HOMER is a user-friendly micropower design model developed in 1992 by the National Renewable Energy Agency in USA , who have released 42 versions of the program. It can be freely downloaded from  and to date, 32,000 people have downloaded the model. A typical analysis can be run after one day of training.
HOMER simulates and optimises stand-alone and grid-connected power systems comprising any combination of wind turbines, PV arrays, run-of-river hydro power, biomass power, internal combustion engine generators, microturbines, fuel cells, batteries, and hydrogen storage, serving both electric and thermal loads (by individual or district-heating systems). The simulation considers a 1 year time-period using a minimum time-step of 1 minute. It performs a sensitivity analyses which can help the analyst to do what-if analyses and to investigate the effects of uncertainty or changes in input variables. The objective of the optimisation simulation is to evaluate the economic and technical feasibility of a large number of technology options and to account for variation in technology costs and energy resource availability.
A list of publications that involved HOMER is available from the homepage  but numerous others have been completed also. HOMER has previously been used to assess the wind energy potential at individual locations in Ethiopia , to assess the feasibility of a stand-alone wind-diesel hybrid in Saudi Arabia , to assess the feasibility of zero-energy homes  and also, a stand-alone system with hydrogen in Newfoundland, Canada . Finally, HOMER has previously been used to simulate a system where 100% of the electricity and heat demand was met by renewable sources .
- HOMER, HOMER Energy LLC, 2nd September 2009, http://www.homerenergy.com/
- Bekele, G. & Palm, B., Wind energy potential assessment at four typical locations in Ethiopia. Applied Energy, 86(3), pp. 388-396, 2009.
- Rehman, S., El-Amin, I. M., Ahmad, F., Shaahid, S. M., Al-Shehri, A. M., Bakhashwain, J. M. & Shash, A., Feasibility study of hybrid retrofits to an isolated off-grid diesel power plant. Renewable and Sustainable Energy Reviews, 11(4), pp. 635-653, 2007.
- Iqbal, M. T., A feasibility study of a zero energy home in Newfoundland. Renewable Energy, 29(2), pp. 277-289, 2004.
- Khan, M. J. & Iqbal, M. T., Pre-feasibility study of stand-alone hybrid energy systems for applications in Newfoundland. Renewable Energy, 30(6), pp. 835-854, 2005.
- Lambert, T., Gilman, P. & Lilienthal, P., Micropower system modeling with HOMER, in Integration of Alternative Sources of Energy, FA Farret and MG Simões. 2006, Wiley-IEEE Press. p. 379 – 418.