Alan Ambrose Posted May 24 Share Posted May 24 See: https://markets.businessinsider.com/news/commodities/solar-panel-supply-german-electricity-prices-negative-renewable-demand-green-2024-5 Link to comment Share on other sites More sharing options...
joe90 Posted May 24 Share Posted May 24 Yes but what percentage of the year is it negative?, it’s not the Sahara so I would have thought a bigger percentage of the year was cloudy/cold. Needs putting in perspective. Simply supply and demand. What about ice cream sellers in winter 🤷♂️ Link to comment Share on other sites More sharing options...
ProDave Posted May 24 Share Posted May 24 The report focuses on price as though it is a bad thing. The real question is how much fossil fuel generation shut down during the mid day solar peak? and a technical question, how did the grid cope with a lot less "spinning mass" in the generation? If it happened regularly, people would get the idea of load shifting to mid day where possible which would reduce the need for fossil fuel generation at other times. 1 Link to comment Share on other sites More sharing options...
joe90 Posted May 24 Share Posted May 24 58 minutes ago, ProDave said: If it happened regularly, people would get the idea of load shifting to mid day where possible which would reduce the need for fossil fuel generation at other times. Would this be where smart meters benefit the user? Cheap midday lekky 🤷♂️ Link to comment Share on other sites More sharing options...
Alan Ambrose Posted May 24 Author Share Posted May 24 (edited) If I remember rightly, it's what Mark Jacobson at Stanford University predicted i.e. a glut of cheap solar power. Suggests a real push for storage as the input energy cost will be very low at times. Also, as @joe90 said - it might make for two cheap daily periods, overnight when everyone, including most industry is asleep, and in the middle of the sunny day. But will it make the economics worse for all generation capacity but better overall for the consumer? Edited May 24 by Alan Ambrose Link to comment Share on other sites More sharing options...
kevinm Posted May 24 Share Posted May 24 It's not just a lack of storage capacity but grid stability. Grids need the inertia form large spinning turbines to balance the grid as supply and demand fluctuates. PV inverters, dont have any inertia, and they also track the grid frequency, so they dont resist any frequency deviation. For this reason most grids need a mininum number of thermal plants to remain in production to provide inertia to the grid. There are now devices called synchronous condensors, which are basically enourmous flywheels connected to a motor/generator, that provide grid inertia for times of high renewables production. Google synchronous condensors. Link to comment Share on other sites More sharing options...
SteamyTea Posted May 24 Share Posted May 24 (edited) Since the late 1940s when the national grid came into existence, we had relied on spinning devices to synchronise each other. As we move forward, we may well go back to DC bulk transport of electricity, synchronised by a central system. The article paints a rather bleak picture, when in fact it is showing that we can cope with vast amounts of unregulated generation. It has to be remembered that the European electrical grid is designed similar to the USA grid, and not like the UK grid, which is almost a radial circuit. As @kevinm points out, we have mechanical systems in place already for grid syncing, there is one next to a local collage down here. These are relatively cheap bits of kit, and with the old introduction of cheap chemical storage (batteries) can alleviate most problems. Also worth pointing out, as @joe90 has, overproduction does not happen too often, and distributed, unregulated (micro generation) automatically disconnects, or at least limits, delivery when there is a problem. It is early days in the renewable generation journey and we must not fall into the trap of throwing the baby out with the bathwater, which the right wingers with financial interest in fossil fuel generation industries want us to do. Edited May 24 by SteamyTea 1 Link to comment Share on other sites More sharing options...
joe90 Posted May 24 Share Posted May 24 Being a Luddite I like the idea of mass flywheel storage. https://oxsci.org/the-flywheels-on-the-bus/ Instead of batteries in your house why not a shed with a mass flywheel to store lekky from midday to tea time or later. Surely this would be better than the minimal payment for generation offered🤷♂️ Link to comment Share on other sites More sharing options...
SteamyTea Posted May 24 Share Posted May 24 48 minutes ago, joe90 said: Being a Luddite I like the idea of mass flywheel storage. https://oxsci.org/the-flywheels-on-the-bus/ Instead of batteries in your house why not a shed with a mass flywheel to store lekky from midday to tea time or later. Surely this would be better than the minimal payment for generation offered🤷♂️ I thought it was a good idea once, then I looked at the formula. https://www.engineeringtoolbox.com/flywheel-energy-d_945.html Link to comment Share on other sites More sharing options...
saveasteading Posted May 24 Share Posted May 24 13 minutes ago, SteamyTea said: I thought it was a good idea once, Energy is currently stored by pumping water to high reservoirs. 4 in UK. I was driven along one of the tunnel / channels at Cruachan many years ago. Perhaps the issue is finding mountains near London and Birmingham. Aren't they doing something in Australia with lifting big weights to tops of towers? Link to comment Share on other sites More sharing options...
SteamyTea Posted May 24 Share Posted May 24 Just now, saveasteading said: Aren't they doing something in Australia with lifting big weights to tops of towers There is one need Edinburgh https://www.science.org/content/article/gravity-based-batteries-try-beat-their-chemical-cousins-winches-weights-and-mine-shafts 1 Link to comment Share on other sites More sharing options...
saveasteading Posted May 24 Share Posted May 24 5 minutes ago, SteamyTea said: There is one near Edinburgh Well worded. Leith people will not have it that they are in Edinburgh. That is so interesting, thanks. Could one be built into a wind turbine column? Conversely, could a turbine be built on a tower? Can one of you boffs explain in simple terms what happens when there is this flywheel in the system? it detects a tiny shortage of power in the system and generates some more instantly? I'm imagining the weight in the tower shuddering due to constant starting and stopping. Link to comment Share on other sites More sharing options...
joe90 Posted May 24 Share Posted May 24 (edited) 56 minutes ago, SteamyTea said: I thought it was a good idea once, then I looked at the formula. https://www.engineeringtoolbox.com/flywheel-energy-d_945.html I didn’t understand a word of that. A spinning flywheel can store energy like a battery and generate back but no nasty chemicals. I suppose friction with bearings cause the biggest losses but what (without a science lesson steamy) is its efficiency compared to batteries 🤷♂️and surely with good maintenance a longer lifespan than batteries? this for the technically minded bed time reading https://www.sciencedirect.com/science/article/pii/S2352484723008946 Edited May 24 by joe90 Link to comment Share on other sites More sharing options...
SteamyTea Posted May 24 Share Posted May 24 35 minutes ago, saveasteading said: Can one of you boffs explain in simple terms what happens when there is this flywheel in the system It increases the amount of time that the rest of systems have to react to. Why it is called inertia. 22 minutes ago, joe90 said: A spinning flywheel can store energy like a battery and generate back but no nasty chemicals Mainly the noise and physical size. Also, the mass and speed the flywheel has to spin at. Here is a bit about the KERS device that Williams developed. https://www.racecar-engineering.com/articles/f1/williams-f1-kers-explained/ 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted May 24 Share Posted May 24 1 hour ago, saveasteading said: Leith people Link to comment Share on other sites More sharing options...
ProDave Posted May 24 Share Posted May 24 There are a couple of flywheel generators going begging at Culham that they are looking into repurposing to add mass to the grid https://www.newpower.info/2023/09/jet-fusion-site-systems-could-be-repurposed-to-offer-grid-inertia-services/ https://www.facebook.com/UKAEAofficial/photos/a.10150149200649320/10158383444144320/?type=3 Link to comment Share on other sites More sharing options...
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