Diesel-powered generator sets have been the preferred choice for decades. But while they offer a robust solution to all local power supply requirements except a few more specific ones, their environmental impact has put their reputation for using a polluting fossil fuel in question, even when equipped with the latest scrubbers. emissions, which has opened the door for generator sets to use various other alternative fuels.
By Julian Buckley
Generator set manufacturers have been experimenting since the turn of the century with hydrogen as a fuel alternative and over the past 20 years several of them have been seen making plans to adopt this new fuel.
In September this year, Caterpillar revealed that it would introduce generator sets capable of running on 100% hydrogen, a program that includes the development of a range of commercially available products and upgrades for existing equipment. In late 2021, Cat will begin offering the Cat G3516H gas generator set specifically configured to use hydrogen as fuel. Initially available as demo units in North America and Europe and with initial deliveries in late 2022, the generator set will be rated at 1,250 kW for load management applications, and continuous load at 50 or 60 Hz.
More imminently, the company plans to launch, in stages, the CG132B, CG170B, G3500H, G3500 with Fast Response and CG260 gas generator sets, configured to run on natural gas mixed with up to 25% hydrogen.
The company will also offer upgrade kits that will allow other generators built on the same engine platforms to use the fuel mixed with 25% hydrogen. Full production of the machines and kits is scheduled to begin in 2022.
Caterpillar is not the only OEM involved in the development of hydrogen-fueled generator sets. Atlas Copco is also running a hydrogen generator set program as part of the company’s Future Fuel strategy.
The H2-45 is a self-contained 45 kW power generator that runs on 100% hydrogen. Unsurprisingly, this results in zero emissions. Weather-resistant and equipped with a soundproof canopy, the unit is designed for short-term or mobile off-grid power requirements such as electric vehicle charging stations, outdoor events, and urban construction sites in emission zones ultra-low.
Developed by Atlas Copco’s Concept Lab, the H2-45 generator set has two main purposes: to test the fuel strategy and at the same time to test the market’s interest in the new technology. The new generator set concept is expected to be of particular interest to customers with specific sustainability goals, where H2 can be generated on-site to achieve green credentials and generate cost competitiveness.
“The H2-45 prototype is currently in an extensive testing and certification phase. That means our market launch date ‘is not set in stone’. Atlas Copco Specialty Rental wants to stay one step ahead of regulations and have the safest and most efficient H2 temporary solution on the market. That’s why we think, sometimes too much, about every bolt and screw in the machine, ”said Kris Herremans, Marketing Manager for Atlas Copco Specialty Rental Division.
According to the executive, the H2-45 has been well received by customers and the company is already receiving requests for more information and even requests to rent the unit. “While H2 is not the cheapest solution available, the moral conviction of our customers closes the price gap between electric or diesel solutions,” he says.
They are the vehicle charging stations where Herremans sees the greatest potential for the hydrogen generator set. There are areas where the electrical grid cannot handle the demand created by the stations, and in some cases, the required load is delivered by diesel generators. “We find it quite ironic,” he says. “We saw the problem and we thought we could find something better.”
While the H2-45 has the potential to deliver emission-free power, powering generators could still be a problem. While OEMs have launched off-road machinery with internal combustion engines adapted to use a mixture of hydrogen at 100% or some percentage, these machines can be located on a fixed base where the hydrogen can be delivered and stored. In the case of generator sets, the units could be in a remote location that would require delivery of the hydrogen fuel to random sites. “Transportation of fuel is one of the biggest problems,” says Paul Webster, Atlas Copco’s business development manager. “But despite the problems, I still think this is the way to go.”
This is not to say that future generator sets will use hydrogen to the exclusion of other types of fuel. Webster says Atlas Copco is about to launch EU Stage 5 compliant diesel generators and recalls that the Zenergize energy storage system was launched in September. “It is literally a box of lithium-ion batteries, a separate battery unit. It can be charged with a standard generator set, solar or grid power. It’s another route to achieve our goal of net zero, ”he says.
Zenergize’s ZBC model, for example, can deliver powers ranging from 100 kVA to 1,000 kVA and an energy storage capacity of 250 kWh to 2,000 kWh. They can serve as primary power units when used in island mode, or they can be combined with standard generators to create a hybrid solution. There is even the option of creating a microgrid. When in island mode, the energy storage system emits virtually no CO2 or NOx at the point of use and is nearly silent. With minimal maintenance requirements, the units also offer a greatly reduced cost of ownership proposition.
Webster says that while Atlas Copco will continue to market diesel engines, the company sees energy storage as a key component in the company’s future power supply portfolio, which will see increased investment in the technology.
But are new battery solutions in power supply the beginning of the end for diesel generators?
“The diesel engine is becoming the elephant in the room, the dirty diesel,” says Webster. “The way we fix it and achieve low emissions is by using batteries. The ideal scenario at this moment is to pair the two ”.
“The problem is that it is difficult to have a net zero on the site. Some sites are remote and the only way to get charged is by using diesel power. At the moment, we have the cleanest and most efficient diesel generator sets available. Together with an energy storage system like Zenergize, we believe that it is the best solution ”, he says.
Aggreko’s involvement in the development of hydrogen generator sets shows that the concern is not just with manufacturers. The rental company is investing in the development of related technology as part of its Greener Upgrades initiative, a part of its Net Zero program, a project that involves investments of about US $ 41 million and is intended to improve the company’s ability to provide emission-free services.
In partnership with CMB.TECH, the company has developed a 50 kVA hydrogen combustion generator set. After successful tests, the plan is to produce 10 units that will be shipped to customers and used to validate hydrogen as an “energy carrier”.
The generator sets are by default Stage 5 compliant and produce virtually zero NOx. According to Aggreko, the generator sets will be available for installation at European sites by the end of 2021.
In addition to this, Aggreko partnered with Dutch firm Nedstack to develop a fuel cell demonstrator that will integrate zero-emission hydrogen technology into Aggreko’s canopy storage battery solution to make a 45 kVA hybrid. This brings together a proton exchange membrane fuel cell with a lithium ion storage system.