Mark Sweeney 2016-11-16 11:17:11
Traditionally, diesel fuel has been the leader in standby power solutions. Diesel-fueled standby generators are perceived to be the most durable and reliable option available, as well as the most power-dense and cost-effective. These types of generators satisfy the standards that specify standby power sources and onsite fuel requirements. But, diesel generators come with some challenges, including fuel reliability and environmental issues. Bi-fuel generators, which combine diesel and gaseous fuel, are becoming increasingly popular, as they provide an alternative option to this market. These gensets offer end-users the advantages of using both diesel and natural gas fuels, while minimizing potential disadvantages by combining the power density and capital cost benefits of diesel engines with the extended runtime of natural gas. Bi-fuel generators, too, can be an answer to standby power and onsite fuel requirement standards and also provide an environmentally friendly and cost-effective solution. The Importance of Reliable Backup Power When a business loses power, it almost always means at least some lost revenue—sometimes even irreparable damage. Lost power can trigger interruption to mission-critical loads, resulting in potentially catastrophic outcomes. Although some businesses are legally required to have backup power systems, other companies are voluntarily installing these systems to keep business moving seamlessly. Although diesel has been the go-to fuel source for standby power for a long time, there can be drawbacks to using this type of fuel source. For one, diesel-only generators have limited tank capacity, as there is only so much fuel that can be held onsite. This can limit the runtime of these gensets when there is a power outage. In addition, diesel fuel tanks need to be highly maintained to ensure they will start properly and run when standby power is needed. If fuel goes unused for even a short time, it can be susceptible to condensation, corrosion, and bio-growth. If the diesel generator is located in a hot climate or in an area with frequent salt exposure, more frequent maintenance must be performed. Often, when standby power is needed to aid those affected by catastrophic storms—such as Hurricanes Katrina and Sandy—it can be difficult to get enough diesel onsite due to blocked roadways and damage caused to major terminals. Natural Solutions More and more, the standby power industry is seeing a trend moving away from diesel generators and into either straight natural gas or bi-fuel, which carries the benefits of both natural gas and diesel. Bi-fuel generators start on diesel and add natural gas as load is applied until the unit runs primarily on natural gas. If the natural gas supply is interrupted for any reason, the generator can run on 100% diesel fuel. The system will automatically and seamlessly switch to 100% diesel operation with no loss of power during the transition. Notably, this trend toward natural gas or bi-fuel-powered generators tends to be concentrated in areas where natural gas is more prevalent and considered reliable. For example, California is traditionally more reliant on diesel generators on account of a less developed natural gas distribution infrastructure. In the Northeast, where much of the area is granite, the distribution system is rapidly expanding, with new pipelines now delivering natural gas into the area from newly developed, nearby fuel sources. In places like the Midwest, where there are no fault lines or hazards, natural gas is very reliable and a feasible power source. Natural gas will continue to be more widely available throughout the country, particularly as utility companies switch from coal to natural gas for power generation and demand absolute reliability of the fuel supply. One of the biggest drivers for the move to natural gas or bi-fuel power is that companies are constantly being called upon to be more environmentally responsible. The market has shown significant interest toward products that burn inherently clean natural gas as an alternative to diesel solutions. Using natural gas-powered generators helps companies reduce their exhaust emissions and onsite diesel fuel storage. Bi-fuel generators are cleaner than diesel-only generators, typically using up to 75% of clean-burning natural gas, and emitting about 30% less nitrogen oxides and 50% less particulate matter. Also, the Environmental Protection Agency (EPA) prefers to minimize the amount of fuel onsite because there is always the potential for leakage or a spill. Deciphering The Code Certain national standards have been the driver for using diesel for backup power. The two standards that are most frequently referenced regarding standby power are National Fire Protection Association (NFPA) 110 and National Electric Code (NFPA 70/NEC). Specifically, NFPA 70 NEC 700.12(B)(2) states, “. . . an onsite fuel supply shall be provided with an on-premise fuel supply sufficient for not less than two hours’ full-demand operation of the system.” Historically, it’s understood that diesel is the only acceptable fuel supply to answer these standards, as it has long been considered a reliable source. In addition, the authorities having jurisdiction (AHJs), who often set requirements, typically lean toward diesel generators. However, both NEC700 and NFPA 110 offer provisions for the use of natural gas in standby power applications. Natural gas is increasingly reliable and can therefore meet the onsite fuel requirements for emergency systems. Less onsite diesel fuel typically means easier permitting and indoor fuel installations, with capacity limits per NFPA or local codes, become a viable option. It’s often misunderstood that natural gas, or bi-fuel generators, cannot be accepted by the AHJ. Those manufacturers that offer a bi-fuel option can work with local utility companies to obtain a natural gas outage report for the last five to 10 years to confirm reliability. The information is then presented to the AHJ, which has the power to approve the natural gas being an acceptable power source. Voluntary Movement There are numerous industries considered to be mission critical that have long required standby power, no matter the fuel source. Those industries include hospitals and healthcare systems, data and communications centers, and educational buildings greater than four stories. Many of these industries are considering, and even converting to, bi-fuel generators. For example, a Canadian telecommunications data center has converted to bi-fuel, using approximately 40 MW, to keep its data centers working seamlessly. In addition, to keep business viable and customers happy, other industries are starting to convert to bi-fuel standby power so that processes are not disrupted and products are not lost. Power outages can be extremely disruptive and costly for these companies, making optional standby power a smart business decision. Some examples of industries that are voluntarily converting to standby bi-fuel power include: • Pharmaceutical companies and drugstores that need to keep medicine cold, • Injection molding facilities that need to keep plastic flowing and machinery clean, and • Food packaging plants that need to keep processing food and saving perishables from going bad. Long List of Benefits Other benefits to using bi-fuel generators included extended runtimes and mitigating refueling issues by operating primarily on utility-supplied natural gas. The extended runtimes available with using natural gas are not possible with diesel generators. For example, a bi-fuel generator can take a one-day diesel fuel tank and turn it into a tank that will last three to four days. That means less onsite diesel fuel is required and less fuel will need to be cleaned. In addition, bi-fuel generators can be used in demand response applications, providing onsite power independent of the grid. This is a significant benefit during long-duration outages, which can span months. Historically, there have been very few outages in the natural gas distribution system. That system is less likely to be compromised during major disasters. The available large network for natural gas pipelines helps add resilience in the event of a limited failure. Natural gas and bi-fuel generators offer cost savings over diesel-powered gensets. For one, less diesel fuel needs to be stored in order for these generators to operate. Therefore, limited amounts of fuel need to be purchased. Installation, operational, and maintenance costs are all significantly reduced. Overall, natural gas costs less than diesel, helping to significantly reduce costs over the long term. Today, technological innovations are making natural gas or bi-fuel generators much more powerful units than older generators. These recent innovations include implementing high-kWE gaseous-fueled solutions and updates to the combustion process, maximizing the fuel that is being burned. These updates allow such generators to compete with their diesel-fueled counterparts on cost and power. One Option on The Market Generac’s bi-fuel products have a significant benefit over competitive gensets—they’re fully integrated solutions, meaning every component is specifically designed, engineered, and factory-validated to work together. No after-market, third-party conversions are needed. In addition, Generac’s offerings have the added benefits of being EPA-compliant from the factory and are under complete warranty. Lastly, Generac’s system is scalable, as the bi-fuel generators can be configured as part of a Modular Power System (MPS), which is connected via integrated paralleling with multiple Generac generators. For example, MPS units back each other up, as opposed to larger kW generators that don’t provide backups or allow for flexibility as the power needs of companies evolve. Bi-fuel: A Viable Option Bi-fuel generators are justly taking their place alongside diesel-run gensets as increasingly popular standby power options. When continuous operation is at stake, bi-fuel allows for the necessary seamless transition to backup power in an outage. With having the advantages of diesel generators—such as power and capital costs—bi-fuel options can also provide many additional benefits where diesel products can be lacking. This long list includes extended runtimes, high reliability, and cleaner-burning fuel. Bi-fuel is continuing to pave the way for backup power system improvements, while maintaining the dependability that has always been required. DE Mark Sweeney is the business manager for North-Central, Generac Industrial Power.
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