Portable generators advance in functionality and applications
For the past few years, portable industrial generators have been undergoing a transformation in design and performance. Today, these versatile machines comes in a wide array of sizes and power ratings. They can be equipped with their own fuel tanks, outfitted with bifuel systems to burn gas and diesel, and incorporate advanced power distribution equipment.
Many of these features are especially relevant in the oil and gas (O&G) industry. We will explore some of these developments – and discuss the desirable features – that make portable generators ideal for O&G operations.
Portables come of age
Today’s portable generators are sleek, compact and fully enclosed; nothing like the small residential generators many of us might consider the definition of “portable.” In fact, it’s possible to build a generator that is technically portable (can be dragged on a smooth-bottomed skid or hoisted and moved on a crane) with a working power rating of many megawatts.
Unlike most generators of that size, they are also fully enclosed – an important feature for a portable generator. They also bear little resemblance to early enclosed generators, such as the one built for a passenger rail car in 1989.
Back then, an enclosed generator was nothing more than a small stationary generator housed in a stainless steel box. This approach made it more transportable and safer to operate where a traditional generator would not be practical, but it did little to extend functionality.
Today’s portable generators are sleek, powerful workhorses that fulfill a variety of needs and come in a staggering array of configurations and options. Tough and versatile, they are used to drive pumps for oil well production or run quietly alongside man camps, providing heating, light and other electrical needs. They also afford exceptional flexibility, as they can be connected with ease and disconnected just as quickly for transport or to fulfill another need.
Advances in portable generators begin with their enclosures, which can be made of a variety of materials from stainless or carbon steel to polycarbonate and beyond.
Depending on the manufacturer, enclosures can be exceptionally weather resistant and even waterproof, and many are resistant to impact and structural stress, as well. The panels can be manufactured with layers of built-in insulation (preferably rock wool) to provide sound attenuation.
Enclosures must incorporate some form of external access, but the most innovative portable generator enclosures offer access doors with windows so that operators can see controller readings from outside. Better portable generators also have doors wide enough to afford easy access for maintenance and service. Preferably, they incorporate external access to engine components such as the battery disconnect, battery charger and block heater.
Generators get smarter
Miniaturization and other technical innovations have enabled portable generator manufacturers to fit far more features into a small, ready-made package than ever before. One of the big advances is in the area of engine controllers, which used to be both bulky and unsophisticated. Today’s controllers are a different breed – they are compact in size but big on advanced features.
One controller feature that is exceptionally valuable for oilfield sites is remote monitoring and telematics, whereby an operator can receive alerts, operating fault alarms and other important notifications via email or text message. In many cases, technicians can actually interact with the engine over a satellite link, performing troubleshooting that can resolve problems and prevent small issues from becoming big ones.
Fueled, at least in part, by the growth of the generator rental industry where mobility is highly desirable, portable generators can now be both powerful and truly portable. With a truck-style chassis, for example, it’s possible to create a towable unit with a working power rating of more than 2 MW. A generator of this size may appear to strain the definition of portable, but it certainly meets the criteria of being easily moveable.
Highly portable, towable units, permanently mounted on heavy-duty trailers with reinforced tires, are available with power ratings of 400 kW and higher.
At 15,000 pounds, these units are well within the towing capacity of most heavy-duty pickup trucks, especially those with dual wheeled axles.
Portable enclosed generators such as those we are describing here are also exceptionally well suited to use in parallel configurations.
Traditionally associated with data centres and critical care facilities, parallel systems are beginning to appear on O&G sites. There, advanced controllers enable up to 32 generators (four to six is more common) to operate individually or in tandem.
These controllers – specialized versions of those mentioned earlier―are intelligent units that monitor all engine functions continually, not only for operating reliability but also for load. In situations such as man camps where power needs may fluctuate considerably at different times of the day or week, this capability can be very valuable. For example, the operator could preconfigure a parallel system so that all generators would run at optimal efficiency (50-70 percent) as much of the time as possible, turning them on and off as needed for load-sharing purposes. With a large man camp, such an approach could save an O&G operation thousands of dollars in fuel costs, per day.
The bi-fuel bonus
Another development, increasingly popular for portable generators, is a bi-fuel system. Admittedly, these revolutionary devices are not limited to portable models. Nevertheless, they can easily be integrated into an enclosed portable unit, offering significant fuel savings and environmental benefit.
With a bi-fuel system, a diesel engine can run on up to 70 percent natural gas, including scrubbed and cleaned well-head gas, with the system controller managing the fuel mixture for optimal performance under load. Given the growing requirement for petroleum producers to reduce or even eliminate flaring, finding uses for byproduct gas is becoming an imperative.
With a bi-fuel system inside an enclosed, portable generator, operators gain the benefits of bi-fuel in a compact package that can be moved to different sites, if appropriate.
The enclosure provides superior protection from harsh operating environments and increases the safety of operations near a hot-burning engine. The company also gains flexibility of fuel choice, enabling them to run more or less natural gas based on its allocation for other uses such as resale.
Last but certainly not least, portable generators can now both generate and distribute power.
Built-in power distribution panels negate the need for a separate panel or box, which reduces complexity and space requirements.
These panels can include a variety of connectors and receptacles, including NEMA 5-20R GFCI duplex receptacles, California-style twist-lock receptacles, Camlok connectors, mechanical lugs and more.
Some portable generators also have a built-in transformer – even dual-voltage input transformers (preferably CSA and/ or UL-listed, depending on the site location). With a transformer and a voltage selection switch, a generator can provide power for a nearly limitless configuration of items, from heavy machinery to laptops and cellphone chargers.
We believe that portable generators are truly the wonder of today’s generator industry. We also predict they will become the most commonplace installation in the near future and remain that way. It is difficult to illustrate the growth of the industrial portable generator market, because most research firms track industrial generators by fuel type, not form factor. Nevertheless, we have seen the evidence of their growing popularity firsthand. Offering power, attractive aesthetics, compact size and a self-containment straight from the factory, portable generators are truly made to please.