In an ideal world, the most efficient equipment would also cost the least to buy and install. But in the real world that’s usually not the case.
Equipment often runs more efficiently because it’s made from higher grade materials. Higher grade materials cost more.
Anyone who has priced home air conditioning systems is aware of this. But as Energy Star labels often reveal, lower electric bills offset the higher cost to purchase the AC system over time. The efficiency pays off by making the house cheaper to operate.
A similar principle applies to turbine inlet air chilling (TIAC) systems for power plants, but on a much larger financial scale. Lower capital costs (capex) may mean higher operating expenses (opex). That’s why it’s important to consider the total lifecycle costs — and how to minimize them — when investing in a TIAC system.
If you’re outside working on a hot summer day, it’s inevitable that moisture will appear on your brow. A dry breeze evaporates the perspiration and cools down your body. This is nature’s way of keeping you productive because no one works efficiently when they are too hot. Nature’s cooling technique is effective — as far as it goes. But clearly, you’ll cool down more in an air conditioned room than by relying on outdoor breezes. This is especially true when it is humid, since damp air cannot absorb as much moisture as dry air.
So AC is more effective and predictable than nature to remove the sweat off your brow on a hot August day.
How does this apply to power generation? Like us, the gas turbines used in power plants operate less efficiently when the air is too hot.
And interestingly, the two most common technologies for cooling power plants — evaporative cooling and mechanical chilling – mirror the way we cool down our bodies. They even share similar pros and cons.
Here is a more detailed description of the two cooling technologies, as they are used in power production.
This paper was delivered at Power-Gen International, December 2015.
Power demand is often greatest at the extreme temperatures due to an inherent desire (or required need) to maintain a steady, comfortable condition. The additional energy required to offset extreme ambient conditions, whether running an air conditioner or a heater, creates additional power demand. Unfortunately, a combustion turbine performance is highly sensitive to ambient air conditions and thus extreme hot and cold temperatures negatively impacts a generating unit’s performance and operation. Coil-based inlet air-conditioning systems are designed and operated to counteract these challenging conditions and maintain a combustion turbine performance and reliability throughout the ambient temperature range.