Background
Flexibilities
are considered a time resource as opposed to real resources like price or
energy amount. Owning a flex-offer means not only owning some energy but also
having the right to choose the time when this energy will be consumed or
produced. In other words, possessing a time resource means that the BRP has a
possibility to change the distribution of energy consumption or production in
time. More specifically, the BRP has time for scheduling and rescheduling
available flex-offers by influencing its mismatch as a response to changing
conditions. The main question is how this time resource or flexibilities
represented by a flex-offer can be represented in terms of real values such as
energy price.
Energy Flexibilities
There
exist different time resources which are represented by different flex-offer
parameters. For example, a flex-offer might have large flexibility interval but
zero energy flexibility. Since flex-offers have several types of flexibilities,
their valuation is broken into the following independent functions:
- Time to assignment
flexibility describes how much time is available for scheduling this
flex-offer. More time for assignment means higher value of the flex-offer.
- Flexibility interval
describes the range within which scheduling is possible. Higher ranges
mean higher value of the flex-offer.
- Energy flexibility
describes the range within which the energy amount can be varied. Larger
energy intervals mean higher value of the flex-offer.
For
each of these flexibilities there is a function which returns its price. The
conversion is formally performed via a monotonic function which with some
limits along x (flexibility) and y (price) axes. An example of such a function
used for converting flexibility in assignment into price is shown in the figure
below.
Flexibility Price
The final flex-offer price is computed as a weighted sum of the prices of threes three flex-offer flexibilities. For example, a flex-offer could have 0.5 ct/kWh price for time to assignment flexibility, 1 ct/kWh for its flexibility interval and 1.5 ct/kWh for its energy flexibility. In the case of equal weights, the final price of this flex-offer is 3 ct.
The price of flexibilities is used for decision making. In particular, it can be used for flex-offer acceptance where only flex-offers with high enough flexibilities are accepted. An alternative (traditional) acceptance procedure is based on accepting flex-offers with high enough (for consumption) or low enough (for production) electricity price. Flexibilities are also used by the price setting module to compute the final electricity price for the prosumer. For example, the price of flexibility could be provided as a price bonus in order to encourage prosumers to issue more flexible flex-offers.