5 ms·

I must criticize this on the grounds that it is ugly, but then almost everything that is built these days is ugly. Secondly, what genius decided to make it a f

I must criticize this on the grounds that it is ugly, but then almost everything that is built these days is ugly. Secondly, what genius decided to make it a flat roof? Flat surfaces are the absolute worst both in capturing the most sunlight in temperate latitudes and in terms of dirt and snow removal. Even a 45° angle would mean a lot of the dust, leaves and snow will just tumble down or get washed down by the next rain, whereas flat surfaces are literally encrusted within months.

high_priest 3y ago
Welcome to publicly funded projects, where the biggest factor is, who can build it cheapest.
- jacquesm 3y ago
  I think they just never really thought that through and were looking for a nice headline, not a technical review.
- ta1243 3y ago
  Unlike privately funded projects, where the biggest factor is who can build it the cheapest?
jacquesm 3y ago
Seconded. I have a bunch of panels at a very low angle (12 degrees) due to siting constraints and they foul up pretty quickly. And that's already much better than what's in TFA.
- usrusr 3y ago
  I wonder how much a few simple maintenance bots could help, basically a solar roomba that opportunistically travels along the roof, zig-zagging as far in a day as much or little in a day as it's energy supply allows. Something like that clearly can't work for a small installation, but when a city has a network of roofed bike paths, you'd expect first glimpses of economy of scale. Could nicely hit a sweet spot between doable, futuristic, real-life utility and not served by commercial offerings for a university project.
  - jacquesm 3y ago
    Likely not worth it. Even when they look pretty fouled up they still work very well, less than 5% off peak performance and the first good rainsquall and they're back to new state.
JoeAltmaier 3y ago
'Solar roads' are uniformely a miserable idea. They are eco-theatre. You want solar, put it in an uninhabited ground-level unobstructed serviceable cheap location near the grid outside of town. Because, wires can transmit electricity anywhere it's needed. Elaborate structures for solar cost more than the panels these days. Never build them. At most, tilt them to the local lattitude. If tempted to do more, instead buy more panels. Power per dollar works out better.
- jacquesm 3y ago
  Yes, definitely. In the early 00's I put up an elaborate system with two axis trackers, it was very nice but fragile, not nearly as sturdy as a regular rack would have been and the extra money spent on the trackers would have been better spent on more panels, even at the prices back then. So today this is a complete no brainer (assuming you have the space, but tracking panels use more space than stationary ones so even then it probably won't work to your advantage).
  - JoeAltmaier 3y ago
    This! Even so my local utility is putting in tracking solar projects. Got to be eco-theatre as well. And they track over the day! not over the year. Here the sun varies 42 to 78 degrees to the south, but the panels are flat overhead (90 deg). Again, all that mechanism for so little gain.
    - cesarb 3y ago
      > This! Even so my local utility is putting in tracking solar projects. Got to be eco-theatre as well. They probably did the math, and at that location, the ROI for a single-axis tracker was better than the ROI for fixed panels. > And they track over the day! not over the year. This probably means it's a single-axis tracker, which points east in the sunrise and west in the sunset. To track over the year it would need a second (north-south) axis, but the ROI for that probably wasn't better than a single-axis tracker. > Again, all that mechanism for so little gain. A single-axis tracker isn't that complicated (and a single axis with a single motor can move a whole row of panels at once), so even if the gain is small, it can be more than enough to pay for the mechanism.
ianpurton 3y ago
Don't worry all the panels will be stolen soon anyway.
juujian 3y ago
It looks super jank. Nice to get some shade though, for sure. Are solar panels so cheap now that they just didn't bother designing something that would hold them at a 45 degree angle while still offering the same amount of shade?
usrusr 3y ago
Think of this as a cheap-ish roof first, and a solar generator second. If all your cycle commuters switch mode when the weather isn't super nice they don't reduce the capacity needs for driving or public transit at all. Keeping bike commuters on bikes in inconvenient weather can be very valuable, compared to the cost of keeping all that idle-unless-rainy capacity. The success threshold of this project is recouping the premium over a corrugated sheet roof. And once you start considering north-south connections an angled roof stops looking that obviously superior, it might well not be worth the effort. You can't just do south-facing rows like a standalone installation of your primary goal is keeping the rain and snow out.

high_priest 3y ago

Welcome to publicly funded projects, where the biggest factor is, who can build it cheapest.

jacquesm 3y ago
I think they just never really thought that through and were looking for a nice headline, not a technical review.
ta1243 3y ago
Unlike privately funded projects, where the biggest factor is who can build it the cheapest?

jacquesm 3y ago

Seconded. I have a bunch of panels at a very low angle (12 degrees) due to siting constraints and they foul up pretty quickly. And that's already much better than what's in TFA.

usrusr 3y ago
I wonder how much a few simple maintenance bots could help, basically a solar roomba that opportunistically travels along the roof, zig-zagging as far in a day as much or little in a day as it's energy supply allows. Something like that clearly can't work for a small installation, but when a city has a network of roofed bike paths, you'd expect first glimpses of economy of scale. Could nicely hit a sweet spot between doable, futuristic, real-life utility and not served by commercial offerings for a university project.
- jacquesm 3y ago
  Likely not worth it. Even when they look pretty fouled up they still work very well, less than 5% off peak performance and the first good rainsquall and they're back to new state.

JoeAltmaier 3y ago

'Solar roads' are uniformely a miserable idea. They are eco-theatre. You want solar, put it in an uninhabited ground-level unobstructed serviceable cheap location near the grid outside of town. Because, wires can transmit electricity anywhere it's needed. Elaborate structures for solar cost more than the panels these days. Never build them. At most, tilt them to the local lattitude. If tempted to do more, instead buy more panels. Power per dollar works out better.

jacquesm 3y ago
Yes, definitely. In the early 00's I put up an elaborate system with two axis trackers, it was very nice but fragile, not nearly as sturdy as a regular rack would have been and the extra money spent on the trackers would have been better spent on more panels, even at the prices back then. So today this is a complete no brainer (assuming you have the space, but tracking panels use more space than stationary ones so even then it probably won't work to your advantage).
- JoeAltmaier 3y ago
  This! Even so my local utility is putting in tracking solar projects. Got to be eco-theatre as well. And they track over the day! not over the year. Here the sun varies 42 to 78 degrees to the south, but the panels are flat overhead (90 deg). Again, all that mechanism for so little gain.
  - cesarb 3y ago
    > This! Even so my local utility is putting in tracking solar projects. Got to be eco-theatre as well. They probably did the math, and at that location, the ROI for a single-axis tracker was better than the ROI for fixed panels. > And they track over the day! not over the year. This probably means it's a single-axis tracker, which points east in the sunrise and west in the sunset. To track over the year it would need a second (north-south) axis, but the ROI for that probably wasn't better than a single-axis tracker. > Again, all that mechanism for so little gain. A single-axis tracker isn't that complicated (and a single axis with a single motor can move a whole row of panels at once), so even if the gain is small, it can be more than enough to pay for the mechanism.

ianpurton 3y ago

Don't worry all the panels will be stolen soon anyway.

juujian 3y ago

It looks super jank. Nice to get some shade though, for sure. Are solar panels so cheap now that they just didn't bother designing something that would hold them at a 45 degree angle while still offering the same amount of shade?

usrusr 3y ago

Think of this as a cheap-ish roof first, and a solar generator second. If all your cycle commuters switch mode when the weather isn't super nice they don't reduce the capacity needs for driving or public transit at all. Keeping bike commuters on bikes in inconvenient weather can be very valuable, compared to the cost of keeping all that idle-unless-rainy capacity. The success threshold of this project is recouping the premium over a corrugated sheet roof. And once you start considering north-south connections an angled roof stops looking that obviously superior, it might well not be worth the effort. You can't just do south-facing rows like a standalone installation of your primary goal is keeping the rain and snow out.