Methods of small-scale energy production have advanced dramatically since the introduction of the first solar panels. In high-density locations, solar water heating systems take up very little room and improve efficiency, reducing energy costs. Suburban homes can use more advanced solar panels, and may be able to receive tax benefits, in addition to selling excess production back to the county. In buildings with high density, e.g. high rises or dorms, geothermal climate control is an economical option, while corporate campuses can use co-generation (simultaneously producing electricity and heat). While on-site energy generation is vital, moving towards large-scale alternative energy methods is something that must still be considered.