During World War II construction and maintenance work had delayed, and after the war the SECV had difficulty with keeping up with increasing electricity demand. Existing thermal power stations were expanded at Yallourn and Newport, with much bigger generators of 50 MW capacity used, much larger than the 15-25 MW units used pre-war. The hydroelectric resources at Eildon and Kiewa also saw continued development. The Richmond Power Station was also converted to oil firing, and smaller 'prefabricated' power stations were erected in Geelong and Ballarat. These additions resulted in a reduction in the dependence on black coal by the 1950s.