DE SB266

Adds definition of "cost effective energy efficiency projects" as improvements with a Return on Investment of less than 3 years, including insulation, lighting, windows, and HVAC work.

Modifies the Green Energy Endowment Program to require applicants (except those with prior funding commitments) to first conduct a Home Performance with Energy Star Audit and identify cost-effective efficiency projects before applying for grants.

Allocates 60 percent of available grant funds to the residential pool and 40 percent to the nonresidential pool on an annual basis.

Allows the Secretary to suspend the Technology Demonstration and Research and Development programs indefinitely and redirect all available funds to the Endowment program if demand exceeds capacity.

Authorizes the Secretary to suspend or modify Green Energy programs entirely if incentives under the Delaware Renewable Energy Portfolio Standard are determined to be substantially equivalent, with funds redirected to energy efficiency, green building, renewable energy loans, and non-profit incentive programs.