The main
advantages of using diesel driven electrical power generators are (not in rank
order):
1. Performance. Diesel engines normally have high thermal efficiencies,
in the region of 40% and higher, almost regardless of their size. Some current
state-of-the-art engines can achieve efficiencies over 50%, and engine manufacturers
have forecast efficiencies as high as 60% by the twenty-first century.
2. Maintenance. Diesels represent mature and well-developed
technology and are comparatively easy to maintain on site without the need for
fully skilled personnel except for certain nonroutine tasks.
3. Durability
and Reliability. Diesels have long lifetimes
in the range, on average, of at least 20 to 25 years, and they can operate 7000
to 8000 h per year and in some cases up to 12,000 h between regular major
overhauls.
4. Fuel
Efficiency. In most power-generation
applications, diesels have the most competitive fuel consumption rates, and
between half-load and full-load their fuel consumption rate is reasonably
constant. Depending upon the application, size of engine, loading, and the operating
environment, diesel engines normally have a specific fuel consumption in the
range 160 to 360 g/kWh. The new Sulzer Diesel RTA two-stroke engines are
claimed to be able to produce up to 35,431 kW (47,520 bhp) with a specific fuel
consumption as low as 154 g/kWh (115 g/bhp).
5. Transportability. Diesel-generators can be transported on
purpose-built trucks or in specially equipped containers by land, sea, or air
so that they can be used immediately on arriving on-site even in remote areas. For
their physical weight and size, they can generate large amounts of electrical
energy, sufficient to supply a small town.
6. Cost. The cost per unit power installed is very
competitive, but it must be emphasized that in costing diesel-power generation
it is crucial to determine the total installed costs, not simply the capital
cost of the engine and the generator. As a general rule of thumb, the speed of
crankshaft rotation basically determines the weight, size, and cost of an
engine in relation to its output power.
7. Operational
Flexibility. Diesels can use a wide
variety of fuel quality and can be designed to use both liquid and gaseous
fuels; that is, they are ‘‘dual–fuel’’ engines. They can also be adopted for
use in cogeneration and total-energy systems and in ‘‘non-air’’ environments.
8. Environmentally
Compliant. Diesels inherently produce
low amounts of harmful exhaust emissions. However, in recent years, engines
have had to be redesigned and exhaust-emissions treatment systems upgraded to meet
increasingly stringent regulations. It is certain that further advances in the
efficacy of emission reduction techniques will be required for all fossil-fuel
power systems in the future.
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