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So when does solar power become cheap and efficient enough that it's a real game changer? It seems like the numbers have gotten a lot better in recent years, a

So when does solar power become cheap and efficient enough that it's a real game changer? It seems like the numbers have gotten a lot better in recent years, at least in terms of efficiency.

jacquesm 13y ago
Price per Watt of installed PV is what drives adoption so with efficiency as one term in there (Wattage output is a direct result of efficiency) the remaining ones (lifespan, efficiency over lifespan and production costs / unit area of panel) are still problematic enough to slow down wholesale adoption. To some extent this is right now offset by subsidies, you'll know that it has arrived when the subsidies are stopped and adoption still increases.
danielharan 13y ago
We're at a tipping point already. What's helped the most recently is financing. Solar is already cheaper than retail in a few states; see e.g. this map that lets you play with dates and scenarios: http://ilsr.org/projects/solarparitymap/ http://ilsr.org/projects/solarparitymap/ As for game changers, see e.g. http://www.greentechmedia.com/articles/read/are-utilities-ready-for-the-coming-death-spiral http://www.greentechmedia.com/articles/read/are-utilities-re... http://grist.org/climate-energy/solar-panels-could-destroy-u-s-utilities-according-to-u-s-utilities/ http://grist.org/climate-energy/solar-panels-could-destroy-u...
tsotha 13y ago
Solar is already cheaper in most places provided you have net metering, which is a subsidy. But there's a limit to how many people can use the grid for free.
- evolve2k 13y ago
  Don't forget to take into account that grid connected solar houses feed excess power produced into the grid, there's no free about it, these are essentially micro power stations which enhance the grid.
  - tsotha 13y ago
    You're missing the point. The free part is they're selling back power at retail rates. In net metering if you generate as much power as you use you don't pay any per kWh charges. Where I live the power company is selling power to consumers for about 22 cents per kWh. From normal wholesale vendors it's buying power for somewhere around seven cents, but it's buying buying power from net metering people for 22 cents. That's where the "using the grid for free" part comes in. People who purchase wholesale-generated power are paying the power company's overhead, whereas the net metering people aren't.
    - reitzensteinm 13y ago
      In addition, the home owners are selling a electricity at a fixed time and buying it back with flexibility, not taking into account the spot price of the electricity (which is going to lower drastically during peak solar times over the next few decades). If every home owner installed sufficient solar power to be neutral under net metering, the grid would have to be maintained, with traditional generation supplied at off peak solar times at no cost to the home owner. If that doesn't show how heavy a subsidy net metering is, I don't know what will. It's not sustainable and should never be used to price out solar.
Symmetry 13y ago
There won't be any single tipping point. Solar works better in equatorial countries than in northern ones like England. Solar doesn't gain in efficiency from centralization like turbine based power generation does, so you'd expect less dense countries to use it first. And the more solar you use the less valuable solar is, since solar output varies with time of day and weather and energy storage is relatively expensive. But solar efficiency is increasing exponentially and cost is decreasing exponentially. So I expect solar to be ever more significant, limited in the long run by tradeoffs between power storage and non-solar generation, though the line there is sort of fuzzy.
g8oz 13y ago
It's already just $500/kw for reputable Chinese cells. Assume you get on average 5 hours of usable sunlight a day and electricity is 10 cents/kwh. The 1 kw panel will give you 5 * 365 * .10 = $182.50 worth of electricity. So that gives you a $182.50/$500 * 100 = 36.5% annual return on your investment. (I realize I'm simplifying here, storage blah blah). The elements declining slowest in cost are installation and regulatory hurdle jumping.

So when does solar power become cheap and efficient enough that it's a real game changer? It seems like the numbers have gotten a lot better in recent years, at least in terms of efficiency.

jacquesm 13y ago

Price per Watt of installed PV is what drives adoption so with efficiency as one term in there (Wattage output is a direct result of efficiency) the remaining ones (lifespan, efficiency over lifespan and production costs / unit area of panel) are still problematic enough to slow down wholesale adoption. To some extent this is right now offset by subsidies, you'll know that it has arrived when the subsidies are stopped and adoption still increases.

danielharan 13y ago

We're at a tipping point already. What's helped the most recently is financing. Solar is already cheaper than retail in a few states; see e.g. this map that lets you play with dates and scenarios: http://ilsr.org/projects/solarparitymap/ http://ilsr.org/projects/solarparitymap/ As for game changers, see e.g. http://www.greentechmedia.com/articles/read/are-utilities-ready-for-the-coming-death-spiral http://www.greentechmedia.com/articles/read/are-utilities-re... http://grist.org/climate-energy/solar-panels-could-destroy-u-s-utilities-according-to-u-s-utilities/ http://grist.org/climate-energy/solar-panels-could-destroy-u...

tsotha 13y ago

Solar is already cheaper in most places provided you have net metering, which is a subsidy. But there's a limit to how many people can use the grid for free.

evolve2k 13y ago
Don't forget to take into account that grid connected solar houses feed excess power produced into the grid, there's no free about it, these are essentially micro power stations which enhance the grid.
- tsotha 13y ago
  You're missing the point. The free part is they're selling back power at retail rates. In net metering if you generate as much power as you use you don't pay any per kWh charges. Where I live the power company is selling power to consumers for about 22 cents per kWh. From normal wholesale vendors it's buying power for somewhere around seven cents, but it's buying buying power from net metering people for 22 cents. That's where the "using the grid for free" part comes in. People who purchase wholesale-generated power are paying the power company's overhead, whereas the net metering people aren't.
  - reitzensteinm 13y ago
    In addition, the home owners are selling a electricity at a fixed time and buying it back with flexibility, not taking into account the spot price of the electricity (which is going to lower drastically during peak solar times over the next few decades). If every home owner installed sufficient solar power to be neutral under net metering, the grid would have to be maintained, with traditional generation supplied at off peak solar times at no cost to the home owner. If that doesn't show how heavy a subsidy net metering is, I don't know what will. It's not sustainable and should never be used to price out solar.

Symmetry 13y ago

There won't be any single tipping point. Solar works better in equatorial countries than in northern ones like England. Solar doesn't gain in efficiency from centralization like turbine based power generation does, so you'd expect less dense countries to use it first. And the more solar you use the less valuable solar is, since solar output varies with time of day and weather and energy storage is relatively expensive. But solar efficiency is increasing exponentially and cost is decreasing exponentially. So I expect solar to be ever more significant, limited in the long run by tradeoffs between power storage and non-solar generation, though the line there is sort of fuzzy.

g8oz 13y ago

It's already just $500/kw for reputable Chinese cells. Assume you get on average 5 hours of usable sunlight a day and electricity is 10 cents/kwh. The 1 kw panel will give you 5 * 365 * .10 = $182.50 worth of electricity. So that gives you a $182.50/$500 * 100 = 36.5% annual return on your investment. (I realize I'm simplifying here, storage blah blah). The elements declining slowest in cost are installation and regulatory hurdle jumping.