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Solar farm has to switch off every second day due to negative prices

reneweconomy.com.au

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Re: Solar farm has to switch off every second day due to negative prices

#71

Post by eecc »

thaumasiotes wrote: post #52
duckymcduckface wrote: post #38

Earlier quoted context omitted.

The ground is a poor load and also there's a finite amount of energy you can dump into it because every watt that goes in gets turned into heat, you'd liquify the ground very quickly at the multi MW scale.

We routinely dump lightning bolts right into the ground and they go well beyond multiple megawatts. They're very brief, but if lightning took ten seconds to strike, it would still provide several dozen megawatts of power. How quickly would we be melting the ground at the multi-MW scale? How many lightning bolts would it take before the ground around my house melted and flowed downhill?

Yes very localized and for a very short amount of time and most of the energy radiated away into the surroundings, including the atmosphere

Re: Solar farm has to switch off every second day due to negative prices

#72

Post by eecc »

steve19 wrote: post #15
wyxuan wrote: post #12

Earlier quoted context omitted.

Can’t they discharge it for free? Why do they have to pay to send it into the grid? The crypto one won’t work because there would only be free electricity half of the time, and the water idea is good but it takes immense capex and time to make

The grid has to finely balance supply and demand. You can't just dump power into the grid. If you did the grid frequency would increase out of spec and it could damage connected equipment and machinery. Water storage would only work if there is a steep mountain or big hill nearby. Another way to look at negitive pricing is the grid is paying industrial users to burn as much power as they can.

Hmm has anyone experimented with variable frequency transmission and solid state frequency synthesizing power transformers?

Re: Solar farm has to switch off every second day due to negative prices

#73

Post by bseidensticker »

solotronics wrote: post #58
apendleton wrote: post #17

Earlier quoted context omitted.

Anything you could do it with it would have capital costs. Maybe it's transient enough that that money would be better invested elsewhere. Like, if you only run your cryptocurrency mining when the price is negative, your capital is stuck in an idle asset most of the time, and if you run it all the time, it's the average price you want to consider, not the minimum price (even if the minimum price is negative), and my…

There are older bitcoin ASIC miners that aren't nearly as efficient but if you are getting totally free electricity... definately an opportunity here.

Yes this happens.

Re: Solar farm has to switch off every second day due to negative prices

#74

Post by Iv »

JMTQp8lwXL wrote: post #6

An explanation of the mechanics of how I'd have to pay somebody else to take my electricity (e.g., a negative rate) would be helpful. As prices approaches 0, I could take the excess electricity and say, mine cryptocurrency. Is nobody considering the arbitrage opportunities here? Take the 0-cost electricity, move water up a hill, and convert it back to electric when it's needed, etc.

tl;dr: the Australian grid is working on a faulty system because of politics. This is not a technical limitation there.

Re: Solar farm has to switch off every second day due to negative prices

#75

Post by [deleted] »

movedx wrote: post #32
dev_dull wrote: post #9

Earlier quoted context omitted.

why would they pay for someone else to use their energy? It just eats into their profits and means that their normal customers have to pay more for the solar energy.

I think the power grid should be socialised and electricity handed out for free, especially given our increasing dependency on it. Solar is technically "free" energy given there's nothing to setup and maintain except the infrastructure, versus coal/oil/gas which requires mining, refining and transportation of materials before you get to the generating and delivery parts of the process.

[deleted]

Re: Solar farm has to switch off every second day due to negative prices

#76

Post by moooo99 »

atupis wrote: post #68
brownbat wrote: post #4

Storage is definitely the wise answer here, as the article mentions. The fun answer here is giant crypto farm.

Smart air-condition and cooling is also a possibility, a here Finland we have started to piloting programs where heating is smart so houses are heated more when electricity prices are low.

That reminds me of the so called "Niedertarif-Speicherheizung" (storage heater) that were installed until the 80s here in Germany. They used the comparatively cheaper energy during the nighttime to heat up and then emit the heat during the day. They were controlled by the energy provider to turn on when the energy price was low.

Re: Solar farm has to switch off every second day due to negative prices

#77

Post by synchro77 »

Iv wrote: post #74
JMTQp8lwXL wrote: post #6

An explanation of the mechanics of how I'd have to pay somebody else to take my electricity (e.g., a negative rate) would be helpful. As prices approaches 0, I could take the excess electricity and say, mine cryptocurrency. Is nobody considering the arbitrage opportunities here? Take the 0-cost electricity, move water up a hill, and convert it back to electric when it's needed, etc.

tl;dr: the Australian grid is working on a faulty system because of politics. This is not a technical limitation there.

I'm not sure I understand, in what system would this not happen?

You can say that the goverment should store the extra electricity but that's not as easy as it sounds. Most things need very specific geographical or technical conditions for pumped hydro, compressed air energy storage, boreholes, hydrogen, molten salts.

So in what system wouldn't this happen?

Re: Solar farm has to switch off every second day due to negative prices

#78

Post by jeen02 »

nosuchthing wrote: post #24
LAMike wrote: post #21

Might want to buy some of the Power Miners: https://powerminingshop.com/ As chips reach the limits of the cutting edge tech, the only advantage will be how expensive your electricity is rather than replacing chips every 12 months

Why waste energy on a system that's designed to grow increasingly inefficient over time (Crypto PoW mining), when you could simply store the energy or use it on something that is helpful to the local community, as in food or manufacturing?

Why work for money when you can volunteer your time instead to the local community?

Re: Solar farm has to switch off every second day due to negative prices

#79

Post by mcv »

flukus wrote: post #64
peteretep wrote: post #50

Earlier quoted context omitted.

> that's enough to boil an Olympic-sized swimming pool in about 25 minutes This is in a country that — as I understand it — could definitely do with more desalinated water. How capital intensive can putting a huge kettle element in the sea with something to catch the vapour be?

More desalinated water would be handy, but typically it's not needed anywhere near the salt water and where it is needed more electricity isn't.

So use the energy to pump the water to where it is needed. Use it to generate hydrogen or methane or something to sell as fuel. Mine bitcoin even. It seems weird and wasteful to just shut off free energy.

Re: Solar farm has to switch off every second day due to negative prices

#80

Post by ZeroGravitas »

I'm not a fan of most reporting of these negative price events.

First, they rarely explain why the price is negative. As the article explains, solar can switch itself off, so it's nothing physical about solar that can cause negative prices, as all solar can switch itself off before it goes negative it would bottom out at zero for those reasons.

In most cases I've seen so far, contractual agreements with gas, coal or nuclear (who struggle to switch themselves off quickly without hurting themselves) have been the reasons for negative pricing and the grid wasn't actually at 100% renewable at the time of the curtailment. In other words, solar switches itself off, while other, dirtier plants get fined (negative price!) for demanding that they be allowed to still run.

In South Australia they're doing pretty well on renewable, so it's possible they actually are at 100% renewable at these times (would be good for the stories to clarify). If that's the case then the negative price is most likely caused by subsidies to wind that are paid per generation. If the subsidies to two renewable plants are different then one will bid the other off the market at that point since the price can go down to the opposite of the subsidy before they make an actual loss.

All in all, these negative prices are useful market signals. I wish the weren't covered by journalists who seem to think negative numbers are taboo for some reason.

The fact that it's the same plant that gets switched off repeatedly (rather than all solar reducing output) makes me think this is either a contractual thing that only affects its owner or a regional transmission thing that only affects its geographic location. Again, would be nice for stories to find out which.

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