||Conventional energy generation techniques such as coal and oil power plants release
large amounts of greenhouse gases (GHGs) due to fossil fuel combustion while renewable
energy sources, particularly, hydroelectric generation, are considered as climate-benign
since they do not emit fossil carbon to produce energy. However, dams and their associated
reservoirs are not entirely GHG-neutral and their emissions need further investigation.
In particular, reservoirs contribute to a major source of methane emission owning
to the energy and material input in the construction and the decommissioning phase
as well as the anaerobic decomposition of flooded biomass in the operation phase.
This master’s project evaluates the greenhouse gas (GHG) emissions associated with
Nam Theun 2 hydroelectric power plant in central Laos. A life cycle perspective is
coupled with two Monte Carlo Simulations and time-specific global warming potential
(GWP) for methane, all to predict the statistically most likely 100-yr GWP of Nam
The stochastic models indicate GHG emissions of 2.5±0.5 gCO2 eq/kWh GWP in the construction
phase, 75±5 gCO2 eq/kWh GWP in the operation phase and 0.60±0.05 gCO2 eq/kWh GWP in
the decommissioning phase. The operation phase emission estimation is larger than
previously believed (around 10 gCO2 eq/kWh for hydropower) due to the accounting for
biomass decomposition. However, the hydropower plant is still significantly lower
than the lifetime GWP of a typical coal plant (800-1000 gCO2 eq/kWh).
A literature review on the topic of reservoir GHG emissions is conducted, an introduction
of the Nam Theun 2 project is presented and GHG mitigation recommendations are provided
for various stages of a dam’s life.