Combined Cycle Natural Gas
During optimal conditions, Holland Energy Park™ will be able to boast nearly 60% thermal efficiency in the production of power and heat for the community. Learn how it all works in the diagram below:
- Natural Gas Combustion Turbine Generators (CTGs)
- Heat Recovery Steam Generators (HRSGs)
- Steam Turbine Generator (STG)
- Snowmelt System
- Cooling Towers
Holland Energy Park features two Siemens SGT-800 turbines rated at 50 megawatts each. A natural gas turbine operates like a jet engine, except the thrust is used to generate electricity instead of propulsion.
- First, air from outside is drawn in and compressed by several layers of compressor blades before flowing at high speed into the combustion system.
- Then, in the combustion chambers, the air mixes with natural gas fuel and burns at temperatures of more than 2000°F.
- The result is a high-pressure, high-temperature gas stream that rapidly propels the engine’s turbine blades. The rotating blades turn a central shaft that performs two functions:
- Driving the attached generator to produce electricity.
- Driving the compression blades at the front of the turbine to draw in more air for combustion.
Combined Cycle Technology
The exhaust gas from each natural gas turbine flows into the plant’s Heat Recovery Steam Generation (HRSG) units. In the HRSGs, hot exhaust works its way through a closed system of pipes to heat water and convert it to steam. The steam is carried to a separate 45MW steam turbine generator (STG) to create more electricity before it’s cooled to a liquid in the condenser and cycled back to the HRSGs. This process increases the plant’s thermal efficiency to around 55% (the average coal plant is only 32-42% efficient).
Holland Energy Park has a three-fan cooling towers to dissipate the heat from the combined cycle process. Hot water from the plant’s condenser unit is pumped out to the towers to be cooled down before returning to the plant.
Snow Melt System
Our city is home to a 602,000 square foot snow melt system, a network of warm water pipes that keep the downtown sidewalks clear of snow during Michigan’s harsh winters. While the snowmelt system isn’t a new concept for Holland, Holland Energy Park changes the way we power it. Instead of heating the system using a coal-fired boiler at James De Young, hot water in the cooling system will supply heat to snowmelt before it is pumped to the towers. This will increase the thermal efficiency of the plant to nearly 60%, ensuring that we get the most out of each molecule burned.