Mar. 31—HOUNSFIELD — Convalt Energy made a big announcement on Wednesday with plans to build a second 300,000-square-foot manufacturing plant near the Watertown International Airport.

The news came a day after the renewable energy company received an approval from the Jefferson County Planning Board for a 330,000-square-foot solar panel manufacturing plant at the site near the airport. It was the company's first hurdle for its original investment. The Hounsfield Town Planning Board is slated to take up the site plans for the first plant on Tuesday night.

During an interview with The Watertown Daily Times on Wednesday, Hari Achuthan, CEO of Convalt Energy and DigiCollect, revealed his plans for the second manufacturing plant, which would make components for the solar panels.

"We knew he had something else coming and he made the announcement (Wednesday)," said David J. Zembiec, CEO of Jefferson County Economic Development.

Construction of the first plant would start in June or July, at the latest, and the plant would be operational in February or March next year, Mr. Achuthan said. The company had originally hoped that construction would start in May.

Convalt needs 300 megawatts of electricity for the first plant, which would generate as many as 2 million solar panels a year. The first plant would initially employ between 150 and 200 workers, Mr. Achuthan said. That number would grow to 382 by year three, Mr. Zembiec said.

The second plant would add 200 to 300 workers, Mr. Zembiec said.

While the first one is under construction, Convalt would start the site plan process for the second plant, Mr. Zembiec said. The second plant could be ready for operation in 2024.

On Wednesday, the Jefferson County Industrial Development Agency's Revolving Loan Fund Committee approved an $850,000 bridge gap loan to Convalt for working capital to move equipment from Oregon, and for personnel and miscellaneous expenses. The full board is expected to approve the bridge loan next week.

The economic development agency plans to arrange a long-term loan to the company for seven years. The agency plans to approach the Sackets Harbor Local Development Corp., the Watertown Local Development Corp. and the North Country Economic Development Fund to see if they would become involved in the financing.

During the interview on Wednesday, Mr. Achuthan said he's in the process of acquiring two buildings that he plans to use for warehousing.

The buildings will be used to store 100,000 pieces of equipment that he purchased from a defunct Oregon solar manufacturing plant and will be trucked to New York. He would not identify the two buildings.

Mr. Achuthan said that national supply chain problems have delayed the start of construction for the first plant, resulting in increasing costs.

While some costs have gone up, Mr. Achuthan said he has worked out a better deal with National Grid to provide power to the airport site.

National Grid had originally told him that it would charge the company $19 million to provide electricity. Instead, he's gotten National Grid to provide a mile-long transmission line for $1.2 million, Mr. Achuthan said.

If the Hounsfield project is fully developed, the Convalt plant could create 4,555 jobs in 10 years, according to the company.

Convalt's sister company, DigiCollect, a software company that manufactures sensors for monitoring residential grids and transmission lines, would also build a 50,000-square-foot facility near the airport.