Off-highway primary power through the tiers

Success comes to those who stay ahead

The technology of diesel-driven primary power has come a long way over the years. 

We used to have units that billowed black plumes of smoke so thick operators felt like they were standing behind a city bus. Now diesel generators run so clean they don’t produce much more than a puff of steam when you drop a heavy load.

Operators will tell you things have changed a lot over the past decade. They don’t go home with the odor of exhaust smoke stuck to their clothing anymore. Not to mention the benefits improved air quality has on their overall health and wellness.

But owners can have a hard time keeping up with the ever-progressing regulatory demands of the day. Updating an entire fleet of diesel generators can be a long, complicated and expensive process. 

When new regulations come down the pipe, owners and fleet managers ask:

  • “Do we need all new equipment, or can old units be updated?”
  • “Will the next line of generators’ new dimensions impact our application?” 
  • “How does all this new technology affect our service and maintenance schedule?”

We help customers get ready for the next round of industry advancements so they can take full advantage of new technology and market trends. Always have, always will. 

Step by step: the regulatory tiers

Let’s take a trip down memory lane and review how these diesel emission regulations developed over the past few decades. Some will recall the financial gut punch of periodically moving to larger, more complicated, higher price units — with all of the included challenges.

The EPA began regulating nitrogen oxide (NOx) emissions from diesel engines in 1990 under the Clean Air Act in an effort to limit ozone and carbon monoxide levels in the atmosphere. Units weren’t allowed to emit more than 9.2 grams of NOx per kilowatt-hour, but off-road mobile diesel engines and generators weren’t added to the list until 1994.     

The early tiers: 1 and 2, an easy like-for-like swap

These were simpler times, when a muffler was all a high-quality gen set needed to meet requirements.

Tier 1 standards were phased in from 1996 to 2000 to give operators time to prepare their equipment. The first round of regulations in 1996 affected units ranging from 130 to 560 kW. Two years later, units as low as 37 kW were phased in.

Tier 2 standards were adopted in 1998 and phased in from 2001 to 2005, expanding the list of regulated emissions to include NOx, carbon monoxide, unburned hydrocarbons and particulate matter.

We made it our goal to help reduce the hardship these regulations placed on owners. A simple engine swap got older units within compliance, so we developed our engine replacement and refurbishment programs to help customers update their generators.

Tier 3: ECUs and application reviews

Tier 3 was rolled out from 2006 to 2008, placing additional restrictions on exhaust fumes for engines ranging from 37 to 560 kW.

Electronic control units (ECUs) were added, allowing operators to control the speed of the engine by varying the amount of fuel injected into the cylinders. 

These systems were sensitive to engine vibrations, so our engineers had to reduce shaking around the computers without drastically increasing the gen set’s overall size. 

Since this was new and complicated technology, our team performed application reviews on prototype or pre-production gen sets to ensure that our units ran according to the standards of the ECU and engine manufacturers, respectively.

Tier 4 Interim: DOCs and containerized units

But adding ECUs was nothing compared to the advanced equipment required in the next tier. 

This phase added many new emission-control systems to the gen sets, further complicating the application review process and adding to the units’ overall footprints. 

Diesel oxidation catalyst (DOC) systems were initially required to oxidize carbon monoxide, hydrocarbons and sulfur dioxide, as well as deplete diesel particulates. And they’re still used in new systems to generate nitrogen dioxide that enhances the effectiveness of DPR and SCR systems — but we’ll get to those later. 

On top of learning how to use the new systems, many end users had to change their workspace layouts to make room for larger units.

Fortunately, our design team has been doing this for a while. We’ve been able to create tighter, smaller packages to meet the demands of our customers.

Tier 4 also brought stationary diesel generators like containerized units under these regulations in 2007 after the EPA implemented the New Source Performance Standards.

The initial Tier 4 Interim period from 2011 to 2012 enabled a gradual phase in before the Tier 4 Final regulations were placed on manufacturers beginning in 2013.

Tier 4 Final: DEF, SCR and engine replacement

The final emission regulations included restrictions on carbon monoxide per kilowatt-hour, non-methane hydrocarbons, NOx and particulate matter. 

Customers were initially afraid that Tier 4 models wouldn’t be reliable or easily maintained, so we worked hard to design user-friendly units that made the transition as simple as possible. 

Our engineers consulted with manufacturers to understand the best way to integrate new emission controls onto their engines. We found the optimal process for all of the engines we offer so customers can purchase complete packages that are ready to work. 

Tier 4 also made it a lot harder to update older units to meet new requirements. Systems like the diesel exhaust fluid system (DEF), selective catalytic reduction (SCR) and exhaust gas recirculation became necessary parts of compliance for many models.

Now operators had to worry about keeping more than just diesel fuel on hand.

DEF, a 32.5% urea, 67.5% de-ionized solution, is sprayed into the exhaust stream of diesel engines to break down NOx into nitrogen and water before exiting the system. 

The SCR injects the fluid into the exhaust stream, where it converts nitrogen oxide into nitrogen, water and a little carbon dioxide. DOCs add heat-up catalysts to the process, which helps oxidize soot collected in filters and enhances the reduction of NOx.

Tier 4 engines’ advanced fuel injection systems continually monitor engines to maximize performance and minimize the emission of harmful pollutants, increasing efficiency by up to 5%.

These devices considerably increased the size and complexity of Tier 4 units, requiring some owners to redesign their operational layouts to make room for the large models.

So, we expanded our engine replacement and refurbishment programs, upgrading Tier 2 and 3 generators to meet the new standards. This is a great alternative for customers looking to utilize their existing equipment without going to a new Tier 4 model. 

We also offer Tier 4 consultations so we can customize units to overcome obstacles like fitting customers’ existing space constraints.

A proven track record of clearing regulatory hurdles with custom power solutions

Remaining prepared for new regulatory changes put us in a great position to develop some of the first large-scale Tier 4 fleets of the day.

Our team helped develop an entire custom fleet of powerful, fuel-efficient generators in 2015 to get one of the largest construction equipment providers in the U.S. up to speed with some of the first user-friendly Tier 4 rental generators on the market. 

There were very few Tier 4 products in the field, so we had to engineer the new technology largely from scratch. 

And yet, it only took six months.

We also developed a first-in-class charging trailer tailored to power a line of all-electric buses for North America’s leading heavy-duty transit bus company. The units were customized to fit within a 20-foot steel container that’s towed behind the buses for roadside recharges.

It took about four months to get the first unit out the door.

Preparing for what’s ahead

We’re already looking toward the next round of regulations that are previewing in Europe. Tier 5 is expected to look a lot like Europe’s Stage V.

Europe has jumped ahead with Stage V regulations introduced in 2019 to limit particulate matter by overall mass and the number of individual particles per million, requiring a DEF system on every unit.

It’s only a matter of time before the U.S. catches up to regulations across the Atlantic. CK Power began integrating the new requirements into our products for our European exports, and we’ll be ready for the full transition if and when it arrives.

Ready to get ahead?

If your team wants to stay ahead of regulations and keep units up to date and running clean at an efficient cost, give us a call. We’re also available to help troubleshoot any issues that may arise with your emission control or other equipment.

Let’s work out the perfect plan for your specific needs.