Rights and obligations of customers and prosumers
Under the Electricity Market Act, small consumers have the right to purchase electricity from the DSO to which their electrical installation is connected, at a price that is reasonable, justified, and adheres to the principle of equal treatment, referred to as the "universal service." If the DSO does not sell electricity directly, it must arrange a public procurement to find a seller without favouring any associated undertakings. In cases where public procurement fails to find a seller, the TSO must designate a temporary seller until a new procurement can be arranged promptly. If the designated seller is required to provide service, it must be the one with the largest market share at the time of designation, particularly if the designated operator serves over 100,000 consumers and cannot sell electricity directly.
Consumers can consume self-generated electricity from a renewable source. Renewable self-generated electricity can be generated, stored, or sold, either individually or through an energy broker. The generator can be owned, installed, and operated by a third party, not a self-consumer of renewable electricity. They are entitled to support.
Rights and obligations of plant operators
The operators have to be legal entities registered in the European Economic Area. The share capital of a network operator or of a line possessor who uses a direct current line that crosses the national border is at least 127,800 euros. The share capital of a producer or seller is at least 31,950 euros. Unless they generated electricity that has been produced by a generating installation they own and which has a total net capacity of up to 1 MW. These rules also don't apply to people who sell and convey electricity solely to persons who use the building or are immovable on lawful grounds, in case the sale of electricity is not the seller’s main activity. Or in the case of a non-profit organisation that sells and conveys electricity to its members solely to supply electricity to the apartments, cottages, garages, or private dwelling houses the members own or occupy, according to the Electricity Market Act.
Are there any specific rules or obligations concerning RES plant operators?
There are exceptions to plant operators who use self-produced energy, if it's from renewable energy.
Producers may not subsidise generation from renewable energy sources at the expense of generation from other sources and vice versa.
If the amount of electricity generated from renewable energy sources is less than the amount of electricity sold, by using support, is at least two consecutive calendar months, the electricity can no longer be sold by using the support.
The support is only allocated for the amount of electricity generated from renewable energy sources.
Task of the DSO/TSO
DSOs must be registered in the European Economic Area and have a minimum share capital of €127,800 for those using cross-border direct current lines and €31,950 for producers or sellers. These requirements do not apply to smaller installations (up to 1 MW) or certain non-profit organizations, according to the Electricity Market Act.
The TSO ensures the security of supply and formulates an annual action plan to ensure the supply for the following year. TSO also plans and manages generation, the transmission of electricity in the transmission network and the electricity consumption. TSO formulates the principles for intra-hour regulation of the system, creates the plan for the allocation of cross-border capacities, and the principles of congestion management. TSO ensures interoperability with neighbouring systems in real-time. It prepares, brings into effect, and monitors the implementation of action plans for network operators for the restoration of the electricity supply. TSO settles the balance of the system.
Role of National Regulatory Agency (NRA)
According to the Electricity Market Act, the ECA exercises supervision and regulates prices in the electricity market. DSO and TSO submit their reports to ECA for review, and any other information concerning shares or investments where additional oversight is required. For example, DSO notifies ECA in case someone acquires shares in a network operator, a line possessor or a producer who is in possession of generating installations with a net capacity of over 1 MW.
Grid use/management on islands
Most islands in Estonia are very sparsely populated. Only 3% of the population lives on over 2,200 islands. The biggest islands, Saaremaa, Hiiumaa, and Muhu, are connected to the transmission grid. With many recent blackouts on these islands, the need for micro-isolated networks is growing.
A micro-isolated network is created in areas where the consumption density is less than 15 megawatt-hours per kilometre of power line. In those service areas, the network operator ensures the security of supply and the balance of the network.
Curtailment
The transmission system operator may oblige plant operators to increase or reduce their output due to technical reasons or to guarantee stability in supply (Art 40 par. 2 ELTS). There is no special regulation concerning renewable energy regarding curtailment.
Priority for RES
Statutory law does not give priority to renewable energy. The grid operator has to respect the principle of non-discrimination when providing grid services to market participants.