This is a set of openly-available data pre-processed to facilitate county-level energy planning using the Open Source Spatial Electrification Tool (OnSSET) in Kitui County, Kenya. It provides a ready-to-use starter kit of data inputs for county-level OnSSET analysis. The work to identify these data is submitted for publication - publication details will be added here as soon as possible upon release. These data are contained in spatial data files used to create the input for OnSSET in Kitui, and a prepared CSV data input for OnSSET in Kitui (kitui_OnSSET_data). The following spatial data files are included in the dataset: kitui_admin: A vector (.geojson) file containing the administrative boundaries of Kitui county. kitui_clusters: A vector (.geojson) file locating population clusters generated in data processing for OnSSET. kitui_demand: A raster (.tif) file containing merged health, agriculture, commercial, and residential demands for Kitui county in kWh. kitui_elevation: A raster (.tif) containing elevation information. kitui_GHI: A raster (.tif) file containing global horizontal irradiance data for Kitui county. kitui_hydro: A vector (.geojson) file containing the locations of hydropower stations in Kitui county. Note that there are none, and that this is expected. kitui_night_lights: A raster (.tif) file capturing the light emitted from Kitui county at night. kitui_power_stations: A vector (.geojson) file showing the locations of power stations in Kitui county. kitui_roads: A vector (.geojson) file showing the main roadways in Kitui county. kitui_transformers: A vector (.geojson) file showing transformer locations in Kitui county. kitui_transmission_lines: A vector (.geojson) file locating transmission lines in Kitui county. kitui_travel_hours: A raster (.tif) file showing travel time to the nearest market center in Kitui county. kitui_wind_100: A raster (.tif) file of wind speeds at 100 m in Kitui county. This dataset has been produced through work undertaken in the Climate Compatible Growth Programme.