The integration of a DER portfolio can be done following the concept of the Virtual
Power Plant (VPP). Although the size can vary, the concepts found are very similar. We
can however make the distinction between two types of integrated DER portfolio. The
first one is purely commercial and aims at aggregating units in order to mitigate risks and
to be able to act on the different power or capacity markets. The other one is the smart
grid concept and includes technical aspects such as local network management.
From the technologies point of view, both VPP systems have elements in common. They
are often organized with a central unit gathering information from smaller dispatched
units and sending them orders according to the market or network situation. As it has
been discussed already, the collection of metered data as well as the orders can have
different forms and be realized with different time scales.
The information sent from the dispatched units can include:
- consumption / production of one or several resources
- amount of available flexible power and its price bidding
- confirmation that an order has been realized as required
- situation on the network
And the information from the central unit to the dispatched ones can be:
- direct orders or requests (such as time schedules)
- remote control signals
- prognosis data
- price signals
Sending price signals seems to be the most convenient way to control dispatched units.
The local units can then transform these price signals into direct control or into an alert
to the consumer