I see there's now over 1GW of installed PV capacity in tracking systems.

What have been the economic factors behind this? I'd pretty much written off both 1-axis and 2-axis tracking in my mind, because of the maintenance issues, and the increased land requirements: together, these meant that fixed mounting would be superior to trackers. And even more so, given how cheap the PV panels themselves have become.

And yet lots of tracking PV capacity has now been built. What are the economic drivers behind this?

Solar Professsional claims lower levelised cost of energy for trackers in various US states:

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I guess the IRENA figures for increase in capacity factor in tracking systems is part of the story: enter image description here

But how did tracking PV get so cost-competitive?

  • demand? The CSP trackers use the same hardware so I suspect there's both supply and expertise available. As well, I'm guessing that the cost of a large facility is less about the land and more about the cost of installing and maintaining whatever system they have. Since CSP have to use trackers, a company with CSP experience would find tracking PV business as usual. – Móż Jul 13 '14 at 0:20
  • From the 2nd graph you show, it looks highly unlikely that 2-axis tracking would be worth it over 1-axis. – Chris H Jan 5 '16 at 15:30
  • The question is cost of land vs cost of silicon. If land is cheap compared to silicon it'll make sense to use expensive trackers on more land (and vice versa). Buying more efficient cells and getting most use out of them via trackers can pay off. Microconcentrators are also an option with trackers (although I don't think anyone uses them any more). Secondary land use may also be a consideration - with trackers you get more sun on the ground so cropping or grazing are more viable and in high-sun areas partial shading may help rather than hinder. – Móż Feb 8 '16 at 1:59

Lots of tracking PV has NOT been build. Recently I read a story that current PV installations are running about 1 GW/week. Yes, WEEK. That is about the same amount as all of the 20th century.

PV tracking made sense when the price of PV was very high compared to the price of tracking. Tracking doesn't drop very fast. As PV costs come down it becomes cheaper just to install more racks.

  • Please check the units. GW/week does not make any sense. Power is already energy per time unit. Do you mean GW * w or GJ/w? Either way, these are not conventional. – Hurelu Feb 18 '15 at 15:11
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    The use is correct: 1 GW installed capacity per week. e.g 4000 250 watt modules per week. – Sherwood Botsford Feb 19 '15 at 18:43
  • Thanks I understand now. On my first pass I had understood the sentence as in "installed units are running at x GW/wk" – Hurelu Feb 21 '15 at 2:59

Tracking PV means (by it's definition) a more complex construction. It means more complex servicing and installation. But why not add features to reach a much better solar gain and lower price per Watt? The pros can outweigh the cons.

I give you one example for all, a concentrating PV ZenithSolar Z20 (just acquired by SunCore). The advantages it features are:

  • Better land use (not fixed installation)
  • Combined Heat and Power generation
  • Much more efficient PV cells (claimed 72%). Thanks to cooling the PV cell works at a lower temperature (better efficiency).
  • Many times less silicone (cheaper, less material to recycle)
  • Much higher solar gain in hot climates than fixed installation (sun path is changing significantly during day and seasons). It's supported by the stated IRENA figures.
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    Thanks for this, Peter. But with only one installation location in the world that I can see (Yavne), this combined CPV & solar thermal plant doesn't seem to be representative of the 1GW of tracking PV capacity. Do you have any figures on the actual performance at Yavne? I'm interested to learn more. – EnergyNumbers Feb 7 '15 at 19:40

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