HOMER is a user-friendly micropower design model developed in 1992 by the National Renewable Energy Agency in USA [1], who have released 42 versions of the program. It can be freely downloaded from [1] 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 [1] but numerous others have been completed also. HOMER has previously been used to assess the wind energy potential at individual locations in Ethiopia [2], to assess the feasibility of a stand-alone wind-diesel hybrid in Saudi Arabia [3], to assess the feasibility of zero-energy homes [4] and also, a stand-alone system with hydrogen in Newfoundland, Canada [5]. Finally, HOMER has previously been used to simulate a system where 100% of the electricity and heat demand was met by renewable sources [6].


  1. HOMER, HOMER Energy LLC, 2nd September 2009, http://www.homerenergy.com/
  2. Bekele, G. & Palm, B., Wind energy potential assessment at four typical locations in Ethiopia. Applied Energy, 86(3), pp. 388-396, 2009.
  3. 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.
  4. Iqbal, M. T., A feasibility study of a zero energy home in Newfoundland. Renewable Energy, 29(2), pp. 277-289, 2004.
  5. 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.
  6. 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.