Standby generation as a profit center

Natural gas-powered reliability.


This Waukesha mobile standby generator set could also be used in a demand-response role to reduce utility demand and energy charges at times of peak use. Courtesy: General ElectricFor healthcare centers, universities, and government facilities, it has been typical to install diesel engine-generator sets as standby generation. They are able to pick up critical elements of the facility electrical load if the utility power goes down. Diesel engines start quickly and, if properly maintained and periodically tested, provide reliable backup power. But what if another approach could supply reliable power not just to cover short-term outages, but could carry a major part of the site load in demand-response service, supplementing central-station power at peak times? Such a solution exists.

Natural Gas Engine-Generators

In a recent presentation at a Technology and Market Assessment Forum conducted by the Energy Solution Center, Aaron Trexler, Waukesha Senior Product Line Manager from GE Power discussed this alternative route. He noted the traditional approach for facilities that require standby power was diesel-fuel powered engine-generator sets. These are often sized between 500 kW and 3 MW. If properly maintained, they operate reliably for the relatively short hours needed in standby service.

However, Trexler noted, diesel units have their limitations. "They require on-site fuel storage for two or more days of operation, and that fuel has to be kept in good condition. Because of emission restrictions, unless they have significant upgrades for pollution control, they cannot be operated other than in emergency service.

Emission Restrictions on Non-Emergency Diesel

He explained that recent court decisions have confirmed emission restrictions for standby engines used on demand-response applications. "According to the U.S. Court of Appeals for the District of Columbia Circuit, beginning May 2, 2016, engines used for any demand response activity must meet emissions requirements for non-emergency engines. They must be fully compliant. Older engines are not grandfathered — they must be updated. Demand response with diesel just got more expensive, and fast-start natural gas units are a viable alternative."

Trexler suggests as an alternative that institutional and industrial owners should consider these natural gas-fired engine-generator sets such as the Jenbacher and Waukesha models offered by General Electric. "These units not only provide reliable standby power, but can also be used in a demand-response mode, reducing utility demand charges and providing economical site energy for 1,000 hours a year, or more. They are no longer a 'stranded asset,' but in effect become a profit center.

Rapid Start Now a Feature

Trexler indicates that at one time natural gas engines couldn't meet the requirement to carry full load within 15 seconds. This has been overcome. This criterion for rapid startup in emergency situations can now be achieved by many Waukesha and Jenbacher natural gas engines, matching the performance of diesel engines. Qualifying Waukesha sets are available in sizes from 200 kW to 3.6 MW, and Jenbacher sets range from 200 kW to 10.0 MW. "These units are well proven, with over 36,000 units operating in over 170 countries."

Trexler noted the high efficiencies available with today's natural gas-fired engines, with proven performance levels ranging from 35% to 50%, depending on size and type. "Application of gas-fired engine-generators in combined standby and demand-response service can show a payback as short as two and a half years. If yours is also a potential cogeneration application, it could be even sweeter."

Large gas-fired engine-generator sets such as this Jenbacher unit are in widespread use around the world for demand-response or full-time power supply as well as serving as a reliable backup unit with a 15 second start time. Courtesy: General ElectricAlternative Gaseous Fuel Options

Several of the GE lines of engine-generator sets are designed to use alternate gaseous fuels such as propane, CNG and LNG. This makes them practical alternatives even when there are no pipeline gas sources. This also fulfills the need when it is a critical standby classification that requires on-site fuel storage.

He noted that conversion of existing diesel engines to dual fuel (diesel+gas) service has some significant limitations. "You're still using diesel fuel, so there are emission restrictions. Unlike engines designed for natural gas, these conversions do not have pistons, cylinder liners, crevice volumes or bowl configurations designed for gas. Their efficiency and reliability suffers. Our gas engines are designed to combust air/fuel in such a way to extract the maximum amount of power. The same cannot be said of today's dual fuel engines."

Striking Fuel Cost Comparison

Additionally, Trexler pointed out the fuel economies with natural gas as compared with diesel. He indicated that with diesel at $1.88/gallon, the fuel cost would be $14.56/MMBtu, compared with natural gas at $2/MMBtu. "This would result in a diesel-only fuel cost for electricity of $131/MWHr versus $24/MWHr with pipeline natural gas."

He states that the cost of a natural gas-fired unit would typically be about 50% more expensive that a standby-only diesel. However, if the gas unit operates for 2,500 hours per year in demand-response mode, the project payoff is 2.5 years. This assumes no cogeneration application. There is no payoff for the diesel unit, because it can only operate in standby situations.

Quieter and Cleaner

Other advantages of gas engines include the fact that they are significantly quieter than diesel units. According to Trexler, the difference can be as high as 20 dB. Gas units on pipeline have no limitation on operating hours, and require relatively inexpensive emission controls as compared with diesel. He indicates the diesel unit will require five to ten times more expensive emission controls.

Now that the rapid-start issue has been overcome, for most institutional owners the choice of natural gas engines for combined standby and demand-response service is obvious. It's the way for your standby system to pay its way. When you are installing standby power, keep this option in front of you.


Energy Solutions Center Info on Engine Generation

DOE Information on Distributed Energy

General Electric Power Generation

This article originally appeared in the Gas Technology Summer 2016 issue.

The Top Plant program honors outstanding manufacturing facilities in North America. View the 2017 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
SCCR, 2018 Maintenance study, and VFDs in a washdown environment.
Welding ergonomics, 2017 Salary Survey, and surge protection
2017 Top Plant winner, Best practices, Plant Engineering at 70, Top 10 stories of 2017
Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Setting internal automation standards
Knowing how and when to use parallel generators
PID controllers, Solar-powered SCADA, Using 80 GHz radar sensors

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me