The white papers available here will help you get started on understanding HOMER as well as many of the issues surrounding microgrids, distributed power generation, and the components necessary to make it all work.
Micropower System Modeling with HOMER, by T. Lambert, P. Gilman, and P. Lilienthal. Published in: “Integration of Alternative Sources of Energy”, by F. Farret and M. Simões. Copyright ©2006 by John Wiley & Sons, Inc.
High Penetrations of Renewable Energy for Island Grids, by Peter Lilienthal. Link to original article
Economics of Grid Defection: When and Where Distributed Solar Generation Plus Storage
Competes with Traditional Utility Service
Co-authored by the Rocky Mountain Institute, HOMER Energy, and CohnReznick Think Energy. The link is to a 4-page summary. Click here to download the full report.
Underwater Compressed Energy Storage.