ADVANCED REPAIRS MEAN
IMPROVED EFFICIENCY AND
LONGEVITY FOR HYDRO
POwER SYSTEMS
A
n increased focus on
controlling greenhouse
gas emissions, coupled
with escalating demand for
electricity and slow progress on nuclear
projects is leading to an expansion of
alternative renewable energy sources.
Leading the pack at the moment is
hydro electricity, the basic principles of
which were commercialised in the late
1880’s and now accounts for around
16% of global electricity generation
capacity.
One of the advantages of Hydro-power
is actually the age of its base level
technology; as a mature generation
method, the equipment is tried and
tested and although a large proportion
of it is due for refurbishment, it means
that refinements in materials and
manufacturing techniques can be
applied to existing installations.
Improved generation efficiency and
longevity can now be built-in during
routine maintenance, delivering 10%
increases in power output from the
same source, without re-investing
in replacement hardware, surely a
massive win-win for the industry. It
should be noted that not all repairers
offer the same level of service
32
PECM Issue 14
and expertise, so hydro generator
operators need to choose carefully.
Installed base
The variety of plants is huge, from the
smallest Pelton wheel to the largest
hydroelectric power station in the
world, the 22,500MW Three Gorges
Dam in China. However, the principle
remains the same, using flowing
water to turn a turbine and generate
electricity. The key to a successful
installation is efficiency and reliability,
both of which are benefitting from the
latest technological advancements in
the sector.
In recent years, many hydro projects
have begun operating in ways not
envisioned during their original design
and new installations have been
made possible through improvements
in technology. Of course, work
is still needed to determine how
equipment can be improved through
new materials technology as well
as identifying actions and tools for
predicting and preventing failures.
Turbine technology
As hydropower increases in
popularity so the demand for new
installations grows. Thanks to
ABOVE
As part of a generator
refurbishment, it
is essential that
inspection and tests
be carried out on the
stator core and rotor
inherent shortcomings with traditional
technology, it may not be suitable
to meet these demands in some
locations, such as those with large
fish populations. Here, development
programmes, such as the Alden turbine
project, have produced new designs
that significantly improve the mortality
rate of fish travelling downstream while
also improving generating efficiency.
Improved generation
efficiency and
longevity can now be
built-in during routine
maintenance
Hydro turbine research has also
produced a new fish-friendly design
criteria for Kaplan and Francis turbines
that can be incorporated either into
units during rebuild projects or in new
hydroelectric facilities. In the USA,
the Department of Energy (DOE) has
implemented a new hydro programme
called “The Advanced Hydropower