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Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

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Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#291

Post by Kliment »

rmetzler wrote: post #288
yayana wrote: post #98

Earlier quoted context omitted.

I think Pumped Hydroelectric Storage is what you are looking for. I've seen a few of them here in Switzerland. I think many were originally built out with the train system's grid for it's reliably scheduled low and high capacity times. http://energystorage.org/energy-storage/technologies/pumped-...

There is a video in German on youtube where Prof. Hans Werner Sinn explains, why Germany can't store the excessive amounts of renewable energy in Pumped Hydroelectric Storage. You would need too much storage capacity, especially since you need two basins and the geological features necessary aren't there. He even calculated how this would work in a compound with Norway. https://www.youtube.com/watch?v=rV_0uHP3BDY I r…

This is somewhat misleading - there is a Europe-wide energy grid, Germany has many neighbors, and a lot of power has been flowing across borders even before this project started. It doesn't make sense to look at Germany in isolation. While I agree that the German approach is misguided (should have shut down coal first, not nuclear) I don't think it's as problematic as you make it seem - the spikes in wind average out excellently when you look on the scale of several countries, and daytime demand for solar power is large and growing due to industrial use (residential use peaks in the evenings, but residential use is insignificant compared to industry). A significant component of the Energiewende is replacing baseload fossils (coal) with peaker gas plants but the coal industry is very powerful and very much opposed to this, and many local governments are in coal industry pockets and resist any coal reduction (this is one reason why nuclear was shut down first). Peaker gas plants operate only when the demand is high and supply is low, running on a much lower duty cycle than a baseload plant. The way things are going now, there's been a rapid nuclear phaseout and there's a glacial coal phaseout very slowly happening, but solar and wind installations have been growing and are displacing more and more baseload. Eventually this will price baseload coal power out of the market, and then we'll see if the coal terrorists are powerful enough to get a bailout or to get solar legally destroyed like they did in Spain.

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#293

Post by Kliment »

xigma wrote: post #88
nostrademons wrote: post #40

Earlier quoted context omitted.

It's likely a short-term problem. There are plenty of ways to fix it (besides the one you mention, just shut down coal & oil power plants for good and replace them with technologies like natural gas or hydro that can easily react to spikes in demand), but all of the fixes require capital investments and time to build factories & tooling. Basically this is a problem because a bunch of existing incumbents are probably…

> Basically this is a problem because a bunch of existing incumbents are probably going to go bankrupt, or at least have to write down a lot of capital equipment and invest in new technologies. That's not how it works. In Germany, the government subsidizes farmers to put up Windfarms, then forces the electric companies to buy the electricity at an inflated price, which those companies charge their customers for. As a…

The coal terrorists are able to demand subsidies not because of their poor workers (they are in fact laying off lots and lots of workers as a side effect of mergers, and their total employment is just several thousand people) but because a lot of local government is funded by coal company shares held by cities. This is why coal is still a thing.

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#294

Post by eigenvector »

toomuchtodo wrote: post #198
eigenvector wrote: post #95

Earlier quoted context omitted.

You hit at an important dimension which is that the problem is not technical per se, it's really a problem of market design. Wind power purchase agreements should allow curtailment (since it is very easy to ramp a wind farm /down/) when needed for system reliability. However, this reduces the rate of return for wind farms so politicians that are looking to maximize wind build-outs will not favour this. It's also bene…

You do not want to force curtailment of clean energy. You either force curtailment of fossil generators (and let those operators deal with the operational complexity of doing so) or incentivize storage.

In the real-time operating window, some generators may have must-run characteristics. For instance, hydro with downstream flow requirements for fish habitat or agricultural use or nuclear without thermal bypass. It's easy to say 'let the operators deal with the operational complexity', but if you're going to need to that nuclear unit in 6 hours you can't tell them to pound sand and poison their reactor now. Furthermore, even if the energy from some conventional generators may not be needed, they may be required to run to provide grid ancillary services such as operating reserve (the ability to ramp up or down rapidly) or to avoid violating system operating limits due to physical constraints on the transmission system.

Since wind turbine generators will not experience or cause physical damage due to rapid curtailment, only commercial harm, in a scenario where the spot price is going to zero or negative (i.e. the marginal energy being produced is not valued by anyone), it can make operational sense to curtail them before higher emitting generators under certain conditions.

Keep in mind I'm speaking only to the real-time operating considerations (think a time horizon of 24 hours) not the larger generation planning perspective. The system should be planned in a way that minimizes the need for renewable curtailment, but that's a long-term goal that isn't accomplished yet. Operating on a strict zero-curtailment basis for wind turbine generators reduces system flexibility and maneuverability and results in costs for all ratepayers.

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#295

Post by dwd »

thinkcontext wrote: post #61
DoctorOetker wrote: post #22

I don't truly understand this "problem". I understand storing the energy in batteries is currently very expensive economically and materially. However I believe there are plenty of "goods" (irrespective of if they are bulk materials, or partially processed products) which have a high processing energy per volume ratio (this does not need to be recoverable stored energy). Allow me to give an example: currently we have…

If you wait for power prices to be negative (or merely lower than usual) you are not getting an economic return on the money you put into the desalination plant when it is not running. Think about it, if you get a 100M Euros loan to make a desalination plant, how long will it take to pay that off if you only run your plant a few hours per day vs 24 hours per day. Whether it makes economic sense depends on the differe…

http://www.abc.net.au/news/2018-08-08/hydrogen-fuel-breakthr...

Ammonia would be preferrable as it is carbon-free and readily liquified.

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#296

Post by undreren »

eloff wrote: post #236
floatrock wrote: post #48

Earlier quoted context omitted.

Capital costs vs. marginal costs. You're going to build a $100M desalination plant and run it for three hours a day? That's a ton of money sitting idle most of the day, far more than what is recovered with zero operating costs. (This is called the utilization factor -- how long a piece of equipment is used vs. staying idle) Ideally you want useful processes with low capital costs and expensive marginal/energy costs.…

Desalinization isn't a good example for the reasons you say, but theptip writes below that heating water in residential and commercial settings might be better. Since water once heated stays hot for a good while in the insulated storage tank. Also buildings can be heated with hot water instead of forced air, typically through pipes in the floor. Which is nicer because it keeps your feet toasty and doesn't dry out the…

> but theptip writes below that heating water in residential and commercial settings might be better.

When I worked at Ørsted, we did this all the time. We had a huge electric kettle, which we used to produce district heating water.

But there are many more things you can do with surplus energy. You can make methane gas from pure CO2 and hydrogen when you apply electric power as a catalyst.

The methane can then be eaten by bacteria to provide protein powder to be used as supplements to feeding livestock.

Or, we can yank CO2 out of the atmosphere and store it as ethanol. I think this was discovered last year or so? Ethanol is a really good "battery", and it only discharges as much CO2 as was captured by the surplus energy used to make it, making it a clean fuel that only exhausts CO2 and sterile water.

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#297

Post by kilotaras »

hoschicz wrote: post #290
WalterBright wrote: post #218

Earlier quoted context omitted.

During the winter, one can electrically heat concrete blocks during the day, they release their heat at night. (A concrete block makes for a pretty cheap "battery" !! )

Why heat concrete blocks? Doesn't water have a higher thermal capacity?

Depends on the actual concrete. It will have lower thermal capacity per weight, but that may be offset with higher density. (The most common concrete would be worse than water with capacity being 1.3 (vs 4.2 in water) and density of 2400 kg/m3).

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#298

Post by petre »

Kliment wrote: post #291
rmetzler wrote: post #288

Earlier quoted context omitted.

There is a video in German on youtube where Prof. Hans Werner Sinn explains, why Germany can't store the excessive amounts of renewable energy in Pumped Hydroelectric Storage. You would need too much storage capacity, especially since you need two basins and the geological features necessary aren't there. He even calculated how this would work in a compound with Norway. https://www.youtube.com/watch?v=rV_0uHP3BDY I r…

This is somewhat misleading - there is a Europe-wide energy grid, Germany has many neighbors, and a lot of power has been flowing across borders even before this project started. It doesn't make sense to look at Germany in isolation. While I agree that the German approach is misguided (should have shut down coal first, not nuclear) I don't think it's as problematic as you make it seem - the spikes in wind average out…

Peaker gas plants running on gas imported from whom, Russia? At least Germany has the biggest gas sorage capacity in Europe.

https://www.ecfr.eu/article/commentary_europes_vulnerability...

A possibly better strategy would be to produce DME using excess capacity and convert diesel vehicle engines to DME. Then export both the cars, the fuel and the tech to produce the fuel locally. Maybe even use it as input for peaker gas plants and shipping fuel. Germany has all the resources necessary to establish and lead such a market. Plus they don't need to throw away decades of investment into diesel ICE R&D. See chapter 2.2 of this article.

http://www.oil-gasportal.com/dimethyl-ether-dme-production-2

http://www.iea-amf.org/content/fuel_information/dme

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#299

Post by rebuilder »

DoctorOetker wrote: post #22

I don't truly understand this "problem". I understand storing the energy in batteries is currently very expensive economically and materially. However I believe there are plenty of "goods" (irrespective of if they are bulk materials, or partially processed products) which have a high processing energy per volume ratio (this does not need to be recoverable stored energy). Allow me to give an example: currently we have…

It's a problem for infrastructure investors, or more precisely, investors in traditional power plants. Since most traditional power plants tend to produce CO2 and other pollutants, I'm actually inclined to think it's a good thing if economic incentives begin to turn against them. We'll still need power, and energy is big business, so there's tremendous incentive to solve any problems in that sector.

Re: Power Worth Less Than Zero Spreads as Green Energy Floods the Grid

#300

Post by WalterBright »

hoschicz wrote: post #290
WalterBright wrote: post #218

Earlier quoted context omitted.

During the winter, one can electrically heat concrete blocks during the day, they release their heat at night. (A concrete block makes for a pretty cheap "battery" !! )

Why heat concrete blocks? Doesn't water have a higher thermal capacity?

Concrete blocks do not leak or wear out. They are cheap and zero maintenance. For more thermal capacity, use a bigger block. You can even make them structural - using concrete for walls.
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