Leakage current, which happens even in darkness, wastes power at a fixed rate per unit area. By concentrating sunlight, one can generate far more than this leakage rate making it insignificant.
That's the operative word here. And that is far from a run race with this particular technology, it is going to be close enough that it bears watching but not so good that it is a slam dunk winner.
You could use some of that energy to have tiny motors that track the sunlight.
This would net in more energy and less cost per square meter right?
- you only need one motor to aim a whole array of mirrors
if you're willing to make some exotic gears
- the lifespan of the cells will shorten measurably
- you will need to cool the cells if you don't want them
to die very quickly
- there will be a serious fire riskAt this point in time there are no cheap and easy solutions in sight to make the next 2 to 5% gain in efficiency in a cost effective manner.
But given enough time and effort I'm sure that that will happen, I expect the final cut-off to be somewhere around 25% net efficiency (solar incidence to electricity out of the system) for smaller installations and maybe up to 30% for much larger installations.
Will this require more complex installation than flat panels?
Will this require more lifetime maintenance than flat panels?
If the answer to either question is a yes, it doesn't matter how good your system is in any other measure, you will lose against simple flat panels in total cost per electricity produced for any small-scale installation.
This cell is the blue dot "Kaneka".
Multijunction cells are very expensive to make. The reason the multijunction cells in that chart all have concentrators is that without them, the cost is ridiculously too much to even consider.
This particular cell is noteworthy because it is cheap enough that you can eschew the added cost and complexity of the concentrator and just use more cells and potentially still be cheaper.