Germany pays for you to use electicity - Page 1
Forum section: electronics / general

author: tszaboo
author_rank: Super Contributor
timestamp: May 11, 2016, 10:47:04 am
content: http://qz.com/680661/germany-had-so-much-renewable-energy-on-sunday-that-it-had-to-pay-people-to-use-electricity/The price of electricity went negative for a few hours, when renewable energy production went 87% of the demand. It was a windy day.So I guess it is time for massive scale storage developments.

author: depeje
author_rank: Contributor
timestamp: May 11, 2016, 11:19:48 am
content: It was a windy day indeed, and sunny too. My tow plane pilot didn't dare to fly in this wind. (I got sunburn too, from being on the ground all day, rigging and de-rigging gliders.)

author: tautech
author_rank: Super Contributor
timestamp: May 11, 2016, 11:26:39 am
content: Quote from: NANDBlog on May 11, 2016, 10:47:04 amMagnetically levitated high speed flywheels

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 11, 2016, 12:32:12 pm
content: It's also time to have some sensible discussion about demand-side management. The technology is really easy to allow more flexible pricing to domestic consumers, but (certainly here in the UK) the only tariffs you can get are fixed rate 24/7 or slightly more expensive during the day and cheaper at night.When the suppliers make some smart tariffs that are flexible, I think we'll see the demand more closely follow the supply. I'd happily put four loads of laundry on and put the immersion heater on if the price went super low for a few hours.Also: more interconnectors! The UK could have bought 5GW of that surplus power if there was infrastructure to transmit it.

author: Delta
author_rank: Super Contributor
timestamp: May 11, 2016, 01:00:30 pm
content: This has been the case for quite a while now.It's the obvious result of adding more and more intermittent renewables to a grid without adding any large scale storage. Not only does it result in the price going negative, but fossil fuelled plants have to run more and more outside their optimum load points, causing a significant drops in efficiency and increases in emissions.Activists and politicians like to shout about building more wind farms and solar arrays, but you never hear anyone talking about building storage. It's just not exciting enough...

author: station240
author_rank: Unknown
timestamp: May 11, 2016, 11:52:48 pm
content: If I recall there was also a news story for one of the southern US states where power was free at certain times, due to all the wind/solar output.Was it Texas ?This is an example where a internet linked system in every home would be an advantage.If there is an excess of power (especially renewable power), then increase demand.For instance, set the electric car to recharge, home battery storage, hotwater heater.If an aircon is running but the thermostat has switched the compressor out, bypass the thermostat for a brief period.Problem is it needs to be selective, as turning everything on would blow fuses. So you have priorities:1. Energy storage built without a renewable power input (no solar panels, wind etc).2. Electric cars (but beware of high power draw).3. Heating/Cooling (minor changes to operation).Fun and games start when you compare start up times, Power Factor etc of various devices.If you have a short spike in demand/price (up or down), then anything with a relay may not be fast enough.So you need highspeed, low latency network connections to do this. *As you need to be able to switch rapidly to avoid making the grid unstable.Which means fibre, I know Germany does have a lot of VDSL over copper lines.*Rules out Australia as we are currently building a shitty non fibre based broadband network, due to corrupt politicians.

author: bitslice
author_rank: Frequent Contributor
timestamp: May 12, 2016, 12:16:45 am
content: Quote from: DenzilPenberthy on May 11, 2016, 12:32:12 pmWe'll need to bring back dumb washing machines first,if I put mine on a timer to run overnight, it will happily sit there waiting for someone to press the start button

author: Someone
author_rank: Super Contributor
timestamp: May 12, 2016, 02:44:02 am
content: Quote from: Delta on May 11, 2016, 01:00:30 pmWha wha wha, there is a competitor in town to the entrenched power suppliers. Also that should be:increases in emissionsper unit of energy producedIf you're throttling back inefficient plants due to an excess of energy supply (which is largely predictable in advance) they'll produce less pollution.

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 12, 2016, 04:42:37 am
content: Quote from: NANDBlog on May 11, 2016, 10:47:04 amLuckily the renewable plants don't have a fixed price for their energy with the delta payed by the government (us). #ohnowaitLuckily we don't have a new energy minister who seems to believe we just have to chuck all rooftops full of PV's because that's an investment that makes sense even without government interference (sic).

author: FrankBuss
author_rank: Unknown
timestamp: May 12, 2016, 08:26:54 am
content: I understand that a nuclear or coal plant can't be shut down fast, but why do they pay to feed energy to the grid? Doesn't look too difficult for me to get rid of too much energy for a short time, like heating a sea or underground. AndhereWikipedia says that modern nuclear reactors can follow the load anyway.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 12, 2016, 09:56:01 am
content: because if the price is still positive there is no incentive at all for plants to not feed their excess power in to the grid.

author: Kilrah
author_rank: Unknown
timestamp: May 12, 2016, 02:23:03 pm
content: Quote from: bitslice on May 12, 2016, 12:16:45 amDon't all current machines have a built-in delayed start feature already?

author: zapta
author_rank: Super Contributor
timestamp: May 12, 2016, 02:23:45 pm
content: Quote from: DenzilPenberthy on May 12, 2016, 09:56:01 amEverybody gets paid. Isn't it wonderful?

author: MikeW
author_rank: Regular Contributor
timestamp: May 12, 2016, 02:29:24 pm
content: Quote from: Kilrah on May 12, 2016, 02:23:03 pmNot only that once started and the door locks, every washing machine I have ever used insists on finishing the cycle. So you could press start, cut the power and when the power comes back on it will resume (maybe).

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 12, 2016, 02:32:19 pm
content: Quote from: zapta on May 12, 2016, 02:23:45 pmNo because supply has to match demand. The only way to incentivise people to not feed power into an oversupplied grid is to make the price negative.I don't really get what point you're trying to make...

author: elgonzo
author_rank: Unknown
timestamp: May 12, 2016, 02:38:47 pm
content: Quote from: MikeW on May 12, 2016, 02:29:24 pmThe few fully electronic washing machines i used in my life only exhibit such "resume" behavior if it has been switched off for a short time. After being switched off for a longer time (i can't tell from memory how long this "longer time" would be; but it certainly was longer than just a few minutes), the washing machine has been reset. Iirc, even my front loaders would unlock the door no matter whether there was still water in the drum or not; although there is a chance i remembered this bit incorrectly...Old electro-mechanical machines are more likely matching your description: When a power cut occurs, the program wheel stops and remains at the position, only to continue the program as soon as power is being restored (with the help of a button press perhaps)...

author: zapta
author_rank: Super Contributor
timestamp: May 12, 2016, 03:14:07 pm
content: Quote from: DenzilPenberthy on May 12, 2016, 02:32:19 pmMy point is that it's wonderful that at the same time some people are paid to feed the grid while others are paid to consume from the grid. It's a win/win.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 12, 2016, 03:58:31 pm
content: Quote from: zapta on May 12, 2016, 03:14:07 pmWell yep. That's how you incentivise non polluting resources to generate and polluting ones to not generate. It's not as bonkers as it seems.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 12, 2016, 04:34:19 pm
content: Meanwhile here in Ontario when we produce excess they pay the US to use it, and charge us more!

author: Kleinstein
author_rank: Super Contributor
timestamp: May 12, 2016, 08:48:14 pm
content: The negative (wholesale) price occurs a few times a year for a short time. Sometimes they turn on some street light to get rid of excess (under the control of the energy companies). But this is only really short time, so no big incentive yet to invest much money because of this.For large use costumers (e.g. industry, large cooling facilities) there are already supply dependent prices. So the use of power is adjusted by the supply situation - usually its not that much the few times of over-supply, but more to avoid extra load in times where supply is rather low or peak loads. So you can get an extra discount if you accept to run only at times the energy company likes it. I would guess this might get used more, even if this means higher investment costs.For the consumers the power is relatively low, so the costs for controlling it might be to high. Even the washing machine is running only a few times a week, so not that much energy to shift around.There are a few new build storage facilities, but not that many and not that large.They also may need some of the generators in conventional power plants running to have the possibility to control the frequency and blind power.

author: Red Squirrel
author_rank: Super Contributor
timestamp: May 12, 2016, 11:26:41 pm
content: Come to think of it how does the grid manage to supply the exact amount of power needed at any given instant, as I'm sure that changes from minute to minute, do most power plants have a decently wide range they can operate at just naturally? Like I imagine the turbines have so much momentum in them that the demand fluctuations arn't really a big deal until they are sustained or too big?

author: Macbeth
author_rank: Super Contributor
timestamp: May 12, 2016, 11:45:36 pm
content: Quote from: bitslice on May 12, 2016, 12:16:45 amGet with the times. I recently dumped an old Hotpoint despite my years of maintenance including replacing the drum bearings (what a hell of a fucking job!) and upgrading its shitty deliberately designed to break shock absorbers. A few solenoid tap changes and one pump. A couple of door seals too.The new "super eco-friendly+++" model has a timed start mode, so you can delay it all you please. It was also far cheaper than fixing an extremely hard to find fault betwixt the control panel and the motor that insisted on smashing the machine against all the cupboards and trying its best to self destruct. I actually took this one down to the Atmel controller and was messing about with live mains and decided the time has come to downgrade to a modern one.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 13, 2016, 01:20:04 pm
content: Quote from: Red Squirrel on May 12, 2016, 11:26:41 pmBasically there's a very stressed out person in front of a big control panel switching generators on and off to keep the system running at 50Hz. It's a much bigger problem here in the UK because we all get up at the end of popular TV programmes and put on the kitchen light, put on the electric kettle to make a tea and flush the toilet (water pumps turn on). It means we get really big demand spikes.I think the longer term fluctuations are dealt with by market pricing of wholesale electricity which incentivise people to either feed in or not as required.You're correct that the system inertia really helps with short term stability but it's becoming less as we move away from large steam plant towards renewables. See my thread here about what is being done about that:https://www.eevblog.com/forum/renewable-energy/it's-happening-the-power-grid-is-changing/

author: tszaboo
author_rank: Super Contributor
timestamp: May 13, 2016, 03:52:35 pm
content: Quote from: Red Squirrel on May 12, 2016, 11:26:41 pmLike the turbines in the power plants are not only producers, but also consumers. And the grid changes frequency, so with lower frequency the load is less. And the voltage is fluctuating, so with more voltage the load is more. Off the top of my head. Ask an electrical engineer.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 13, 2016, 06:44:27 pm
content: The large rotating generators help to stabilize the grid frequency. It also helps that the grid is connected from Portugal to Poland / Finnland (AFAIK). So even if there is short time to much demand in the UK, they could use extra capacity from France, Italy or Spain. Here however the capacity of the lines is limited, even if the power is not really going that long distance, but just shifts a little. At least in Germany they start to increase the allowed power limits to the lines - so much as allowing higher power if there is more wind for cooling.

author: SeanB
author_rank: Super Contributor
timestamp: May 14, 2016, 12:15:52 pm
content: Power stations can absorb power ( somewhat, limited by the cooling capacity of the generation plant, not the steam condensers) by deliberately increasing the rotor current so the generator runs as a synchronous capacitor, and cutting the steam feed to a low level, so the turbine acts as a turbo pump instead and actually heats the stem entering so it is hotter going out than in. As it is still non saturated steam this only increases the load on the cooling condenser, allowing the power station to be a very quick acting ( though insanely expensive) power limiter, so they can safely ramp down coal feed ( or handle the control rod lag on a nuclear reactor that will take 20 minutes or more to start responding to a step change in loading, and which will take hours to drop power level to the desired point) and steam generation to handle a reduced load. Then for a step change up that is enough that the remaining plant can generate without the synchronous capacitor they reduce excitation so it becomes a synchronous motor with unity power factor, only drawing a little power while still being available for ramp up fast.Big generation plant is not something you can turn on and off fast, black starting a plant will take days before it gets up to full power, and even a plant running at low power with a single steam generator and turbo running will take hours to ramp up the rest to full power, you have to keep it spinning at all times and keep the cooling and lubrication running at all times or you will destroy it. A hundred ton rotating mass does not respond fast to any step change, especially if it involves a massive temperature change and your tolerances are in the sub millimeter ranges for many of the blade clearances. If you have a blade touch you will be replacing large pieces of plant. If you really oops it it leaves via the roof or the wall, and anything in the way goes with as well.

author: botcrusher
author_rank: Regular Contributor
timestamp: May 14, 2016, 01:40:05 pm
content: Quote from: Red Squirrel on May 12, 2016, 04:34:19 pmYep. Sucks to be Ontarian when it comes to that.As far as i know, it's primarily the Windsor wind turbines that throw excess power into detroit.

author: mos6502
author_rank: Frequent Contributor
timestamp: May 15, 2016, 12:02:24 am
content: Once electric cars take off, it will be easy to take care of this problem. An 85kWh battery will still be extremely useful for grid power storage after it's been used in a car for 10 years and lost 50% of its capacity. Isn't Tesla already making deals with power companies for their old batteries?Also, if there are many electric cars, a lot of them will be connected to the grid at any given time. Most cars sit either at home or at work. I could imagine power companies paying electric car owners for their cars to be used as a giant distributed energy storage system.

author: FrankBuss
author_rank: Unknown
timestamp: May 15, 2016, 10:20:57 am
content: Quote from: DenzilPenberthy on May 13, 2016, 01:20:04 pmThat's interesting, I thought it is all automatic. Video is from 2010, is it still manual? What happens when the frequency drops too much? IIRC all of Europe has one big grid running at the same frequency. I guess the wires across the English Channel would get really hot then.BTW, for early TV voting in Germany they used the"Lichttest"(light test) : The TV viewers were asked to turn on all lights and other electrical devices, when they were asked to vote for something. Nice stress test of the grid

author: Jeroen3
author_rank: Super Contributor
timestamp: May 15, 2016, 11:21:10 am
content: The same problem applies to water pressure during world cup final half time.Everybody flushes their toilets.

author: SeanB
author_rank: Super Contributor
timestamp: May 15, 2016, 12:16:21 pm
content: Big power interconnects are all DC links, with voltage converters at each end that act as a rectifier one way and as a SMPS the other side, so you can both send power either way on demand and change frequency as you do so.

author: meeder
author_rank: Regular Contributor
timestamp: May 15, 2016, 01:27:25 pm
content: It was only on that particular day.In general Germany has about 35% renewable energy.

author: Delta
author_rank: Super Contributor
timestamp: May 15, 2016, 03:28:18 pm
content: Quote from: mos6502 on May 15, 2016, 12:02:24 amWithout a major breaktrhough in battery technology, can this dream become reality? Is there enough lithium for most of the world's cars to be electric, and some large scale grid storage to be built? I know I sound like a broken record, but I can't see how we can get off fossil fuels without significant leaps forward in storage technology...

author: mos6502
author_rank: Frequent Contributor
timestamp: May 16, 2016, 01:18:44 am
content: Quote from: Delta on May 15, 2016, 03:28:18 pmThere iseasilyenough Lithium availableright nowfor 10 billion cars. Lithium is more common than lead.https://www.quora.com/Is-there-enough-lithium-in-the-world-to-replace-all-petroleum-cars-with-battery-electric-vehiclesLithium can be easily recycled as well. So after 10 years in a car and 10-20 years as grid storage, virtually all of the Lithium in the battery can be reused.Also, what more leaps in storage technology do you need? We already have cars that can go >500km on a single charge. The Tesla S is projected to get a 1000km range in 2017.

author: Delta
author_rank: Super Contributor
timestamp: May 16, 2016, 02:48:57 am
content: Quote from: mos6502 on May 16, 2016, 01:18:44 amEnough to provide the 24GW of power the UK is consuming right now would be a good ball park figure. And that's at quarter to four in the morning!

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: May 16, 2016, 03:37:11 pm
content: 24GW / 35.8M registered UK vehicles (June 2014)= 670W670W/12V = 55AI'm going to say that the average capacity of a 12V automotive starter battery is 55Ah. So there is a sufficient number of car batteries out there to power your 24GW for an hour.I'm not suggesting this as a practical solution but people seem to think it it ludicrously far fetched to imagine manufacturing vast quantities of batteries to provide grid scale storage but no-one blinks an eye that there are at least 35 Million car batteries sitting around out there. Imagine how impossible it would have seemed once that we would have the resources to manufacture hundreds of millions of precision engineered internal combustion engines or even dig enough asphalt and gravel out of the sand to build a worldwide network of paved roads.