3 ms·

Very relevant: https://www.youtube.com/watch?v=obS6TUVSZds https://www.youtube.com/watch?v=obS6TUVSZds Many of you probably know EEVblog. In this video he does

by comboy 11y ago

Very relevant: https://www.youtube.com/watch?v=obS6TUVSZds https://www.youtube.com/watch?v=obS6TUVSZds Many of you probably know EEVblog. In this video he does the math. Spoilers: as common sense suggests, those roads are not such a good idea (at least with currently available technology).

nkoren 11y ago
Interesting analysis -- although his numbers actually go off-track in a number of places. The flubs the math on the maximum power output (it's actually about 20% worse than he estimates) while making too strong a case against LED lighting (you can use reflective baffles to send the light at the appropriate shallow angles; there's no need to waste energy projecting lane-markings straight up. Also, an "intelligent" road which presumably has built-in car sensors needn't project lane markings indefinitely -- just a few hundred metres in front of whatever cars are present. During low-traffic periods this could save a lot of energy). But all of that is beside the point. What's interesting is that in his analysis, he makes the same mistake that the solar roadways people make (and which I've just made here), of chasing technical details too far down the rabbit hole. That's just not necessary: a simple financial analysis leads to a much quicker and more certain refutation. For any given amount of money invested, you can either build A.) a solar roadway, or B.) a conventional roadway plus a solar farm. If the LTV (lifetime value) of A is greater than the LTV of B, then A is a good idea. If it isn't, then it isn't. It took me about 5 minutes of high-level analysis to conclude that the LTV of solar roadways was orders of magnitude worse than the LTV of conventional roads + solar farms -- sufficiently so that no amount of technical fiddling would ever close the gap. That's pretty much the end of the story.
- shalmanese 11y ago
  That's enough for all right thinking people to agree it's a dumb idea but not enough to convince someone who isn't well versed in the field. For that, you need to go into far more detail.
- yakult 11y ago
  Where exactly would you draw the line between 'high-level analysis' and 'too much technical detail', here? Which numbers exactly would go into your simple financial analysis? Genuinely curious.
reustle 11y ago
Thunderfoot also made a good response to the solar roadways thing https://www.youtube.com/watch?v=H901KdXgHs4 https://www.youtube.com/watch?v=H901KdXgHs4

by comboy 11y ago

nkoren 11y ago

Interesting analysis -- although his numbers actually go off-track in a number of places. The flubs the math on the maximum power output (it's actually about 20% worse than he estimates) while making too strong a case against LED lighting (you can use reflective baffles to send the light at the appropriate shallow angles; there's no need to waste energy projecting lane-markings straight up. Also, an "intelligent" road which presumably has built-in car sensors needn't project lane markings indefinitely -- just a few hundred metres in front of whatever cars are present. During low-traffic periods this could save a lot of energy). But all of that is beside the point. What's interesting is that in his analysis, he makes the same mistake that the solar roadways people make (and which I've just made here), of chasing technical details too far down the rabbit hole. That's just not necessary: a simple financial analysis leads to a much quicker and more certain refutation. For any given amount of money invested, you can either build A.) a solar roadway, or B.) a conventional roadway plus a solar farm. If the LTV (lifetime value) of A is greater than the LTV of B, then A is a good idea. If it isn't, then it isn't. It took me about 5 minutes of high-level analysis to conclude that the LTV of solar roadways was orders of magnitude worse than the LTV of conventional roads + solar farms -- sufficiently so that no amount of technical fiddling would ever close the gap. That's pretty much the end of the story.

shalmanese 11y ago
That's enough for all right thinking people to agree it's a dumb idea but not enough to convince someone who isn't well versed in the field. For that, you need to go into far more detail.
yakult 11y ago
Where exactly would you draw the line between 'high-level analysis' and 'too much technical detail', here? Which numbers exactly would go into your simple financial analysis? Genuinely curious.

reustle 11y ago

Thunderfoot also made a good response to the solar roadways thing https://www.youtube.com/watch?v=H901KdXgHs4 https://www.youtube.com/watch?v=H901KdXgHs4