Comment by torgoguys | Hacker News Reader

Comment by torgoguys | Hacker News Reader

Parent Full thread

Re: 1-I support balanced development (yes, including nuclear, but I get why some don't like it), but solar is AWESOME to pair with central electric production. It actually HELPS out with this issue. Very hot, sunny days is when there is peak power consumption. It's also the peak of solar production and can help avoid utilities having to spin up the (very expensive) temporary peaker plants.

Re: 2-Again, depending on how you look at it, solar helps with this, at least for homeowner rooftop production. If I'm producing my own electricity on-site, the utility company electricity never has to step-down voltages and move that last mile. I'm not using it (or I'm using less of it) so the energy coming from a central power plant never has to come down the "last mile" to me! Feeding back in is where you've got a bit of a point, but it's not really worse than with central production. In general distributed generation is going to be vastly more efficient (from the perspective of line losses) than central generation. Also, why bring up batteries? You don't need batteries to produce solar. If you have extra power, most people are feeding it into the grid, not batteries.

Re: 3-Agreed. Creating the panels is in general a very energy intensive process (in ways unrelated to the rare earth components), not to be ignored. It takes time for an "energy payback" if you will, but it's there. And the panels are very long-lasting.

> Also, why bring up batteries? You don't need batteries to produce solar. If you have extra power, most people are feeding it into the grid, not batteries.

Because feeding back to the grid is only a sustainable solution when a minimal number of entities are doing it. What happens when the majority of entities are feeding back to the grid? Where is all that energy supposed to go? The answer, of course, is storage.

And this isn't just some made up problem either; it happens right now with a different solution. There's a huge slack in power demand at night. Sometimes enough that the power providers will offer deep discounts to bulk buyers to get rid of excess supply. So you see some industries that use massive amounts of power, like aluminum refineries, shift to mostly night operations. But shifting demand around will only help so much.

Now, while distributed generation is fine, I don't think distributed storage is going to work. Storage cost (both economic and ecologic) and efficiencies are simply much better scaled up.

>Because feeding back to the grid is only a sustainable solution when a minimal number of entities are doing it. What happens when the majority of entities are feeding back to the grid? Where is all that energy supposed to go? The answer, of course, is storage.

I was talking about solar and it's benefits at shaving peak demand. I'm not talking about moving all of our power generation to solar and storing it in batteries. That would be silly. However, that you mention the huge slack in power demand at night helps illustrate my point. Solar matches up quite well with our needs for when electricity is consumed. No, the sun doesn't always shine, but yes, it can be a great tool in managing our power needs.

See the post you replied to--I'm not one that thinks all of our power should be coming from renewables at this point--but we could use a lot more solar (and also other renewables in different scales) than we already do. Is Germany's grid in shambles because they use so much solar? Are they doing widescale battery storage of extra energy? Of course not.

If there does end up being some sort of HUGE central energy storage happening, I doubt it would be in batteries. Talk about being difficult/expensive to scale...

>If there does end up being some sort of HUGE central energy storage happening, I doubt it would be in batteries. Talk about being difficult/expensive to scale...

Why would it be difficult/expensive to scale? As long as battery costs go down, there's absolutely no issue scaling. You just put as many of them as you want together.

I think there will be "grid scale storage" using various battery technologies (in the loosest sense, including things like pumped hydro, electric storage heaters in people's houses, as well as just standard lithium cells) but I also think that the rise in electric cars will also create a distributed storage and demand management solution.

Your car can receive a signal from the grid and either stop charging or actively feed power back in to the grid. This can be beneficial on even a very short timescale, e.g. lots of UK soccer fans put their kettles on during half-time of the FA cup, and all the electric cars currently plugged in stop charging for 30 seconds or so to counteract the demand spike.

I'm sure I saw an analysis that claimed you needed surprisingly few electric cars before that has a dramatic impact on the optimal way to design an electric grid.

Yes, but storage at scale can use more efficient and environmentally friendly solutions like pumped water which are not viable on a per home basis. This option is already in use at nuclear plants for absorbing peaks in demand.

Apparently distribution of storage to the extremities of a grid helps massively with reducing the peak power you have to force over a long distance interconnect, and it actually works out cheaper now in many situations to put in lithium at the far end, than upgrade the cable.

At least one US utility claims that residential solar has a similar win/win impact if the solar generation coincides with the transmission peak. Presumably the two technologies would work together well in this regard too.

Reply on news.ycombinator.com