From the results above, we can suggest that Vietnam is able to supply demand at all times in the six scenarios and there will be no issues relating to loss of load. However, there are still large issues concerning curtailment. The subsections below highlight the main insights from this study’s results and potential policy recommendations to initiate and sustain the optimal energy pathway.
4.1. Main Insights
The analysis of power system flexibility of six different scenarios highlights five main findings: (1) hydropower is capable of being baseload; (2) renewable energy will support Vietnam achieve its climate goals; (3) as VRE installed capacity increases, VRE curtailment increases; (4) flexible electric vehicle charging will be useful in addressing curtailment; (5) utilization of sustainable biomass may be beneficial to lower levels of VRE, and therefore curtailment from VRE. The paragraphs below explain the main insights in detail.
In all scenarios, hydropower can be the backbone of the electric grid. This pairs well with Vietnam’s geographical location at the Lower Mekong region and will provide stable and secure energy, whilst contributing to a net zero future. The uptake of solar and wind power is also expected to minimize carbon emissions greatly, therefore, future energy plans should incorporate such technologies to achieve the nation’s climate commitments and avoid the risks of climate change.
However, VRE curtailment increases rapidly as VRE installed capacity increases. As shown in Fig. 9, curtailment is first seen when the VRE electricity generation share is 97%. At a VRE electricity generation share of 83%, curtailment is still negligible. Therefore, there may be scope to increase VRE generation share between 83% and 97% without causing curtailment. Nonetheless, curtailment may be a pressing issue when striving towards a net zero future. In this study, Vietnam is also modelled as a single node (i.e., with no transmission networks) due to lack of data. Thus, curtailment due to transmission congestion may appear at lower VRE penetration than what is presented in this analysis. If transmission capacity is expanded to avoid congestion, results are not likely to change using a multi-node model.
The incorporation of unidirectional EV charging installed in the system greatly reduces the expected VRE curtailment, as seen in the PDP8 (draft), REDS, and RLP scenarios (Fig. 11). In these scenarios, the demand of EV charging to address curtailment increases each year, with a large jump between 2030 and 2040. Thus, this implies that there is an upward trend of installing charging stations and implementing EVs around Vietnam, with largest growth being in the decade of 2030–2040. Incorporating EV charging will also require battery storage technologies, to allow a flexible charging schedule throughout the day. With the addition of EVs on the road, Vietnam will also emit less CO2 emissions and air pollution will decrease, improving society’s health in the country. This could avoid 60,000 deaths from air pollution each year (Tran 2018), a reduction in life expectancy by one year, and a loss of 5% of GDP per year (Thang 2020).
Although flexible EV charging can contribute to a balanced power system, this infrastructure may need to be paired with other sector coupling technologies such as pumped hydro, heat pumps, hydrogen, and demand response to address large curtailment as seen in the NZ and CET scenarios. As shown in the CET scenario in 2025, sustainable biomass can also be utilized more to diminish the amount of VRE to around 83–97%, where curtailment is negligible (Fig. 10). In this study, FlexTool is given the choice to pick any power technology, and so it chooses to utilize only minimal amounts of biomass power when generating results (Table 9). Thus, future studies should ‘force’ investment and utilization into biomass, which may help with the existing curtailment issues.
Table 9
Biomass capacity and utilization in the NZ and CET scenarios.
| | 2025 | 2030 | 2040 | 2050 |
NZ | Capacity (MW) | 255 | 255 | 0 | 0 |
Utilization (%) | 1.7 | 0.6715 | 0 | 0 |
VRE share (% of annual demand) | 97.06 | 95.11 | 102.9 | 102.6 |
Curtailment (% of VRE gen.) | 25.69 | 86.43 | 206.1 | 285.3 |
CET | Capacity (MW) | 15,849 | 17,361 | 32,867 | 69,043 |
Utilization (%) | 21.48 | 0.3453 | 0.2232 | 0.5944 |
VRE share (% of annual demand) | 83.08 | 104.6 | 102.6 | 101 |
Curtailment (% of VRE gen.) | 0.2003 | 112.6 | 141 | 110.5 |
4.2. Policy Recommendations
Renewable Energy Prioritization
Renewable energy is suggested to be prioritized in the final PDP8 with long-term plans and targets, due to its climate and energy security benefits. To achieve this, the market should be reformed so that international investors and developers can contribute to the expansion of renewable energy with ease. Introducing international standard bankable PPAs should be adopted to support this. Tariffs should also be cost-reflective, subsidies should be explicit and transparent, and a future price plan should be adopted following this. Lengthy processes for renewable energy development should be modified to provide a straightforward, one-stop shop where developers have a single point of contact. Additionally, developers should be exposed to competition to further drive capital and O&M prices down, thereby reducing the overall energy system costs. The current feed-in-tariff in the country could also be expanded to include renewable electricity generation from homes, thereby encouraging the uptake of rooftop solar PV and overall renewables generation. The multiple benefits of renewable energy including health and climate should be advertised in local communities and at the stakeholder level to ensure acceptance. Vietnam could also consider implementing environmental studies into the national school curriculum to ensure a future generation of renewables skills and knowledge.
Push for Sustainable Biomass
To avoid excess curtailment via a rapid uptake of VRE, sustainable biomass can be utilized. This will ensure there is a balanced power system, whilst minimizing carbon emissions. Sustainable biomass in the energy system should therefore be highlighted in the final PDP8, with long-term plans and targets on how much of the system can be supplied by biomass, and where to obtain sustainable biomass. International organization GIZ noted that Vietnam has a “strong potential for bioenergy as the available biomass resources in the country include post-harvesting and post-processing agroforest residues and waste such as bagasse, straw, rice husks, coffee husks, coir, wood residues and other agricultural/industrial by-products” (Moore, n.d.). A challenge to incorporate sustainable biomass into the energy system is that investors are not aware of the complete potential and feasibility of sustainable biomass projects. Thus, to overcome this, the nation may promote datasets, academic journals, organizational reports, and life-cycle assessments to raise awareness of the multiple benefits sustainable biomass energy has, including its role as an intermediate baseload, net zero enabler, and curtailment avoider. Adopting sustainable biomass via the agroforest waste mentioned above will also encourage Vietnam to incorporate a zero-waste, circular economy approach. Lastly, to aid the investment of sustainable bioenergy, capacity of provincial governments may increase for timely planning and licensing procedures.
Uptake of Electric Vehicles
Unidirectional EV charging could be incorporated to address the large amounts of curtailment with increasing VRE share. To initiate this uptake, public city fleets could be electrified to accelerate the EV market. A long-term plan for EVs and a definitive end date for internal combustion engines could be developed and noted in the final PDP8 to support this. Financial incentives may also be adopted to encourage uptake of EVs, until they reach the same level of competition with ICE vehicles. Focus should also be on electric motorbikes, Vietnam’s main mode of transport, as the country has one of the highest motorbikes to people ratios in the world. As of x, Vietnam has 3.6 million automobiles and 58 million motorbikes, and this is expected to increase (Thang 2020). Thus, the production of electric motorbikes should be rapid to reach this level and affordable for everyone to transition to and incorporate into daily life. To facilitate rapid uptake of electric motorbikes in society, the long-term economic and health benefits should be publicized.
Adoption of Battery Storage
As seen in Fig. 12, battery storage is used throughout the week for flexible EV charging. Thus, battery storage is suggested to be implemented to allow a flexible, unidirectional charging schedule for EV vehicles throughout the country. To accelerate the battery storage production, a government fund could be set up to award projects that are developing innovative energy storage technologies. Developing a government-backed competition may increase the awareness of storage technologies, as well as drive the market. A long-term plan and targets for storage implementation in the country, which could be detailed out in the final PDP8, may also be beneficial. This recommendation may also allow Vietnam to explore different benefits and applications for stored energy outside of the EV charging system. For example, excess energy stored in the nation can be sold internally or externally, helping shape market design for things like ancillary services and price arbitrage.
4.3. Areas for Further Development
As noted in the supplementary article, there are gaps in available data which led to this study using values not Vietnam-specific. It would be highly beneficial to gather up-to-date, country specific data to allow accurate analysis regarding over the modelling period. The possibility of adopting large-scale sustainable biomass as an intermediate load should also be researched in more detail to judge its feasibility in the country. This should be paired with other sector coupling technologies such as heat pumps and pump hydro. As this study replicates Vietnam’s power system with a single node, transmission and distribution capacities are not studied. Thus, further modelling should incorporate multiple nodes to represent the transmission and distribution system throughout the country.
Modelling has shown that renewable energy, including solar and wind power, will be essential in driving down CO2 emissions. Additionally, sustainable biomass may be helpful as an intermediate load to avoid curtailment. However, such technologies may affect land use including arable or pasture farming in Vietnam. The Climate, Land (food), Energy and Water strategies (CLEWs) tool should therefore be incorporated to study the nexus between food, water, and energy.