HOMER Energy Support

Finding data to run HOMER

Last Updated: Jul 19, 2016 03:05PM MDT

One of the biggest challenges in using a model like HOMER is finding the numbers to put into it. This page is meant to help you find the information you need. If you know of any other helpful sources, please let us know so we can add them. Note that NREL cannot guarantee the accuracy of any data from external sources, and does not endorse any manufacturer or retailer.

Electric Load Data

The only source of hourly load data that we're aware of is the DG Marketplace, which you can visit at www.dgmarketplace.com. This website sells typical residential, commercial, and industrial load data for locations across the US.


To find your latitude and longitude, check www.multimap.com or www.maporama.com. Or check the list of world cities at www.infoplease.com/ipa/A0001769.html.

To find your time zone, check www.worldtimezone.com.

Solar Radiation Data

HOMER will accept solar radiation data as monthly averages or as a time series. Time series solar radiation data is most commonly available with an hourly time step, but HOMER can accept any time step down to one minute. One of the best sources of solar radiation data is the TMY2 and TMY3 data sets provided for free by the US National Renewable Energy Laboratory. You can import TMY2 and TMY3 files directly into HOMER's Solar Resource Inputs window.

  • NREL provides TMY2 data at: http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2/).
  • And TMY3 data at: http://http://rredc.nrel.gov/solar/old_data/nsrdb/1991-2005/tmy3/).
  • NASA's Surface Solar Energy Data Set provides monthly average solar radiation data for everywhere on earth at http://eosweb.larc.nasa.gov/sse/.
  • In the Solar Resource Inputs window if you specify monthly data there is a button labeled "Get Data Via Internet".  If you are connected to the Internet, that button retrieves monthly solar data for the specified latitude and longitude from NREL's and NASA's satellite databases.  Give that a try, it's really handy. If you specify a lat/long outside North America, HOMER refers to the NASA SSE dataset.  So depending on what location you request data for, HOMER might ask you to specify a username for NASA on their SSE website. Please use skip@larc.nasa.gov as your NASA SSE username in HOMER2. NASA recently re-configured their website and eliminated the need to validate specific email addresses. To enter this in the HOMER software, open HOMER2, select File >> Preferences, and enter skip@larc.nasa.gov into the field for NASA SSE username.
  • This help file contains a table of monthly solar data for selected worldwide locations.
  • The South African Renewable Energy Resource Database provides solar, wind, hydro, and biomass resource data at www.csir.co.za/environmentek/sarerd.
  • The US Renewable Resource Data Center provides US data and maps at http://rredc.nrel.gov/solar.
  • The World Radiation Data Center provides worldwide solar data at http://wrdc-mgo.nrel.gov. Note that data from this website need a lot of processing to be useful in HOMER.

Wind Speed Data

It can be difficult to obtain measured wind speed data. Proper measurement of wind speed is expensive and time consuming, and average wind speeds can vary markedly over short distances because of terrain effects. For these reasons, it is often necessary to synthesize wind data from estimated monthly average wind speeds.

Many countries have published wind atlases:

A number of other websites provide wind speed data:

Renewable Power System Components

Several retailers sell components for renewable power systems . The website www.ecobusinesslinks.com maintains a list of renewable power retailers around the world. A few have very helpful websites providing cost and performance data for PV panels, wind turbines, hydro turbines, batteries, converters, and other system components. Check out:

Other sources of cost and performance data for renewable power system components include:


  • A very useful document covering the technology, emissions, and costs of natural gas-fired reciprocating generators, microturbines, fuel cells, and Stirling engines is the Gas-Fired Distributed Energy Resource Technology Characterizations, available at www.eea-inc.com/dgchp_reports/TechCharNREL.pdf.
  • The Distributed Generation Information Center provides summary technical and economic data on reciprocating engine generators, microturbines, and fuel cells, as well as a large library of links, at www.distributed-generation.com.


The US Environmental Protection Agency provides emissions coefficients for CO2, SO2, and NOx for US locations at their Power Profiler website at www.epa.gov/cleanenergy/powpro/screen1.html.

The EPA's eGRID website contains even more emissions data, including state-by-state average emissions factors for all the pollutants that HOMER models.

Policies and Incentives

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