Energy Service Companies, ESCOs, contract with institutional energy users in the public and private sectors to provide cost-effective energy efficiency retrofits across a wide spectrum of client facilities, from college campuses to water treatment plants. Effectively utilizing a performance-based contract business model, ESCO's have implemented significant comprehensive energy efficiency retrofit projects over the last three decades. A recent Lawrence Berkeley National Laboratory report estimates that ESCO investment in energy efficiency retro-fit projects currently runs about $5 billion a year. Since 1990, ESCOs have delivered: