In this report, we review the experience of utilities with a variety of lighting efficiency program designs, as illustrated by a dozen recent utility programs for residential, commercial, and industrial customers. This experience is then examined in terms of regulatory implications in the context of least-cost utility planning. The key questions explored in our report are as follows:

• How effectively are current utility programs mobilizing the technical potential of lighting efficiency resources?
• How does the program-based cost of lighting efficiency differ from the technology-based costs used in technical potential studies?
• What program designs appear to be most effective in reaching participants?
• What are the trade-offs between maximizing participation rates and per-customer savings and minimizing program costs?

In addition to these program evaluation questions, we also explore regulatory implications of lighting program experience:

• Could lighting program offer resources substantial enough to defer the construction of power plants?
• What measures could be taken by regulatory commissions to ensure and facilitate further utility program improvements?