The rapid development of energy program evaluation has broad implications for the policy porcess and policy design. Evaluation plays a far-reaching role in the energy policy process, affecting all segments of the population and the allocation of billions of dollars in public and private expenditure. The authors have selected a variety of energy program evaluations from the hundreds that have been conducted over the past five years to illustrate this development in energy policy. Thus, they inform the policy community in both academia and in government of the impact of evaluation in the energy context. They also enlighten practitioners in energy program evaluation of the policy implications of this work.