What Is Curtailment and How It Affects Renewable Energy

As renewable energy adoption accelerates worldwide, curtailment and grid congestion are becoming critical challenges. Studies show that curtailment of renewables already costs billions, with Europe alone seeing over 12 TWh of curtailed renewable electricity in 2023,  a figure projected to rise sharply in coming years (TotalEnergies Accelerator).

The rapid growth of solar, wind, and other renewable energy sources has been a major step toward a greener, more sustainable future. However, one of the least discussed yet most critical challenges in this transition is energy curtailment.

Simply put, curtailment occurs when renewable electricity that could be produced is deliberately reduced or turned away from the power grid.

While it may sound counterintuitive, power curtailment is sometimes necessary to keep the power grid stable. But at what cost? And how can the industry strike a balance between grid reliability and renewable integration? Let’s explore.

What is Curtailment

Curtailment in the renewable energy sector refers to the intentional reduction of electricity production from sources such as wind farms or solar plants. This is not due to a technical failure but a strategic decision made to protect the stability of the power grid.

For example, during sunny or windy days when energy generation exceeds demand or when the grid cannot transport the electricity efficiently, operators may enforce power curtailment to prevent overload.

The concept of curtailment energy is central to grid management in countries with high renewable penetration. It ensures that frequency and voltage levels remain within safe limits.

Enline Dynamic Line Rating (DLR) directly tackles curtailment by unlocking hidden transmission capacity, allowing more renewable power to flow safely through existing grids.
Though curtailment is sometimes necessary, it represents both lost clean energy and missed revenue for developers. Understanding its scope is key to designing smarter grids and storage solutions for a decarbonized energy future.

Benefits of Energy Curtailment

While often seen as a problem, energy curtailment can bring immediate operational benefits.

Here’s your text converted into a clear, well-structured list, without removing a single word:

1. Provides grid flexibility
   
   

   • When renewable production outpaces demand, curtailment prevents the grid from becoming unstable.
     
     

   • This is especially important in regions where investment in storage or transmission capacity lags behind renewable growth.
     
     
     

2. Avoidance of negative electricity prices
   
   

   • In wholesale energy markets, oversupply can push prices below zero.
     
     

   • By limiting generation, operators reduce the financial losses faced by producers and maintain healthier market conditions.
     
     

   • This approach also supports long-term investments in renewables by keeping profitability intact.
     
     
     

3. Reduces strain on transmission lines
   
   

   • Curtailment can delay the need for costly expansions.
     
     

   • Yet, with Enline’s DLR system, much of this congestion can be avoided altogether by providing real-time transport capacity.
     
     

   • This helps grids absorb more renewable generation without relying on curtailment.
     
     
     

4. Emergency response option
   
   

   • In emergency scenarios, curtailment offers a rapid response option compared to shutting down thermal plants, which require longer lead times.
     
     

So, while curtailment may appear counterproductive, its benefits lie in safeguarding grid reliability and smoothing the renewable transition in the short term.

What is Curtailment of Electricity?

Curtailment of electricity means renewable energy that could have been generated is not delivered to the grid. 

For example, a wind farm capable of producing 100 MW may be ordered to operate at only 70 MW, leaving 30 MW of curtailment energy unused. This is not because turbines fail or solar panels stop working but because the grid cannot absorb all the power safely. This differs from an outage, where energy cannot be produced due to technical issues. 

Instead, curtailment is a deliberate management strategy. It ensures grid operators can balance supply and demand in real time, keeping voltage and frequency stable.

In practice, curtailed electricity is often the result of too much renewable generation during periods of low demand. 

California, for example, has experienced record levels of solar curtailment in recent years due to midday oversupply.  

In 2024, CAISO (California Independent System Operator) curtailed 3.4 million MWh of utility-scale wind and solar output, this was a 29% increase over the year 2023. (EIA)

Curtailment happens most in spring and fall, when solar generation is high at mid-day but electricity demand is relatively low (California Independent System Operator). These conditions lead to significant renewable energy losses, underscoring the need for smarter, more flexible grids.

Enline addresses this challenge with its Sensorless Dynamic Line Rating (DLR) solution. Unlike traditional approaches that depend on extra hardware, Enline leverages existing grid data to deliver real-time insights.  By doing so, Enline’s DLR helps to reduce grid congestion and minimize the need for curtailment, while also delaying costly transmission upgrades.

How Can the Curtailment of Electricity be Avoided?

Avoiding curtailment requires structural and technological solutions. Key strategies include:

1. Grid Upgrades: Expanding transmission capacity to move renewable electricity from production sites to demand centers.
   
   

2. Energy Storage: Deploying batteries, pumped hydro, and long-duration storage to capture excess power for later use.
   
   

3. Flexible Demand: Encouraging consumers and industries to shift usage to periods of renewable surplus.
   
   

4. Market Reforms: Adjusting electricity pricing mechanisms to reflect supply-demand realities, reducing negative pricing events.
   
   

5. Advanced Forecasting: Using AI-driven tools, such as those developed by Enline energy solutions, to better align renewable generation with demand and grid capacity.

Instead of relying solely on static ratings, operators gain real-time insights into safe line capacity, allowing more renewable electricity to flow through the grid and reducing the need for costly curtailment orders.

Ultimately, curtailment avoidance requires coordinated policy, investment, and innovation. The less energy curtailed, the more effectively renewables can replace fossil fuels.

Harnessing the Power of Energy Curtailment

Rather than seeing curtailment as waste, it can be reframed as an opportunity to unlock new value streams. For example, curtailed electricity can be redirected into green hydrogen production, EV charging, or energy storage systems. This transforms excess renewable generation into long-term assets for decarbonization.

Another way to harness curtailment is through demand response—incentivizing industries or households to consume more when renewables are abundant. Flexible demand helps absorb peaks, reducing reliance on power grid curtailment.

Enline energy solutions highlights advanced analytics and AI-driven forecasting as tools for predicting when curtailment is likely. This allows operators to schedule storage, demand, or market responses ahead of time, minimizing waste.

Harnessing curtailment intelligently ensures it becomes a catalyst for innovation rather than an obstacle, supporting a more resilient and decentralized energy ecosystem.

Final Thought

As renewable adoption accelerates, tackling curtailment becomes critical. With solutions like Enline’s Dynamic Line Rating (DLR) & Monitoring System, the industry can turn today’s grid challenges into tomorrow’s opportunities, ensuring clean energy is delivered where and when it is needed most.

FAQs

What are the risks of grid curtailment?
Grid curtailment can lead to financial losses for producers, reduced investor confidence, wasted clean energy, and missed climate targets.

What is solar curtailment?
Solar curtailment is the reduction of solar power output, often during midday when supply outpaces demand or grid capacity.

What does grid curtailment mean?
Grid curtailment refers to limiting renewable generation to prevent overloading transmission lines or destabilizing grid frequency.

What is the difference between curtailment and outage?
Curtailment is deliberate reduction for stability, while outage is an unplanned failure to generate or deliver electricity.

What is the main effect of grid cut-off?
The main effect is wasted renewable energy and lost economic value, alongside continued reliance on fossil fuels.