Power lines and wind turbines symbolize the balance between traditional and renewable energy.

Balancing Act: How Renewable Energy Impacts Power Grid Stability

Reese Marlowe in Tech & Innovation September 2025 • 4 min read.

"Explore how the rise of renewable energy sources is reshaping reactive power demand and voltage control in distribution grids."

The global shift towards renewable energy is undeniable. Solar panels are adorning rooftops, and wind turbines are becoming a familiar sight on the horizon. This transition is driven by the urgent need to reduce our carbon footprint and combat climate change. However, integrating these distributed energy resources (DRES) into existing power grids presents complex challenges, particularly concerning reactive power demand.

Traditionally, large synchronous generators in centralized power plants have been the primary source of reactive power, essential for maintaining voltage stability and ensuring efficient power transmission. As we replace these conventional sources with renewables like solar and wind, which often connect at the distribution level (medium and low voltage grids), the dynamics of reactive power change dramatically.

High voltage (HV) grid operators face the task of accurately forecasting reactive power demand to effectively plan reactive power compensation and ensure voltage control. But, the fragmented nature of the underlying medium voltage (MV) and low voltage (LV) grids, coupled with limited real-time data, makes this a formidable challenge. This article delves into a simplified approach for modeling reactive power demand, providing valuable insights for grid operators and anyone interested in the future of energy.

The Reactive Power Puzzle: Understanding the Core Components

Power lines and wind turbines symbolize the balance between traditional and renewable energy.

Reactive power isn't as straightforward as the active power that runs our appliances. It's more like the unsung hero working behind the scenes. In essence, reactive power is the power required to establish and maintain the magnetic fields in inductive components (like transformers and motors) and electric fields in capacitive components (like cables).

MV grids, responsible for distributing power to our homes and businesses, sees its reactive power demand stemming from three key areas:

Grid Components: Power lines, particularly underground cables common in MV and LV grids, are inherently capacitive. Transformers, on the other hand, consume inductive reactive power.
Loads: Household appliances, commercial equipment, and industrial machinery all contribute to reactive power demand, typically inductive in nature.
Distributed Energy Resources (DRES): Solar inverters and wind turbines can either consume or supply reactive power depending on grid conditions and control strategies.

DRES can present a unique issue. Too much DRES can lead to unacceptable high voltages, so reactive power schemes like coso(P) and Q(U) are utilized to deal with this. Automatic voltage controls for transformers on the MV side are also used for maintaining a constant voltage, which affects overall reactive power flows.

Looking Ahead: Embracing a Balanced Energy Future

The transition to renewable energy sources requires careful planning and innovative solutions to ensure grid stability and reliability. Simplified reactive power models, while not perfect, provide a valuable tool for HV grid operators to estimate reactive power demand and plan for a future powered by clean energy. Future research should focus on validating these models with real-world data and refining them to capture the dynamic behavior of increasingly complex distribution grids. By proactively addressing these challenges, we can unlock the full potential of renewable energy and build a sustainable energy future for all.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1109/isgteurope.2018.8571901, Alternate LINK

Title: Modelling Reactive Power Demand Of Distribution Grids Subjected To Renewable Energy Sources

Journal: 2018 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT-Europe)

Publisher: IEEE

Authors: Patrick Larscheid, Kim Michael Taylor, Tobias Van Leeuwen, Albert Moser, Roland Hermes, Gunnar Schaarschmidt

Published: 2018-10-01

Everything You Need To Know

Why is reactive power important when integrating renewable energy sources?

Reactive power is essential for maintaining voltage stability and ensuring efficient power transmission. Traditionally, large synchronous generators in centralized power plants have been the primary source of reactive power. Now that renewables like solar and wind are being integrated, the dynamics of reactive power change dramatically, because solar and wind connect at the distribution level (medium and low voltage grids).

What are the main sources of reactive power demand in medium voltage grids?

In MV grids, reactive power demand comes from three key areas. First, grid components such as power lines (especially underground cables) are capacitive, while transformers are inductive. Second, loads like household appliances, commercial equipment, and industrial machinery contribute inductive reactive power demand. Third, Distributed Energy Resources (DRES) such as solar inverters and wind turbines can either consume or supply reactive power.

How are high voltage issues managed when integrating Distributed Energy Resources?

When too much DRES is present, it can lead to unacceptable high voltages. Reactive power schemes like coso(P) and Q(U) are utilized to manage voltage levels. Automatic voltage controls for transformers on the MV side are also used to maintain a constant voltage, which also affects overall reactive power flows.

What is the impact of simplified reactive power models on grid operators' capacity to estimate reactive power demand, and what future actions could improve these models?

Simplified reactive power models provide a valuable tool for HV grid operators to estimate reactive power demand and plan for a future powered by clean energy. Future research should focus on validating these models with real-world data and refining them to capture the dynamic behavior of increasingly complex distribution grids. This can help in proactively addressing challenges that prevent us from unlocking the full potential of renewable energy and build a sustainable energy future.

What challenges do High Voltage (HV) grid operators face in forecasting reactive power demand when integrating renewable energy, and how can these challenges be addressed?

HV grid operators face the task of accurately forecasting reactive power demand to effectively plan reactive power compensation and ensure voltage control. However, the fragmented nature of the underlying medium voltage (MV) and low voltage (LV) grids, coupled with limited real-time data, makes it a formidable challenge. Simplified reactive power models can provide valuable insights for grid operators.