- Investment costs by producers: Producers may bear costs for grid upgrades if necessary to support their projects, prioritising minimal environmental impact and cost-efficiency, according to article 16 of Decree-Law 76/2019 of 3 June, rectified by Declaration of Rectification no. 36/2019 of 30 July.
- New Grid Development Incentives: Intensive consumers and producers over 50 MWh are now required to invest in renewable energy infrastructure as part of their concession obligations, either by installing local renewable capacity or contributing financially.
- Mandatory Investment Plans: Both transmission system operators (TSOs) and distribution system operators submit biennial investment plans to ERSE, which evaluates and approves them, ensuring transparency and alignment with national energy objectives.
Procedure
Grid development plans and investments are conceived by both the transmission operator (REN) and the distribution system operators via a 5-year investment plan. However, if producers are willing to invest in the improvement of grid infrastructure so as to better accommodate their projects, they can do so by entering into an agreement with the distribution operator, in which producers state their willingness to bear the costs arising from the renovations and constructions in the grid (art. 5 of DL 76/2019). System operators must always choose solutions that minimise environmental impacts and incur less costs to the electricity system (art. 16 of DL 76/2019).
Role of the TSO/DSO
The TSO is the network operator of the transmission grid. It is responsible for planning, construction, and management of the transmission grid and interconnections under appropriate reliability conditions. The TSO is also responsible for monitoring the security of supply.
The DSO is the network operator of the LV, MV, and HV distribution grids. It is responsible for planning, construction, and management under appropriate efficiency and reliability conditions.
Obligations and rights of plant operators
Both TSO and DSO are required to present to the regulator every two years a plan of investments for the reinforcement and expansion of their grids. After these investments are approved, the corresponding costs are reflected in the grid tariffs.
The same procedure applies to the grids of the islands of Madeira and Azores.