5 ms·

We researched this thoroughly in the early 2000s and came to pretty much the same conclusion even back then. For us the main problem was the reliability of the

We researched this thoroughly in the early 2000s and came to pretty much the same conclusion even back then. For us the main problem was the reliability of the mover. If enough panels face the wrong direction for long enough it is worse than facing the sun in a good enough fixed position all the time. Our angle was to use a simple motor that runs with constant speed and use a special patented gear (called VIAX) to turn that simple movement into a sun following motion. The bet was that a still simple mechanical gear would be more reliable than complicated electronics. In the end none of our simulations made us confident any moving solution wouldn't eat the profits. EDIT: For anyone interested, here is the patent. I think it is a really nice idea. https://patents.google.com/patent/EP0114240A1/en https://patents.google.com/patent/EP0114240A1/en

deleted 1y ago
[deleted]
Gibbon1 1y ago
I saw some guy in Britain that replaced his old fence with one made of solar panels because the cost difference between that and traditional was nil.
- thechao 1y ago
  I have a fence that gets absolutely blasted with High Grade Texas Sunlight. It shortens the fence’s effective life by years — this idea is brilliant. Now I just gotta price out 80 sq m of solar panels. EDIT: The fence gets at least 4 hours of direct sun in the winter; up to 7 in the summer. I can easily install 10KW of panels. I don’t have any way to store the power. I suppose I could build a giant Tesla coil and zap the neighbor’s dog?
  - cake-rusk 1y ago
    You can push excess power into the grid. It will reduce / reverse your electricity bill. Look into local regulations.
    - thechao 1y ago
      I've got a co-op that won't net meter below a fixed cost that's close to my monthly. I just like the idea.
      - solardev 1y ago
        Can't you buy some home battery backups and either use them for time shifting (buy low, sell high) or just for backup power?
      - adrianN 1y ago
        A kWh of batteries costs about 200€ where I live, but if the panels cost a comparable amount to a normal fence you can probably just run the AC a bit cooler when the sun shines and use your house as a thermal battery.
        thechao 1y ago
        Hold on, let me translate my stupid freedom units into Science™. My exterior house walls are already ... 30cm thick? That's 15cm of insulation + structure, a thermal gap, and then 10cm of stone facade. I only have to run the AC for a few hours at night, once the house warms up after a full day of sun. The only time of year I need "full AC" is during the high summer when the temps go above 40°C. What really kills me is that house is heated with propane, owned by a local monopoly, and the cost of propane has a 300% surcharge. The next time the HVAC packs up, I'm getting a heat pump, and adding solar panels (I only need a few); the savings in propane will pay for the HVAC/solar in a few years (in fucking TEXAS). The irony of this is not lost on me.
        adrianN 1y ago
        If you had a solar fence you could run the AC during max solar production for a couple of hours and not use it the rest of the day then. You might want to do the math on replacing the HVAC with a heat pump before it breaks, might be a good investment.
johnea 1y ago
This was going to be the gist of my reply. I don't have the depth of experience with solar installations cited in your comment, but I have worked with systems that expected automated moving parts to continue to function in an outdoor environment. They all required near continuous maintenance. Having a high level of cynicism regarding the utility industry, I wonder if the preference for moving parts is due to the requirement that only a large company with a constantly employed force of service personal can manage such a system. This would provide a certain amount of cost-of-entry that only large utilities could provide. To quote what a utility company's compliance office once said to me, in a different context, "Only big companies can do that".
didgetmaster 1y ago
I always thought that someone would invent a cheap, simple, reliable, and passive tracking system. No need for sensors or intelligent electronics. You have a simple motor that slowly tilts the array from facing East to facing West as power is being generated. The motor does not start until the panel is generating a certain amount of power. The motor runs at a fixed rate with a screw that takes about 7 hours to move the panel. Once power stops (when the sun sets) weights on the opposite side slowly tilt the panel back to the starting position so it is ready for the next day.
- b_emery 1y ago
  Like a big, very simple clock basically.
  - solardev 1y ago
    A big, not so simple clock moving a heavy array in all weather conditions, having to deal with constant changes in humidity, temperature, thermal stress, potential salinity, wear and tear, lubrication, gears, jams, etc. A large reason solar is winning out over wind is because the lack of moving parts drastically simplifies installation and maintenance. A solar tracker isn't as complex or high up as a wind turbine, but it's still much more complex than a standard roof or ground mounted array that doesn't move. Trackers made sense back in the 70s and 80s when solar PV tech was still new, but now it's far cheaper to just add more module capacity than to try to dynamically optimize each module's facing through the day.
    - fc417fc802 1y ago
      I agree that it adds complexity, but it seems to me that the minimum there is on the order of the joints on a lawn chair, a screw drive, and a stepper. Not exactly high tech and if sufficiently overspec'd not likely to fail even in extremely adverse conditions.
      - solardev 1y ago
        The thing is that most solar projects are commodity energy projects optimized for cost per watt, not necessarily reliability or efficiency (watts per area). We're not building them for the constraints of Mars bases or fancy spacecraft, just run of the mill generation. Thus the tracker has to not just pay for itself, but be a better investment than simply buying more modules. The goal isn't reliability at any price, but cost effectiveness compared to making the project a little bigger and adding a few more modules. Even with home rooftops (which have limited space), it's much cheaper to buy more premium modules with higher efficiency, or optimize their outputs with per module micro inverters or optimizers, than to mount the array on a tracker. With big commercial installations, there's even less of a space premium. Trackers aren't just a one time upfront cost of manufacturing either, but an ongoing maintenance cost over the lifetime of the project. They get more expensive as less and less of the industry uses them and fewer parts and labor are available for them. They just can't compete with the Chinese dumping of cheap modules, which are so cheap now that almost all non Chinese manufacturers have gone bankrupt. So the industry is left with a glut of modules, which are probably just going to get cheaper and more efficient, while tracking technology and costs haven't improved anywhere near the same amount. It's all relative, and the trackers are losing big time. Sure, as a science project with infinite funding, maybe you can make a super reliable one. In the real world, though, installations across the world have found them largely unappealing from a cost effectiveness standpoint.
deleted 1y ago
[deleted]
otherme123 1y ago
Our research around the same time came to the conclusion of a sun tracker, with wind protection, would be the best option. The panels were very expensive (a 400'ish W panel that today cost $80 costed around $2,500-$3,000), so aiming for the absolute best performance for the panels was key. The trackers fail sometimes, but I would say once a year or so. The electronics are not that complicated, and its reliability was higher than the motor itself. I remember calculating with fixed tracking of the sun (because you know were it is at all time) vs photocells that tell the motors were to move and by how much. The trackers win because when the day is cloudy the best performance is to put the panel flat and let it rest there (instead of tracking a sun that isn't there so the motor that day consume more energy that the panels generate), and with enough cloudy days the tracker outperform the fixed tracking by a significant amount. It's not until recently, with 400W panels under about $500, that tracking no longer makes sense, at least in our latitude.

deleted 1y ago

[deleted]

Gibbon1 1y ago

I saw some guy in Britain that replaced his old fence with one made of solar panels because the cost difference between that and traditional was nil.

thechao 1y ago
I have a fence that gets absolutely blasted with High Grade Texas Sunlight. It shortens the fence’s effective life by years — this idea is brilliant. Now I just gotta price out 80 sq m of solar panels. EDIT: The fence gets at least 4 hours of direct sun in the winter; up to 7 in the summer. I can easily install 10KW of panels. I don’t have any way to store the power. I suppose I could build a giant Tesla coil and zap the neighbor’s dog?
- cake-rusk 1y ago
  You can push excess power into the grid. It will reduce / reverse your electricity bill. Look into local regulations.
  - thechao 1y ago
    I've got a co-op that won't net meter below a fixed cost that's close to my monthly. I just like the idea.
    - solardev 1y ago
      Can't you buy some home battery backups and either use them for time shifting (buy low, sell high) or just for backup power?
    - adrianN 1y ago
      A kWh of batteries costs about 200€ where I live, but if the panels cost a comparable amount to a normal fence you can probably just run the AC a bit cooler when the sun shines and use your house as a thermal battery.
      - thechao 1y ago
        Hold on, let me translate my stupid freedom units into Science™. My exterior house walls are already ... 30cm thick? That's 15cm of insulation + structure, a thermal gap, and then 10cm of stone facade. I only have to run the AC for a few hours at night, once the house warms up after a full day of sun. The only time of year I need "full AC" is during the high summer when the temps go above 40°C. What really kills me is that house is heated with propane, owned by a local monopoly, and the cost of propane has a 300% surcharge. The next time the HVAC packs up, I'm getting a heat pump, and adding solar panels (I only need a few); the savings in propane will pay for the HVAC/solar in a few years (in fucking TEXAS). The irony of this is not lost on me.
        adrianN 1y ago
        If you had a solar fence you could run the AC during max solar production for a couple of hours and not use it the rest of the day then. You might want to do the math on replacing the HVAC with a heat pump before it breaks, might be a good investment.

johnea 1y ago

This was going to be the gist of my reply. I don't have the depth of experience with solar installations cited in your comment, but I have worked with systems that expected automated moving parts to continue to function in an outdoor environment. They all required near continuous maintenance. Having a high level of cynicism regarding the utility industry, I wonder if the preference for moving parts is due to the requirement that only a large company with a constantly employed force of service personal can manage such a system. This would provide a certain amount of cost-of-entry that only large utilities could provide. To quote what a utility company's compliance office once said to me, in a different context, "Only big companies can do that".

didgetmaster 1y ago

I always thought that someone would invent a cheap, simple, reliable, and passive tracking system. No need for sensors or intelligent electronics. You have a simple motor that slowly tilts the array from facing East to facing West as power is being generated. The motor does not start until the panel is generating a certain amount of power. The motor runs at a fixed rate with a screw that takes about 7 hours to move the panel. Once power stops (when the sun sets) weights on the opposite side slowly tilt the panel back to the starting position so it is ready for the next day.

b_emery 1y ago
Like a big, very simple clock basically.
- solardev 1y ago
  A big, not so simple clock moving a heavy array in all weather conditions, having to deal with constant changes in humidity, temperature, thermal stress, potential salinity, wear and tear, lubrication, gears, jams, etc. A large reason solar is winning out over wind is because the lack of moving parts drastically simplifies installation and maintenance. A solar tracker isn't as complex or high up as a wind turbine, but it's still much more complex than a standard roof or ground mounted array that doesn't move. Trackers made sense back in the 70s and 80s when solar PV tech was still new, but now it's far cheaper to just add more module capacity than to try to dynamically optimize each module's facing through the day.
  - fc417fc802 1y ago
    I agree that it adds complexity, but it seems to me that the minimum there is on the order of the joints on a lawn chair, a screw drive, and a stepper. Not exactly high tech and if sufficiently overspec'd not likely to fail even in extremely adverse conditions.
    - solardev 1y ago
      The thing is that most solar projects are commodity energy projects optimized for cost per watt, not necessarily reliability or efficiency (watts per area). We're not building them for the constraints of Mars bases or fancy spacecraft, just run of the mill generation. Thus the tracker has to not just pay for itself, but be a better investment than simply buying more modules. The goal isn't reliability at any price, but cost effectiveness compared to making the project a little bigger and adding a few more modules. Even with home rooftops (which have limited space), it's much cheaper to buy more premium modules with higher efficiency, or optimize their outputs with per module micro inverters or optimizers, than to mount the array on a tracker. With big commercial installations, there's even less of a space premium. Trackers aren't just a one time upfront cost of manufacturing either, but an ongoing maintenance cost over the lifetime of the project. They get more expensive as less and less of the industry uses them and fewer parts and labor are available for them. They just can't compete with the Chinese dumping of cheap modules, which are so cheap now that almost all non Chinese manufacturers have gone bankrupt. So the industry is left with a glut of modules, which are probably just going to get cheaper and more efficient, while tracking technology and costs haven't improved anywhere near the same amount. It's all relative, and the trackers are losing big time. Sure, as a science project with infinite funding, maybe you can make a super reliable one. In the real world, though, installations across the world have found them largely unappealing from a cost effectiveness standpoint.

deleted 1y ago

[deleted]

otherme123 1y ago

Our research around the same time came to the conclusion of a sun tracker, with wind protection, would be the best option. The panels were very expensive (a 400'ish W panel that today cost $80 costed around $2,500-$3,000), so aiming for the absolute best performance for the panels was key. The trackers fail sometimes, but I would say once a year or so. The electronics are not that complicated, and its reliability was higher than the motor itself. I remember calculating with fixed tracking of the sun (because you know were it is at all time) vs photocells that tell the motors were to move and by how much. The trackers win because when the day is cloudy the best performance is to put the panel flat and let it rest there (instead of tracking a sun that isn't there so the motor that day consume more energy that the panels generate), and with enough cloudy days the tracker outperform the fixed tracking by a significant amount. It's not until recently, with 400W panels under about $500, that tracking no longer makes sense, at least in our latitude.