READY, STEADY. Sthyr Energy co-founders (from left) Muhammed Hamdan, COO; Akhil Kongara, CTO; and Gunjan Kapadia, CEO

Imagine converting industrial quantities of electricity into solid metal plates, stacking them onto trucks and delivering them across states to power up factories.

While this may sound like an invention concocted by Dr Doofenshmirtz from the American animated TV series Phineas and Ferb, a Chennai-based energy startup is, in fact, working on bringing this intriguing proposition to life.

Sthyr Energy — founded by IIT-Madras alumni Gunjan Kapadia, Muhammed Hamdan and Akhil Kongara — is building a rechargeable zinc-air battery system that can store energy for long-term use.

On the rationale behind the project, Kapadia explains that while renewable energy generation is scaling up rapidly in India, it is seasonal and requires long-term storage solutions to bridge supply gaps.

“At present, you have lithium-ion batteries, which are great if the goal is to store energy for 3-4 hours. But to truly reach net zero and make renewable energy reliable for daily use, we will need to store energy for 3-5 months. For this you would need batteries the size of a city. Even if economically viable, the batteries self-discharge over time, making them infeasible,” he says.

The solution, he suggests, is to store electricity outside the battery ecosystem, in a material that is safe, cost-effective and does not self-discharge. Zinc fits the bill perfectly.

Off-grid answer

Sthyr’s solution, currently at the development stage (technology readiness level 5), is a three-stage system. The first stage is the charging section, where the generated renewable power will be used to split zinc oxide into electroplated zinc and oxygen.

In stage two, the zinc, which is now the energy store, is transported in its solid form — the power thus travels without need for transmission lines, substations or any other components of a traditional grid.

The third stage would kick in at the destination — typically an industrial cluster or data centre — where a traditional large-scale zinc-air battery is used to discharge the zinc to retrieve the electricity.

Interestingly, the residue from stage 3 would be powdered zinc oxide, which can return to stage 1 for recycling. Kapadia says the unit economics suits only large-scale deployments of at least 0.5 megawatts and not residential or small commercial use.

The company expects to have three pilots by the year end and an operational deployment soon after. “We have signed MoUs and are in discussions with multiple government and private customers who are looking to replace old-school generators with our technology,” Kapadia says.

In June last year, the company closed a seed funding round of $1 million.

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Published on May 11, 2026