Thailand has many natural gas and coal power plants that will reach the end of their expected design or contracted life of 20 or 25 years during the course of the PDP 2010 (from 2010‐2030). If‐well maintained and/or additional investment is made to replace certain parts, the plants may be able to be in service for additional years. This is similar to using your old car for another year or more rather than purchasing a new one. Delaying decommissioning of power plants, or “plant life extension” can be less expensive and less socially disruptive than building new power plants. It also has the advantage of very short (or essentially zero) lead time depending on the conditions of the plant. While extending the life of plants is not always the optimum solution (particularly if the plant is inefficient or prone to unscheduled outages), in many cases life extension makes sense. IEA figures have shown that financially life extension of existing plants “significantly outperformed” investment in new plants (both coal and gas) (Blyth 2010). Delayed plant decommissioning, either planned or unplanned, has been a common practice at EGAT in the past.
Often, it makes most sense to “repower” an existing plant, through more extensive upgrades including generators, boilers, or other equipment to increase efficiency or capacity. Advances in metallurgy, motor and generator efficiency, computational modeling of combustion, and computerized power plant controls offer a myriad of opportunities to keep make older power plants operate more efficiently, predictably, and cleanly.
In the PDP 2012, plant‐life extension for gas‐fired generation (mostly 5 years) is strategically chosen on nine separate occasions, on power plants ranging from 680 MW to 1910 MW.