Since these cannot meet the cooking/thermal needs of households, one of the requirements of the DoE is that the suppliers of non-grid technologies augment their services by selling thermal fuels such as paraffin and liquefied petroleum gas (LPG). The installation of SHS must be such that the maximum densification of the installed base is achieved in a specific area. The service provider, who holds a monopoly for servicing an area, must make sure that universal access is achieved in a village identified as a non-grid area. In early 1999, the DoE issued a call for proposals for non-grid rural electrification.