Brazil Is Rewriting the Connection Rules for a Two-Way Grid

Brazil’s electricity regulator has opened a 60-day consultation on rules for connecting distributed energy resources. The proposal covers solar generation, storage, electric vehicles, microgrids and loads able to adjust their consumption. Its importance lies less in adding another list of technologies than in changing the basis on which the distribution network sees them.

Under the proposed revision to Module 3 of PRODIST, the national distribution procedures, a connected device would be treated according to what it can do: inject electricity, absorb it, respond to a command, support voltage or alter demand. Monitoring, communications, protection, power quality and control requirements would then reflect the resource’s size and effect on the network.

That is a response to a structural change. The distribution grid was designed around electricity moving outward from large generators to passive customers. A home with solar panels can now export at midday and import later. A battery can switch between load and supply. An electric vehicle may add demand at a difficult moment or provide flexibility if charging can be coordinated. Millions of individually small decisions can become material to the national system when they occur together.

From connection permission to operating capability

Traditional connection rules ask whether equipment can attach safely. Brazil’s proposal asks a second question: what capabilities must remain available after connection so that the network can continue to operate safely as conditions change?

The distinction matters because protection settings and one-time technical studies cannot give a distributor a live view of every relevant resource. Observability provides information about what is happening. Operability allows the network company to coordinate behavior. Controllability allows defined interventions when network security requires them. These are different capabilities, and the rule will need to specify which resources must provide each one.

A functional approach can age better than a catalog of named devices. New equipment can enter the market without waiting for a bespoke regulatory category if the rules already describe the behavior expected from any resource with a comparable impact. It can also reduce the risk that technically similar devices face different obligations merely because they arrived through different product markets.

Proportion is the hard design problem

The same approach creates a regulatory challenge. A small household system should not carry the communications, testing and control burden of a commercial battery fleet. If obligations are too light, the distributor may lack the information and response capability needed to manage reverse flows, voltage and system disturbances. If they are too heavy, connection costs and complexity can deter useful investment.

The proposal says requirements should vary with scale and impact and should describe functions rather than prescribe brands or equipment. Consultation will have to turn that principle into thresholds that installers, manufacturers, consumers and distributors can apply consistently. The rules also need fallback arrangements for communications failures, limits on control actions, and a record of when commands were issued and followed.

Those details determine whether flexibility is a usable service or merely a technical possibility. A battery may be capable of responding, but the grid cannot rely on it without an agreed signal, verified availability and an operating rule that resolves conflicts with the owner’s commercial preferences. An electric vehicle can adjust its charging, but consumers need to know what participation means for mobility, tariffs and control over their equipment.

Distribution and national operations must meet

The proposal grew from work by the National System Operator, ANEEL and university specialists. That institutional origin is significant. Brazil’s system operator has reported that micro- and mini-distributed generation already exceeds 43 gigawatts and is changing minimum demand, ramping needs and reverse power flows. Effects that begin on local networks can therefore become national operating conditions.

Distribution companies will need a more active role, but local action must remain coordinated with the national operator. A distributor solving voltage or congestion on its own network could change the resources available to the wider system. Conversely, a national instruction can create local consequences that only the distributor can see. Common data definitions, authority boundaries and event records will be as important as device capability.

Brazil has not adopted the revised rules. Consultation runs from 10 September to 9 November 2026. The next evidence is not the number of responses but whether the final module establishes workable thresholds, interoperable communications and a clear division of operational responsibility. That would turn a diverse population of devices into resources the grid can safely accommodate without pretending they are all the same.