7 ms·
As the production costs with windpower decrease due to the technological progress, the question of grid storage and grid interconnection becomes more pressing.
by shaqbert 8y ago
As the production costs with windpower decrease due to the technological progress, the question of grid storage and grid interconnection becomes more pressing.
E.g. in Germany, they frequently have days of negative energy prices, where producers need to pay to feed energy into the greed because of overproduction of energy on windy/sunny days [0](in German). Without storage and grid interconnection, there is only so much renewable energy from intermittent sources like wind and solar you can handle.
[0]: https://blog.energybrainpool.com/bereits-103-mal-in-2017-negative-preise-am-stromspotmarkt/ https://blog.energybrainpool.com/bereits-103-mal-in-2017-neg...
- NullPrefix 8y agoThis sounds like an opportunity for collaboration between crypto miners and the wind people.
- mhb 8y agoAnd maybe it can be mediated by fungible electricity transmitted over a grid of conductive wires. Or an electricity market.
- NullPrefix 8y agoWhat I've meant was mining on the wind mills themselves. So there would be no need of passing through the grid.
- emiliobumachar 8y agoI heard that crypto mining hardware has to have decent-ish (80-90%) uptime to be profitable. That would make it infeasible to have it on standby waiting for excess energy on the grid.
- ccozan 8y agoAfter the windmill is paid off, the mining is then practically ( some maintenance will be needed ) for free.
- NullPrefix 8y agoIsn't the number 80-90% based on electricity price?
- emiliobumachar 8y agoI'm afraid I have no idea. I vaguely remember reading about it, do not remember where.
- imtringued 8y agoElectricity prices matter but lower prices give diminishing returns. Going from $0.20 per kWh $0.05 to per kWh only increases profits by 50% http://whattomine.com/coins/151-eth-ethash?utf8=%E2%9C%93&hr=27.9&p=115.0&fee=0.0&cost=0.05&hcost=300.0&commit=Calculate http://whattomine.com/coins/151-eth-ethash?utf8=%E2%9C%93&hr... vs http://whattomine.com/coins/151-eth-ethash?utf8=%E2%9C%93&hr=27.9&p=115.0&fee=0.0&cost=0.05&hcost=300.0&commit=Calculate http://whattomine.com/coins/151-eth-ethash?utf8=%E2%9C%93&hr... and going from 0.05 to -0.05 only increases it by 20% http://whattomine.com/coins/151-eth-ethash?utf8=%E2%9C%93&hr=27.9&p=115.0&fee=0.0&cost=-0.05&hcost=300.0&commit=Calculate http://whattomine.com/coins/151-eth-ethash?utf8=%E2%9C%93&hr... By the way, these mining calculators are very "optimistic" but for relative comparisons they are sufficient. In practice you will get significantly less because of increasing difficulty and hidden costs like motherboards, CPUs, etc.
- mhb 8y agoI know. And there's really no difference between colocating mining hardware on wind turbines and just mining using the lower cost electricity which will be on the grid thanks to the turbines. Except the inconvenience of the colocating.
- rplnt 8y agoAs for storage, shouldn't there be plenty of hydroelectric dams that could run "backwards"? Or is there an interconnection issue you mention?
- cesarb 8y agoFor a hydroelectric dam to be able to "run backwards", it needs a lower reservoir. Many dams have only an upper reservoir.
- mrfusion 8y agoSimply turning them off would be running backwards since water would build up behind them.
- nothrabannosir 8y agoIt’s not about building up capacity alone: you want to take power off the grid at negative energy price times.
- vidarh 8y agoYou are taking power off the grid: The power otherwise produced by the hydro plant. Of course with a lower reservoir, you can go into negative territory instead of "just" taking the plant down to 0.
- jimktrains2 8y agoNo, you need to consume what other methods, e.g. wind, are producing when there isn't the demand to use it.
- vidarh 8y agoThere is always demand. The issue is that sometimes demand exceeds supply. Taking away supply has the same net effect as increasing demand. EDIT: with the one caveat of transmission capacity, which certainly can be an issue.
- kylegordon 8y agoIsn't this where pumped storage and other forms of storage come into play? Here in Scotland we routinely pump water back up into our lochs in order to store it for future use. There's also various news articles reporting on German mines beginning to be used as pumped storage sites, with a reservoir on the surface, and water dropping into the mines below when there's sudden demand. This is a good problem to have, though.
- maxerickson 8y agoA lot of the best sites for pumped storage are already developed as pumped storage. It's kind of the opposite of other storage technologies. As sites get developed the economics of future sites get worse.
- nmeofthestate 8y agoAccording to Wikipedia we have 15 GWh of pumped storage capacity in Scotland. Per annum we use 27,000 GWh. So by my calculations we have a pumped storage battery that lasts about 5 hours. (NB: I didn't check whether the power output of this battery is enough to actually meet demand, but wikipedia says it can run at full capacity for 22 hours, so no)
- mattmanser 8y agoIt can be reused more than once a year. You could use it every day, charge at night when there's no demand, discharge it during the peak. Really depends on how fast it can charge and discharge.
- bluGill 8y agoDepends more on how variable your supply is. If you have to meet a two week window with below average wind it isn't enough. If you have to just meet day to day variation in wind it is probably enough. Unfortunately two weeks without much wind are common in general weather patterns. Thus my gut reaction is it isn't enough. However we are now talking weather where local patterns are the important thing which means each situation needs to be considered separately.
- Brakenshire 8y agoAs turbines get larger, not only do the costs go down, but the reliability of supply goes up. It becomes more economical to place them out at sea, where winds are more reliable, and the size allows them to run more effectively off low speed winds. These turbines are claiming 60%+ capacity factor, compared to 20-30% for smaller, onshore turbines. The UK is already up to about 15% of its electricity from wind right now, these developments will open that up significantly more. Obviously at high levels of penetration there are going to be issues, we'll just have to see how far we can go, but even 25-40% of electricity would be a huge contribution. Combine that with the new and existing nuclear, another 15%, some biomass and tidal lagoons, with the rest from gas (which produces half as much CO2 as coal) and it will go a long way towards meeting the UK's 80% CO2 reduction target from 1990 to 2050.
- vidarh 8y agoGermany has at least one example of an aluminium producer testing dialing the power use of their melter up/down by 25% in response to input from the grid [1]: > Trimet says that implementing its technology across Germany’s four aluminum smelters, three of which it owns, could provide a demand response capacity equal to a third of Germany’s 40 gigawatt-hours of pumped hydro storage. There was a lot of confusion about this one when it was published, but as the article points out, they're not using their molten aluminium pools as a liquid battery - they're merely dynamically adjusting the electricity usage of their hydrolysis cells, which also requires some other adjustments to keep the process going, but it's still a lot of power and more responsive than what they do today (which involves taking the smelters entirely offline for short periods). It helps that their test plant is near Hamburg in the North, "close" to most of Germany's wind turbine capacity which helps alleviate transmission/interconnection problems to the South. [1] https://www.greentechmedia.com/articles/read/german-firm-turns-aluminum-smelter-into-huge-battery#gs.aOAMAos https://www.greentechmedia.com/articles/read/german-firm-tur...
- ZeroGravitas 8y agoCan you explain why you think these negative prices are a bad thing? I think they're an efficient use of market based tools to ensure that the group who can reduce the input to the grid does so, and to incentivize electricity production that can meet the flexible demands of the grid (e.g. slow ramping coal would be penalised over fast ramping gas without any regulation needing to specifically target the coal and the coal plant can do anything it wants to improve this, e.g. fit batteries, since no technology is mandated.
- toomuchtodo 8y agoNegative price signals that cause solar or wind production curtailment is essentially throwing clean energy away. Negative prices are a helpful market signal, but must be combined with battery storage requirements.
- ZeroGravitas 8y agoNegative price signals encourage people to use that excess energy as they are paid to do so at exactly the times that solar or wind are overproducing. They are the solution to that problem, not part of the problem. As for batteries, there needs to be an economic incentive for people to invest in deploying batteries (or any other type of storage). Negative prices are that incentive. Negative prices don't need batteries, batteries need negative pricing.
- deleted 8y ago[deleted]
- graycat 8y agoIMHO: (1) Cheap, large scale storage of electric energy might be a big game changer. (2) Without such storage, basically a country has to notice what their peak load is and assume that they have installed capacity that is reliable, e.g., independent of the weather, and meets this peak load. (3) So, net, intermittent sources such as wind and solar don't much lower the capital expense needed. That is, the country still needs the same capacity to meet peak loads without the intermittent sources. So for this capacity they can use nuclear fission, coal, oil, natural gas, hydro, geo-thermal, and that's about it. So, net, when power from intermittent sources is available, then get to save on the fuel cost of fission, coal, oil, and natural gas and accumulate some water behind hydro. So, e.g., a big fission or coal plant is still there, still with its capital expense and operating expense but is running at reduced power and, thus, saving on direct fuel costs. At that point, I'm wondering if, really, just for the money part, if the intermittent sources are wanted on the grid even for free. There is an issue about the intermittent sources: They are not very predictable and, thus, can cause some grid stability problems. E.g., IIRC, can't just change the power level of a fission or coal plant minute by minute to match the minute by minute fluctuation in the intermittent sources; so, can get some grid instability, and that is bad stuff for the whole grid and country.
- bluGill 8y agoWorse, the big power plants get much less fuel efficient at lower loads. In some cases you will actually burn more fuel at 50% than 80%!
- EADGBE 8y ago> frequently have days of negative energy prices, where producers need to pay to feed energy into the greed because of overproduction of energy on windy/sunny days This is one reason why I'm skeptical for home production of solar and wind for the ability to "feed back" into the grid while getting a credit on your account. If the power company is also doing this, at scale, I find it really hard to believe that there's no reason the power company won't discredit/discount my rates being returned to the grid. In which case, I'd rather have a battery installation and not rely on the power company at all. Most service reps for solar disagree with me. Maybe because battery storage isn't super common/in their inventory?
- maxerickson 8y agoIt's more that batteries are expensive. Especially in places where there is a law saying that the power company has to pay a nice rate for power fed back to the grid.
- EADGBE 8y agoUnderstandable, the legislation isn't brought up (but maybe this concern isn't, either) that often. It could certain be a non-issue. Though I rarely experience power outages, knowing almost all instances would be non-existent is really nice (for a battery backup program), especially as more and more heating solutions are using electricity as the main component (heat pumps; winter power failures are most of the power failures for me).
- lscharen 8y agoI think is a totally reasonable point of view and comes down to a classic cost-benefit analysis. Are you OK with using the grid as a highly-reliable, ~infinite capacity power source to smooth over your uneven solar generation at a cost of selling your excess back at a discounted rate, or do you want to try and capture that discount yourself at the cost of having to buy, install and maintain your own integrated battery backup system? Maybe the calculus works out in your favor for you, specifically. Maybe not. But it's good to have options.
- _ph_ 8y agoIt is important to note, that here in Germany, wind and solar does not quite reach 100% of our energy consumption yet - I think it has done so only once on a public holiday. The more frequent overproduction comes from high wind/solar output combined with the output of power plants which can't be shout down quickly enough, that is coal/nuclear. If those would be replaced by gas plants with faster reaction times, a much higher amount of reneweable energy could be used without requiring storage. But indeed, as the amount of renewal energy production increases, more storage is needed. Perhaps less so for wind which has a more smooth output over days, but for solar, which has a strong peak over noon and of course shuts down alltogether in the evening. Distributing the solar curve over more time of the day would be very useful.
- Reason077 8y agoCoal power plants can ramp up and down pretty quickly in response to demand. Not quite as quickly as gas, but generally quick enough to respond to changes in renewables supply when operated as "spinning reserve". Nuclear plants, of course, can not.
- jhayward 8y agoThere are plenty of coal plants that absolutely can not ramp up and down in less than many hours, and will lose money as they do so. There are also many nuclear plants perfectly capable of "load following", responding in the time frame of minutes to 10's of minutes to load changes.
- Reason077 8y agoMy understanding is that while load following is possible in nuclear plants, there are significant design, efficiency, and cost compromises involved. For these reasons, load-following nuclear is fairly rare. In the UK, all of our nuclear power plants operate at their design capacity all the time. Their output only changes during scheduled periods when they are shut down for maintenance, refuelling, etc. In contrast, all of the remaining coal-fired power plants in the UK effectively operate as load-following reserve. They ramp up only on cold winter days when demand is high and when wind generation is low. There are now many "coal free" days in the warmer months where there is no coal-fired power generation in the UK at all (it looks like today will be one of them!)
- Pxtl 8y agoI think the dream is just to make wind power so ludicrously plentiful that the fact that it's kind of mediocre during daytime is overwhelmed by sheer quantity of generators.