Coal-to-gas conversion for cleaner energy

In principle, a "full repowering" means that one or more gas turbines with downstream heat recovery steam generators replace the old steam generator previously fired with coal or oil. In order to achieve this, various modifications of the steam cycle are necessary, as well as the exchange and retrofit of various components. 

For a full repowering, one needs to make sure that the appropriate gas capacities are available. For the final plan, other factors to be considered are the plant capacity, the heat quantities, and levels to be supplied for district heating and/or process steam applications. Also, one needs to consider the space available, and the condition of the power plant. The overall aim is to keep as much of the existing infrastructure as possible. 

While it is impressive that by converting a conventional coal power plant to a CCPP CO₂ emissions get reduced by up to 70%, it’s worth mentioning that this is a result not just from the fuel switch, but also from an increase in the power plant’s efficiency from an average of 38% to up to 63%.

Boiler conversion

A boiler conversion involves a modification of the burner technology and a change of coal or oil to gas. While switching to gas as a fuel does not increase the efficiency of the steam plant, it does reduce CO₂ emissions by up to 50%.