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Not true at all. Your statement about available land is correct of course, but the important part of picture is that the soft costs for construction of solar el

Not true at all. Your statement about available land is correct of course, but the important part of picture is that the soft costs for construction of solar electric power plants are already much higher than hard costs. And, improving efficiency is a great way to cut them. Imagine a 10 MW power plant built out of panels with 10% efficiency. If you replace them with 20% efficient panels, you increase output 2x without measurably increasing soft costs - like land provision, fixtures on which the panels stand, installation work, insurance, etc. Only part that will increase will be inverters (not a particulary big item) and thicker cables connecting it to the grid. So, soft costs per watt will fall by 40-45%. So, given that the wholesale price of solar panels now stand at 40 cent per watt, and even in cheapest countries the complete plant is $2 per watt, increasing efficiencies 2x means building a 2x more powerful plant for about $1.4 per watt (soft costs fall from $1.6 to $1.0 - i.e. they slightly increase but power output doubles) and hard costs stay the same. Big deal. And almost all of the progress in solar power costs we can have now lies in this field - increase of panel efficiency, not decreasing their costs. Even if panels were free, costs won't fall much... Of course this article bears no relation to that - these are high concentration cells, and cost to build collectors is already much higher than just buying enough of flat panels... better show me a non-concentrated cell with at least 35% efficiency.

dredmorbius 13y ago
Sure, you can increase your efficiency, but: There's a hard upper limit. 1 kW/meter^2 (mis-typed as 1W above). And you've got diminishing marginal returns of more efficient cells. The truth is that the land requirements are likely to go down by a factor of 2-4 maximum. Other cost factors (transmission, but especially storage) will dwarf these. Once you've provisioned land for solar, the key costs are in replacing the panels every 20-40 years or so. Wind, stones, hail, and simple degredation will mandate this. Physical support infrastructure is likely more robust. Land use for solar isn't dedicated-purpose for most applications. Even solar thermal can be used for grazing or other uses. PV can simply go on top of existing structures. You're not talking land acquisition so much as site acquisition. Solar and wind are likely to be overprovisioned where possible. In the sense that you'll provide more capacity than is strictly needed to meet electrical demand. In part because you're not going to get 100% duty cycles ("capacity factor", which is how power installations are rated, are typically ~20 - 40%), and because you don't have an accelerator pedal, only a brake. Solar and wind aren't dispatchable, only sheddable. With overcapacity you've got the option of converting "excess" into other usable and storable forms of energy (hydrogen, methane, battery storage, electricity-to-fuels, etc.), or for intermittent but high-energy needs. We've got cost reductions built in to PV production for the foreseable future. Again, efficiency improvements need to be considered in terms of total cost per Watt / kWh delivered*.
- anovikov 13y ago
  Correct, i agree to all these. I just meant that there are hardly many ways to decrease costs for large-scale solar available now except cell efficiency (not for U.S. where majority of costs are red tape and scarcity of installers, i mean countries where markets are established like Germany or Italy). Also, there is not much NEED to decrease costs below those achievable with efficiency increases (especially if efficiencies ca. 30% are achieved, which is possible like, 10 years down the road). A solar power plant with fully installed system cost of $1.5 per watt will be cheaper that high-voltage grid in majority of places, at $1 per watt in nearly every place. >We've got cost reductions built in to PV production for the foreseable future. In which way? Production capacity-related economy of scale? Current production capacity is already close (well, at least half of) what can be sustainably loaded worldwide. Maybe, another 2x growth is possible because factory builders don't care much if their business is sustainble long-term, they will work until worldwide demand is filled. But i will be very surprised to see over 300 GW/y production capacity worldwide anywhere in the coming 10 years. Apart from economy of scale, there is little way to reduce price.
- anovikov 13y ago
  Germans in their Kombikraftwerk study back in 2007, figured out that you need 5x the capacity (compared to the average usage) to cover entire annual (and daily) fluctuations of the grid with renewables, without storage (more exactly, with that little storage they already have - in the form of a few pumped hydro plants). I tend to still trust this study, there are no counter-arguments to speak of.
  - tsotha 13y ago
    I believe that, assuming the study includes wind and biomass. But 5x capacity is going to be expensive to maintain.
    - anovikov 13y ago
      Yes, it included biomass and more importantly, biogas, which acted as flexible means of generation. That 5x capacity in fact, did not result in significant losses of power, it was in the range of a few percent as i remember.

dredmorbius 13y ago

Sure, you can increase your efficiency, but: There's a hard upper limit. 1 kW/meter^2 (mis-typed as 1W above). And you've got diminishing marginal returns of more efficient cells. The truth is that the land requirements are likely to go down by a factor of 2-4 maximum. Other cost factors (transmission, but especially storage) will dwarf these. Once you've provisioned land for solar, the key costs are in replacing the panels every 20-40 years or so. Wind, stones, hail, and simple degredation will mandate this. Physical support infrastructure is likely more robust. Land use for solar isn't dedicated-purpose for most applications. Even solar thermal can be used for grazing or other uses. PV can simply go on top of existing structures. You're not talking land acquisition so much as site acquisition. Solar and wind are likely to be overprovisioned where possible. In the sense that you'll provide more capacity than is strictly needed to meet electrical demand. In part because you're not going to get 100% duty cycles ("capacity factor", which is how power installations are rated, are typically ~20 - 40%), and because you don't have an accelerator pedal, only a brake. Solar and wind aren't dispatchable, only sheddable. With overcapacity you've got the option of converting "excess" into other usable and storable forms of energy (hydrogen, methane, battery storage, electricity-to-fuels, etc.), or for intermittent but high-energy needs. We've got cost reductions built in to PV production for the foreseable future. Again, efficiency improvements need to be considered in terms of total cost per Watt / kWh delivered*.

anovikov 13y ago
Correct, i agree to all these. I just meant that there are hardly many ways to decrease costs for large-scale solar available now except cell efficiency (not for U.S. where majority of costs are red tape and scarcity of installers, i mean countries where markets are established like Germany or Italy). Also, there is not much NEED to decrease costs below those achievable with efficiency increases (especially if efficiencies ca. 30% are achieved, which is possible like, 10 years down the road). A solar power plant with fully installed system cost of $1.5 per watt will be cheaper that high-voltage grid in majority of places, at $1 per watt in nearly every place. >We've got cost reductions built in to PV production for the foreseable future. In which way? Production capacity-related economy of scale? Current production capacity is already close (well, at least half of) what can be sustainably loaded worldwide. Maybe, another 2x growth is possible because factory builders don't care much if their business is sustainble long-term, they will work until worldwide demand is filled. But i will be very surprised to see over 300 GW/y production capacity worldwide anywhere in the coming 10 years. Apart from economy of scale, there is little way to reduce price.
anovikov 13y ago
Germans in their Kombikraftwerk study back in 2007, figured out that you need 5x the capacity (compared to the average usage) to cover entire annual (and daily) fluctuations of the grid with renewables, without storage (more exactly, with that little storage they already have - in the form of a few pumped hydro plants). I tend to still trust this study, there are no counter-arguments to speak of.
- tsotha 13y ago
  I believe that, assuming the study includes wind and biomass. But 5x capacity is going to be expensive to maintain.
  - anovikov 13y ago
    Yes, it included biomass and more importantly, biogas, which acted as flexible means of generation. That 5x capacity in fact, did not result in significant losses of power, it was in the range of a few percent as i remember.