- Combined-cycle technology uses two processes.
The first process includes a combustion turbine that operates like a jet engine, drawing in and compressing outside air to a high pressure. The pressurized air mixes with natural gas and then burns, creating hot exhaust gases. These gases power a combustion turbine, spin a generator and ultimately make energy.
The second process sends the hot exhaust gases from the combustion turbine generator to a heat recovery system. This system captures heat from the hot exhaust gases to produce steam to rotate a steam turbine generator and make more energy.
Combined-cycle technology is highly efficient because of this heat recovery system. Without this system, all of the heat from the hot exhaust gases would be wasted and released to the atmosphere instead of captured and reused to make more energy.
Building highly efficient natural gas plants is part of Duke Energy’s balanced approach to meeting future demand for reliable and increasingly clean energy.
As a regulated utility, Duke Energy is required to meet customer needs 24/7 in the most cost-effective manner possible and with limited environmental impacts. Doing this requires a mix of energy resources. Investing in natural gas infrastructure will help Duke Energy meet customer needs, close coal plants faster and reach its aggressive goals for cutting carbon emissions by at least 50% by 2030 and net-zero by 2050.
Natural gas-fired combined-cycle plants offer a variety of benefits to the environment and the energy system. Combined with the retirement of older, less efficient coal-fired units, the projects:
- Increase fuel supply diversity
- Add generation in more remote parts of the Duke Energy service area to reinforce the energy system
- Reduce environmental emissions, including nitrogen oxide and sulfur dioxide
- Add new, efficient intermediate gas-fired generation to our portfolio
Duke Energy carefully manages a variety of uncertainties and closely monitors natural gas prices.
As a regulated utility, Duke Energy is required to meet customer needs 24/7 in the most cost-effective manner possible and with limited environmental impacts. Today, with historically low natural gas prices and projections expected to remain stable, it's the most cost-effective option for customers.
These new facilities boost local economies in three main ways. First, the large construction workforce, ranging from 600 to 2,800 temporary workers depending on the size of the project, spends months or years living in these communities investing in local hotels, restaurants, shops and recreation. Second, the new plant becomes part of the local tax base, contributing to schools, emergency services and other governmental programs. Third, employees work and live in these local communities, often giving back through Duke Energy's employee volunteerism and financial contribution programs that benefit nonprofits.