4 ms·

Making them cheaper won't improve their efficiency

by ScotterC 15y ago

marze 15y ago
The only efficiency metric that matters is $ per generated watt. And that figure is dropping like a stone.
- ScotterC 15y ago
  yes, but it's easy to miss external costs of power sources like solar such as the land involved and maintenance (i.e. cleaning the panels to eek out that extra 10%). Density of power is what matters in the long run. We need a solution that produces the most power for the given space it occupies. Hence, it's not a question of 'if' we use fission, it's a question of 'when'.
  - InclinedPlane 15y ago
    This is not entirely true. If solar were super cheap and battery technology were also super cheap and significantly improved from what we have today then distributed solar power (on rooftops, for example) could be feasible. But that's a lot of ifs.
    - ScotterC 15y ago
      As I mentioned in another comment, if battery technology is super cheap then it benefits all power generation, even coal, because it would marginalize the fluctuating operating costs. Nuclear would actually be perfect because current nuclear reactors are kind of like diesel engines, they thrive when operating at a steady, ongoing power so we could fill up batteries all day and night.
      - InclinedPlane 15y ago
        That's an excellent point. Every power source would be boosted by better/cheaper batteries, even coal, nuclear, and hydro. In fact it could actually hurt solar/wind because with lots of batteries you could rely on a much smaller total generating capacity equal to just a little over average power usage (since peak loads could come from batteries). So there'd be less demand for new capacity of any sort to be built. It would also improve the safety of fission power since it would likely be easier to provide extended electricity to the cooling system in case grid power goes down.
        ScotterC 15y ago
        It all hinges on batteries. I really really hope we find something. So many innovations have been held back by inadequate or expensive energy solutions. Portable, powerful and efficient energy storage could allow so much.
        ars 15y ago
        We do actually have "Portable, powerful and efficient energy storage" - it's called gasoline :) (Or natural gas.) Think about the insane size of the inverters you would need to power the grid off of a DC battery. Instead you use cheaper types of energy during the night, and avoid the natural gas. Then during peak usage you fire up your natural gas battery and run a turbine.
        InclinedPlane 15y ago
        This is not storage, not unless the gasoline is entirely synthetic and made from atmospheric CO2, which is not the case today.
        ars 15y ago
        Sure it's storage. It might not have been stored by you, but it's storage. Don't confuse moving away from CO2 emitting fuel with energy storage, they are two different things.
- tjmc 15y ago
  Not at night it isn't. High costs for storage mean that photovoltaic solar will need to be complemented by other sources for a good while yet.
  - ScotterC 15y ago
    It's funny. If storage costs drop then everything improves. Hydro would become amazingly useful cause you could run the dam all the time and store the energy in batteries. The biggest problem with power generation is the fluctuation of starting and stopping the plants. Solar would not be a sole beneficiary.
    - hyperbovine 15y ago
      You can store energy in a dam. Pump it up during the day, run it through the turbines at night. Probably not too efficient but lack of storage is not a convincing reason for giving up on renewables, IMO.
      - tambourine_man 15y ago
        “Water in lakes has ~300k cubic kilometers ~ 3 * 10^14 kg http://ga.water.usgs.gov/edu/earthwherewater.html http://ga.water.usgs.gov/edu/earthwherewater.html Potential energy is ~ 9.81weightheight Storage requirements (USA): 336 billion kWh = 1.2 10^18 J height = 1.2 10^18 / (9.81 * 3*10^14) kg ~ 408m We would need to pump water in all lakes about 408m high to have 7 day worth of reserves for USA.” http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/#comment-194 http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
        Inufu 15y ago
        Actually, that's wrong by three orders of magnitude. One cubic km has 10^9 cubic meters. Each cubic m has 1000 kg of water, so one cubic km has 10^12 kg. If you now have 300k cubic km, that's 3*10^17 kg. So you actually only need to use 0.1% of all lakes.
    - 15y ago
- Someone 15y ago
  I do not think anybody would want to build a large installation with cells with a 0.1% efficiency, even if they could get them for free. $ per m² is important, too. Reason is that, the lower prices get, the greater the fraction of installation costs that are not due to the price of the solar cells themselves. Those costs scale with panel area, not with power output, and they do not sink.
InclinedPlane 15y ago
It'll make them more cost effective. Making them cheaper won't improve their ability to produce power on demand though. That's necessary to replace base load power stations, and neither solar nor wind are capable of it yet.

Making them cheaper won't improve their efficiency

marze 15y ago

The only efficiency metric that matters is $ per generated watt. And that figure is dropping like a stone.

ScotterC 15y ago
yes, but it's easy to miss external costs of power sources like solar such as the land involved and maintenance (i.e. cleaning the panels to eek out that extra 10%). Density of power is what matters in the long run. We need a solution that produces the most power for the given space it occupies. Hence, it's not a question of 'if' we use fission, it's a question of 'when'.
- InclinedPlane 15y ago
  This is not entirely true. If solar were super cheap and battery technology were also super cheap and significantly improved from what we have today then distributed solar power (on rooftops, for example) could be feasible. But that's a lot of ifs.
  - ScotterC 15y ago
    As I mentioned in another comment, if battery technology is super cheap then it benefits all power generation, even coal, because it would marginalize the fluctuating operating costs. Nuclear would actually be perfect because current nuclear reactors are kind of like diesel engines, they thrive when operating at a steady, ongoing power so we could fill up batteries all day and night.
    - InclinedPlane 15y ago
      That's an excellent point. Every power source would be boosted by better/cheaper batteries, even coal, nuclear, and hydro. In fact it could actually hurt solar/wind because with lots of batteries you could rely on a much smaller total generating capacity equal to just a little over average power usage (since peak loads could come from batteries). So there'd be less demand for new capacity of any sort to be built. It would also improve the safety of fission power since it would likely be easier to provide extended electricity to the cooling system in case grid power goes down.
      - ScotterC 15y ago
        It all hinges on batteries. I really really hope we find something. So many innovations have been held back by inadequate or expensive energy solutions. Portable, powerful and efficient energy storage could allow so much.
        ars 15y ago
        We do actually have "Portable, powerful and efficient energy storage" - it's called gasoline :) (Or natural gas.) Think about the insane size of the inverters you would need to power the grid off of a DC battery. Instead you use cheaper types of energy during the night, and avoid the natural gas. Then during peak usage you fire up your natural gas battery and run a turbine.
        InclinedPlane 15y ago
        This is not storage, not unless the gasoline is entirely synthetic and made from atmospheric CO2, which is not the case today.
        ars 15y ago
        Sure it's storage. It might not have been stored by you, but it's storage. Don't confuse moving away from CO2 emitting fuel with energy storage, they are two different things.
tjmc 15y ago
Not at night it isn't. High costs for storage mean that photovoltaic solar will need to be complemented by other sources for a good while yet.
- ScotterC 15y ago
  It's funny. If storage costs drop then everything improves. Hydro would become amazingly useful cause you could run the dam all the time and store the energy in batteries. The biggest problem with power generation is the fluctuation of starting and stopping the plants. Solar would not be a sole beneficiary.
  - hyperbovine 15y ago
    You can store energy in a dam. Pump it up during the day, run it through the turbines at night. Probably not too efficient but lack of storage is not a convincing reason for giving up on renewables, IMO.
    - tambourine_man 15y ago
      “Water in lakes has ~300k cubic kilometers ~ 3 * 10^14 kg http://ga.water.usgs.gov/edu/earthwherewater.html http://ga.water.usgs.gov/edu/earthwherewater.html Potential energy is ~ 9.81weightheight Storage requirements (USA): 336 billion kWh = 1.2 10^18 J height = 1.2 10^18 / (9.81 * 3*10^14) kg ~ 408m We would need to pump water in all lakes about 408m high to have 7 day worth of reserves for USA.” http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/#comment-194 http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
      - Inufu 15y ago
        Actually, that's wrong by three orders of magnitude. One cubic km has 10^9 cubic meters. Each cubic m has 1000 kg of water, so one cubic km has 10^12 kg. If you now have 300k cubic km, that's 3*10^17 kg. So you actually only need to use 0.1% of all lakes.
  - 15y ago
Someone 15y ago
I do not think anybody would want to build a large installation with cells with a 0.1% efficiency, even if they could get them for free. $ per m² is important, too. Reason is that, the lower prices get, the greater the fraction of installation costs that are not due to the price of the solar cells themselves. Those costs scale with panel area, not with power output, and they do not sink.

InclinedPlane 15y ago

It'll make them more cost effective. Making them cheaper won't improve their ability to produce power on demand though. That's necessary to replace base load power stations, and neither solar nor wind are capable of it yet.