It looks like France is exporting to neighbouring european countries (including to the UK), the equivalent more than the UK's total current nuclear supply (~7.89GW).
I had no idea it was possible to transport such power by submarine link (2GW power to the UK).
Remember it's only 34 kilometres between the closest points. The current inter-connector is currently 70km, with the planned second connector longer at 230km (but with a reduced capacity of 1 GW)
Also interesting to note is that the UK and Germany top a list of the EU’s most polluting coal-fired power stations. These were the findings from a recent report by environmental campaigners. The report called "Europe’s dirty 30" looks at CO2 emissions from coal power plants in the EU.
From the report:
"Germany and the UK are the self-declared climate champions of the EU. However, Germany uses more coal to generate electricity than any other EU country, while the UK comes third in absolute coal consumption for power after Poland;"
Here's the 10 most co2-polluting thermal power plants in the EU according to the report
I'm not sure I understand what the point of that list is, Drax is the UK's largest coal-fired power station, of course it emits the most CO2! Were it replaced by two power stations of exactly half the capacity it wouldn't be in the list anymore, yet the end result would be the same.
If I remember correctly, I think the link was established initially with the assumption that it will be good for the UK since it will mostly be used for exporting electricity to France.
I work on collecting (ETL) data of European power data sources and supply them to clients via web service (in almost real time). For the client i work on - wrote cloud based distributed ETL system to collect data from approx 100 importers and exporters of power, gas, wind, nuclear. Its quiet possible to collect this data in real time as EU regulations asks each of them to provide data on their websites. For some of the websites - i use selenium which is much better than using webrequest via http/s
As I write this, it appears that the UK grid is running around 30GW, of which about 55% comes from local fossil fuels, 29% nuclear, nearly 10% imported from France and Holland, and a mere 5% or so from the major (non-nuclear) renewable sources.
There is an interesting note that coal (only 15% right now) is still the largest contributor to the UK grid overall, but used more in winter because running hours are restricted for environmental reasons so they do more in winter when it's more profitable.
I am surprised (and, honestly, disappointed) to see that so little of the total is still drawn from clean, renewable sources after all the concern about both fossil fuel supplies and environmental effects in recent years. Having just been on holiday to a country not a million miles away where they have essentially no native fossil fuels and so almost everything is run on relatively clean renewables, it's clear that we still have a long way to go.
Iceland. Its unique situation gives it a lot of geothermal, but there's quite a bit of hydro as well. Of course most of us are in much bigger countries, often with higher population densities, and not sitting on such convenient geography, but it was more the different mindset that I noticed than any specific technology.
Try and put up a new onshore wind farm anywhere in the UK, and every NIMBY and countryside group for a hundred miles will turn up to complain. Propose a new nuclear power station, and it'll be 200 miles, even though not far away in continental Europe there are nuclear power stations that could pose just as big a threat here if anything catastrophic happened. No doubt the same people will be the first to complain if they can't afford a guaranteed 100% electricity supply and have to put up with rolling blackouts in a decade or two. (If you're in the UK, I encourage you to do the maths and consider the geopolitical situation; that isn't as implausible a future as we'd all like to believe.)
Meanwhile, it looks like Wikipedia has several whole articles about the remarkable achievements of the Icelandic in this area (though I think the figures we heard while there were actually slightly better than even what is cited there):
Technically true, bu this is a bit like "Single German City runs entirely off bio-mass". My favourite author on this (David McKay - http://www.theguardian.com/environment/cif-green/2009/apr/29...) is clear on the need for making the sums add up at scale.
The UK has little terrain suited for hydro and negligible geothermal. Its not very sunny. It has the worlds largest offshore wind installed capacity but few other countries are interested so its quite expensive. It also has had no real policies for a decade and is running on what was there and this needs fixing as most existing power stations are end of life soon.
The imports and export are changing all the time, depending on the production or demand of each country, to keep the production and consumption in balance. It's sometimes easier/faster to import power when you need it (when there is a demand spike) than start your own generators to match the demand with internal production. Then when the other country has a demand spike, you pay them back with your production. In many cases no actual money change hands, these are kept as "power debts" that will be paid later.
It can also be easier/cheaper to import power for one point near the border than transport it from farther production facilities.
The price differences are less important there rather than the total system balance - locations of supply and demand, and the exact current amount of supply and demand at each location at each moment.
In a connected power system, if power 'needs' to get from A to B, it won't only flow through the direct connection, but along the longer loops as well, which often creates 'transit'. For example, in that map from NO5 to SE5 through Denmark, and from NO1 to NO3 through Sweden. This is normal and pretty much unavoidable - it's more efficient to optimize the flows to reduce total system losses, and then just try to bill everyone fairly.
You can't simply set a specific flow amount (well, you can force it to 0) to some country and keeep it there without mucking up the rest of the system, unless high voltage DC links are used to connect separate power systems.
It's actually specific to combined cycle gas turbine plants where the waste heat from the GT is used to generate steam and eventually additional energy. This is opposed to simple cycle GTs where the mechanical output gas turbine is the only source of energy to the grid.
UK's load balancing has some quirky features that always fascinated me, like the fact they require a unique calibration for the end of each episode of Eastenders, right after which millions of households put the kettle on.
The frequency one would scare me a bit--it is 49.960 as I see this. So long as you can control the entire grid from a central point (not possible in North America, I think--much more complex) it is probably ok.
Otherwise, a generator that lags in phase becomes a motor.
There's literally a single person who adjusts the whole power grid according to second-by-second fluctuations in power which result from half the nation boiling water for tea after the most popular TV shows finish: https://www.youtube.com/watch?v=slDAvewWfrA
The US Grid is split into three relatively unconnected grids, east coast, west coast, and texas. Each section has one plant designated to keep the frequency, sort of a "master plant" that is used to balance instant load. All of these are synchronized across the US using phaser measurement units that are timed to GPS.
The other cool thing about AC power is that you can send power based on the relative phase of a node on the grid. This means that a node at a lower AC voltage can send power to another node at a higher voltage by adjusting the relative phase. Mostly this is done by switching capacitor banks at various transmission nodes to adjust the reactive power component at that node.
I don't know how it works in the UK, but in the US, there are three major interconnections within the country, and each interconnection has system operators. The system operators are responsible for managing the grid, including the frequency. I've been in several US-based power control rooms, and the current system frequency always gets pride of place on the instrument panels (along with the current system load and sometimes the grid time). System operators are also very concerned about maintaining the balance between their generation and their load.
The grid time is itself an interesting concept. Because the grid runs at a known frequency, it's possible to use it as a time base for a clock. The grid time is considered to be the current time for such a clock. It basically integrates the grid frequency error over time.
Regarding generators that lag the grid, it's not quite as simple as generators turning into motors. The generators all have real time governors that adjust their throttles based on their current operating speed. (The operating speed is directly linked to their operating frequency, for the vast majority of units.) In the case of a generator operating too slowly, the governor immediately requests more input power to compensate. Because this happens grid-wide, this gives the entire grid the ability to quickly respond to short-term fluctuations in operating frequency. Longer term frequency response is handled by dispatching individual units up and down to balance power and load.
In the event that a generator cannot adequately respond, it will trip (shut down) and disconnect from the grid entirely. This is a protective measure that keeps the generator from skipping cycles. (You can think of this as the electrical equivalent of gears skipping teeth, and can be hugely destructive to the equipment.)
I don't necessarily think this is what he meant, but generators can sometimes be operated in synchronous condensing mode. In this mode, the generator is run as a motor, which consumes real power but can help with reactive power issues important to grid stability.
No, electrically generators and motors are the same circuitry. If you have two generators hooked to the same output line, and one gains a few degrees of phase angle on the other, the one lagging draws power from the leader in proportion to the phase angle difference.
49.960 is pretty exact; the frequency can reasonably deviate much further. Some systems try (tried?) to keep a 'daily average' of 50.000 hz, but the grid will run quite okay at 49.960 hz, at 49.900 hz and at 49.000 hz; not that it's recommended but it's an option if there's a supply/demand disbalance.
Well within a fraction of a cycle/second. One of the big reasons is that a generator's mechanical speed is directly tied to the electrical frequency. This includes the prime-movers that actually drive the generators. Many of these large machines don't react well to operating far from their design speed, which can cause huge issues.
.01 cycle was my memory of a threshold from some years ago.
Part of the problem is lower frequencies don't meet as much impedence in inductors (e.g., transformers), and another part is that interconnects can have control system stability problems keeping them synced.
It's important to note that wind power in Denmark only works at that scale because they can export it to Norway and Sweden. Those neighbors can absorb variable power output while load balancing their grid with hydroelectric dams.
Hydroelectric is currently the only economical "grid-scale battery", and it is not available everywhere.
Yes it is up to date. The info/about section is a great read -- he talks about the reason he created this site, the source of the data and also explains the software stack: http://www.gridwatch.templar.co.uk/about.html
It looks like France is exporting to neighbouring european countries (including to the UK), the equivalent more than the UK's total current nuclear supply (~7.89GW).
I had no idea it was possible to transport such power by submarine link (2GW power to the UK).