Brazil's National Electric Energy Agency (Aneel) Has Again Postponed Its Decision On Energy Storage Regulations, Raising The Upper Limit On MUST/D Reductions From 20% To 30% in The Network Usage Fee Dispute

 

Brazil's National Electric Energy Agency (Aneel) has postponed its decision on energy storage system regulations after Director Fernando Mosna requested more time to analyze the network usage fee structure for transmission and distribution systems. At a recent board meeting, the agency appeared close to approving an increase in the upper limit on the reduction in transmission and distribution system fees (MUST/D) from 20% to 30% for generator assets mixed with energy storage. This adjustment stems from a proposal by Lead Director Daniel Danna to resolve the dispute over the fee structure.

 

Danna argued that energy storage installations should pay transmission fees like other market participants to comply with current regulations, and emphasized that developers have the freedom to determine contractual arrangements to match their business models, thereby correcting negative externalities and incentivizing efficient network use. Technical simulations show that for a plant with a maximum transmission demand of 100 MW, a 30% MUST/D reduction would correspond to 18.3% of the total generation capacity from storage, but a maximum injection reduction of more than 40% is generally not technically feasible.

 

Danna acknowledged that regulatory issues should be further studied and possibly included in the 2027–2028 regulatory agenda.