Solar Ready CCR Site Closures Help Energy Companies Move Toward a Sustainable Future
Electricity is the one big energy source that can be free of carbon emissions. You can make it from the sun. You can make it from the wind. Tap the heat of the Earth, hydropower. While all utilities are moving in a sustainable, environmentally friendly direction, Aliant Energy stands out for making progress and keeping rates reasonable for consumers.
At the recent USWAG Workshop on Decommissioning, Repurposing & Expansion of Utility Assets held October 2019, Eric Nelson presented on the opportunities for solar generation at closed CCR sites and provided an overview of civil and geotechnical considerations when redeveloping closed sites as solar generating assets. His presentation demonstrated these considerations through the use of a case study.
SCS Engineers has assisted Alliant Energy with the design and/or construction of multiple coal combustion residual (CCR) surface impoundment closures. Two of the completed closures are the former Rock River Generating Station in Beloit, Wisconsin, and the M.L. Kapp Generating Station in Clinton, Iowa.
Both sites were closed by incorporating Alliant Energy’s vision to create “solar ready” sites. The Rock River site is now home to just over 2 megawatts (MW) of solar photovoltaic (PV) generating capacity, which was developed on the footprint of the now-closed on-site landfill and ash ponds. Although no solar assets have been developed at the site, the M.L. Kapp ash pond closure represents another opportunity for Alliant Energy to repurpose a closed ash pond for clean power.
Two additional closure designs are in process that incorporates similar elements, making them available for future solar generating asset development.
Eric J. Nelson, PE, is a Vice President of SCS Engineers and one of our National Experts for Electric Utilities. He is an experienced engineer and hydrogeologist.
An aggressive carbon abatement goal often referred to as deep decarbonization, requires systemic changes to the energy economy. The scale and complexity of these projects are enormous, but achievable in our children’s lifetime. Legal Pathways recently published a legal toolkit Legal Pathways to Deep Decarbonization in the United States containing key recommendations and information from its larger publication to be released later this year. Both are a treasure trove for public and private decision-makers who desire pathways to a smaller carbon footprint.
The slimmer version works as a legal guide for businesses and municipalities interested in reducing greenhouse gas (GHG) emissions in the U.S. While each entity may draw on some, but not all, of the publication, it is a significant resource for public and private decision-makers who desire, or are working toward meeting stricter regulatory policies.
The authors identify all the legal options for enabling the U.S. to start addressing a monumental environmental challenge. Decision-makers can use combinations of resources to achieve their desired goals by employing these legal tools.
Thirty-four chapters cover energy efficiency, conservation, and fuel switching; electricity decarbonization; fuel decarbonization; carbon capture and negative emissions; non-carbon dioxide climate pollutants, and a variety of crosscutting issues.1 Each topic area identifies the main legal issues; then covers the options involving federal, state, and local laws.
With enough detail for readers to comprehend pathways best suited for them, the book is written for those who do not have legal or environmental engineering backgrounds. The authors include options even if they are not politically realistic now, recognizing that some may have value over time by becoming a legal pathway.
Notes and Citations
1 “Legal Pathways to Deep Decarbonization in the United States,” by M. Gerrard and J. Dernbach, Editors, 2019, Retrieved from https://www.eli.org/eli-press-books/legal-pathways-deep-decarbonization-united-states
Compressed air powers thousands of industrial applications and processes. It is vital to nearly every industry. For example in the printing industry, compressed air is
used for presses, cleaning machinery, hoisting stereotype plates, powering pneumatic tools, packaging, and automating equipment.
Ensure you’re not losing value from your compressed air systems. Don’t let leaks drive up operating costs. Use this advice to keep your systems running at their peak performance.
Did you know that the overall efficiency of a typical compressed air system is between 10 percent and 15 percent? While that seems low, compressed air may be your best choice. However, carefully evaluate each application to make sure it makes business sense.
For example, if you are using compressed air as your energy source for a motor, consider that the annual energy costs for a 1 hp. air motor vs. a 1 hp. electric motor, operating five days per week, over two shifts, at $0.10/kWh would potentially cost the facility $2,330 (compressed air) vs. $390 (electric).
A properly managed system uses compressed air for appropriate applications.
Did you know that a ¼-inch leak can cost the typical facility $8,382 per year in wasted electricity? The chart below shows the calculated cost of leaks in a typical compressed air system.
Leaks cause a drop in system pressure, which can make equipment or systems function less efficiently and adversely affect production. Leaks can shorten the life of nearly all system components by forcing the equipment to cycle more frequently. Increased running time also can lead to additional maintenance requirements and increased downtime.
Audits show that operators have a tendency to add expensive and unnecessary air compressor capacity instead of addressing leaks. Make sure you’re regularly checking for and repairing leaks. Systems with leaks waste money.
A typical air compressor system that has not been well maintained could have a leak rate
between 20 percent and 50 percent of total compressed air production capacity. Leakage can come from any part of the system. Here are some of the most common sources of leaks:
A good leak prevention program will include the following components: identification (including tagging) of leaks, tracking, repair, verification, and overall system re-evaluation. We recommend that all facilities with compressed air systems establish an aggressive leak prevention program. You can include it as part of an overall program aimed at improving the performance of the facility’s compressed air system, or energy use.
For every 2 psig. reduction in system pressure, the energy consumed by the system reduces by 1 percent. Increasing system pressure increases leakage rates and compounds friction losses associated with a poor piping design or poorly maintained, clogged filters.
Check the system pressure and resist the urge to turn up the pressure.
Compressed Air System Assessment
A comprehensive air compressor system assessment can identify the true costs of
compressed air and identify opportunities to improve efficiency and productivity. Generally, a fully instrumented audit, which can take 3-7 days, can identify between 30 percent and 50 percent energy savings opportunities.
A comprehensive compressed air system assessment should include an examination of both the supply side, demand side, and the interaction between the two. Auditors typically measure the output of a compressed air system, calculate energy consumption in kilowatt-hours, and determine the annual cost of operating the system. Third-party leak surveys also can be performed.
Losses and poor performance caused by inappropriate uses, system leaks, inappropriate system controls, poor system design, and total system dynamics are evaluated, and a written report with a recommended course of action is provided.
Author: Tony Kriel, an SCS Professional Engineer with more than a decade of experience specializing in energy saving projects. He is a Sustaining Member Representative in SAME and has been a Member of ASHRAE for 10 years. His project experience includes compressed air system assessments, energy audits, commissioning, retro-commissioning, energy modeling, and renewable energy technology analysis.
Material recovery facilities (MRFs) are seeing many challenges that directly impact operations. Some of these challenges include: new recycled material quality standards from China, the ratcheting up of voluntary and mandatory local and state recycling goals, lower tolerance for worker injury, increasing volumes and a changing waste stream, disposal bans on organics in landfills, and high demand from emerging energy
markets for organics.
MRFs equipped with the latest technologies are able to meet tightening standards for traditional quality recycled materials and some are also starting to provide a separate, clean organics stream for downstream alternative energy projects. Many MRF operators are now benefitting from these new technologies, with increased throughput and quality of end product.
The article by Bruce Clark and Mike Kalish of SCS, provides an overview of the latest developments in MRF processing equipment systems that are helping owners and operators meet these challenges and at the same time helping maintain a healthy bottom line.