LCOE Formula for Renewable Energy & Alternative Criteria for VietNam

Chi phí điện năng quy dẫn (LCOE) cho năng lượng tái tạo và đề xuất tiêu chí thay thế trong bối cảnh Việt Nam

In the special report ‘Evaluation of the Levelized Cost of Electricity (LCOE) for Renewable Energy and Proposed Alternative Criteria in the Context of Vietnam‘, experts from the Scientific Council of Vietnam Energy Magazine examine the limitations of applying the LCOE formula to renewable energy sources, particularly Variable Renewable Energy (VRE), in the context of Vietnam’s ambitious energy transition goals.

The report also provides preliminary recommendations and analysis of alternative indicators that consider not only costs but also the system-level value of VRE. These indicators offer a more comprehensive framework for energy planning and investment decisions in Vietnam.

Part 1 of the report focuses on the aspects that are often overlooked when using the LCOE formula to evaluate renewable energy projects in Vietnam.

Background and Key Issues of Renewable Energy LCOE

Energy Transition and Renewable Energy Development Trends

The global energy sector is undergoing a major transition toward sustainable and cost-effective electricity generation. Renewable energy is increasingly replacing fossil fuel-based technologies, while global electricity demand is expected to reach approximately 7,000 TWh by 2030.

LCOE as a Widely Used Metric in the Power Industry

In this context, the Levelized Cost of Electricity (LCOE) has become a widely used metric for comparing different power generation technologies.

The LCOE formula represents the average lifetime cost of electricity generation or the minimum electricity price required for a project to break even.

Challenges Associated with Variable Renewable Energy (VRE)

The main challenge lies in Variable Renewable Energy (VRE) sources such as solar and wind power.

Because VRE generates electricity only when natural conditions allow, its output is variable and difficult to predict. This can result in both surplus generation and power shortages, challenges that are not fully reflected in the traditional lcoe formula.

Understanding the Levelized Cost of Electricity (LCOE):

What Is LCOE?

LCOE is a metric used to evaluate the average net present cost of electricity generation over the lifetime of a power plant.

The LCOE formula is used for planning, investment analysis, and comparing different power generation technologies on a consistent basis. In essence, it represents the minimum electricity price required for an energy project to break even.

điện năng quy dẫn lcoe trong điện năng lượng mặt trời

Traditional Applications of LCOE

The LCOE formula is most useful when comparing similar technologies under similar conditions, such as one natural gas power plant against another.

It serves as a powerful screening tool for preliminary feasibility studies and strategic investment decisions.

Policymakers also use LCOE to assess the economic competitiveness of different energy sources and technologies, helping guide decisions on incentives and support mechanisms.

Key Components of the LCOE Formula

The table below summarizes the main components of the LCOE calculation.

ComponentDefinitionUnitImpact on LCOE
Capital Expenditure (CapEx)Initial investment required to build the project$/kWIncreases LCOE
Operation & Maintenance (O&M) CostsOngoing costs to operate and maintain the plant$/kW-year (fixed), $/kWh (variable)Increases LCOE
Fuel CostsFuel expenses for coal or gas plants. Zero for most VRE technologies$/MMBtuIncreases LCOE
Discount Rate (r)Reflects financing costs and investment risks%Increases LCOE
Capacity Factor (CF)Ratio of actual output to maximum possible generation% (0-1)Reduces LCOE
Plant Lifetime (n)Expected operating life of the facilityYearsReduces LCOE

This table summarizes the fundamental variables used in the LCOE calculation, providing a clear foundation for understanding the LCOE formula before examining its limitations.

Limitations of the LCOE Formula for Variable Renewable Energy (VRE)

Although the LCOE formula is a useful tool, it has significant limitations when applied to Variable Renewable Energy (VRE) sources such as solar and wind power. These limitations arise from the intermittent nature of VRE and the additional system costs required to support it.

Intermittency and Variability of VRE

VRE sources are inherently non-dispatchable. They generate electricity only when sunlight or wind is available, making their output variable and difficult to predict.

This variability is an intrinsic characteristic of renewable energy generation and directly affects how these resources interact with the power system.

Impact of VRE on Grid Stability

Continuous fluctuations in renewable energy output can affect grid stability.

High levels of VRE penetration may result in surplus generation during off-peak periods, particularly on weekends and holidays, leading to renewable energy curtailment and financial losses.

For example, Vietnam curtailed approximately 364 GWh of solar power in 2020.

Conversely, VRE cannot meet demand during periods without sufficient sunlight or wind, requiring backup generation capacity to maintain system reliability.

This challenge is particularly important for Vietnam’s power system, where hydropower, traditionally a major source of electricity, is increasingly vulnerable to climate-related impacts such as drought.

LCOE Does Not Reflect the Time-Dependent Value of Electricity

The traditional LCOE formula relies on an average capacity factor and does not account for the changing value of electricity over time.

Electricity is generally more valuable during peak demand periods. Solar power, for example, often reaches maximum output at midday when electricity demand may be lower, reducing its actual economic value to the system and, in some cases, contributing to negative electricity prices.

As a result, the LCOE calculation may not accurately reflect the true value of electricity generation.

Grid Integration Costs Are Not Fully Reflected

High levels of VRE penetration increase the need for ancillary services that maintain grid frequency and voltage stability.

These additional costs are typically not included in the traditional LCOE formula.

Existing power grids were not originally designed for large-scale, distributed, and variable renewable energy resources. Integrating VRE requires significant upgrades to transmission and distribution infrastructure.

This may include new transmission lines, substations, and high-voltage direct current (HVDC) transmission systems to connect remote renewable energy projects to demand centers.

The Role of Energy Storage Systems and Ancillary Services

Energy storage solutions such as Battery Energy Storage Systems (BESS) and Pumped Storage Hydropower (PSH) play an important role in balancing electricity supply and demand.

These technologies store excess electricity and release it when needed, helping reduce the impact of VRE intermittency.

Vietnam’s revised Power Development Plan VIII includes significant targets for battery energy storage deployment and increased storage capacity.

At the same time, existing incentives for ancillary services remain insufficient, resulting in limited reserve capacity to manage renewable energy uncertainty.

Developing a robust ancillary services market will be essential for the effective integration of VRE.

The Difference Between the COST and VALUE of Renewable Electricity

The LCOE formula primarily measures the cost of electricity generation at the power plant level.

However, it does not capture the value that electricity provides to the grid, which varies depending on time, location, and reliability.

The same amount of electricity may have a higher value during peak demand periods and a lower value during periods of oversupply.

In situations where generation exceeds demand, renewable electricity may have little or no economic value and can even contribute to negative pricing.

In addition, LCOE generally does not account for environmental and social impacts. Benefits such as reduced carbon emissions or avoided health impacts from fossil fuel generation are not monetized within the traditional LCOE calculation framework.

Hidden Costs of Renewable Energy

One of the main strengths of the LCOE formula is its simplicity. However, this simplicity becomes a major limitation when evaluating VRE.

By averaging generation costs over time, the LCOE formula overlooks both time-dependent costs and time-dependent value.

VRE output depends on natural conditions and cannot be controlled in the same way as conventional power plants. Most LCOE calculation methods use an average annual capacity factor, which smooths out actual generation patterns.

In reality, the value of electricity changes throughout the day depending on demand and grid conditions.

Solar power, for example, often produces the most electricity during periods when electricity prices are relatively low, reducing its overall economic value to the system.

The Gap Between Project Economics and System Costs

By relying on average capacity factors and ignoring time-based value, the LCOE formula oversimplifies the relationship between project economics and system requirements.

A renewable energy project may appear highly competitive based on LCOE alone, while its actual cost to the power system is significantly higher once grid impacts and integration costs are considered.

Another important issue is that many of the hidden costs associated with VRE are transferred to the broader electricity system and ultimately borne by consumers or taxpayers.

This creates a disconnect between the project-level costs measured by the LCOE formula and the actual costs incurred by the power system.

Why Are Additional Evaluation Criteria Needed Beyond the LCOE Formula?

The LCOE formula focuses on the direct costs of building and operating an individual power plant. However, it does not capture the full costs required to support a large-scale electricity system.

The intermittent nature of VRE creates additional system costs, often referred to as integration costs. These include:

  1. Backup generation and energy storage to ensure a reliable supply when VRE is unavailable.
  2. Grid reinforcement through transmission and distribution upgrades to accommodate variable renewable energy and connect remote projects.
  3. Ancillary services are required for frequency control, voltage regulation, and overall grid balancing.

These integration costs are generally not reflected in renewable power purchase agreements and are instead absorbed by utilities, electricity consumers, or government support mechanisms.

As a result, there can be a significant gap between the low project-level cost suggested by the LCOE formula and the actual cost of integrating renewable energy into the broader power system.

This gap highlights the need for more comprehensive evaluation metrics that better reflect both project economics and system-wide impacts.

Recommendations for Vietnam’s Energy Planning and Policy

To ensure a sustainable and efficient energy transition, Vietnam should adopt a broader approach that goes beyond relying solely on the LCOE formula.

Adopt a Multi-Metric Approach

While the lcoe formula remains a useful screening tool, energy planners, investors, and policymakers should also consider indicators such as LACE, VALCOE, and SLCOE to better assess the value and impact of VRE on the power system.

Given the important role of energy storage in addressing renewable energy variability, LCOS should also be included in project evaluations to measure the cost-effectiveness of storage technologies and their contribution to grid stability.

Strengthen Grid Infrastructure

Modernizing transmission and distribution networks is essential to support higher levels of VRE penetration. Key priorities include:

  • AI-based load management systems to improve demand forecasting and real-time operation.
  • HVDC transmission lines to efficiently transfer electricity from renewable energy regions to major load centers.
  • Battery Energy Storage Systems (BESS) to absorb excess generation and provide electricity during supply shortages.

At the same time, Vietnam should continue developing ancillary service markets to support frequency regulation, grid balancing, and greater renewable energy integration.

Enhance Market Mechanisms

Moving toward a more competitive electricity market and adopting flexible pricing mechanisms can better reflect the actual value of electricity at different times.

In addition, regulatory barriers should be reduced and approval procedures streamlined to encourage investment in renewable energy and energy storage projects.

Strategic Planning for Flexibility

Vietnam’s energy strategy should maintain a balanced generation mix that combines VRE with flexible resources such as LNG, hydropower, and energy storage systems to ensure system reliability and energy security.

The adoption of AI, smart grid technologies, and automated control systems can further optimize operations, improve load forecasting, and manage renewable energy variability more effectively.

Conclusion

The LCOE formula is a useful indicator for preliminary project assessments, but it does not fully capture the intermittency of VRE, grid integration costs, or the time-dependent value of electricity.

Additional metrics such as LACE, VALCOE, SLCOE, and LCOS can provide a more comprehensive evaluation of the economic performance and system impacts of renewable energy.

As Vietnam accelerates its energy transition under the Revised Power Development Plan VIII, investments in smart grids, solar power operations, energy storage, flexible market mechanisms, and reliable generation resources will play a critical role in ensuring long term energy security and sustainable development.

Source: Advanced Criteria for Evaluating Variable Renewable Energy Resources for Power Planning in Vietnam

Dr. Nguyen Anh Tuan (B)
Scientific Council, Vietnam Energy Magazine

Frequently Asked Questions about LCOE

What is LCOE?

LCOE (Levelized Cost of Electricity) is the average lifetime cost of generating electricity from a power plant, expressed as the minimum electricity price required for a project to break even.

What is the purpose of the LCOE formula?

The LCOE formula is used to compare the cost competitiveness of different power generation technologies consistently.

What factors affect an LCOE calculation?

Key factors include capital costs, O&M costs, fuel costs, discount rate, capacity factor, and project lifetime.

Why is the LCOE formula limited for renewable energy?

The lcoe formula does not fully account for intermittency, grid integration costs, energy storage requirements, or the changing value of electricity over time.

What alternatives to LCOE should be considered?

Common alternatives include LACE, VALCOE, SLCOE, and LCOS, which provide a broader assessment of both costs and system value.

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