHERE!!

*

Offline Pete Svarrior

  • e
  • Planar Moderator
  • *****
  • Posts: 16073
  • (◕˽ ◕ ✿)
    • View Profile
Re: Solar Roadways
« Reply #158 on: June 08, 2014, 04:09:51 AM »
Meanwhile, nuclear power plants (the resolution of all our problems, our energetic lord and saviour) are being slammed down by the very same people who consider moving away from coal a priority.
Read the FAQ before asking your question - chances are we already addressed it.
Follow the Flat Earth Society on Twitter and Facebook!

If we are not speculating then we must assume

*

Offline Rushy

  • Planar Moderator
  • *****
  • Posts: 8569
    • View Profile
Re: Solar Roadways
« Reply #159 on: June 08, 2014, 04:24:24 AM »
Meanwhile, nuclear power plants (the resolution of all our problems, our energetic lord and saviour) are being slammed down by the very same people who consider moving away from coal a priority.

but what if we get chernobyl'd? Who will save us when all the nuclear plants meltup? WILL SOMEONE THINK OF THE CHILDREN!?