Through the royal decree 244/2019 Spain has provided a framework for energy sharing through two main ways, cooperatives, or collective self-consumption.
Collective self-consumption (CSC) is defined in article 4 of royal decree 244/2019 and consists of several consumers associated with renewable energy units, either through an internal network or using the public grid. CSC is not exclusive to energy communities but can be used by them.
The shared production installation needs to meet at least one of the following criteria to be eligible for CSC (notably being an EC is not one):
Being connected to the internal network of associated consumers
Being connected to a low-voltage network of the same transformation centre
Have a maximum distance of 500 meters between the production installation and consumers (1 000 meters if the installation is on a roof)
The installation and consumers must share the initial 14 digits in their land registry numbers
CSC can belong to either the modality of self-consumption with surplus or the modality of self-consumption without surplus.
If the CSC employs self-consumption without surplus the generation unit is prevented from injecting surplus energy into the transmission or distribution grids. Self-consumption with surplus mean that the generation unit can inject surplus energy into the transmission or distribution grid and this category is further divided into two subcategories, whether it is subject to compensation or not for the injected electricity.
In the first subcategory, modality of surplus with compensation, the producer and consumer choose to benefit from a simplified compensation mechanism using a bidirectional meter. In each billing period, the value of the consumption deficit (taken from the grid) will be compensated with the value of the surplus generation (fed into the grid). This option is only possible when the unit meets certain conditions such as: The energy source is renewable, the total production of the installations does not exceed 100kW.
In the second subcategory, modality without compensation, the surplus generated can be sold on the electricity market. The residents will be required to either sign a contract with a retailer or register as an energy producer, making this option more complex than the previously mentioned subcategory.