Hydroelectricity: New mission from controversial energy source 16:30                                    Despite its long history, hydroelectricity and its sustainable development have always been a matter of controversy.  Despite its long history, hydroelectricity and its sustainable development have always been a matter of controversy. But in the future, hydropower will still be the world's largest source of renewable electricity generation, and will play an important role in reducing carbon emissions and improving the flexibility of the power system. In addition to new projects, countries will invest in expanding existing plants and types of stored hydroelectricity.   Over the past decades, Vietnam has made good use of this energy source. The period from 1995 to 2005 was the peak of hydropower development in many countries. In Vietnam, many hydropower projects were built and put into operation, including large and multi-purpose hydropower projects like Ialy Hydroelectricity, Ham Thuan - Da Mi Hydroelectricity, Se San 3 Hydroelectricity, and Tuyen Quang Hydroelectricity, among others. Since 2006, the largest hydropower projects of Vietnam were built, including Son La Hydroelectricity (2,400 MW), Lai Chau Hydropower (1,200 MW) and Huoi Quang Hydropower (560 MW). According to the Ministry of Industry and Trade, in many cases, the growth of hydroelectricity has been facilitated by renewable energy development. As a result, over the past two decades, global hydropower capacity has increased by 55% and electricity generated from hydroelectricity has risen by 21%. Advantages and disadvantages of hydroelectricity According to the International Energy Agency, global hydropower capacity in 2050 will reach 2,000 GW, with output to double the current level, to about 7,000 TWh. Contributions will come mainly from emerging and developing economies. In the next two decades, to meet the sustainable development goals in the energy industry, including the 2oC reduction target under the Paris Agreement, the additional hydropower capacity will rise by about 800 GW. East Asia and the Pacific are the leading regions for hydropower development in the future, especially China. According to China's plan, by 2050 the total installed capacity of hydropower will be 660 GW, equivalent to one-third of global capacity, with an estimated output of 2190 TWh. Another country with a high output of hydroelectricity is Brazil. Currently, hydroelectricity accounts for more than 64% of the total electricity output in the country. Within the next 10 years, about 44 GW of hydropower will be available in the Amazon River region. India is the world's 7th largest hydroelectricity producing country, and ranks 4th in the world for hydropower potential with about 148.7 GW untapped. However, India's potential is mainly small hydroelectricity, which accounts for more than 70% of the total estimated potential. Regarding the future development of hydropower, the Indian government has committed 40% of the total capacity of the system to come from clean energy sources. Thus, there will be about 20 GW of hydroelectricity that need to be built in the next 12-13 years. According to the US Energy Agency, the US could add 50 GW of hydropower between now and 2050, another 6.3 GW will be added to the system through upgrade and expansion of hydro projects and existing plants, which includes the restoration of decommissioned hydroelectricity plants. Vietnam leads Southeast Asia in hydroelectricity In Southeast Asia, Vietnam currently takes the lead in hydropower but its large hydropower potential has almost reached the limit. Laos and Myanmar will be new potential destinations to attract IPP capital sources for hydropower. The estimated hydropower potential in Laos is up to 18 GW, while it is 108 GW for in Myanmar. Small and micro-hydroelectricity is also a concern of ASEAN countries, especially countries with areas fragmented by oceans and many rivers and streams. Indonesia is currently investing in small off-grid hydropower to improve electricity shortages in remote areas. Similarly, in the Philippines, projects with a capacity of less than 1 MW only take about six months to build are the focus. According to the Vietnamese Ministry of Industry and Trade, the economic and technical potential of medium and large hydroelectricity in Vietnam is about 75-80 billion kWh, equivalent to about 20,000 MW of installed capacity. Vietnam's total medium and large hydropower capacity built by 2019 was about 17,930 MW. Most of the remaining capacity has been invested in and is in the pre-construction stage or under construction. In the period of 2020-2025, the country’s power system can add about 1,840MW from medium and large hydroelectricity plants (including expanded projects such as Hoa Binh, Yaly, Tri An). Small hydropower projects would contribute an additional 2,700MW in the period up to 2030. In addition to conventional hydropower sources, Vietnam has the potential to build stored hydroelectric power sources. According to a study by the Japan International Cooperation Agency (JICA) entitled “Study on the master plan of stored hydroelectricity and optimization of power generation in Vietnam” in 2004, from 38 potential locations, the report selected 10 locations that can be developed under criteria such as construction cost, distance to grid connection, distance to protected areas, with eight locations in the North and two sites in the South. The Ministry of Industry and Trade said that hydropower would continue to play an important role in the clean energy transition in Vietnam by providing cost-effective, low-carbon electricity and production services and improve reliability of the power system. VNN