Substitute House Bill No. 5248 aims to improve energy efficiency and transmission planning in Connecticut by granting the Commissioner of Energy and Environmental Protection (DEEP) enhanced authority to establish and review energy efficiency standards. The bill introduces a provision that allows the Commissioner, in consultation with the Commissioner of Consumer Protection, to endorse a voluntary energy efficiency certification program if the federal Energy Star program is eliminated. It mandates periodic reviews and updates of efficiency standards, ensuring they take precedence over the State Building Code when in conflict. The bill also expands the scope of efficiency standards to include water conservation and allows for the incorporation of standards from other recognized programs, while streamlining the regulatory process by removing previous requirements for public hearings.

Significant changes include the repeal of existing provisions related to efficiency standards and the introduction of new criteria emphasizing cost-effectiveness and consumer payback periods. The bill specifies that manufacturers must submit compliance documentation from recognized programs, and it enhances the DEEP commissioner's enforcement capabilities by allowing inspections of distributors and retailers. Additionally, the Siting Council's criteria for determining the public need for electric transmission facilities are modified to include evaluations of future electric grid reliability needs. The bill is set to take effect on October 1, 2026, and is expected to yield significant energy savings for Connecticut residents without imposing additional costs on the state or municipalities.