4. Case study
This case study refers to the refurbishment and uprating of
Chabba project commissioned in the tributary of river Sutlej known
as Nauty Khad in District Shimla of Himachal Pradesh in India. The
Chabba Hydro Project has been commissioned by Col. B.C. Battye, to
provide electricity to the then summer capital of India, Shimla,
bayback in 1913e14. The plant capacity is 1.750 MW consisting of
two machines of 500 KW each and 3 machines of 250 KW each.
Since its commissioning, the plant is still running without any
major renovation, refurbishment and uprating. Though there is a
clear provision for one more generator-turbine set to be installed in
power house with available hole drilled on power house floor,
tailrace provision and penstock way with supports, but it has not
been installed till date. In spite of tremendous strides in technology
since last hundred years, the power plant is still running with old
class B insulation in generators, electromechanical governors and
with manual (hand operated) governors. This project in fact holds a
number of options for refurbishment and uprating. To meet this
end, fresh hydrological studies have been conducted as the stream
flow pattern since then has changed, with a few small streams
merging with main Nauty stream but water not being utilized. So,
three options of refurbishment and uprating have been analyzed in
this finding with their economic analysis.