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A package is for the entire day, i.e., if they sell than package they promise to provide 20 MW/Hz within 50±0.1 Hz during all hours.
A bid of 40 MW/Hz is equivalent to a bid of two packages, which will be paid 1 000 ¤ each, i.e., in total 2 000 ¤.
Hi!
It's probably my inability but I can't find a deadline for this assignment. So when is it?
Thanks in advance.
The deadlines are listed in the course syllabus, which you find on the entry page ("Course overview").
I don't understand the solutions of questions 4.2 and 4.6, and there is an error in the solution of 4.3:
4.2: the correct solution is said to be 2 (only statement III is true). But why is statement II false? If you have most of the time wind, hydro and nuclear (with very low variable cost -> very low electricity prices), how do you recover the fixed costs of power plants if not by a capacity payment? (statement II even says 'may require', so by saying it is wrong, you say that there is no possible situation in which a capacity payment is needed to cover fixed costs)
4.6: the correct solution is said to be 4 (I and II are true, III is false). Why is III false if II is true? Both batteries and PV panels have an absolute maximum output (due to the thermal stability limits of batteries and the solar radiation on PV panels). From a technical point of view, both can deliver inertia if their normal output is below their maximum output (then their converters can be programmed to increase the output if the frequency decreases). Of course, this is not economic to do this (PV = free electricity so they should produce as much as possible, and batteries are so expensive that you should always use them to their full extend, (i.e. fully consuming at low prices and fully producing at high prices if the battery is suited for cycling operation and providing secondary reserves if it isn't). So from a technical point of view, both II and III are true (they can be designed to deliver system inertia), but from a practical/economic point of view, both are false (it isn't economic to do this, at least not with the current prices of PV panels, batteries and with current prices for inertia services compared to prices of the other services (energy production, peak shaving, secondary reserves etc.)). So how can II be true but III false?
(For batteries, the economic situation also depends which type of batteries you're considering. Batteries which are not suitable for cycling (e.g. flooded cell Lead-acid batteries face chemical stability problems when operating in cycling mode and Nickel-Cadmium batteries have a low round-trip efficiency) can be used (and have been used) to provide spinning (secondary) reserves because they are not suitable to use them to flatten the demand. I haven't heard of a single type of batteries which is used to provide system inertia)
4.3: the assignment says that the variable cost is 800 /MWh and the solution says 1000 (the needed tariff is 1000 + 150M/20k where this last is to cover the fixed costs)
4.2: You are right, this is a printing error. The correct solution is 4 (II and III are true but not I).
4.3: You are right agian, this is another printing error. The correct solution is 8300 ¤/MWh.
4.6: You are correct about photovoltaics; technically it might be possible to provide inertia, but it would not be economical. Batteries on the other hand are a form of energy storage, and can be compared to the reservoir in a hydro power plant. Yes, they are expensive, and yes, there could be an opportunity cost if some of their power output is reserved for providing inertia (in the same way as you have costs for keeping primary control reserves in a hydro power plant), but these costs could still be reasonable compared to other alternatives for providing inertia.
Lärare Mikael Amelin korrigerade 19 maj 2015
Grid regulation added to exercise book Basic exercises on grid regulation are now included in the draft edition of the exercise book.
In the text it's said that the package price is 1000* .
But is the package for one hour or for the full day?
and is it 1000* for a package of 20MW/Hz which means that a package of 40MW/Hz is 2000* or do you have to sell separately two different packages of 20MW/Hz? ( a package of 20MW/Hz and a package of 160 MW/Hz costs the same or is the second one 8 times more?)