Indiana and Virginia Pass Laws to Accelerate Grid Capacity via Surplus Interconnection Service — The Pew Charitable Trusts

Event summary

Indiana and Virginia passed laws in 2026 to leverage Surplus Interconnection Service (SIS) for faster grid capacity expansion.
Indiana's Senate Enrolled Act 240 requires utilities to evaluate existing power plants for SIS opportunities, signed into law on March 5, 2026.
Virginia's FAST Act mandates evaluation of solar farms for battery storage additions via SIS, signed into law on April 22, 2026.
SIS allows new energy resources to bypass the typical 4-year interconnection wait time by utilizing unused capacity in existing plants.

The big picture

Indiana and Virginia's laws represent the first state-level efforts to capitalize on federal requirements for Surplus Interconnection Service, addressing both timing and cost challenges in expanding grid capacity. This approach allows for quicker integration of new energy resources, particularly renewables and storage, by utilizing underused infrastructure at existing plants. The strategy could set a precedent for other states looking to modernize their grids while keeping costs low for consumers.

What we're watching

Adoption Pace: Whether other states will follow Indiana and Virginia's lead in adopting SIS legislation to meet rising energy demand.
Cost Savings: How much consumers will save by avoiding the need for expensive new transmission lines through SIS implementation.
Regulatory Impact: The extent to which state-level SIS policies will influence federal energy regulations and grid operator procedures.