Why do I need an on-line UPS with my generator?
- Many times the generator will take a few minutes to start up when utility is lost.
The UPS supplies battery backup during that period of time for seamless power to the
connected load. To handle this situation, most any UPS type (off-line, line-interactive
or on-line) will probably work.
- Generators typically exhibit poor voltage regulation due to loads turning on and
off on the output of the generator. This affects the generator speed, which then
results in a change in its output voltage. Off-line UPS units are not acceptable for
this problem.
- Generators are also prone to poor frequency regulation due to loads turning on and
off on the output of the generator. This also causes the generator to change speed
which results in a change in its output frequency.
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(Generator Shown Without Tank)
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Bottom Line:
Only a true on-line UPS will protect against all three of these problems.
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SCOPE OF UTILITY DIESEL APPLICATIONS
Within the electric utility industry, diesels serve as prime power, standby power and
emergency power applications, ranging from 8 kW generators to 4000 kW power units.
- Diesel generators serve as backup power to nuclear power plants because of their
reliability. They are used to power critical systems and maintain plant safety in
emergencies.
- Portable rental power units have been used in disaster situations as a temporary
source of power, providing critical community services, thus saving lives.
- During preparations for the possible "Y2K computer problem," diesel generators
served as a critical backup power supply for individuals as well as businesses and
industry. It was almost impossible to find a generator for sale in some parts of the
country, as year-end 1999 approached.
- Coal-fired power plants also rely on diesels for materials handling - such as
conveyer equipment and heavy trucks.
REGULATIONS AND STANDARDS
As in many diesel applications, diesel engines used in the electric utility industry
are faced with emission challenges. Environmental benefits of diesels - such as low
greenhouse gas emissions - are balanced by concern with emission of nitrogen oxides and
diesel particulates. Increasingly tighter environmental regulations worldwide call for
advanced emission controls and near-zero diesel emission levels in the years to come.
In the United States, the USEPA has published regulations which impact diesel engine
emissions in the "non-road" category, which covers most heavy equipment, as well as for
stack emissions from power plants. The European Union and other countries are adopting
similar regulations.
Engine manufacturers and the utility industry are rising to these new challenges and
are already producing and designing engines and diesel generators to meet the US and
international regulations. The diesel industry has expressed confidence that the new
emissions standards can be met without disruptive impacts on the power output,
reliability, ease of maintenance and fuel economy of diesel engines.
EMISSION REDUCTIONS
EPA regulations are intended to reduce emissions of nitrous oxides (NOx), total
hydrocarbons (THC), carbon monoxide (CO) and particulate matter (PM). MARPOL
regulations are intended to reduce NOx and SOx emissions.
Engine manufacturers and suppliers are addressing the reduction of emissions through:
engine design, fuel and lubrication formulations, and exhaust aftertreatment.
Engine design enhancements include: compression chamber redesign; enhanced turbo
charging; common rail fuel injection; exhaust gas recirculation; water injection and
advanced electronic engine control systems.
The use of low-sulfur diesel fuel is one strategy designed to reduce emissions both
directly and by enabling exhaust aftertreatment. Other diesel fuel options include
raising the cetane number in diesel fuel; which improves the combustion process. New
lubricants that reduce friction thereby lowering emissions are another technique.
Exhaust aftertreatment consists of using catalytic converters and particulate traps to
control emissions after the combustion process.
ALTERNATIVE TO DIESEL ENGINES
In terms of power generation, diesel generators are one means to produce electricity.
Hydro-electric, nuclear power, various types of fossil fuel boilers, and alternative
technology such as wind and solar, make up the range of options being employed to meet
electric needs. But as noted, many of these power sources rely on diesel engines at
some point in their power production process. Diesel engines will continue to be an
integral part of the world power generation picture for the foreseeable future.
To help businesses protect critical facilities during a power outage, the Diesel
Technology Forum offers the following tips:
- Assess the Risk. Identifying your facility's critical loads is an important first
step. Assign a cost to the risks associated with utility power interruptions,
production losses and downtime.
- Install a standby generator. Frequent outages of a few seconds, a few minutes or
more can often disrupt production lines and have significant cost implications to
businesses. While other fuel sources take up to two minutes to engage, diesel-powered
standby generators are uniquely qualified to provide power quickly and continuously
during a power outage. And, the combination of greater fuel efficiency and lower fuel
costs for diesel generators means that they offer the most cost-effective source of
reliable backup power available.
- Have sufficient fuel storage. For extended outages, running out of generator fuel
before the outage is over may mean you're out of luck. The chemical structure of diesel
fuel allows more energy to be released per unit that any other source of commonly used
power. This greater power density means less fuel consumption than other sources. Still,
it is important to make sure that you have sufficient fuel storage capacity on-site for
an extended outage of several days. Additionally, diesel fuel degrades over time, so be
sure to use and replenish the supply on an annual basis.
- Maintain your equipment and exercise the standby generator monthly. As required by
electrical codes, standby generators should be "exercised" monthly to insure they will
operate as designed in the event of an emergency. Be sure to operate the generator
under load to make sure the entire system works, and keep up with recommended
maintenance procedures.
- Contract rental power. If installing your own standby generation is not feasible
for your business, you might consider contracting with a firm to reserve rental
generator power for use in the event of an extended outage. In the case of disaster,
it may be too late to secure rental power after the fact.
SUMMARY
Domestic and international emissions laws-along with advances in technology and
competition among engine suppliers-will continue to serve to reduce emissions while
maintaining diesel power as an important part of our total energy picture.
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