Innovation in Global Power - Parsons Brinckerhoff

Hydropower – New Technologies, New Considerations
The OASIS model and how it was used evolved during the
consultation process. Initially,Tapoco and the stakeholders
developed alternatives independent of the model and evaluated
the alternatives in an office setting. We first used the model
to simulate a “base case” condition, which was the Tapoco
project with current operating rules in effect. Next, we
simulated alternative operating scenarios and the results for
each alternative (estimated reservoir water levels, stream
flows, generation, and value of generation) were compared
to the base case.
As Tapoco moved into formal negotiations with stakeholders,
OASIS was used more in real-time discussions. During
negotiations, the stakeholders discussed the model results
and requested modifications to the alternatives. We made
modifications and ran OASIS real-time at meetings, and
presented and discussed the preliminary results. After the
meetings, we verified the preliminary results and obtained
final results. If there were any notable differences between
the two, then the final results were distributed to stakeholders
via e-mail within a few days. This approach kept the
pace moving quickly for all those involved in the
settlement process.
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Using OASIS to evaluate alternative operating scenarios in
a real-time environment proved to be key to reaching a
negotiated settlement between Tapoco and the stakeholder
coalitions. FERC issued a new license implementing the
agreement in January 2005. This license and the associated
settlement agreement were critical to Alcoa’s continued
operation of the smelter facility located at Alcoa,Tennessee.
Paul Shiers is a PB vice president with 38 years’ experience in hydroelectric
power and water resource engineering. He is qualified as an independent consultant
and PFMA facilitator for FERC Part 12 safety inspections under the new FERC
DSPMP requirements. He has served as project manager for multiple hydropower
projects, and completed an assignment as principal engineer for work performed
under a multi-year continuing services agreement with FERC as the senior technical
resource for hydro relicensing and compliance tasks.
Shirley Williamson is a senior supervising civil engineer with 29 years’ experience
in hydropower. She has been responsible for several NEPA-based environmental
assessments ranging in size from the 35-plant Tennessee Valley Authority system to
an individual 2.5 MW facility under FERC jurisdiction. In addition, Shirley has
developed and implemented reservoir operations studies, flood studies, and project
safety response plans and training programs for owners of hydroelectric facilities,
including interfacing with owners and public safety agency staff.
Chii-Ell Tsai is a supervising engineer with 44 years’ engineering experience.
His water resources activities have include: OASIS modeling; spillway adequacy
evaluation and stability analysis; water profiles and evaluation of power and
energy for a proposed hydroelectric project; the preparation of emergency action
plans for dam failure; and studies of energy consequences of modified reservoir
operation policies on generation.
Planning for Mini Hydro... (continued from page 26)
achieve. These suppliers are more than likely exaggerating
their machines’ capabilities. Unfortunately, efficiency claims
are difficult to verify before the asset is installed because
model efficiency tests are simply not cost effective for
machines of this capacity. Ideally, the supplier has either built
a turbine close to the head and flow available at the site
from which the efficiency can then be based on, or has completed
a model test of a similar turbine as part of the development
process. In any case, tenderers should be asked how
they derived the efficiency figures presented in the tender.
In most cases, verification to site efficiency test codes, such
as IEC600041, can occur only once the turbine is at site. The
measurement accuracy can be expected to be about 2 percent
at best. Compensation from the supplier for an underperforming
turbine will normally be capped at a maximum of 10 percent
of the value of the contract, which may not provide adequately
for the lost revenue over the life of the equipment. This point
further emphasises the need for caution when evaluating tenders.
Conclusions
Hydro is an essential part of the renewable generation mix of
the future, even though some consider it to be “old technology.”
As we know, planning is the key to the success of a project.
I hope this article has provided useful insight into the
development in small hydro.
Q and A
Question:
What measures were adopted in the selection of bidders,
specification or bid evaluation process to screen our
poor quality or performance?
John Wichall, Senior Consultant, PB Network Guest Technical Reviewer
Answer:
That is a bit of a complex subject to get into here,
as this topic could be an article in itself. As a minimum,
bid evaluation should focus on reputation, referees, technical
compliance with the specification, and performance
(weighted efficiency) of the turbine for the smallest turbines.
Then many other factors need to be considered, such as
long-term operating cost, non-price attributes etc.
Non-price attributes generally cause havoc with tender evaluation,
and I am a subscriber to the view that if you can’t ascribe
a value or potential value, then it should not be included
in your evaluation (e.g., no points system). The non-price attributes,
cost adjustments, plus the performance evaluation can be
added to the tender price to identify the “best” tender.
Tony Mulholland, a mechanical engineer who has been with PB for more than two
years, has played a key role in all phases of several mini-hydro facilities, being
involved in planning, design, and construction. He also has extensive experience in
other hydro-electric projects, and has a keen interest in renewable energy sources.
37 PB Network #68 / August 2008