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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

#111

Post by potentialverand »

ZeroGravitas wrote: post #80

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…

Agree with all your points.

South Australia gets additional energy from grid interconnections from other states, and it's gas turbine power plant at Torrens Island. Additional power from other sources like diesel generators when required

https://www.sa.gov.au/topics/energy-and-environment/energy-s...

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

#113

Post by dwd »

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.

They mentioned moving water uphill with the Wivenhoe pumped hydro which is about 3000km away in Qld. This is also where the NSW interconnect will help as most pumped hydro is in NSW.

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

#114

Post by iguy »

Iv wrote: post #103
synchro77 wrote: post #77

Earlier quoted context omitted.

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?

If you suppose a well-designed grid, I really doubt that free electricity is something that clients would refuse. Electricity is valuable, at any time of the day. There is no reason for it to go below zero. Sure, storing energy is hard but spending it is easy. Hell, give me free electricity and I will be running a pyrolysis rig, making biofuel for free.

No, it's not always valuable. If you get free electricity for an hour, some days of the week, then your giant biofuel plant spends a lot of time sitting idle.

It's not obvious that your mostly-idle plant is a better business than a much smaller one which runs all the time. The costs of building and maintaining the thing are real too. (Not to mention needing to design the plant to ramp up to full production in minutes, while a more traditional one might spend a day warming up all the pieces to operating temperature.)

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

#115

Post by beachy »

Udik wrote: post #102
beachy wrote: post #95

Earlier quoted context omitted.

It's electricity. Break the circuit and it stops flowing.

When I stop a turbine I'm not simply breaking the circuit- I stop converting some fuel into energy, and keep it for later. If I break the circuit on a solar panel, the "fuel" keeps hitting the panel anyway. I guess the panel just reaches a different thermal equilibrium. Which is the same as dumping the energy in the ground, only more distributed.

According to this https://physics.stackexchange.com/a/71445:

> Electric power is the product of voltage and current. If there is no external circuit, there can be no current and thus no electric power can be delivered by the panel, i.e., the "electricity" is never developed and thus, there is no need to consider "where it goes".

There's also an interesting discussion in the linked post in more depth about electron hole-pairs.

My takeaway is that the temperature in the panel will not rise due to it absorbing any power that would otherwise go down the wires were the circuit complete.

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

#116

Post by DevoidSimo »

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.

People do, we have snowy hydro who normally correct these negative prices by pumping water uphill into a dam. They then double dip on profits by generating when the cost is positive. Very profitable operation although the initial infrastructure cost is high.

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

#117

Post by ThrustVectoring »

jillesvangurp wrote: post #100

The solution is to deregulate the market and allow multiple companies to buy and sell electricity. The problem here is not an over supply but poorly regulated demand that causes energy to be priced higher than is justified; mainly to protect expensive sources of energy such as coal and gas plants. The basic issue is not that there is no demand but that it is unevenly spread. People turn on their ACs when they get hom…

Your analysis completely ignores the capital costs associated with building out a variable demand system. Every battery built will tie up a certain amount of money into fixing grid pricing variability, as well as depreciate in value and usefulness over time.

If electric overproduction is an infrequent enough condition, it may well be cheaper to waste energy than to build a battery that just sits there 300+ days a year doing nothing.

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

#118

Post by MaysonL »

ZeroGravitas wrote: post #80

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…

Towards the end of the article there is discussion of coming factors that may eliminate the negative price shutdowns: a) construction of grid interconnects to New South Wales, and b) new pumped hydro storage to enable time shifting (i.e. using daytime power to enable nighttime generation).
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