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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 s

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.
atoav 1y ago
Good idea but has one major drawback: Shadows cast on single panels mid sequence would offset the angle. But majbe it is still worth it.
solardev 1y ago
The motor itself is a moving part that is subject to wear and tear and reliability and parts availability problems. Solar manufacturers and retailers are notoriously short lived and fragile (in terms of being able to survive changing conditions, like Chinese subsidies, price dumping, and now tariffs, not to mention technological improvements in module efficiency). If you buy a bunch of commodity modules (panels) without moving parts, you generally don't have to maintain anything except maybe replace the inverters in a couple decades. And you can do that with any electrically compatible parts. If you have a moving motor, suddenly you need to find all the specific parts for that particular motor, and hire a specialist crew to maintain and replace it, requiring a team with not just electrical knowhow but motor mechanics too. That's largely incompatible with the US model of solar deployment we have now, which is largely "install and forget" using whatever equipment is currently cheap and available. It's very likely that the equipment manufacturer won't be around in a few years, and that installation company probably won't be for much longer. So any additional possible failure mode should be avoided. At commercial or utility scale it might be different, but generally it's still more cost effective over time to just buy more modules to offset the less than optimal facing than to try to actively adjust their direction with moving parts. Modules keep getting cheaper. Motors, and more importantly, shipping and labor don't. Installing an overcapacity upfront is still cheaper than maintaining the trackers later.

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.

atoav 1y ago

Good idea but has one major drawback: Shadows cast on single panels mid sequence would offset the angle. But majbe it is still worth it.

solardev 1y ago

The motor itself is a moving part that is subject to wear and tear and reliability and parts availability problems. Solar manufacturers and retailers are notoriously short lived and fragile (in terms of being able to survive changing conditions, like Chinese subsidies, price dumping, and now tariffs, not to mention technological improvements in module efficiency). If you buy a bunch of commodity modules (panels) without moving parts, you generally don't have to maintain anything except maybe replace the inverters in a couple decades. And you can do that with any electrically compatible parts. If you have a moving motor, suddenly you need to find all the specific parts for that particular motor, and hire a specialist crew to maintain and replace it, requiring a team with not just electrical knowhow but motor mechanics too. That's largely incompatible with the US model of solar deployment we have now, which is largely "install and forget" using whatever equipment is currently cheap and available. It's very likely that the equipment manufacturer won't be around in a few years, and that installation company probably won't be for much longer. So any additional possible failure mode should be avoided. At commercial or utility scale it might be different, but generally it's still more cost effective over time to just buy more modules to offset the less than optimal facing than to try to actively adjust their direction with moving parts. Modules keep getting cheaper. Motors, and more importantly, shipping and labor don't. Installing an overcapacity upfront is still cheaper than maintaining the trackers later.