4 ms·
That's actually a very good question. My understanding is incomplete, but this is what I make of it: What you suggest turns out to be impossible. The amount
by hyperman1 8y ago
That's actually a very good question. My understanding is incomplete, but this is what I make of it:
What you suggest turns out to be impossible. The amount of energy that goes in and out must be identical. So this means:
* Either less goes in: The required mechanical effort to make the turbine turn goes down. It will have to dissipate the extra energy as heat and catch fire, or it will become less efficient, and have stronger winds behind it as less wind energy has been used.
* Or more goes out: The transparting cables are not perfect, they are a kind of very low resistor. They do convert electricity to heat. A short is an extreme example of this. In this case, a smaller version will happen: cables will get slightly hotter.
As I understand it, monitoring and balancing the electrical grid is a very complicated problem.
Recently, and discussed on hacker news, the opposite happened in Europe: Not enough power was available on the net because of political circumstances. All the generators had to push a little harder, so they all slowed down a tiny bit. Result was the 50HZ of the european grid went a very tiny bit down to 49.999...Hz, and some clocks lost 6 minutes of time as a result.
- severine 8y ago> Recently, and discussed on hacker news, the opposite happened in Europe This news had an interesting discussion recently: Continuing frequency deviation in the Continental European Power System (entsoe.eu) 478 points by Aissen 80 days ago | 323 comments https://news.ycombinator.com/item?id=16535067 https://news.ycombinator.com/item?id=16535067 https://www.entsoe.eu/news-events/announcements/announcements-archive/Pages/News/2018-03-06-press-release-continuing-frequency-deviation-in-the-continental-european-power-system.aspx https://www.entsoe.eu/news-events/announcements/announcement...
- hyperman1 8y agoA small appendix: This is what would happen if nobody controls the grid. Of course, humans and automatic systems do control the grid. So if you have a gas turbine, and you see it slowing down, you feed it a little more fuel and vice versa. Unfortunately, solar and wind energy make this impossible. So for wind, the turbine has brakes, but there are videos on youtube where they fail or get overloaded, resulting in burning turbines. I guess solar does something similar (Edit: the braking not the burning of course). In practice, the non-renewable energy turbines like gas are the easiest to control so these are used to balance the grid. On top of all of this, running a turbine costs a lot, so there is a lot of grid management going on to decide who can generate which amount of electricity. Decisions made at this level better match the actual load on the grid, or the catastrophic consequences of the post above happen. Brning turbine: https://www.youtube.com/watch?v=6y1Ib0GM5x8 https://www.youtube.com/watch?v=6y1Ib0GM5x8
- filmor 8y agoThis sounds very odd to me. Most wind turbines built today with a capacity of over a few hundred kW are not synchronised to the grid frequency. They run at whatever speed they can run at with the current wind speed, which is converted to DC, goes down to the root of the wind mill and gets converted back to regular 50Hz AC when it's put into the grid. They only thing that could happen there is that this converter station blows up. Also, those modern turbines always have turnable rotors that can just be moved into a longitudinal position relative to the airflow, stopping immediately.
- hyperman1 8y agoMy knowledge of turbines is about a century out of date, so please be so good to add everything you know to this discussion. As I understand it:. It used to be that every turbine on the grid was synchronized and people found out how the grid communicated its energy behaviour by changing frequency. This happened as emergent behaviour, almost by accident. As the grid operators came to rely on it, newer technology has to emulate it. But today, most of Europe shares the same grid, which was impossible at the time. There have to exist technological advances to make this possible. And solar doesn't even have an inherent frequency, it's DC. So what you say sounds very reasonable. But I hope never to see from close by what happens if modern energy equipment fails catastrophically.