Natural gas-fueled power generation

Tenaska has been developing a carbon capture and storage (CCS) project in this area for the past few years. 

Due to the economic growth of South Alabama, the region’s need for power and the positive reception of our proposed CCS project, we are expanding the Longleaf project to include a natural gas-fueled power plant. 

We’ve always considered CCS to be an enabler – as an emissions solution for existing industry and as an attractor for new business investment. Tenaska’s robust development experience allows us to propel this concept and meet a growing need for new sources of reliable power generation through the addition of a power plant. 

Our site in northern Mobile County has the attributes needed to support affordable power generation: access to transmission infrastructure, natural gas supply and water. At the same time, it is relatively isolated, providing ample sound and visual buffers for neighbors. 

We intend to obtain natural gas from the major natural gas pipelines already present in the area. We do not intend to have gas wells on site or directly connect to gas wells. 

Tenaska has not finalized an offtake contract for this project, as these types of agreements typically come later in development. There is a significant need in the market for natural gas projects that can provide reliable energy and help meet increased electric demand to support economic development in the region.

The Longleaf power plant project cannot move forward until it has received all required local, state and federal permits, which may include: 

• Prevention of Significant Deterioration (PSD) Air Quality Permit (Alabama Department of Environmental Management) 
• Title V Operating Permit (Alabama Department of Environmental Management) 
• National Pollutant Discharge Elimination System (NPDES) Wastewater Discharge Permit (Alabama Department of Environmental Management) 
• Local permits (Mobile County) NPDES Construction Storm Water Discharge Permit (Alabama Department of Environmental Management)
• Clean Water Act Section 404, 408 and Section 10 permits (U.S. Army Corps of Engineers) for wetland and navigable water impacts which includes state water quality certification and consultations regarding T&E species and cultural and historical resources  
• Certificate of Use (Alabama Department of Economic and Community Affairs’ Office of Water Resources)

Pending all the required permits, the earliest construction start would be in 2029, with the earliest operations in 2032 or 2033. 

The proposed power plant will be located within the CCS footprint; on land we have secured adjacent to a proposed carbon dioxide (CO₂) injection well site near Bucks in northern Mobile County. 

We expect to build the Longleaf Energy Hub in phases. As a result, we have the flexibility to fully integrate the power plant and the CCS portion of the project, or to advance these independently. 

One of the positive attributes of the Longleaf gas site is that it is largely isolated with few close neighbors. This helps to minimize the impact on the community. 

Once complete, the power plant will encompass approximately 50 acres of the 520-acre site. (If carbon capture is included, the facility would occupy an additional 40 acres.) The remainder will be used as buffer. Existing trees and the natural topography of the area will help mitigate viewshed and sound impacts.  

Outdoor lighting at the facility would be pointed downward and inward. Neutral paint colors and landscaping will enhance the aesthetic look of the facility. 

We believe that our plans include ample buffer land to help with sound mitigation, as we only intend to use 50-90 acres of the 520-acre site. Other mitigation measures may include: 

• Housing steam turbines and combustion turbines in outdoor enclosures to reduce sound levels 
• Equipping exhaust stacks with silencers 
• Low-noise fans  
• Air inlet silencers 
• Planting additional trees and vegetation 

The new plant will become operational only if it receives an Air Permit from the Alabama Department of Environmental Management (ADEM) stating it will meet stringent air quality standards under the U.S. Clean Air Act and ADEM regulations.  

The Clean Air Act establishes the process for protecting public health from air emissions. This is done through National Ambient Air Quality Standards (NAAQS) that are based on criteria allowing for an adequate margin of safety and are requisite to protect the public health. ADEM will not issue a permit if the project does not demonstrate compliance with NAAQS.  

The primary NAAQS standards provide public health protection, including the health of ‘sensitive’ populations such as asthmatics, children and the elderly. In 2024, the EPA under the Biden administration significantly strengthened the annual standard for PM 2.5. The new standard was widely praised by public health organizations.  

Tenaska is currently evaluating the water supply options that can meet our needs without impacting other water use in the area. The amount of water needed will be dependent on final plant design and chosen technology; however, average water use for a 750-megawatt power plant is anticipated to average 5 million gallons per day.

The plant will apply for a water discharge (National Pollutant Discharge Elimination System, or NPDES) permit from the Alabama Department of Environmental Management to discharge wastewater. The permit will establish effluent limits and monitoring requirements. Tenaska will be responsible for ensuring compliance with the permit. Average daily discharge for a 750-megawatt power plant is anticipated to be 1 to 1.5 million gallons per day. Tenaska is currently evaluating potential discharge locations. 

Safety is of utmost importance to Tenaska, and we work hard to design a safe plant that is protective of the employees, residents and wildlife. This has been demonstrated through the safe operation of the Tenaska fleet, which encompasses 7,700 megawatts of generation.  

Our power plants have received dozens of awards from the National Safety Council, and the majority of our facilities have been named Voluntary Protection Program (VPP) Star Worksites by the U.S. Occupational Safety and Health Administration – a recognition obtained by only 0.03% of work sites (3 in every 10,000), demonstrating our strong safety culture. 

The Alabama Department of Environmental Management has requirements related to air quality and natural gas power plants, including compliance with ambient air quality standards. Our facility will be designed, built and operated in compliance with these standards, which are intended to be protective of human health and the environment. 

Construction will cause some temporary traffic disruption, but we want to minimize the impact on county residents and motorists.   

Prior to construction, the project will develop a detailed traffic management plan that takes into account Tenaska’s strong commitment to safety and local concerns around busy intersections, timing of construction traffic around school and other peak times, road conditions and other factors. We will also explore, with our contractors, the potential for shuttling, staggered shifts and incentives for carpooling. 

Of note, the project will: 

• Evaluate the number, direction of travel and timing of light vehicles travelling to the site and consider existing traffic and school traffic patterns to ensure minimal disruption   
• Work to avoid exacerbating peak travel times by ensuring plant workers arrive outside of those peak times or avoid congested areas.  
• Work with DOT, local schools and the county to select routes that are safe and optimize flow of traffic 
• Provide an adequate construction parking area on our property 
• Carefully schedule deliveries and follow approved travel routes; signage will be provided to ensure that delivery vehicles do not deviate from approved routes 
• Delivery vehicles prohibited from parking or staging along public roads 
• Pre-construction condition of roads will be carefully documented by a third-party engineer prior to the project; roads will be restored post-construction to as good or better condition 

During construction, the project would have a traffic management plan to ensure roads are maintained, to reduce traffic congestion and to mitigate dust and other construction impacts.  

We anticipate entering into a road use agreement and providing a road bond to help protect local infrastructure throughout the construction period.  

Public education and community outreach are critical for projects like the Longleaf Energy Hub. This fosters trust and a productive dialogue around community concerns. 

Our team has had many conversations in Mobile County. We have and continue to incorporate community feedback into our plans. This will continue over the course of lengthy development period and beyond. 

Our goal is to work with local leaders to mitigate project impacts and maximize local benefits.  

Tenaska understands the importance of two-way communication about the project and the need to be responsive to questions. Information is available on our project website: longleafenergyhub.com. 

At any time, questions can be directed to our local representative Jessica James at community@longleafccs.com or 205-789-3502. Jessica is also available at our local development office. 

Innovation Portal 
358 St. Louis St., Suite 1
Mobile, AL 36602
Office hours: 10 a.m. to 2 p.m. Tuesdays & Thursdays 

Additionally, there will be defined public comment processes as part of the various approvals needed for this project to move forward.