POWER December 2014 - 26

Top planTs
Though there is clearly a need to diversify
Albanian generation resources, and efforts to
develop new thermal, wind, and solar capacity
are under way, the fact remains that the nation's
largest potential resource will remain
hydropower for the foreseeable future. Estimates
are that only 35% of its hydroelectric
potential has been exploited, but the delay in
bringing major hydroelectric projects online
is a deterrent.
Instead, since the late 2000s, Albania has
been focused on building small hydropower
plants under 100 MW, with about half the
capacity being built under foreign concessions.
Much of the initiative is intended to
increase generation capacity in the southern
end of the country, but it is also intended to
further exploit potential on the Drin River-
the nation's longest-where 95% of its capacity
is located.
The lowest dam on the Drin is at Vau
i Dejes, about five miles southeast of the
city of Shkoder, where a 250-MW hydroelectric
plant has operated since 1973. But
because the dam harnesses only part of the
Spathara Reservoir outflow, there remained
unexploited flow between the reservoir and
Lake Shkoder, where the Drin joins the Bojana
River.
1. Simple design. The Ashta project
uses an array of 45 Andritz Hydromatrix turbine
generators. These small modular units allow
quick addition of run-of-river generation to existing
watercourses with minimal site work.
Courtesy: Andritz (top), Energji Ashta (bottom)
Albanian officials had identified this
stretch of the Drin as a possible site for future
hydropower development in the 1990s,
but existing hydroelectric technology at
the time would not have resulted in an economic
project. Not until the development
of modern run-of-river generation technology
in the 2000s did the idea finally show
promise.
Filling a Need
In January 2008, the Albanian government
put out a call for tenders, and in September
signed a concession agreement with Austrian
firms Verbund and EVN. Verbund is
one of the largest hydropower producers in
Europe, and EVN also has substantial hydroelectric
assets. The €160 million deal
was the first large-scale hydropower plant
concession contract in Albania signed with
a foreign firm.
Under the agreement, the plant would be
owned 50/50 by Verbund and EVN. All of
the power would be purchased by the staterun
Albanian electricity company Korporata
Elektroenergjetike Shqiptare (KESH)
under a 15-year contract. After the expiration
of the power purchase agreement, the
term can be extended or, if not extended,
the power can be sold on the open market.
After 35 years, the facility will revert to the
Albanian government.
Verbund and EVN formed a joint venture
company, Energji Ashta, to oversee the project.
Permitting was completed in less than a
year. Ground was broken in May 2009, with
formal construction beginning in March
2010. Full project financing was completed
in December.
The Ashta Hydropower Plant was built in
two phases. Ashta 1 was built below the existing
plant, at the bottom of the reservoir's
effluent weir. Ashta 2 was built 5 kilometers
downstream. To minimize impact on the local
watershed, the plants were not built across the
existing river; instead, a lined headrace channel
was built parallel to the riverbed. Below
Ashta 2, a tailrace channel eventually rejoins
the river.
Because the site could not have been
economically developed using conventional
hydroelectric turbine technology, the innovative
design instead employed modular
Hydromatrix turbine generators from Andritz
(Figure 1). The Hydromatrix is an axial-type
propeller turbine using a bulb-style,
synchronous, permanent-magnet generator.
These compact turbines enable the use of
slower currents and lower heads: Ashta 1
has a head of 4.98 meters while Ashta 2 has
a head of 7.53 meters.
Hydromatrix turbines are shipped as
prefabricated modules, each comprising a
26
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single turbine generator, allowing them to
be installed directly into an existing watercourse
with minimal site work.
Each phase of Ashta employed 45 of them,
making Ashta the largest Hydromatrix-based
plant ever built. As installed, each Hydromatrix
turbine can be taken in or out of service
individually, or raised out of the water for
maintenance, without affecting operation of
the other units.
The first turbine was installed in August
2011, with the channel completed and
flooded the following April. Test operations
started thereafter, with the first electricity
fed to the grid in June 2012. Ashta 1 was
completed and inaugurated in September,
with Ashta 2 commissioned the following
March. The project officially began supplying
power to KESH in April 2013, with final
completion declared in July-a rapid pace
of less than three years from start of construction
to operation. Total project cost was
just over €200 million.
Environmentally Friendly
The Ashta project was constructed to comply
with the requirements of the Clean Development
Mechanism (CDM) under the
United Nations (UN) Framework Convention
on Climate Change, and was registered
and approved for the CDM in August 2012.
According to the UN, the CDM allows
emission-reduction projects in developing
countries to earn certified emission reduction
credits, each equivalent to 1 metric
ton of CO2. These credits can be traded
and sold, and used by industrialized countries
to meet a part of their emission reduction
targets under the Kyoto Protocol. The
mechanism is designed to foster sustainable
development and emission reductions, while
giving industrialized countries flexibility in
meeting emission reduction targets. Ashta is
certified to avoid 78,989 metric tons of CO2
annually.
The project also added a fish bypass to the
Spathara Reservoir, allowing fish from the
Adriatic to reach the reservoir for the first
time since the Vau i Dejes hydroelectric plant
was built in the 1970s. This is the first fish
bypass installed on any of the hydroelectric
plants in Albania.
In its first year of operation ending in
March 2014, Ashta generated a total of 267
GWh, exceeding its projected average by
11%. It has also experienced no lost-time accidents
or unplanned outages.
For demonstrating the speed of development
and possibilities of modern run-of-river
hydroelectric generation, Ashta is a worthy
POWER Top Plant. ■
-Thomas W. Overton, JD is a POWER
associate editor.
POWER | December 2014
http://www.powermag.com
POWER December 2014

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