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Vietnam is among the South-Asian regions the one that better supplies remote areas. However, many islands and remote areas are still not connected to the main grid and this fact jeopardizes their development, while forcing people to move to urban areas. With a high potential from renewable energy sources and a lot of islands, Vietnam has thus many favorable environmental features for developing the microgrids technology. In this chapter, a detailed analysis about opportunities and challenges for widespread deployment of microgrids technology in Vietnam is considered. Such analysis is based on the assessments of the potential from renewable energy sources in the country and of the national policy framework for the development of renewable energy sources. In the application section, results from the test of improved optimized control strategies to one microgrid system are presented. The results show that such cutting-edge technologies can improve the applicability of the microgrid technology thus reducing its Return on Investment cost.

Under non-homogeneous solar irradiation, photovoltaic (PV) panels receive different solar irradiance, resulting in a decrease in efficiency of the PV generation system. There are a few technical options to fix this issue that goes under the name of mismatch. One of these is the reconfiguration of the PV generation system, namely changing the connections of the PV panels from the initial configuration to the optimal one. Such technique has been widely considered for small systems, due to the excessive number of required switches. In this paper, the authors propose a new method for increasing the efficiency of large PV systems under non-homogeneous solar irradiation using Series-Parallel (SP) topology. In the first part of the paper, the authors propose a method containing two key points: a switching matrix to change the connection of PV panels based on SP topology and the proof that the SP-based reconfiguration method can increase the efficiency of the photovoltaic system up to 50%. In the second part, the authors propose the extension of the method proposed in the first part to improve the efficiency of large solar generation systems by means of a two-levels architecture to minimize the cost of fabrication of the switching matrix.

In the Vietnamese Mekong Delta (VMD), river beds have been degraded and salinity intrusion has been increased. Hydro-, sediment and salinity dynamics modelling of a complex river network in the VMD requires detailed bathymetric, turbidity, and salinity data. Therefore, we conducted two field surveys in the flood and dry seasons of 2017-2018 to measure river bed elevations, turbidity and salinity concentrations along Tien and Hau Rivers due to lacking of homogeneous data available in the delta. The results show that thse rivers can be divided into upper and lower reaches according to the variations of river bed elevation, turbidity, and velocity. These parameters are high in the upper reach, decreased seaward while low in the lower reach, increased seaward. The beds of Tien and Hau Rivers have been significantly degraded due to upstream dam developments with a rapid rate recently. Salinity intrusion varies seasonally. Horizontally, high salinity concentrations appear in the middle of the river. Vertically, salinity concentrations are almost the same near the banks but markedly increase downward in the middle of the river.

Since the end of 2015, salinity intrusion and drought of different degrees hit the Vietnamese Mekong Delta (VMD). Between March and April 2016, China increased the released outflow discharges from Jinghong Hydropower station to the downstream reach of the Mekong River, following Vietnamese request after the worst drought event over the last 90 years. The released flow may mitigate the drought and high salinity intrusion occurred in several provinces in the VMD. This research aims at summarizing some damages information caused by drought event 2015-2016 and figuring out some possible impacts of six existed and eleven proposed dams in the mainstream Mekong River on the VMD. Water levels in the period of 2012-2015 is about 1m lower and two months shorter than that in period 1993-2001. This leads to salinity concentration increasing about 10-15 g/l in some locations. The timing and duration of salinity levels of the VMD at post-dam periods is shifted about 1 month earlier than pre-dam period. Eleven proposed mainstream dams along with 47 cm sea level rise will lead to a maximum reduction of about 15% and a maximum water level increase of approx. 220% in the VMD.

This paper uses recurrent neural network (Long Short – Term Memory - LSTM network) to build a model to forecast short-term generation capacity of Phong Dien solar power plant, (48 MWp – 35 MWAC) located in Thua Thien Hue Province, Viet Nam, with input factors including meteorological parameters. The authors conducted experiments to find the optimal structure of the model corresponding to the conditions of the plant and the data collection. Through this model, meteorological forecast data sets from commercial suppliers were used to forecast the plant's output power. The comments about the result as well as the further study direction are analysed and suggested.