How Coal Plants Can Increase Efficiency and Cut Emissions

power plant retrofits

The latest trend in the coal industry – beyond the gradual decrease in market share thanks to rising use of renewables and natural gas – is emissions regulation.

Over the past decade, the American coal power plant fleet has been struggling with reducing carbon emissions in the face of new regulations. This increased focus has resulted not only in a slowdown of new construction – there were only five proposed new plants and plant expansions in the U.S. as of December 2015 – but a gradual retiring of older, less-efficient plants.

Additionally, the cost of building a new coal-fired plant is behind only advanced nuclear, MSW landfill gas, and offshore wind.

Demand for power will only increase, and renewables aren’t to the level where they can make up for decreased coal use. What are utilities and power plant owners to do if new plant production is more or less off the table?

Increasing efficiency and lowering emissions through smarter power plant retrofits and upgrades may be the solution.

The Promise of More Efficient Power Production

According to the International Energy Agency, modern coal-fired power plants across the world average 33 percent efficiency. The average efficiency for American coal plants is roughly 33 percent (as of 2015), with the most efficient coal-fired plant in the U.S. boasting 40 percent efficiency (the John W. Turk Jr. plant in Arkansas). Ultra-supercritical (USC) plants like John W. Turk can reach higher levels; the most efficient coal-fired plant in existence today is Denmark’s Nordjylland Power Station, at 47 percent.

Pursuing higher levels of efficiency has been the strategy of choice for coal power plant owners for the last decade. It’s cheaper to retrofit and upgrade an existing plant – particularly a newer one – than build a new plant or upgrade an older plant that was built over 10-15 years ago.

Each point of efficiency equals millions of tons of CO2 emissions that are not produced by the plant. Higher heat efficiency also equals higher economic efficiency, which can help mitigate the financial threat posed by natural gas. This path is worth pursuing not just because it will help plant owners stay on the compliance side of federal and state regulators; it will also result in better bottom-line performance for a plant.

Improving Efficiency with Strategic Power Plant Retrofits and Upgrades

There are several broad ways to improve efficiency and curb emissions in a coal-fired power plant. These include:

  • Enhancing combustion efficiency
  • Optimizing boiler performance
  • Streamlining the steam cycle
  • Lowering overall energy consumption
  • Creating better maintenance practices and procedures

In addition to the above, plants have also begun considering carbon capture and storage (CCS) technology. CCS can significantly reduce CO2 emissions through pre- and post-combustion capture and oxyfuel combustion. While there is some evidence that full-scale CCS adaptation can be costly – namely, in the form of increased energy consumption required to separate and process the CO2 – CCS is one of the more palatable environmental control methods from a Republican standpoint, and that party currently controls Congress and the White House.

CCS or no CCS, improving efficiency starts with a full audit of a power plant’s existing infrastructure and capabilities. It can be difficult for owners and managers to identify areas for improvement without detailed statistical analysis from engineers skilled at inspecting and evaluating a plant’s performance.

Even if a plant has updated equipment, there is still room for improvement. Regular maintenance is one of the best ways to not only keep a power plant’s efficiency ratings up, but to make even more gains in efficiency through maximizing the operational performance of your equipment. Indeed, in some cases, many gains can be made through regular and thorough maintenance without the need to carry out a full-scale equipment upgrade.

Contact Southern Field for more information on timely plant upgrades and proactive, ongoing maintenance and service.