[bdhdbebebeb]

If I were to deliver you 1000 gallons of milk that expires in 10 minutes*, would you pay me or want to charge me for that priviledge. Assume you have enough milk already.

* (< 1 millisecond for electricity but hey for the milk analogy say 10 minutes).

[theturtle32]

I don't think this is an apt analogy. Electricity is pulled, not pushed. (Well, I realize it is actually a bit more complicated than that, but for the purposes of this conversation, I think the generalization is sufficient.)

If there is no grid-side demand for the energy from my solar panels, then they're not going to be force-feeding it to a grid that doesn't want it.

When you plug a light bulb that's rated to draw 20 watts into a power source capable of delivering 1000 watts, it doesn't blow up your light bulb, because the light bulb only takes what it needs from the source.

[Ekaros]

It is more complicated on grid level. Some inverters might be smart enough, but some are not. Thus there is both push and pull going on. And this can affect voltage and frequency.

[noahjk]

This is the only reply I understand, so I’ll follow up here - in this case, is the end user paying to push the energy into batteries that the power company owns? Or is the extra energy just dissipated somewhere? Or does the power company stop producing their own energy once the grid is saturated? (I believe that electricity doesn’t actually flow like water, so it’s not the exact same electrons that the solar panel is producing which would be stored on batteries or dissipated somewhere)

[orwin]

[edit] if you don't produce the exact amount consumed at the exact same time, the current will loose its phase and the effective energy transported will be reduced, while producing surtensions at different grid points (don't quote me on that, but accumulator try to keep the phase, and too much divergence can cause their failure from what I understand. But I'm no physic major and I might be completely wrong). Grid coordination is vital.

The main issue with consumer solar connected to the grid is the lack of predictability. The reason why we charge if you put electricity on the grid when too much energy is produced is because we did not plan on offsetting this production, and the network people have to keep it balanced. Reducing the output of thermal fossil plants is usually free, but while we can module nuke plants, it's best and way cheaper when that is predicted (also, opportunity cost is high, so for privately owned nuke plants, it cost even more. EDF is the bitch of the European electricity market so they eat the opportunity costs, but they are the only plant owner who does it (and I won't talk about ARENH here, but again, EDF is the bitch of the EU). Then, when really to much shit is on the grid, and you have reservoir space, you pump the water up the STEP (batteries, but better). Up to 4500€/mwh if unpredicted (it's never actually that, but it's the price seer in the SPOT command order). And lastly, if it's the only solution, wind/solar farms are shut down. Again, if predicted, good time to do the maintenance.

In the future consumer grade installations will probably come with a lot of stuff to help with the lack of predictability. I don't love it, but that's actually my current job (well, I actually love the actual job, really interesting shit, I'm not so sure about the moral implications of even more surveillance. Because we do have the geoloc of the newer installations. We don't link it with anything relevant yet, and it's anonymous for the moment, but will it stay that way?)

[noahjk]

Interesting!

Is there a reason that consumer solar can’t be accounted for as smaller stable nodes in the system (sounds like they are still considered volatile and not a reliable source of inflow power)? For instance, maybe a rooftop solar array can easily be sucked up if the home decides to do a few loads of laundry that day, and therefore since there aren’t enough homes with solar arrays, it’s harder to predict an average influx per day from consumer solar to power the grid?

Are there any goals to shut down larger plants or not build larger solar fields by instead subsidizing distributed solar on peoples’ property?

Utilities are so interesting. The other afternoon I was looking out at the hills as the trees change, and said to my friend, “what a beautiful view… besides all these power lines! Although, I’d rather have the infrastructure than an unmolested view…”

[orwin]

> Is there a reason that consumer solar can’t be accounted for as smaller stable nodes in the system

It's not my subject (i mostly work on automation for the network and security teams), but when i consider some changes we did last year, i think the issue with consumer-grade solar is that we didn't know where installation number XXXX was set, not even which country it was from. That is changing, we will now know if it's near Paris, near Munich, near Barcelona... That will probably help with output prediction. I think at some point there were talk about using geoIP, but that was shut down for some reason (i think it was a mix of geoIP lying, and privacy/GDPR considerations we weren't ready to tackle on yet).

[toast0]

When there's too much energy available for the grid, and the price goes negative, producers are paying for someone to use that energy or paying another potential producer to reduce their output.

Some industrial users have variable demand, and a lower (or negative) price could encourage them to use more. A multi-region internet service might send more traffic to a datacenter with negative electricity prices, even if in increases latency for users.

Some producers need time to modulate output, and stopping and restarting can be expensive. Solar and Wind are at least technically easy to start/stop, but subsidies may make it economic to pay the grid to deliver electricity; either because of contracts/subsidies, or because the expense to deliver unwanted electricity is less than the expense to monitor pricing and reduce production.

[bdhdbebebeb]

What happens if no one takes the power (not one solar installation but lets assume lots of surplus power). Does it screw up the grid? Increase voltage/frequency?

Would this lead to grid needing to be shut down?

[toast0]

Yes, if nobody removes the excess, grid frequency will increase. Running too high or too low frequency can damange equipment, on both the supply and demand sides.