[4][5] The power station was sold to the Electricity Supply Commission (Eskom) in January 1927.

Between 1944 and 1959 a series of new generators were commissioned, resulting in the power station's capacity being increased to 160 MW.

In the early 1980s Eskom initiated a major development programme: in 1980 new large power stations at Kriel (3,000 MW), Hendrina (2,000 MW) and Camden (1,600 MW) had been commissioned and in the next few years a number of other new power stations gave South Africa a surplus of generating capacity and many of the 1960s vintage power stations (including Colenso's refurbishment) had become uneconomic.

[8] This meant that the continued use of the Colenso power station was no longer economically viable.

With a substantial coal resource discovered near the town and with the gradual liberalising of the South African electric power generation industry, a modern coal technology power generation unit is planned.