For an owner or operator of a coal- or gas-fired power plant, continuing normal business operations in the future could mean making a choice between taking on the ever-changing landscape of regulations, taxes and renewable energy requirements — or shutting down.
As environmental regulations change and renewable energy becomes more cost-effective to produce and store, operating these plants successfully might require owners and operators to look for new ways to become part of the diverse energy mix of the future — including lowering carbon dioxide (CO2) emissions using carbon capture and storage or sequestration (CCS) technology.
Boosted by Department of Energy (DOE), state initiatives and academic support — and spurred by federal legislation and state mandates — CCS technology is fast becoming a more viable and effective option for removing CO2 from the emissions of power plants. Having a detailed understanding of this technology, how its implementation can impact plant operations, and the economic challenges associated with the storage of CO2 could help plants comply with new regulations and continue operations.
The amount of CO2 captured depends on how far the CCS technology is integrated into the plant’s process — and whether it is an amine-based absorption process or membrane technology. No matter the process, however, all CCS technologies have a direct impact on plant efficiency, output and operating costs.
For instance, amine-based CCS technology utilizes a large amount of steam and electricity to operate. It is critical to analyze the most effective source of steam for the operation, as a significant amount of steam taken from an existing source, coupled with the additional auxiliary load required for the carbon capture equipment, could have unintended consequences on the operational capabilities of existing equipment and, in turn, reduce overall plant performance.
These impacts to plant performance further alter the plant’s dispatch. In the past, base-loaded units were ramped up to a certain dispatch to maintain base load for weeks or even months at a time. Today, some of these plants follow renewable energy sources, requiring daily ramping up and down — and often significant operating time at reduced loads — which can be hard on equipment not originally designed for this type of operation.
Coupled with tax equity income from carbon capture, CCS may be able to ease this burden and increased operating and maintenance expenses on equipment by dampening the large load swings experienced due to renewables while maintaining a higher minimum load.
Use of Stored CO2
Having a plan in place for using captured and sequestered CO2 is key to making a viable economic case for the introduction and integration of CCS technology.
Location is the biggest consideration when it comes to making a case for CO2 storage. The cost to transport CO2 is substantial, so power plant owners need to be relatively close to the end storage reservoir, oil field or process user, for it to make economic sense.
Oil reservoirs and saline aquifers offer opportunities for storing CO2 underground. However, geologic sequestration of CO2 in saline aquifers involves technical and permitting issues, and there is little industry experience in doing so but is currently being investigated by DOE funded research. Injection of CO2 for use in enhanced oil recovery (EOR) to extract additional crude oil from existing oil fields, on the other hand, is more readily understood and is a long-standing practice for which stored CO2 can be utilized, extending the life of current wells. Proximity to EOR resources or CO2 transport pipelines is a primary factor in the viability and cost-benefit for the use of CO2 injection in EOR.
The economics of CCS rely heavily on the balance of many factors: amount of CO2 captured, cost to capture, impact to host plant efficiency and output, cost-benefit of and ability to leverage tax credits, capital cost, and operations and maintenance costs.
Owners and operators must ask themselves what the end goal is for the plant and how the facility will fit into their current states decarbonization goals and initiatives. Some of these technologies are efficient but have a high upfront cost. Finding that sweet spot between cost and meeting business plans and efficiency goals will make the implementation of CCS technology more realistic and effective.
Planning for Tomorrow
The prominence of CCS technology at coal- and gas-fired power plants will be a function of the regulatory environment, and the future promises to bring new challenges to utilities in the form of more stringent environmental regulations and grid decarbonization plans.
Continuing operations at these plants means building a business plan that looks ahead at the landscape of the power industry. If future decarbonization plans require the implementation of CCS technology, owners and operators will need to gain an understanding of these solutions today to build a plan for handling costs, operational impacts and changing regulations.
Integrating carbon capture and storage technology to meet the requirements of changing environmental regulations could help coal- and gas-fired power plants keep their generators running in the future.