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How LDES Can Help Balance Renewable Energy Supply and Demand?
As solar and wind power become a larger part of the electricity mix, balancing renewable energy supply with electricity demand is becoming increasingly important. Renewable generation is naturally variable: solar output changes throughout the day, while wind generation depends on weather conditions.
This creates a fundamental challenge. Electricity may be generated when demand is low, while periods of high demand can occur when renewable generation is limited.
Long Duration Energy Storage (LDES) can help address this mismatch by storing electricity when renewable generation is available and releasing it later when it is needed. By shifting energy across longer periods, LDES can improve renewable energy utilisation, reduce curtailment, support grid flexibility, and provide longer-duration energy backup.
But how exactly does LDES help balance renewable energy supply and demand?
What Is Long Duration Energy Storage (LDES)?
Long Duration Energy Storage, commonly referred to as LDES, describes energy storage technologies designed to store and deliver electricity for extended periods.
Unlike storage systems designed primarily for short-duration applications, LDES can provide energy over several hours or potentially much longer, depending on the technology and system design.
The basic principle is straightforward:
Generate electricity → Store excess energy → Release stored energy when required.
This makes LDES particularly relevant to renewable energy systems because it allows electricity generated by variable renewable sources to be used at a different time from when it was produced.
How LDES Differs From Short-Duration Energy Storage
Short-duration storage is useful for applications that require rapid responses over relatively short periods. These can include frequency regulation, short peak-demand events, and other grid-balancing applications.
LDES focuses on a different challenge: moving energy across longer periods of time.
For example, a battery storage system could charge using excess solar electricity during the afternoon and discharge that energy during the evening when solar generation has fallen but electricity demand remains high.
The longer the required energy-shifting period, the more important storage duration becomes.
Why Long-Duration Storage Matters for Renewable Energy
Solar and wind generation do not necessarily follow electricity demand.
A solar system can produce significant electricity during the middle of the day, even when demand is relatively moderate. Later, solar generation declines just as residential and commercial electricity demand may increase.
LDES provides a way to shift some of that renewable electricity from the period of generation to the period of demand.
This can make renewable generation more flexible and useful across a wider range of operating conditions.
Why Renewable Energy Supply and Demand Can Be Difficult to Balance
Electricity grids need to continuously balance generation and consumption. When renewable generation varies, additional flexibility is needed to maintain this balance.
Solar Power Generation Changes Throughout the Day
Solar generation follows the availability of sunlight.
During sunny periods, solar systems can produce substantial amounts of electricity. However, generation declines in the late afternoon and stops after sunset.
This can create a timing mismatch:
High solar generation → daytime
Higher electricity demand → potentially later in the day
Without sufficient flexibility or storage, some surplus renewable electricity may need to be curtailed rather than used immediately.
Wind Generation Is Variable
Wind generation also changes over time because it depends on weather conditions.
Wind farms can sometimes generate substantial electricity during periods when electricity demand is relatively low. At other times, wind output may decrease while demand remains high.
Energy storage can help move some of this electricity to a more useful time.
Electricity Demand Does Not Always Follow Renewable Generation
The fundamental challenge is not simply how much renewable energy is generated. It is also when that energy is generated.
A grid could have sufficient renewable generation over an entire day while still experiencing periods when renewable output does not match demand.
This is where energy storage becomes valuable.
How LDES Helps Balance Renewable Energy Supply and Demand
LDES can provide a bridge between renewable electricity generation and electricity consumption.
1. Stores Excess Renewable Energy
When solar or wind generation exceeds immediate electricity demand, an LDES system can charge using the available electricity.
Instead of allowing all surplus electricity to go unused or requiring renewable generation to be reduced, the energy can be stored for later use.
For example, excess solar electricity generated during the afternoon could be stored and discharged during the evening.
2. Releases Energy When Renewable Generation Falls
When renewable generation decreases, stored electricity can be discharged to help meet demand.
For solar power, this can be particularly useful after sunset.
Instead of relying entirely on electricity generation from other sources when solar output falls, stored renewable energy can continue supporting the system.
3. Shifts Renewable Energy to Higher-Demand Periods
One of the most important functions of LDES is energy time-shifting.
Consider a simple example:
Afternoon
Solar generation is high → LDES charges.
Evening
Solar generation falls → LDES discharges.
Result
Renewable electricity generated earlier can be used later when demand is higher.
This ability to shift energy through time can increase the practical value of variable renewable generation.
4. Supports Grid Stability and Flexibility
As renewable penetration increases, electricity systems need sufficient flexibility to respond to changes in generation and demand.
Energy storage can provide flexibility by changing its operating mode according to system requirements.
An LDES system can charge when electricity is abundant and discharge when additional electricity is required.
Depending on the system and market, storage can also participate in services such as peak support, balancing, and other grid-support applications.
5. Helps Reduce Renewable Energy Curtailment
Renewable energy curtailment occurs when available renewable generation is reduced even though the resource could otherwise produce electricity.
This can happen when generation exceeds demand or when the electricity system cannot absorb all available output.
LDES can provide additional capacity for absorbing surplus renewable electricity.
Instead of immediately reducing renewable generation, excess electricity can potentially be stored and used later.
6. Provides Longer Backup During Supply Gaps
Short-duration storage may not be designed to provide energy for extended periods.
LDES can provide longer-duration energy delivery, depending on the technology, system configuration, and project requirements.
This can become particularly valuable during periods of prolonged low renewable generation or other supply constraints.
How LDES Works With Solar and Wind Energy
The main value of LDES in a renewable-powered electricity system is its ability to move energy through time.
Solar and wind generation can vary according to weather conditions and the time of day, while electricity demand follows a different pattern. Renewable energy storage helps connect these two profiles by storing electricity when renewable generation is available and delivering it when it is needed.
The IEA expects solar PV and wind to account for an increasing share of global electricity generation through 2030, increasing the importance of flexibility and storage for integrating variable renewable energy.
LDES and Solar Power
Solar energy is one of the clearest examples of why energy storage duration matters.
Solar generation typically peaks during daylight hours and falls toward zero after sunset. Electricity demand, however, continues after sunset.
A solar-plus-LDES system can store some of the electricity generated during the day and release it later.
For businesses, this can potentially increase the amount of onsite renewable electricity that can be used beyond the hours of direct solar generation.
LDES and Wind Power
Wind generation can occur throughout the day and night, but its output varies according to wind conditions.
LDES can store electricity during periods of strong wind generation and release it when wind output decreases.
This can help reduce the impact of short-term or longer-duration variations in wind generation.
Combining Solar, Wind and LDES
Using different renewable generation sources alongside LDES can provide greater flexibility than relying on a single generation profile.
For example, solar may generate strongly during the day while wind output varies independently. Energy storage can act as a buffer between these variable sources and electricity demand.
The result is not that LDES makes renewable generation constant. Instead, it provides a mechanism for shifting renewable electricity through time, helping electricity systems make greater use of available renewable generation.
This is becoming increasingly relevant as electricity systems add more variable renewable generation and require additional flexibility to balance supply, demand and storage.
What Types of LDES Technologies Can Support Renewable Integration?
LDES is not a single technology. Several storage technologies can provide longer-duration energy storage, with different characteristics and applications.
Flow Batteries
Flow batteries store energy in liquid electrolytes contained in external tanks.
Vanadium redox flow batteries (VRFBs) are one example of this technology.
A key characteristic of flow batteries is that their power and energy capacity can be designed relatively independently. Increasing the amount of electrolyte can increase energy-storage capacity, while the power capability is associated with the size and configuration of the electrochemical stack.
This characteristic can make flow batteries suitable for applications requiring extended energy discharge.
Thermal Energy Storage
Thermal energy storage stores energy as heat or cold rather than directly storing electricity.
Depending on the system, stored thermal energy can later be used for industrial processes, heating, cooling, or electricity generation.
Its suitability depends heavily on the application and required energy-conversion pathway.
Compressed Air Energy Storage
Compressed air energy storage stores energy by compressing air.
When electricity is needed, the stored compressed air can be released through equipment that converts the stored energy back into useful electricity.
This approach can be suited to larger-scale applications where appropriate infrastructure and geological conditions are available.
Pumped Hydroelectric Storage
Pumped hydroelectric storage uses electricity to pump water to a higher elevation.
When electricity is required, the water flows back down through turbines to generate electricity.
Pumped hydro is an established form of large-scale energy storage, although suitable geography and significant infrastructure are required.
Other Emerging LDES Technologies
The LDES sector also includes a range of developing technologies designed to provide extended-duration energy storage.
The appropriate technology depends on factors such as storage duration, project scale, location, operating profile, efficiency, cost, safety requirements, and the intended application.
What Are the Benefits of LDES for Renewable Energy Systems?
When appropriately designed, LDES can support renewable energy integration in several ways:
Better renewable energy utilisation: Store electricity when renewable generation is abundant and use it later.
Reduced renewable curtailment: Provide additional flexibility for absorbing surplus generation.
Grid flexibility: Respond to changes in generation and demand.
Peak demand support: Discharge stored electricity during periods of higher demand.
Longer-duration backup: Provide energy over extended periods compared with systems designed only for short-duration applications.
Improved renewable integration: Help align variable renewable generation with electricity consumption.
Energy resilience: Provide an additional source of stored electricity when grid conditions require it.
However, the benefits of LDES depend on the specific technology, project design, operating conditions, and electricity market.
LDES vs Battery Energy Storage Systems
A Battery Energy Storage System (BESS) stores electricity in rechargeable batteries and can be used for applications ranging from short-duration grid services to longer-duration energy shifting.
It is important to distinguish between the terms BESS and LDES. BESS describes a system based on battery technology, while LDES describes the intended storage duration and application. Some battery energy storage systems can therefore be configured for longer-duration applications.
The IEA reports that battery storage was the fastest-growing power technology in 2025, with 108 GW of new battery storage capacity deployed globally. It also reports that storage durations are gradually increasing, with a growing number of projects offering four hours or more of storage.
Factor | Short-Duration Storage | Longer-Duration Storage |
Primary purpose | Rapid response and short-term balancing | Longer energy shifting |
Storage duration | Generally shorter | Several hours or longer |
Renewable integration | Manages short-term variations | Addresses longer supply-demand mismatches |
Peak demand | Short peak periods | Extended peak periods |
Renewable curtailment | Provides some flexibility | Can absorb surplus energy for longer periods |
Typical applications | Frequency response, grid services, short peaks | Energy shifting, renewable integration, longer-duration backup |
The appropriate BESS configuration depends on the required power output, energy capacity, discharge duration, cycling profile, site conditions and project economics.
For a detailed explanation of how battery storage systems operate, see our guide to Battery Energy Storage System.
Can LDES Support Businesses and Commercial Energy Users?
As electricity demand becomes more variable and renewable generation continues to expand, industrial energy storage is becoming an important part of energy management for large electricity users.
Managing Peak Electricity Demand
Businesses may experience periods of high electricity demand that do not coincide with onsite renewable generation.
An energy storage system can charge when electricity is available and discharge during selected periods of higher demand.
The financial value of this strategy depends on the site's electricity tariff, demand charges, operating profile, and storage system economics.
Improving Renewable Energy Self-Consumption
Businesses with onsite solar can use energy storage to shift renewable electricity beyond the hours of direct solar generation.
For example, solar electricity produced during the afternoon could be stored and used during evening operations.
Supporting Energy Resilience
For facilities where electricity availability is particularly important, longer-duration storage can provide additional stored energy during grid interruptions or supply constraints.
The actual backup duration depends on system capacity, load requirements, and operating configuration.
Supporting Future Electrification
As businesses electrify more processes, electricity demand can increase.
Examples include:
Electric vehicle charging
Electrified industrial equipment
Heat pumps
Data centres
Manufacturing processes
LDES can potentially provide additional flexibility by storing electricity and making it available when required.
The Role of LDES in a Renewable-Powered Grid
As electricity systems incorporate more variable renewable generation, balancing resources become increasingly important.
LDES can form one part of a broader flexibility strategy alongside:
Electricity transmission
Demand response
Short-duration battery storage
Flexible generation
Grid interconnection
Renewable generation diversification
Energy efficiency
This is important because no single technology can address every electricity-system requirement.
Short-duration batteries can respond rapidly to certain grid needs, while LDES can address longer periods of energy imbalance. Transmission can move electricity between regions, while demand response can adjust consumption.
A flexible electricity system can therefore use several complementary solutions.
What Factors Should Be Considered When Choosing an LDES System?
Selecting an LDES technology requires more than looking at the advertised storage duration.
Required Storage Duration
Determine how many hours the system needs to discharge and under what operating conditions.
Power and Energy Capacity
Power capacity determines how quickly electricity can be delivered, while energy capacity determines how much electricity can be stored.
Both need to match the application's requirements.
Cycling Requirements
Consider how frequently the system will charge and discharge.
A system designed for daily energy shifting may have different requirements from one intended for occasional backup.
Efficiency and Performance
Round-trip efficiency, operating conditions, response characteristics, and other performance factors should be evaluated for the intended application.
Project Location and Grid Requirements
Grid connection requirements, site conditions, available infrastructure, and local electricity-market rules can all influence system design.
System Lifetime and Degradation
The expected operating life and performance over time should be considered when evaluating the overall economics of an energy storage project.
Total Cost of Ownership
The initial equipment cost is only one part of the financial picture.
A complete assessment should consider capital expenditure, operating costs, maintenance, replacement requirements, system lifetime, electricity-market value, and expected utilisation.
Safety and Environmental Considerations
Safety requirements, material selection, installation conditions, end-of-life considerations, and environmental impacts should also form part of the technology evaluation.
The Future of Long Duration Energy Storage
The growing deployment of renewable electricity is increasing the need for flexible energy resources.
As solar and wind generation account for a larger share of electricity production, the ability to store energy and shift it across time can become increasingly important.
LDES technologies can help address this challenge by connecting periods of renewable energy abundance with periods of higher electricity demand.
Different technologies will have different strengths, costs, operating characteristics, and suitable applications. As a result, the future energy-storage landscape is likely to include a combination of short-duration and long-duration technologies rather than a single universal storage solution.
For businesses, utilities, and renewable energy developers, understanding the relationship between storage duration, renewable generation, electricity demand, and project economics will be increasingly important when planning energy-storage systems.
Conclusion
Balancing renewable energy supply and electricity demand is becoming increasingly important as solar and wind generation expand.
The challenge is not simply generating enough renewable electricity. It is also ensuring that electricity is available when it is needed.
Long Duration Energy Storage can help address this challenge by storing surplus renewable electricity and releasing it during periods of lower renewable generation or higher demand.
From reducing renewable energy curtailment and shifting solar power into evening hours to supporting grid flexibility and longer-duration backup, LDES can play an important role in integrating variable renewable generation.
For businesses and energy developers considering energy storage, the right solution depends on the required duration, power capacity, operating profile, site conditions, economics, and long-term energy strategy.
Frequently Asked Questions About LDES
What is LDES in renewable energy?
LDES stands for Long Duration Energy Storage. It refers to energy-storage technologies designed to store and deliver electricity for extended periods. LDES can help shift renewable electricity from periods of high generation to periods when electricity demand is higher.
How does long-duration energy storage balance supply and demand?
LDES stores electricity when supply exceeds immediate demand and releases it when generation is lower or demand increases. This helps address the timing mismatch between renewable generation and electricity consumption.
How long can LDES store renewable energy?
The duration varies by technology and system design. LDES generally refers to storage capable of delivering energy for several hours or longer, with some technologies designed for much longer periods.
Can LDES reduce renewable energy curtailment?
LDES can potentially reduce renewable energy curtailment by absorbing surplus electricity when renewable generation exceeds immediate demand and releasing that stored energy later.
What is the difference between LDES and lithium-ion battery storage?
Lithium-ion batteries can be used for both short-duration and longer-duration applications. The distinction is primarily based on the application's required storage duration and system design rather than simply the battery chemistry. Other LDES technologies, including flow batteries, can also be designed for extended-duration applications.
Which LDES technologies are suitable for renewable energy storage?
Potential LDES technologies include flow batteries, pumped hydro, compressed air energy storage, thermal energy storage, and other emerging technologies. Suitability depends on factors such as duration, power requirements, location, cost, operating profile, and project objectives.
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