Technology Overview

Lithium-ion batteries (LIB) are rechargeable energy storage technologies widely used in power systems to provide electricity over short durations, typically up to 6 hours. The technology includes several subcategories, primarily defined by battery chemistry.

Technical Characteristics

Lithium-ion batteries include several types, among which NMC (Nickel Manganese Cobalt Oxide), LFP (Lithium Iron Phosphate) and LTO (Lithium Titanate), used in applications ranging from consumer electronics to electric vehicles and large-scale energy storage systems. Their key characteristics are summarized below:

NMC batteries are widely adopted due to lower cost and large-scale production, especially in the automotive industry. LFP batteries are known for high safety, as they do not release oxygen during combustion. LTO batteries offer fast charging and long lifetime, but have higher cost and lower energy density.

Application in Vietnam

In Vietnam, lithium-ion batteries are currently deployed mainly at pilot scale and in systems integrated with renewable energy, particularly solar power, to support load balancing and enhance system flexibility. With rapidly declining costs and high efficiency, this technology is expected to become a dominant energy storage solution in the future, playing a key role as the share of renewable energy continues to increase.

Technology Overview

Vanadium Redox Flow Batteries (VRFB) are a type of secondary battery used for electrical energy storage. VRFB stores energy in liquid electrolytes, with vanadium as the active element due to its ability to exist in four different oxidation states. This technology allows power and energy capacity to be scaled independently, making it ideal for short- to medium-duration stationary energy storage systems.

Technical Characteristics

VRFB offers several advantages, including deep discharge capability, no capacity degradation due to electrolyte mixing, and the ability to upgrade power and capacity over its lifetime. However, disadvantages include complex system design, the need for pumps and valves, and lower energy density compared to lithium-ion batteries.

The levelized cost of storage (LCOS) is estimated at approximately 0.05 €/kWh. Energy efficiency ranges from 70% to 85%, with overall round-trip efficiency between 75% and 90%.

Application in Vietnam

In Vietnam, there are currently no commercial-scale VRFB projects, and information on practical deployment remains limited. However, due to its long lifetime, safety, and scalability, VRFB is considered a promising future option, particularly as demand for renewable energy integration continues to grow.

Technology Overview

Hydrogen storage technology plays an important role in modern energy systems, particularly in the context of increasing shares of renewable energy and the need for long-term storage. Hydrogen is a widely available element and has long been used in industries, such as chemicals and oil refining. It is increasingly being considered as a solution for storing surplus energy from renewable sources. With a high gravimetric energy density (120 MJ/kg), hydrogen is suitable for large-scale storage, although its low volumetric energy density requires compression for efficient storage.

Technical Characteristics

Hydrogen storage technologies are classified into two main groups: storage-device-based and material-based methods. Device-based storage includes compression and liquefaction of hydrogen, followed by storage in pressurized tanks, salt caverns, or natural aquifers. For gaseous hydrogen, storage is achieved by compression at various pressure levels, typically below 1,000 bar, using seamless steel or composite tanks.

Underground hydrogen storage is an important solution for future energy systems, with four main approaches: storage in lined rock caverns, salt caverns, aquifers, and depleted oil and gas reservoirs. Each method has its own advantages and disadvantages depending on geological conditions and cost.

Compressed hydrogen storage is currently the most widely used, with four types of pressure vessels: Type I, II, III, and IV, each differing in pressure rating, material, application, permeability, storage duration, and cost.

Application in Vietnam

Currently, hydrogen storage systems have not yet been deployed at a commercial scale in Vietnam, and applications remain largely at the research and feasibility assessment stage. However, this technology is considered an important long-term solution, particularly for storing surplus renewable energy and supplying fuel to hard-to-electrify sectors such as industry and transport.

Technology Overview

Compressed Air Energy Storage (CAES) is a mechanical energy storage technology that stores electricity by compressing air into high-pressure vessels or underground formations, and then releasing it to drive turbines for electricity generation when needed. A more advanced variant is Adiabatic CAES (A-CAES), where the heat generated during compression is stored and reused, improving round-trip efficiency.

Technical Characteristics

Two main technologies are considered: conventional CAES and A-CAES. Conventional CAES uses natural gas to compensate for thermal losses, resulting in CO₂ emissions, whereas A-CAES does not require fossil fuels and produces no emissions.

Advantages of CAES include large storage capacity at relatively low cost and fast start-up capability. However, disadvantages include CO₂ emissions (except for A-CAES) and dependence on suitable geological storage locations. The technology requires relatively low water consumption, but may have environmental impacts associated with fossil fuel use and underground construction.

A-CAES is currently under development and is expected to be commercialized within 10–15 years, with a round-trip efficiency of up to 70%.

Globally, only two conventional CAES plants are currently in commercial operation: one in Huntorf (Germany) and one in McIntosh (USA). The Huntorf plant has a round-trip efficiency of approximately 42% and a cost of 320 DM/kWel, while McIntosh has an efficiency of 52% and a cost of 591 USD/kWel.

Application in Vietnam

CAES has not yet been deployed in Vietnam. However, studies have identified storage potential in Dong Nai and Bien Hoa, where suitable sandstone formations exist. Investment costs for CAES projects are estimated at 400–500 USD/kWac (based on 2003 prices).

Technology Overview

This chapter focuses on flywheel technology, a method of storing energy in the form of rotational kinetic energy by spinning a mass around an axis. This technology is used for rapid energy storage and delivery, making it suitable for applications such as frequency regulation and peak load shaving.

Technical Characteristics

There are two main types of flywheels: metal flywheels and composite flywheels. Metal flywheels are typically used for simple, short-duration storage systems, while composite flywheels are suited for applications requiring high rotational speed and durability.

In terms of cost, flywheels generally have lower basic investment costs compared to technologies such as pumped storage and CAES, although costs depend heavily on rotor materials. Flywheel systems offer very high round-trip efficiency, up to 98%, but still experience energy losses during conversion.

Flywheels provide fast response, high reliability, and minimal environmental impact. However, disadvantages include complexity in bearing design and mechanical stress limitations. The technology continues to be developed to improve performance and reduce costs.

Application in Vietnam

There is currently no specific information on large-scale deployment of flywheel technology in Vietnam. Globally, it has been implemented in projects such as the 20 MW Beacon Power system in Pennsylvania (USA) and systems by Amber Kinetics in California and Taiwan.

Technology Overview

Fuel cells are devices that convert chemical energy into electricity through electrochemical reactions. Hydrogen fuel cells, one of the most common types, convert hydrogen into electricity, producing water and heat as by-products. Unlike conventional batteries, fuel cells require a continuous fuel supply—specifically hydrogen—to operate.

Technical Characteristics

The technologies discussed include Proton Exchange Membrane Fuel Cells (PEMFC), Solid Oxide Fuel Cells (SOFC), and other types such as DMFC, PAFC, AFC, and MCFC. PEMFC is characterized by high power density and low operating temperature, making it suitable for transportation applications. In contrast, SOFC operates at higher temperatures and offers higher electrical efficiency but is more suitable for stationary power generation.

Investment and operating costs of fuel cells remain high, due to the use of precious metal catalysts and specialized materials. Currently, system costs are still higher than many conventional technologies.

Hydrogen fuel cells produce no greenhouse gas emissions at the point of use. However, the overall round-trip efficiency from electricity to hydrogen to electricity is relatively low, typically 25–35%, limiting large-scale energy storage applications. Nevertheless, fuel cells offer advantages, such as high thermodynamic efficiency, low emissions, and long-duration storage potential, especially when using green hydrogen derived from renewable energy.

Application in Vietnam

In Vietnam, there is currently no concrete information on large-scale deployment of fuel cell technology. However, potential applications in transportation, stationary power generation, and portable devices are being researched and developed.

Introduction to Renewable Fuels including Power-to-X

This chapter introduces renewable fuel technologies, including Power-to-X, in the context of Vietnam. These technologies are used to convert renewable energy into various fuel forms, enabling more efficient storage and utilization of energy within the energy sector. Power-to-X refers to the conversion of surplus electricity from renewable sources such as wind and solar into other forms of energy, including hydrogen, methanol, and ammonia, which can be stored and used at a later stage.

The technologies discussed include systems for producing green fuels, characterized by the integration of power generation systems and the necessary infrastructure to supply renewable fuels. Although the chapter does not provide detailed descriptions of individual technologies, it emphasizes that cost and performance data are based on specific projects in Vietnam, as well as international references for medium- and long-term projections to 2030 and 2050.

In terms of comparison, the chapter does not provide a detailed table comparing efficiency, advantages and disadvantages, application conditions, or costs. However, it highlights differences between short-term and long-term perspectives due to regulatory frameworks and varying levels of market maturity across technologies.

Regarding deployment in Vietnam, the chapter does not specify where or at what scale these technologies have been implemented. However, it indicates that data are drawn from specific projects in Vietnam, suggesting that some level of pilot deployment or testing has occurred.

Overall, the chapter provides a general overview of renewable fuel technologies, particularly Power-to-X, in Vietnam, but lacks detailed information on technology comparison, investment costs, and specific deployment status.

Technology Overview

Electrolyzers are technologies used to produce renewable hydrogen through water electrolysis, generating green hydrogen with no CO₂ emissions when powered by renewable energy. This technology plays a key role in the transition toward a fully renewable energy system, meeting the growing demand for renewable hydrogen.

Technical Characteristics

There are three main types of electrolyzer cells: Alkaline Electrolyzer Cells (AEC), Proton Exchange Membrane Electrolyzer Cells (PEMEC), and Solid Oxide Electrolyzer Cells (SOEC). AEC uses a liquid electrolyte and can achieve large-scale capacity; PEMEC uses a solid electrolyte and operates at high current density; while SOEC operates at high temperatures and offers the highest efficiency.

AEC has lower cost and longer lifetime but lower efficiency compared to PEMEC and SOEC. PEMEC is more compact and produces high-purity hydrogen, but has higher material costs. SOEC offers the highest efficiency but has shorter lifetime and requires high-temperature operation.

Application in Vietnam

In Vietnam, electrolyzers have not yet been widely deployed at commercial scale and are primarily at the research and feasibility assessment stage, particularly in connection with green hydrogen production. However, this technology is considered a key long-term component, especially when combined with renewable electricity to produce clean fuels for industrial use and energy export.

Technology Overview

Green ammonia synthesis is a potential alternative fuel solution in future green energy systems. Green ammonia, produced from electrolysis using renewable energy, can replace fossil fuels in maritime transport and power generation, while also playing an important role in green fertilizer production and long-term energy storage.

Technical Characteristics

Green ammonia production includes hydrogen production via electrolysis, nitrogen production through an Air Separation Unit (ASU), and the ammonia synthesis process. Conventional technologies such as Steam Methane Reforming (SMR) and Autothermal Reforming (ATR) are also referenced, with the addition of carbon capture technologies to reduce CO₂ emissions, resulting in blue ammonia.

The production cost of green ammonia remains high, mainly due to dependence on renewable electricity costs and hydrogen electrolysis technology. However, costs are expected to decline in the future with technological advancements and scaling.

Application in Vietnam

In Vietnam, green ammonia has not yet been deployed at a commercial scale. In the long term, it is considered a promising solution for energy storage and use as fuel or industrial feedstock.

Technology Overview

Methanol synthesis (e-methanol) is a technology that converts hydrogen into methanol, commonly used in Power-to-X projects. Methanol is an important chemical compound and can serve as a green fuel when produced from renewable energy and feedstocks. The technology is based on synthesis gas reactions involving H₂, CO, and CO₂, producing methanol through catalytic reactions and water-gas shift processes.

Technical Characteristics

There are four main processes for producing green methanol from green hydrogen:

A typical methanol plant capacity is around 100,000 tons/year, with electricity demand of approximately 100 kWh per ton of methanol. The production cost of e-methanol remains high, due to strong dependence on the cost of green hydrogen from electrolysis and the availability of CO₂ feedstock.

Application in Vietnam

E-methanol technology has not yet been widely deployed in Vietnam.

Technology Overview

This chapter focuses on the production of biomethanol through biomass gasification. The technology consists of two main steps: converting solid biomass into bio-syngas and subsequently converting the syngas into methanol. Gasification occurs at high temperatures (>700°C) with a controlled supply of oxygen and/or steam, producing syngas composed of carbon monoxide, hydrogen, and carbon dioxide.

Technical Characteristics

Gasification reactor designs vary, including updraft, downdraft, and cross-flow configurations, and may use either external heat sources or direct combustion agents. Commercial plants are typically large-scale, although smaller-scale plants also exist in regions without significant natural gas resources.

Comparisons between gasification technologies indicate that plants integrated with solid oxide electrolyzer cells (SOEC) can achieve higher efficiency, with methanol yield per unit of feedstock approximately 8% higher than conventional plants. However, no verified data are available on capital and operating costs; existing estimates depend on feedstock prices and conversion efficiency.

Application in Vietnam

Currently, no commercial plants using this technology exist in Vietnam. Several international projects have been implemented or are under development, such as Trans World Energy (USA) with a capacity of 875,000 tons/year, and Enerkem (Netherlands) with a capacity of 215,000 tons/year. These projects demonstrate the potential of biomass gasification for biomethanol production, although significant economic and technical challenges remain.

Technology Overview

This chapter focuses on biogas production and upgrading technologies, an important area within Vietnam’s renewable energy sector. The process converts organic matter under anaerobic conditions into biogas rich in methane (CH₄) and carbon dioxide (CO₂), which can be used for heat and power generation or upgraded into biomethane.

Technical Characteristics

Industrial biogas plants typically use Continuous Stirred Tank Reactors (CSTR) to process pumpable biomass, such as sludge and wet industrial waste. These systems operate at temperatures of 35–40°C (mesophilic digestion) or 50–55°C (thermophilic digestion). In plants with upgrading systems, excess heat is reused to maintain digester temperature.

Conversion efficiency varies depending on biomass type and hydraulic retention time (HRT):

Biogas upgrading technologies include amine scrubbing, water scrubbing, membrane separation, and pressure swing adsorption (PSA). Each method has distinct advantages and limitations. For example, amine scrubbing offers the highest methane retention efficiency but requires regeneration temperatures of 120–150°C.

Application in Vietnam

Currently, this technology has not been widely deployed in Vietnam, and there is no gas grid infrastructure to support biomethane distribution. However, given the country’s renewable energy potential, broader application is expected in the future.

Technology Overview

This chapter focuses on the production of green liquid fuels using Fischer–Tropsch Synthesis (FTS). The technology uses catalytic reactions between hydrogen and carbon monoxide to produce liquid fuels from syngas. For renewable fuel production, feedstocks must be renewable, such as biomass or green hydrogen. The process typically uses iron- or cobalt-based catalysts under specific temperature and pressure conditions.

Technical Characteristics

FTS technologies include production pathways from biomass via gasification and from electricity using green hydrogen. Biomass-based production involves converting solid biomass into syngas and then into liquid fuel. Electricity-based production uses green hydrogen to generate syngas from CO₂ and H₂, followed by FTS conversion.

FTS has not yet been widely commercialized for green fuel production, although commercial plants using fossil-based feedstocks exist. For example, Shell’s plant in Qatar produces 260,000 barrels/day. Pilot plants using green hydrogen can produce around 160 liters of fuel per day.

Investment costs range from approximately 2.58 to 5.64 million USD/MW, with an average of 3.27 million USD/MW.

Application in Vietnam

Currently, this technology has not been deployed in Vietnam.

Appendix 1 presents the methodology for developing the qualitative descriptions of technologies in the Catalogue, ensuring a consistent approach to evaluating and comparing energy storage and renewable fuel technologies. The appendix focuses on standardizing the structure of information for each technology, enabling users to clearly understand the nature, operational characteristics, and role of each technology within the energy system.

Specifically, each technology is described using a fixed framework, beginning with a technology description, which explains the operating principles and key characteristics. This is followed by inputs and outputs, identifying energy or material flows entering and leaving the system. The energy balance is used to clarify efficiency and losses during operation, forming the basis for comparison across technologies.

In addition, the methodology requires the presentation of key operational parameters such as typical capacity and typical storage duration, reflecting the scale and practical applicability of each technology. For storage systems, another important criterion is the ability to provide ancillary services and adjust output, indicating the level of flexibility in supporting power system operation.

The inclusion of advantages and disadvantages ensures a balanced perspective, covering not only performance but also cost, complexity, technology readiness, and deployment barriers. Furthermore, factors such as land requirements, water consumption, and environmental impacts are assessed to evaluate the suitability of technologies under specific conditions.

The appendix also addresses research and development (R&D) status and provides examples of real-world projects, illustrating the maturity and applicability of each technology. The section on data estimation explains how information is compiled when real-world data are limited, while additional notes provide supporting context for interpretation.

Energy Storage Technologies

Appendix 2 presents the methodology for developing quantitative parameters for energy storage technologies, with the objective of ensuring that data can be directly compared across different technologies. The core of the methodology lies in standardizing the collection, processing, and presentation of technical and economic data, thereby supporting system analysis and modeling.

First, the appendix emphasizes data consistency, requiring that all cost data be expressed in constant 2025 prices and exclude taxes such as VAT. This eliminates distortions caused by inflation or differences in tax policies across countries and time periods, ensuring comparability.

The quantitative description includes two main groups: technical/energy data and economic data. The technical group reflects operational characteristics such as capacity, efficiency, storage duration, lifetime, and system response parameters. The economic group focuses on capital costs, operation and maintenance (O&M) costs, and other lifecycle-related costs.

A key aspect of the methodology is linking parameters to the Final Investment Decision (FID). Data for years such as 2025, 2030, 2040, and 2050 represent the state of technology at the time of investment decision, rather than at the time of operation. This improves the accuracy of long-term modeling and technology deployment analysis.

The appendix also addresses the treatment of O&M costs, including both fixed and variable components. Fixed O&M costs may be expressed as a percentage of total investment cost or per unit of installed capacity per year, while variable O&M costs are calculated per unit of energy output. These include labor, maintenance, consumables, and other operational expenses.

In addition, the methodology considers factors such as reinvestment over the lifecycle, discounting of costs over time, and assumptions related to real-world operation. As a result, the quantitative data capture not only initial costs but the full lifecycle economics of each technology.

Appendix 3 extends the quantitative methodology to renewable fuel technologies (Power-to-X). The objective is to develop a dataset that fully reflects both technical and economic aspects of technologies such as hydrogen, ammonia, and e-fuels.

As with storage technologies, all data are standardized in terms of units, base year, and economic assumptions, ensuring comparability across technologies and development stages. Parameters are developed for multiple time horizons, reflecting technological progress and cost reduction potential over time.

The quantitative description again focuses on technical/energy data and economic data. However, for renewable fuels, technical parameters extend beyond efficiency to include input requirements (electricity, water, CO₂), output production, and characteristics related to the full fuel value chain. This reflects the cross-sectoral nature of Power-to-X technologies.

A distinctive feature is the full value chain perspective, from electricity input to final fuel product. Therefore, quantitative parameters must capture overall system efficiency as well as losses at each conversion stage.

From an economic perspective, the methodology includes capital costs, O&M costs, and input feedstock costs. Assumptions regarding electricity prices, system scale, and deployment levels play a critical role in determining fuel production costs.

The appendix also establishes standard definitions to ensure consistent interpretation of concepts and indicators across the entire catalogue, which is particularly important for emerging technologies where terminology and calculation methods may not yet be fully standardized.

Appendix 4 presents the methodology for developing long-term cost projections for energy technologies, supporting planning and scenario analysis for milestones such as 2030, 2040, and 2050. The objective is to provide a consistent framework for estimating cost evolution over time, reflecting both technological progress and real-world deployment conditions.

The methodology begins with defining a base year (2025), which serves as the reference point for all projections. Cost data for this year are based on actual data and existing studies, ensuring an accurate representation of current technology status. Future values are then derived using structured assumptions.

A key element of the methodology is the learning curve, which represents the relationship between cost and cumulative deployment. As technologies are deployed more widely, costs tend to decrease due to technical improvements, process optimization, and economies of scale. The appendix applies specific learning rates combined with deployment scenarios to project future cost trends.

The methodology also considers technology maturity, distinguishing between commercially established technologies and those still under development. This is important because emerging technologies typically have greater cost reduction potential but also higher uncertainty.

To reflect uncertainty, the appendix introduces uncertainty ranges for cost projections. These ranges are derived by combining current cost data with uncertainty factors related to deployment speed and future learning effects. This allows users to understand not only central estimates but also possible variation ranges.

Finally, the methodology is informed by international energy scenarios (such as those in the World Energy Outlook), which help define future deployment levels and directly influence cost reduction trajectories. This ensures that cost projections are grounded not only in technical assumptions but also in the broader global energy system context.