As researchers in the field of engineering, there is always some intrigue and fascination in what we find either by accident or by discovery regarding the abundance of free energy sources in our environment which can be harnessed to serve some useful purpose.
It takes a bit of imagination combined with our sense for creativity and ingenuity to innovate technologies that have lasting, beneficial impact on human society. Our desire to extract the free energy, however, must be perceived in ways that will not disturb or degrade the natural environment. The primary focus must be on preservation with a deep commitment towards uplifting the living standards of human society.
Ram Prasad came to Vietnam as a U.S. Fulbright scholar with the goal of teaching a course on energy harvesting at Ho Chi Minh University of Technology. Knowing that Vietnam is a country rich in hydropower resources, Ram had a passion to find novel approaches to harvest the vast amount of energy without causing any detrimental environmental impact.
This passion was driven by the needs of underprivileged people living in areas such as the Mekong River Delta in the South, and tribal people living in the mountainous regions of the Central Highlands and far North. The low cost of hydropower generation and the services it can provide could benefit societies that are far removed from conventional energy resources and power transmission facilities.
Possibilities for developing autonomous energy farms give rise to the potential for serving the power needs of communities that are remotely located and isolated, adding towards a better understanding and appreciation for building self-sustainable environments.
From the Red River in the North to the Mekong River in the South, all rivers crossing Vietnam’s borders with China, Laos and Cambodia, flow through Vietnam and drain into the Gulf of Tonkin, the East Sea, and the Gulf of Thailand. The steep drop in elevation from the mountainous regions of the West to sea-level in the East across a narrow landmass vividly portrays the rich hydro potential of Vietnam.
The richness of a long coastline makes it possible to harvest tidal, wave and wind energy. The high mountainous regions of Lai Chau and Dien Bien Phu with perennial streams, mountain waterfalls, and the extensive network of interconnected step-irrigation canals in Sapa provide a rich backdrop of a natural, renewable energy resource for energy harvesting in Vietnam.
The rich natural energy in Vietnam described above isembodied in a late 19th century brush-and-ink and watercolor painting. No words could describe the beauty encapsulated in the painting and the inspiration it provides to conceive and develop a technology for hydropower harvesting.
Nourished by a labyrinth of large rivers from the North to the South, the anatomy of Vietnam’s mythical bird, the Phoenix, stands out as a symbol of Vietnam’s strength to meet 21st century energy challenges.
Brazen and ill-conceived use of any technology to harvest energy from natural resources will undoubtedly cause adverse impact. In Vietnam, as in many other Southeast Asian countries where there is enormous amount of hydropower resources, reckless use of conventional hydropower technologies has resulted in the construction of dams that have severely affected the ecology and biodiversity of large regions of land. Because of this, the natural environment has been altered and in most cases destroyed. The impact on local economies has been devastating.
(Left) Shows the possibility for hydrokinetic power harvesting with a few harvesters.
(Right) Shows the possibility for hydro-potential power harvesting with many harvesters.
As such, there is considerable skepticism on the part of local residents towards government’s efforts to harness the energy from water resources. Rightfully, therefore, many hydropower projects have been stalled or even stopped because of the environmental damage caused. Yet, there is a need for electric power which can be beneficial to the society in a multitude of different ways. The question, therefore, is what can be done to utilize the natural energy in ways that have no effect on the environment. How do we develop a technology that would appear to be part of the natural environment and serve the needs of society?
Presently under development in the U.S. through a U.S. Department of Energy research contract, a revolutionary micro-turbine has been conceived that enables harvesting the hydro-kinetic and hydro-potential power in ways that can maximize the generating capacity at a specified location. It is a scalable technology that has immense potential to harvest the unused power from run-of-river water flow, and a wide range of other low-head flow systems. Possibilities also exist for harvesting power from sewage-flow and urban water supply systems.
The technology concept is based upon a fundamental fact that anything in motion expends energy. This fact allows harvesters to extract a portion of the energy without causing degradation to the environment. Special guards placed at the inlet of the harvesters prevent fish, and other natural water-borne elements from entering the turbine cavity. The harvester can be easily manufactured, assembled and deployed to sites along with a minimum amount of mechanical and electrical infrastructure needed to transport electric power to local load centers. The shape and form of the harvester can be easily modified to blend-in with the environment. For example, modern manufacturing techniques allow the fabrication of highly durable plastic moldings that can closely mimic natural rock formations. As such, if the exterior surface of the harvester is formed out of the imitation rock moldings the harvester would be unrecognizable when used in environments that are sensitive to natural aesthetic appearance. The technology is easily adaptable to any water-flow system because of its scalable attributes.
As a developing nation, Vietnam has immense potential to become a leader in Science and Technology and a significant contributor towards developing revolutionary energy harvesting technologies. Harvesting power from low-head hydro resources will provide a strong basis towards strengthening the power generation infrastructure in Vietnam, and elsewhere, through environmentally benign technologies. Ram Prasad