CHP success stories for commercial and industrial facilities
Combined heat and power (CHP) systems can help provide comfort and stability in large facilities while reducing power costs.
Combined heat and power (CHP) systems are playing a growing role as a key source of power for facilities. By producing electricity at or near the site of use, CHP can reduce transmission and distribution losses therefore resulting in high efficiency, and lower energy costs. They are designed to run 24 hours a day and most systems can operate in island mode if a power grid goes down.
Their profile is getting a boost with the recent passage of the Inflation Reduction Act (IRA), which was signed in August 2022, with increased tax incentives for those that install CHP systems.
“The IRA is probably the most transformative bill that CHP has ever seen,” said Aaron Tasin, vice president of operations and sales at Northeast-Western Energy Systems (NES-WES).
“We’ve gone from having a 10% tax investment credit and now it’s up to 30%. We’re finally on the same level as renewables.”
This added benefit, along with a general push toward greener energy and buildings, could help boost CHP’s potential profile. At the end of the day, though, it will come down to the projects and how they’re helping improve energy efficiency, heating and cooling in these facilities while reducing overall costs. There are over 4,700 sites in the U.S. alone producing almost 82,000 MW of electric with CHP.
In one case, microturbines were installed in a luxury apartment and in another, a CHP system was installed in a food and beverage facility. Both projects had unique demands and expectations that needed to be balanced while still delivering on the project’s original purpose.
Microturbines used in luxury apartment
The Atwater Apartments complex is a 760,000-sq-ft, 54-story building in the Streeterville neighborhood near the Chicago Loop. The facility decided to upgrade their heating and cooling system because their heating costs in the winter were much higher than the cooling costs during the summer.
To accomplish this, Capstone Green Energy distributor Vergent Power Solutions was contracted in 2020 to redesign and convert the building from electric space heating to hot water heating. The new system featured two C65 ICHP microturbines and hydronic boilers that were tied into the existing chilled water piping system.
To ensure the microturbines would maximize their return on investment, the equipment needed to operate as close to maximum capacity as possible. The apartment building developed a custom operating schedule for the microturbines to maximize the heat recovery, while keeping the residents’ safety and comfort top of mind.
The CHP system was projected to save 1,360,000-kWh year. The conversion from electric heating to hot water heating, however, meant the energy usage would shift off tenant electricity bills and onto the building’s natural gas bill.
The microturbines are designed to minimize the environmental footprint by reducing greenhouse gas (GHG) emissions. Generating electric while utilizing the waste heat for space and domestic water heating generally has much lower emissions on a source to site basis.
The microturbines produced both domestic hot water and hydronic heating in the winter.
The project utilized the existing chilled water loop to run hot water to tenants in the winter. Economizer controls were added to tenant air handling equipment.
Results of the project
Replacing the older, less efficient water heaters with microturbines and condensing boilers boilers for domestic water heating, the building uses less energy and reduced carbon emissions. To date, each microturbine has run more than 16,000 continuous hours with 99% uptime per unit. The building produces 1,138,800 kWh of electricity, which means generation, transmission, and distribution losses from the power grid to the building are eliminated.
Food manufacturer installs CHP system
Freshpet is a pet food manufacturer producing fresh pet food that is cooked slowly using steam and then refrigerated. They use a propriety process to produce their preservative-free food from real meat and fresh vegetables, which includes mixing and blending of raw materials, cooking, cooling and packaging.
The process demands large amounts of steam to cook and electricity for refrigeration. Northeast-Western Energy Systems installed a Combine Heat and Power (CHP) system at Freshpet’s Bethlehem, PA., facility, which is utilized to offset the electrical needs of the facility and make use of the exhaust heat from the engine to make steam and reduce the boiler fuel consumption.
“They were looking for sustainability, a hedge on utility rate increases, lowering their carbon footprint and doing something that would be considered green,” said Eric MacBain, business development at NES-WES).
Because it’s a food and beverage facility, there are specific standards that have to be met regarding cleanliness and safety so the company can avoid potential recalls and other hazards.
Purity standards for pet food are the same high level as human food. The system had to be developed, particularly the steam generating capability, to meet these standards.
“We had to ensure during the build and for operations that strict boundaries were maintained to keep their systems clean. The cutovers (electric, steam, feedwater, domestic hot water) for a plant that rarely shuts down operations were particularly challenging and required sacrificing many holidays,” said Adam Masten, vice president of Engineering at NES-WES.
Another challenge during the installation process, Masten said, was the gas tie-in because their existing gas infrastructure was pressure limited and the distance from the gas pipeline riser to the cogeneration unit required extensive routing as a result. He added they could only do the cutovers during major holidays such as Easter, Thanksgiving and Christmas, which made the installation process a challenge. They also had delays due to the switchgear installation, which needed repairs before they could bring everything online. Most importantly were the safety issues because of the strict requirements necessary for food production.
“Since they are manufacturing pet food, they were concerned about any contamination from the CHP System and their product,” MacBain said.
The final installation was a success and the CHP has been able to meet the company’s demands, which are often in a state of flux.
“Since going into operation, the engine and related systems have functions as designed,” said James Gibson, field service manager for NES-WES. “Since the steam is used for cooking, the amount needed changes as well as the volume and pressure. The steam production from a CHP is meant to be consistent, so some changes on the feedwater pump and pressure valve out of the CHP was needed.”
NES-WES, who are no strangers to these kinds of projects, were able to handle the challenges because of their experience.
Tasin said, “It really speaks to how important the true engineer, the guy that’s gonna stamp the system, how much they understand CHP. They’ll look for their local engineer, but they don’t necessarily have that CHP experience.”
Overall CHP benefits
The value added by CHP technologies include facilitating sustainability to improving resilience and reducing costs. These benefits, coupled with the IRA legislation and a growing emphasis on efficiency and green buildings, can be attractive because if they are shown how they can provide benefit for the user by learning about their versatility.
– This article appeared in the GasTechnology supplement.
Northeast-Western Energy Systems (NES-WES)
Capstone Green Energy