Mobile Generators Have Entered a New Era of Efficiency and Versatility

Natural gas generators

The big story in energy generation over the last decade has been the move to cleaner fuels and greater efficiency — themes perfectly encapsulated in the latest mobile generators on the market. From the alternative forms of fuel to the integration of telematics, innovations in generators have changed the environmental story of the utility jobsite.

We start with Tier 4 Final requirements, which reconfigured systems, added complexity and increased the initial price point, but allowed engines to run on the diesel fuel they always have, but in a much more efficient way. And because of that efficiency, the costs to maintain a generator over its lifetime has gone down significantly.

“There is the initial cost impact of the engine’s exhaust treatment, which is typically seen on engine outputs greater than 15 kW,” says Dave McAllister, director of product management, Generac Mobile Products. “Most of the OEM engine manufacturers have extended the service intervals as the Tier 4 engines, overall, run cleaner than before. Fuel efficiencies have also been positively affected. Combined, these two factors do help offset the initial cost.”

Some of this depends on the exhaust aftertreatment method used in the system. Chicago Pneumatic, as one example, made the decision to use only engines that do not have diesel particulate filters (DPFs) for any of its Tier 4 Final generator products, opting for selective catalytic reduction (SCR) and diesel exhaust fluid (DEF).

“This means that there is no regeneration cycle and the associated onboard load banks are eliminated,” says Jim Siffring, generator and light tower product manager, Chicago Pneumatic. “There is less maintenance involved in this configuration.” Chicago Pneumatic offers portable diesel generators ranging from 25 to 330 kVA, with larger generators available on special requests up to 1,200 kVA.

Efficiency and environment aren’t the only virtues here either. Many of these newer Tier 4 generators are more powerful and versatile than older generations. Doosan’s G25 and G50 generator models come equipped with a diesel oxidation catalyst (DOC) aftertreatment system. The introduction of the G50 mobile generator marked a size increase in the Doosan Portable Power generator product line. The G50 (51 kVA) replaced the G40 (35 kVA) generator, a change driven by customer demand for higher kVA output. Further expanding the models’ versatility is a dual-frequency feature that allows an operator to select 50 or 60 Hz, dependent upon the application, and a multi-voltage selection switch.

The Gas Is Always Greener

Tier 4 is just one pathway to efficient, environmentally-friendly portable energy generation. The next challenger in this arena could be natural gas generators. Because of the fuel transportation concerns and emissions regulations regarding diesel, the industry is seeing a shift toward natural gas power generation, which has obvious advantages in fuel savings.

“There is no comparison between a free fuel source from a wellhead and one that has ranged in price per gallon from $2 to nearly $3 in the last 12 months. When you do the math, the cost savings are staggering,” says Todd Howe, global generator products manager for Doosan Portable Power. “In a one-month time span, a diesel generator operating 24/7 in an oilfield can consume upwards of $20,000 in fuel costs. During the course of a year, that adds up to more than $240,000 in fuel costs to operate a diesel generator, while the fuel cost of a natural gas generator is nearly $0.”

Howe says those fuel savings lead to an eight- to 14-month total return on investment and compensates for the higher purchase price. Natural gas generators require more frequent service, including oil changes every three to four weeks, or 500 to 750 hours. On the flip side, natural gas generators don’t require DEF or a regeneration process that is common among diesel engine generators.

Wellhead natural gas can produce an inconsistent flow that isn’t suitable for powering a generator, leading to possible losses in uptime or a flat out inability to run a generator. In these instances, natural gas generators must operate on an alternative fuel source. Doosan Portable Power natural gas generators, for example, are equipped with an automatic dual-fuel switch that allows the generator to operate on liquid propane from an external tank to ensure continuous operation in any circumstance.

Generac is testing hybrid power technology in the European market. The point of these hybrid systems is to reduce fuel consumption and manage smaller power demands that occur during off-peak usage hours.

“These systems are either integrated into a mobile generator package or offered as a stand-alone device that pairs with the generator,” McAllister says. “The system consists of a battery bank, chargers and power inverters with electronic controls that monitor power usage and switch from generator to battery power when demands are low.”

New Applications

Tier 4 engine ECUs are more sophisticated and provide more data and flexibility for the generator equipment packager. Generac developed the Generac Power Zone controller to take advantage of the increased data, which is capable of logging generator load profiles and providing a load profile map over time that shows just how much power is being used and when it is being used.

“This can help ensure, over time, that the generator is sized right for the application. The Power Zone can also be programmed to automatically start and run for a user-specified time each day,” McAllister says. “This can reduce the fuel consumption and ensure the unit is only operated when required.”

Telemetry allows monitoring of equipment and can help jobsite managers keep track of equipment needs, servicing, location and utilization. Features like this will lead to smarter operation of equipment, which is essential to managing overall cost of temporary power.

The monitoring advantages provided by generator telematics also minimize the downtime associated with an unexpected machine shutdown.

“Not only does telematics provide a system alert when a generator experiences a malfunction, but it also improves support and speed of repair by delivering vital diagnostics,” Howe says. “The information allows a technician to troubleshoot the possible cause of a malfunction before arriving onsite, eliminating multiple trips for appropriate parts or tools — and ultimately getting the machine back up and running faster.”

Some advanced telematics systems can warn of a potential problem before enough damage is done to shut down a machine, such as water in a fuel line. Should an unexpected machine malfunction occur, telematics can also provide the exact position of a machine, so a service tech can more easily locate the generator for diagnostics. This geo-locating capability is an especially beneficial tool for machines used in remote areas, like those common to oil and gas operations.

The new Doosan engine controller includes a backlit LCD screen for easy viewing of common parameters, while analog gauges allow at-a-glance monitoring for operator convenience. Fault codes are displayed in simple text for faster diagnostics and troubleshooting. The new controls are also designed to allow integration of a variety of telematics packages for customers that desire remote monitoring capability. Doosan natural gas generators come standard-equipped with telematics.

Chicago Pneumatic is a global company, so it sees a lot of trends that start to take off in other parts of the globe. One in particular that it developed in Europe is a device called the Transformer Maintenance Box (TMB). It allows a utility maintenance team to transfer the load from a transformer onto a generator, without de-energizing the downstream customers. Then the transformer can be disconnected for its required maintenance. Once that work is completed, it can be put back on line again without any disruption.

“We have had great response globally with this product,” Siffring says.

As the generator market continues to shift its focus from mere Tier 4 compliance to overall system research and development, expect even more innovations in terms of data management, clean energy generation (solar?) and improved power.

Chris Crowell is a contributing editor of Utility Contractor.

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