6 ms·

Panels at the side of the roads?

by edoceo 7y ago

agumonkey 7y ago
panels above urban tunnels, maybe powering some air filtering system ?
- edoceo 7y ago
  Right? There are so many other good places with less issues, why pick the road-bed?
- mjevans 7y ago
  You're on the correct track here. My 5 min of reading the article and thinking about it idea is thus: A slanted roof angled to shade and water/snow protect the road, shedding runoff in to a gravel area beside the road with drainage considerations accounted for. The far side might have some sort of attached tarp over part of it, and there'd be a gap between top of said tarp and the bottom of the panel roof. That would promote heat-stack ventilation along the underside of the panels and thus also SOME cooling.
- dredmorbius 7y ago
  Aqueducts have been suggested as siting locations. Benefits: - Reduced evaporation losses. - Extant rights of way / property rights. - Extant technical infrastruction, including power transmission for pumps, etc. Not that this is the only siting location to consider, but it's a reasonable candidate.
  - agumonkey 7y ago
    Never thougt of them. Great indeed.
einpoklum 7y ago
But then, why put them at the side of the road as opposed to, well, anywhere really?
- 6nf 7y ago
  Exactly. We have plenty of room for solar panels.
dredmorbius 7y ago
Median strips and easements are a possible siting location. Shade awnings over car parks another. The challenge with solar power really isn't sufficient area for siting. It's low-cost installation and low-disturbance environments which ensure long panel life and low maintenance costs. Solar panels have a useful lifetime of about 20 years, due to numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. NREL (the National Renewable Energy Laboratory) in Colorado have published research on this. Engineering low-cost, long-lived, readily installable and replaceable panels would be a generally advisable research direction. Looking for extreme siting locations (e.g., high-traffic highways, or even sidewalks), or even, counterintuitively, greater efficiency, is relatively unimportant as compared to total costs and lifetime.
- fencepost 7y ago
  numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. Hasn't a lot of research been focused around ways to capture incident light and focus it down onto the actual cell surface? Iirc a lot of that has been things like surface coatings but is there really a requirement that's such a surface actually be in contact with the cell? Could there be something that was effectively a replaceable capture top surface possibly with an air gap above the actual photovoltaic cells?
  - dredmorbius 7y ago
    A concentrating system isn't going to reduce the overall degradation -- yes, there's less critical surface, but it's weathered about the same as a nonconcentrating surface, and affects proportionately more generating capacity. Or at least that's the theory. NREL conduct longevity / degradation studies for numerous specific PV panel designs and products. Degredation ranges between about 0.5% and 0.8% per year, with an effective lifetime of 20-30 years. Rough number, and actual results depend on specific siting characteristics and events. A tornado passing overhead, sandstorm, or very severe hail, may significantly negatively affect experienced lifetime.

Panels at the side of the roads?

by edoceo 7y ago

Panels at the side of the roads?

agumonkey 7y ago

panels above urban tunnels, maybe powering some air filtering system ?

edoceo 7y ago
Right? There are so many other good places with less issues, why pick the road-bed?
mjevans 7y ago
You're on the correct track here. My 5 min of reading the article and thinking about it idea is thus: A slanted roof angled to shade and water/snow protect the road, shedding runoff in to a gravel area beside the road with drainage considerations accounted for. The far side might have some sort of attached tarp over part of it, and there'd be a gap between top of said tarp and the bottom of the panel roof. That would promote heat-stack ventilation along the underside of the panels and thus also SOME cooling.
dredmorbius 7y ago
Aqueducts have been suggested as siting locations. Benefits: - Reduced evaporation losses. - Extant rights of way / property rights. - Extant technical infrastruction, including power transmission for pumps, etc. Not that this is the only siting location to consider, but it's a reasonable candidate.
- agumonkey 7y ago
  Never thougt of them. Great indeed.

einpoklum 7y ago

But then, why put them at the side of the road as opposed to, well, anywhere really?

6nf 7y ago
Exactly. We have plenty of room for solar panels.

dredmorbius 7y ago

Median strips and easements are a possible siting location. Shade awnings over car parks another. The challenge with solar power really isn't sufficient area for siting. It's low-cost installation and low-disturbance environments which ensure long panel life and low maintenance costs. Solar panels have a useful lifetime of about 20 years, due to numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. NREL (the National Renewable Energy Laboratory) in Colorado have published research on this. Engineering low-cost, long-lived, readily installable and replaceable panels would be a generally advisable research direction. Looking for extreme siting locations (e.g., high-traffic highways, or even sidewalks), or even, counterintuitively, greater efficiency, is relatively unimportant as compared to total costs and lifetime.

fencepost 7y ago
numerous degredation mechansims (it's not just one), from fogging of the transparent surface to cracking, glazing from dust and sand, hail impacts, broken circuits, etc. Hasn't a lot of research been focused around ways to capture incident light and focus it down onto the actual cell surface? Iirc a lot of that has been things like surface coatings but is there really a requirement that's such a surface actually be in contact with the cell? Could there be something that was effectively a replaceable capture top surface possibly with an air gap above the actual photovoltaic cells?
- dredmorbius 7y ago
  A concentrating system isn't going to reduce the overall degradation -- yes, there's less critical surface, but it's weathered about the same as a nonconcentrating surface, and affects proportionately more generating capacity. Or at least that's the theory. NREL conduct longevity / degradation studies for numerous specific PV panel designs and products. Degredation ranges between about 0.5% and 0.8% per year, with an effective lifetime of 20-30 years. Rough number, and actual results depend on specific siting characteristics and events. A tornado passing overhead, sandstorm, or very severe hail, may significantly negatively affect experienced lifetime.