Book excerpt: The Asian Development Bank has implemented a regional technical assistance to develop small hybrid renewable energy systems that will provide reliable, adequate, and affordable energy for inclusive growth in Asian rural areas, and enable access to electricity and energy efficiency in remote rural locations and small isolated islands. This guide was prepared as part of knowledge development activities of the technical assistance, and is intended to support planning hybrid renewable energy systems based on experiences of pilot projects in South Asian developing member countries. It will help find the most cost-effective configuration for a hybrid renewable energy stand-alone system through simulation of operation for each possible configuration of the system.