Brazil’s Wasted Solar, Onchain: Exa Puts Stranded Megawatt-Hours on Solana

The twenty per cent that goes nowhere

Brazil is one of the largest renewable producers in the world, and distributed solar is the fastest-moving part of its matrix: capacity grew from under 1 GW in 2018 to roughly 40 GW in 2025. Transmission did not keep pace. The result is curtailment — generation that exists, was paid for in the sense that the asset was built, and is then simply not used. Brazil curtailed approximately 20% of its solar and wind output in 2025, an estimated US$1.2 billion in losses.

Curtailment is a strange failure mode, and it is worth sitting with. Nothing is broken. The panels work, the sun shines, the electricity is generated or could be. What is missing is a wire, a buyer, or a permit. And because the loss is diffuse — spread across thousands of generators rather than concentrated on one — it is unusually hard to finance a fix for.

Exa’s pitch is that the missing buyer can be created in software rather than in copper.

The marketplace, as described

On 14 October 2026, Solana’s official account announced that Exa, a marketplace startup, is moving Brazil’s surplus clean energy onto Solana. Exa is building a peer-to-peer marketplace in which excess renewable power is matched directly with end customers — homes and businesses — through tokenized representations of clean power, with a third-party verification system confirming the origin of the energy. Solana is the settlement layer, chosen for its ability to handle high-volume, low-cost transactions at the granularity and speed that minute-by-minute energy settlement requires.

Two design choices are worth naming. The first is that the marketplace sits between generators and end users, skipping the intermediaries that the announcement blames for elevated retail costs. That is not a technological claim, it is a market-structure claim, and it is the part that will meet resistance. The second is verification: energy is confirmed by a third party, which in practice means a meter-and-certificate chain that has to survive audit. A token whose greenness cannot be independently confirmed is, once again, an issuer’s word with better plumbing.

Solana’s framing is explicit about which bucket this belongs to: not a stablecoin, not a treasury product, but a physical DePIN use case — one that does not depend on an off-chain custodian, because the underlying asset is a flow of electrons rather than a claim on a vault.

Why Brazil is the testbed

Two features of the Brazilian market make it a plausible first testbed. The first is scale and urgency: 40 GW of distributed solar against transmission that has not kept up, producing a curtailment problem large enough to matter and concentrated enough to name. Brazil is early to this problem, not unusual in having it — the wider industry is shifting from “build more” to “use what is built”.

The second is the retail market opening. Under the planned regulatory timetable, industrial and commercial users can migrate to the free market from 25 November 2027, and other users, including households, become eligible from 25 November 2028. Retail choice is exactly the precondition a peer-to-peer energy marketplace needs: without it, there is no counterparty. Exa is building for a market that is scheduled to exist in two to three years.

There is supporting context in the generation mix as well. Brazil’s ten-year energy plan projects 41.4 GW of additional micro- and mini-distributed generation, serving 13.5 million consumers by 2036, with solar PV taking most of the growth. The direction of the grid — many small generators, many small consumers, cheap local settlement — is the direction a tokenized marketplace is designed for.

The counter-argument, from Brazil’s own data

Brazil’s own market research argues for caution, and it is more specific than the usual regulatory hand-waving. A study by energy analysts Guilherme Susteras and Alexandre Bueno, using data from 88,000 consumer groups connected to 1,400 shared solar plants across 40 distribution utilities between January 2025 and May 2026, found an average monthly payment arrears rate of 17% and a monthly churn rate of 4% — a rate that compounds to more than 40% of the customer base turning over within a year.

Those numbers describe the exact business a peer-to-peer marketplace would be running. If arrears run at 17% and churn at 4%, the platform is not primarily a settlement technology; it is a credit and receivables business with a settlement layer attached. The researchers call for stronger credit assessment, guarantees and receivables management from the early stages of market opening, and warn that retailers chasing share may cut margins to the point of insolvency — leaving consumers dependent on a supplier of last resort.

There is also an under-utilisation problem. Shared solar projects that fail to attract enough subscribers to absorb their available output raise the financial risk of whoever invested. That is curtailment by another name, one which no settlement layer can cure. And a peer-to-peer marketplace explicitly challenges the concession model Brazilian distribution utilities hold, which is precisely the kind of challenge that generates litigation, lobbying and delay rather than a protocol upgrade.

What to watch from here

Three markers. First, pilot transactions and generator onboarding: the announcement is explicit that the project is early-stage, with milestones including pilot transactions, generator onboarding and integration with Brazil’s regulated settlement systems. Until the first real megawatt-hour settles, this is a design. Second, the verification chain: who is the third party confirming origin, at what granularity, and can an outside auditor read it? Third, the regulatory posture — whether the free-market timetable of November 2027 and November 2028 holds, because the entire demand side depends on it.

There is a broader reason to watch. Of all the real-world assets being put onchain, curtailed electricity is one of the few where tokenization addresses a genuinely physical inefficiency rather than a financial one: not a settlement that is already happening, repackaged, but power that is currently thrown away. If that use case can be made to work — financing, metering, settlement, credit risk and all — it is a far more durable advertisement for the technology than any yield-bearing treasury wrapper. If it cannot, the reason will not be the blockchain. It will be the arrears rate.