Strategies for harvesting large scale bulk energy from the Congo river without a conventional dam
The paper provides a summary of the investigations into the capability of the Congo river to support an evolutionary design approach based on the run of river, low head, and hydro-electric generation technology, as employed at the existing Inga 2 power station in the Democratic Republic of Congo. The evolutionary approach builds on existing infrastructure. The results show that the footprint is much smaller. The environmental impact is minimized. These collectively will contribute to lower capital costs. In summary, 10,000 cm3/sec of constant river flow will produce 5,000 MW of base power. On average, the constant recorded flow of the river is 30,000 cm3/sec and a total of 15,000 MW of base power generation is possible.
Africa—Integrated gas and electricity transmission planning in power generation and HVDC engineering in harnessing large-scale hydroelectric sites for interconnected regional power systems
This Paper discusses integrated gas and electricity transmission planning in power generation and energy development in Africa with their benefits, and developments in HVDC Engineering Technology in harnessing large-scale hydroelectric sites for interconnected regional power systems. It focuses on the present status and future prospect of electricity infrastructure from the viewpoint of generation and transmission development, policies and lessons from global deregulation, advances in global research, and development (R&D) and strategies to influence Africa’s integration into the Global transition to knowledge-based economies. It examines regional power pools as an economic development paradigm by emphasizing the systems effects that lead to improving economical, ecological and technological efficiencies by the joint operation of power systems.The paper goes on to discuss the energy crisis and development issues in Africa (strategic diagonal and convergent approach with components), the Southern African power pool development plan, and the Southern African short-term energy market. Active projects such as the Westcor project representing an initial phase of the large regional South African Power Pool are also discussed. The project showcases the new milestones in HVDC technology used to harness large hydro potential contributing to the pool. Also discussed is interconnection of the Gulf States that will facilitate reserve sharing between the systems and electricity trading between the Gulf States.
Velocity moments in alongshore bottom stress parameterizations
The time-averaged alongshore bottom stress is an important component of nearshore circulation models. In a widely accepted formulation the bottom stress is proportional to , the time average of the product of the instantaneous velocity magnitude |u→| and the instantaneous alongshore velocity component υ. Both mean and fluctuating (owing to random, directionally spread waves) velocities contribute to . Direct estimation of requires a more detailed specification of the velocity field than is usually available, so the term is parameterized. Here direct estimates of based on time series of near-bottom currents observed between the shoreline and 8-m water depth are used to test the accuracy of parameterizations. Common parameterizations that are linear in the mean alongshore current significantly underestimate for moderately strong alongshore currents, resulting in overestimation of a drag coefficient determined by fitting modeled (with a linearized bottom stress) to observed alongshore currents. A parameterization based on a joint-Gaussian velocity field with the observed velocity statistics gives excellent overall agreement with the directly estimated and allows analytic investigation of the statistical properties of the velocity field that govern . Except for the weakest flows, depends strongly on the mean alongshore current and the total velocity variance but depends only weakly on the mean wave angle, wave directional spread, and mean cross-shore current. Several other nonlinear parameterizations of are shown to be more accurate than the linear parameterizations and are adequate for many modeling purposes.