One of the major purposes of the CEB was to promote the use of electricity by industry. By 1936, about 80% of the available supply was used in this sector, although many industrial companies continued to rely on their own oil or gas engines to generate electricity for lighting.Domestic use was originally very limited but gradually expanded from use only by the wealthy.y 1936, about 80% of the available supply was used in this sector, although many industrial companies continued to rely on their own oil or gas engines to generate electricity for lighting. Domestic use was originally very limited but gradually expanded from use only by the wealthy.