4 ms·

Efficient renewable energy is great, but isn't the problem storage of that energy? Without storage, the energy generated by renewables needs to be used up by th

by splike 10y ago

Efficient renewable energy is great, but isn't the problem storage of that energy? Without storage, the energy generated by renewables needs to be used up by the grid immediately. Won't most of it be wasted?

cm3 10y ago
I've been wondering why AC units for buildings don't come in solar cell combi packages, where if it's hot, it's sunny, so the ac can be powered by the sun, ideally making it a zero sum calculation.
- __Joker 10y ago
  Because it is not cost effective. Fossil fuel is still cheaper. Unless solar prices ( installation- panel, batteries) comes down or subsidised to match those existing prices, it will still take some time .
  - toomuchtodo 10y ago
    Wind is already cheaper than fossil fuels unsubsidized; solar will get there in the next 12-18 months (without storage).
- pilom 10y ago
  Because the amount of solar required to power an air conditioner is significantly larger than the air conditioner itself and often you need more solar than you have roof space for buildings 2 stories and greater. (i.e. the total amount of solar you can fit on the roof of a 4 story building will likely not be sufficient to run the air conditioner required to cool that building.)
- tim333 10y ago
  You can get them on Alibaba https://www.alibaba.com/product-detail/working-10hours-18-hours-SUNCHI-100_884031161.html https://www.alibaba.com/product-detail/working-10hours-18-ho...
crdoconnor 10y ago
>isn't the problem storage of that energy? That's an overemphasized problem. There's a lot more space to cheaply time-shift electricity demand (i.e. not with batteries) in response to variable pricing than most people realize.
- slfnflctd 10y ago
  I don't think it's overemphasized at all. Time shifting is only effective right now due to oddities of our current system that are in no way guaranteed to be permanent. Once we get enough solar installed that it is powering most of the air conditioning when it's most used (which, contrary to what some are saying, is close enough to grid parity to be inevitable in many places), time shifting will be much less advantageous. At some point, storage is going to play a huge role (there are places where it's already starting to, like Hawaii). It's frustrating that we're still having so much trouble bringing down cost per kWh, but with all the disparate technologies being researched, I think it will happen eventually. Just not as soon as some of us would have liked.
  - paul_f 10y ago
    Everyone interested in this topic should make sure to understand the Duck Curve. https://energyathaas.wordpress.com/2016/05/02/the-duck-has-landed/ https://energyathaas.wordpress.com/2016/05/02/the-duck-has-l...
  - crdoconnor 10y ago
    >Time shifting is only effective right now due to oddities of our current system It's not effective right now because we have a grid built upon the assumption that demand and supply are relatively static.
    - slfnflctd 10y ago
      Well, that of course depends on whether you're talking about monetary efficiency (for which time shifting of large loads to lower night time rates makes monetary sense currently) or actual electrical efficiency (clearly needing a ton of work to properly improve upon). Ultimately the latter is better, but there is so much nuance involved that I don't expect it any time soon. I personally believe that anyone interested in pushing the true efficiency envelope should be looking at getting the most out of off-grid systems right now, at least until more promising innovations show up within the grid itself.
melling 10y ago
Doesn't that really depend on if you can't use it all? If you get 50% of your electricity from solar during the day, can't you use it all? At night you simply have to get the other 50% from fossil fuels. Isn't that still a big win in the short term? If half the world's daytime electricity came from solar, we'd be in much better shape.
dv_dt 10y ago
The more efficient renewable energy the more margin storage has as breathing room against conventional energy.
Retric 10y ago
First you can transport electricity east or west to shift supply. This is only good for around +/- 2 hours before local storage is generally a better idea, but just that works out to ~1/3 of your storage needs. (1040 miles = 1 hours at the equator, less as you move north.) Next, there are many ways to store energy. Desalination is a great example where they need high pressure water so just pump it up a hill in the day and all you need to 'add' is slightly more pumps and a large pond. Heating and cooling are another area where storing the output tends to be very cheap. Finally, people just need less energy when they sleep. Your work PC is probably also asleep for example.

by splike 10y ago

cm3 10y ago

I've been wondering why AC units for buildings don't come in solar cell combi packages, where if it's hot, it's sunny, so the ac can be powered by the sun, ideally making it a zero sum calculation.

__Joker 10y ago
Because it is not cost effective. Fossil fuel is still cheaper. Unless solar prices ( installation- panel, batteries) comes down or subsidised to match those existing prices, it will still take some time .
- toomuchtodo 10y ago
  Wind is already cheaper than fossil fuels unsubsidized; solar will get there in the next 12-18 months (without storage).
pilom 10y ago
Because the amount of solar required to power an air conditioner is significantly larger than the air conditioner itself and often you need more solar than you have roof space for buildings 2 stories and greater. (i.e. the total amount of solar you can fit on the roof of a 4 story building will likely not be sufficient to run the air conditioner required to cool that building.)
tim333 10y ago
You can get them on Alibaba https://www.alibaba.com/product-detail/working-10hours-18-hours-SUNCHI-100_884031161.html https://www.alibaba.com/product-detail/working-10hours-18-ho...

crdoconnor 10y ago

>isn't the problem storage of that energy? That's an overemphasized problem. There's a lot more space to cheaply time-shift electricity demand (i.e. not with batteries) in response to variable pricing than most people realize.

slfnflctd 10y ago
I don't think it's overemphasized at all. Time shifting is only effective right now due to oddities of our current system that are in no way guaranteed to be permanent. Once we get enough solar installed that it is powering most of the air conditioning when it's most used (which, contrary to what some are saying, is close enough to grid parity to be inevitable in many places), time shifting will be much less advantageous. At some point, storage is going to play a huge role (there are places where it's already starting to, like Hawaii). It's frustrating that we're still having so much trouble bringing down cost per kWh, but with all the disparate technologies being researched, I think it will happen eventually. Just not as soon as some of us would have liked.
- paul_f 10y ago
  Everyone interested in this topic should make sure to understand the Duck Curve. https://energyathaas.wordpress.com/2016/05/02/the-duck-has-landed/ https://energyathaas.wordpress.com/2016/05/02/the-duck-has-l...
- crdoconnor 10y ago
  >Time shifting is only effective right now due to oddities of our current system It's not effective right now because we have a grid built upon the assumption that demand and supply are relatively static.
  - slfnflctd 10y ago
    Well, that of course depends on whether you're talking about monetary efficiency (for which time shifting of large loads to lower night time rates makes monetary sense currently) or actual electrical efficiency (clearly needing a ton of work to properly improve upon). Ultimately the latter is better, but there is so much nuance involved that I don't expect it any time soon. I personally believe that anyone interested in pushing the true efficiency envelope should be looking at getting the most out of off-grid systems right now, at least until more promising innovations show up within the grid itself.

melling 10y ago

Doesn't that really depend on if you can't use it all? If you get 50% of your electricity from solar during the day, can't you use it all? At night you simply have to get the other 50% from fossil fuels. Isn't that still a big win in the short term? If half the world's daytime electricity came from solar, we'd be in much better shape.

dv_dt 10y ago

The more efficient renewable energy the more margin storage has as breathing room against conventional energy.

Retric 10y ago

First you can transport electricity east or west to shift supply. This is only good for around +/- 2 hours before local storage is generally a better idea, but just that works out to ~1/3 of your storage needs. (1040 miles = 1 hours at the equator, less as you move north.) Next, there are many ways to store energy. Desalination is a great example where they need high pressure water so just pump it up a hill in the day and all you need to 'add' is slightly more pumps and a large pond. Heating and cooling are another area where storing the output tends to be very cheap. Finally, people just need less energy when they sleep. Your work PC is probably also asleep for example.