5 ms·

An interesting problem is highlighted on that graph: solar seems to be peaking around mid-day, but energy demand peaks at 5 - 7 pm when solar is pretty weak. T

An interesting problem is highlighted on that graph: solar seems to be peaking around mid-day, but energy demand peaks at 5 - 7 pm when solar is pretty weak. The curves showing pre- and post-solar have almost identical peaks; solar hasn't yet successfully reduced peak load. (The California energy system posts a similar graph, with a similar shape: http://www.caiso.com/Pages/TodaysOutlook.aspx http://www.caiso.com/Pages/TodaysOutlook.aspx , made worse by the fact that the California wind farms apparently perform best in the morning and worst in the afternoon.) The difficulty is that, unless storage gets dramatically better, we'll still need a huge conventional electricity base. And it will still burn a huge amount of fuel: most generators are not "instant-on" -- it can take weeks to spin up a nuclear plant, days to spin up a coal plant, and hours [1] to spin up a natural gas plant. Of course, there are some savings, but there is huge waste if you have to keep the whole conventional energy infrastructure spinning during the day just to fuel that 6 pm peak load. Advice to entrepreneurs: finding a cost-effective way to store solar energy for 4 hours will be worth more than another 2% increase in efficiency. And inventing instant-on conventional-fuel plants will also make a huge difference in GHG emissions. [1] - Page 8 of http://www.euec.com/getattachment/euecjournal/Paper_3.pdf.aspx http://www.euec.com/getattachment/euecjournal/Paper_3.pdf.as... gives times between 1.2 hours for a warm start to 6 hours for a cold start.

reitzensteinm 14y ago
We don't need any breakthroughs. Electric cars could handle the entire peak load with today's technology, the right incentives, and capital flowing in the right place. The peak load for South Australia was 1.8 gigawatts. There are 1,275,041 motor vehicles registered in SA. If you could get all of them turned into electric cars plugged into the grid, it would be a 1.4 kW power drain per vehicle, which is less than the power drain of an ordinary kettle here (240V, 10A, ~2.4 kW). The cheapest Tesla Model S has a 40kW hour battery meaning it could sustain that power drain for over 28 hours (a total of 51 GWh). It's got a 10kW charger standard, which is more than enough. So if everyone had the cheapest Model S, kept it plugged in with the ability to send power back into the grid, and didn't mind that their car was sometimes down to 20% charge, you could power the entire grid on solar alone. That's obviously a set of unrealistic assumptions, but it does indicate that it is feasible to solve the problem like this. A more realistic set of assumptions: * 1/10 cars are turned into a Model S base model equivalent * Through financial incentives, the owners are willing to keep them plugged in during the day and using up to 20% of the battery to push back into the grid. * Cars need to shave 0.2 gigawatts off of peak load for four hours to bring it in line with the rest of the day That's 800 MWh of power to satisfy peak demand, at 200 MW. We have 127,504 vehicles, can can use up to 8kWh and 20kW each, giving: 1 GWh of capacity and 2.5 GW maximum power draw. So it's just enough. Alternatively, 5% allowing 40% usage works, etc. The power draw is insignificant. Owners can be heavily compensated for pushing energy back into the grid. I won't run the numbers here for length and time reasons, but knocking out peak power usage is incredibly profitable. You're literally decomissioning a large percentage of power plants. It would be feasible to make all the energy your car uses free; likely the lithium ion battery packs, too. The question is; would 5% of the driving population buy a $50k car if they no longer had to pay for fuel or battery packs? Financially that would probably put it closer to a BMW. I think it's feasible. What about in 10 years when the cars are $20-30k? Undeniably. In 20 years when you only need 2% of the population to be in the scheme due to battery increases and the cars cost $20k? No brainer. The system would require a smarter grid (so you can plug your car in at work and have it all taken care of), 10 years of Moore's Law for batteries, etc. But I think the numbers check out, and it means we could go crazy with solar (the explosion in solar must continue to charge these vehicles during the day). What's needed is the will to make it happen.
- SoftwareMaven 14y ago
  Until fast-charge batteries are a reality (such as the carbon-laced Li-ion discussed previously here), people very much will mind their car being at 20% charge. That means they don't get to drive until the next day, except 5-7pm is key commuting time, when they need to drive now.
  - reitzensteinm 14y ago
    My proposal was not that people would sacrifice 80% of their battery. The first half was exploring the limits of the idea. I was suggesting 20-40%.
- brc 14y ago
  >So if everyone had the cheapest Model S, kept it plugged in with the ability to send power back into the grid, and didn't mind that their car was sometimes down to 20% charge, you could power the entire grid on solar alone. The OP said cost effective, not pie-in-the-sky. Even if you took out the battery packs and sold them separately, the cost would exceed 10 years worth of electricity supply. >Owners can be heavily compensated for pushing energy back into the grid. You're asking people who cannot afford the expensive technology to subsidise those who can. This is the exact reverse logic of most progressive taxation regimes. >The question is; would 5% of the driving population buy a $50k car if they no longer had to pay for fuel or battery packs? Financially that would probably put it closer to a BMW. So you want to subsidise the purchase of expensive cars to the point where it is financially a good deal. This magic money no doubt comes from other taxpayers. And for what end? Just so you can have some type of boutique distributed power generation system? >What's needed is the will to make it happen. No, what's needed it pots of other peoples money. I've spent the best part of 5 years trying to hose down the jetsons fantasies of people pushing ridiculous schemes like this as not only unworkable, but inequitable for forcing up a basic cost input of life - energy - for effectively vanity purposes of a small subset of the population. I usually cop a pile of flamebait and downvotes each time, but I do so because there seems to be a mass delusion going on, and this has become one of those things you can't say.
  - 14y ago
comicjk 14y ago
Or just install twice the solar panels, if they're getting cheap enough. Or put them 4 time zones East (they will have to float in some cases) and send the electricity West.
- grecy 14y ago
  Better yet, go crazy with daylight savings, moving everything by 5 hours. The sun will be high in the sky at 5-7pm, generating power when we need it most.
- nl 14y ago
  Or put them 4 time zones East (they will have to float in some cases) and send the electricity West. This is a good idea, except electricity transmission costs are significant over long distances like that.
Andys 14y ago
I propose a new type of grid with electronic signaling of spot prices. For heavy duty appliances (eg. air conditioning, water heating) the consumer pre-programs it with a desired average cost and a maximum price per kWh. Then as demand and supply rises and falls on the grid, the spot price changes, and the devices receive signals and turn themselves on and off as needed. (There would be a certain minimum of fixed-price energy per month to make sure financially strained families never have to go without any)
brc 14y ago
You still need the conventional energy base. You cannot have a grid reliant on solar, because sometimes the sun doesn't shine for days on end. Solar can top up the grid, and correlates well with air-conditioning driven demand on hot days. But it doesn't coincide with peak load - especially in winter - and will always be a diffuse power source. You would not only need a cost effective storage solution (and none is in the foreseeable solution) you also need a lot of available space. Even if the panels were virtually free - there still remains large problems with solar power as a baseload energy source. If you solved the storage problem - cheaply - you'd still need 4 - 5 times the collecting capacity to get close to being able to reliably produce power over even a 48 hour period. It's a great boutique energy solution, particularly for remote usage. But large scale electricity generation will remain the dominant energy source well into the foreseeable future.
nl 14y ago
Advice to entrepreneurs: finding a cost-effective way to store solar energy for 4 hours will be worth more than another 2% increase in efficiency. And inventing instant-on conventional-fuel plants will also make a huge difference in GHG emissions. This is a solved problem. It's called pump storage[1], and is in use world wide. The US has some existing pump storage power plants (eg [2]), but typically they are used to smooth out demand on non-renewable generators (Coal, Nuclear etc). [1] http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity [2] http://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Station http://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Stat...
- gvb 14y ago
  [2a] http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_...
MikeCapone 14y ago
One potential solution is grid-scale liquid metal batteries: http://lmbcorporation.com/ http://lmbcorporation.com/ http://www.ted.com/talks/donald_sadoway_the_missing_link_to_renewable_energy.html http://www.ted.com/talks/donald_sadoway_the_missing_link_to_...
Daniel_Newby 14y ago
> The difficulty is that, unless storage gets dramatically better, ... Refrigeration! Put all the air conditioners and refrigerators on timers. Run them hard during peak solar hours. Then turn them off during the evening peak. If that would make the buildings too cool, make ice and melt it later to chill the air. (Some event venues already do this to handle air conditioning ten thousand people during midday.)
pippy 14y ago
Capturing energy should only come till after solar PV's generates surplus electricity. If solar panels continue to become cheaper and more efficient it's likely no revolutionary capturing technology needs to be developed. There are plenty of simple, cost effective energy capturing technologies currently in use today (see: http://en.wikipedia.org/wiki/TV_pickup http://en.wikipedia.org/wiki/TV_pickup)

reitzensteinm 14y ago

We don't need any breakthroughs. Electric cars could handle the entire peak load with today's technology, the right incentives, and capital flowing in the right place. The peak load for South Australia was 1.8 gigawatts. There are 1,275,041 motor vehicles registered in SA. If you could get all of them turned into electric cars plugged into the grid, it would be a 1.4 kW power drain per vehicle, which is less than the power drain of an ordinary kettle here (240V, 10A, ~2.4 kW). The cheapest Tesla Model S has a 40kW hour battery meaning it could sustain that power drain for over 28 hours (a total of 51 GWh). It's got a 10kW charger standard, which is more than enough. So if everyone had the cheapest Model S, kept it plugged in with the ability to send power back into the grid, and didn't mind that their car was sometimes down to 20% charge, you could power the entire grid on solar alone. That's obviously a set of unrealistic assumptions, but it does indicate that it is feasible to solve the problem like this. A more realistic set of assumptions: * 1/10 cars are turned into a Model S base model equivalent * Through financial incentives, the owners are willing to keep them plugged in during the day and using up to 20% of the battery to push back into the grid. * Cars need to shave 0.2 gigawatts off of peak load for four hours to bring it in line with the rest of the day That's 800 MWh of power to satisfy peak demand, at 200 MW. We have 127,504 vehicles, can can use up to 8kWh and 20kW each, giving: 1 GWh of capacity and 2.5 GW maximum power draw. So it's just enough. Alternatively, 5% allowing 40% usage works, etc. The power draw is insignificant. Owners can be heavily compensated for pushing energy back into the grid. I won't run the numbers here for length and time reasons, but knocking out peak power usage is incredibly profitable. You're literally decomissioning a large percentage of power plants. It would be feasible to make all the energy your car uses free; likely the lithium ion battery packs, too. The question is; would 5% of the driving population buy a $50k car if they no longer had to pay for fuel or battery packs? Financially that would probably put it closer to a BMW. I think it's feasible. What about in 10 years when the cars are $20-30k? Undeniably. In 20 years when you only need 2% of the population to be in the scheme due to battery increases and the cars cost $20k? No brainer. The system would require a smarter grid (so you can plug your car in at work and have it all taken care of), 10 years of Moore's Law for batteries, etc. But I think the numbers check out, and it means we could go crazy with solar (the explosion in solar must continue to charge these vehicles during the day). What's needed is the will to make it happen.

SoftwareMaven 14y ago
Until fast-charge batteries are a reality (such as the carbon-laced Li-ion discussed previously here), people very much will mind their car being at 20% charge. That means they don't get to drive until the next day, except 5-7pm is key commuting time, when they need to drive now.
- reitzensteinm 14y ago
  My proposal was not that people would sacrifice 80% of their battery. The first half was exploring the limits of the idea. I was suggesting 20-40%.
brc 14y ago
>So if everyone had the cheapest Model S, kept it plugged in with the ability to send power back into the grid, and didn't mind that their car was sometimes down to 20% charge, you could power the entire grid on solar alone. The OP said cost effective, not pie-in-the-sky. Even if you took out the battery packs and sold them separately, the cost would exceed 10 years worth of electricity supply. >Owners can be heavily compensated for pushing energy back into the grid. You're asking people who cannot afford the expensive technology to subsidise those who can. This is the exact reverse logic of most progressive taxation regimes. >The question is; would 5% of the driving population buy a $50k car if they no longer had to pay for fuel or battery packs? Financially that would probably put it closer to a BMW. So you want to subsidise the purchase of expensive cars to the point where it is financially a good deal. This magic money no doubt comes from other taxpayers. And for what end? Just so you can have some type of boutique distributed power generation system? >What's needed is the will to make it happen. No, what's needed it pots of other peoples money. I've spent the best part of 5 years trying to hose down the jetsons fantasies of people pushing ridiculous schemes like this as not only unworkable, but inequitable for forcing up a basic cost input of life - energy - for effectively vanity purposes of a small subset of the population. I usually cop a pile of flamebait and downvotes each time, but I do so because there seems to be a mass delusion going on, and this has become one of those things you can't say.
- 14y ago

comicjk 14y ago

Or just install twice the solar panels, if they're getting cheap enough. Or put them 4 time zones East (they will have to float in some cases) and send the electricity West.

grecy 14y ago
Better yet, go crazy with daylight savings, moving everything by 5 hours. The sun will be high in the sky at 5-7pm, generating power when we need it most.
nl 14y ago
Or put them 4 time zones East (they will have to float in some cases) and send the electricity West. This is a good idea, except electricity transmission costs are significant over long distances like that.

Andys 14y ago

I propose a new type of grid with electronic signaling of spot prices. For heavy duty appliances (eg. air conditioning, water heating) the consumer pre-programs it with a desired average cost and a maximum price per kWh. Then as demand and supply rises and falls on the grid, the spot price changes, and the devices receive signals and turn themselves on and off as needed. (There would be a certain minimum of fixed-price energy per month to make sure financially strained families never have to go without any)

brc 14y ago

You still need the conventional energy base. You cannot have a grid reliant on solar, because sometimes the sun doesn't shine for days on end. Solar can top up the grid, and correlates well with air-conditioning driven demand on hot days. But it doesn't coincide with peak load - especially in winter - and will always be a diffuse power source. You would not only need a cost effective storage solution (and none is in the foreseeable solution) you also need a lot of available space. Even if the panels were virtually free - there still remains large problems with solar power as a baseload energy source. If you solved the storage problem - cheaply - you'd still need 4 - 5 times the collecting capacity to get close to being able to reliably produce power over even a 48 hour period. It's a great boutique energy solution, particularly for remote usage. But large scale electricity generation will remain the dominant energy source well into the foreseeable future.

nl 14y ago

Advice to entrepreneurs: finding a cost-effective way to store solar energy for 4 hours will be worth more than another 2% increase in efficiency. And inventing instant-on conventional-fuel plants will also make a huge difference in GHG emissions. This is a solved problem. It's called pump storage[1], and is in use world wide. The US has some existing pump storage power plants (eg [2]), but typically they are used to smooth out demand on non-renewable generators (Coal, Nuclear etc). [1] http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity [2] http://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Station http://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Stat...

gvb 14y ago
[2a] http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_...

MikeCapone 14y ago

One potential solution is grid-scale liquid metal batteries: http://lmbcorporation.com/ http://lmbcorporation.com/ http://www.ted.com/talks/donald_sadoway_the_missing_link_to_renewable_energy.html http://www.ted.com/talks/donald_sadoway_the_missing_link_to_...

Daniel_Newby 14y ago

> The difficulty is that, unless storage gets dramatically better, ... Refrigeration! Put all the air conditioners and refrigerators on timers. Run them hard during peak solar hours. Then turn them off during the evening peak. If that would make the buildings too cool, make ice and melt it later to chill the air. (Some event venues already do this to handle air conditioning ten thousand people during midday.)

pippy 14y ago

Capturing energy should only come till after solar PV's generates surplus electricity. If solar panels continue to become cheaper and more efficient it's likely no revolutionary capturing technology needs to be developed. There are plenty of simple, cost effective energy capturing technologies currently in use today (see: http://en.wikipedia.org/wiki/TV_pickup http://en.wikipedia.org/wiki/TV_pickup)