Exploring the Challenges and Solutions for Integrating Renewables into the Grid
Integrating renewable energy sources into the electrical grid has become a top issue as the world moves faster toward a sustainable future. Solar, wind, and other renewable energy technologies are key to reducing greenhouse gas emissions, slowing climate change, and achieving energy security.
But grid systems, originally designed for centralized, stable, and predictable sources of power, are encountering significant challenges as they attempt to shift from fossil-fuel power generation to cleaner renewable energy. To make the most of renewables, the grid needs to adapt and be modernized, fit with smart technology, and use new energy management techniques.
Increase in Renewable Energy
Renewable energy is gaining momentum across the world. Solar and wind power, in particular, have experienced significant growth due to decreasing costs, technological advancements, and supportive government policies.
According to McKinsey, renewable energy sources (RES) are expected to account for 45 to 50 percent of the global power supply by 2030 and 60 to 70 percent by 2040. With such booming demand, RES installed capacity could grow nine times from 2020 to 2050.
Source: McKinsey
Challenges of Renewable Energy Integration
Intermittency: Renewable energy is intermittent, which is the major challenge for its integration into the grid. For example, solar energy production is maximized when the sun is shining in the middle of the day, but it sharply decreases when the sun goes down at night. In the same way, wind generation can vary with wind speed, leading to sudden drops or increases in generation according to the weather.
Grid Stability: The higher share of renewable energy also poses a challenge to maintaining grid stability. Grid operators depend on which power plants can turn up or down quickly to bring supply and demand into balance. This flexibility is provided by conventional fossil fuel plants and nuclear plants, while increasing use of renewables such as solar and wind cannot be controlled in this manner, creating issues such as voltage fluctuations, frequency imbalances, and harmonic distortions, all of which violate the stringent high-reliability standards maintained for stable grid operation.
Frequency stability is very important for safe and reliable operations between the electrical grid and the attached appliances.
Transmission and Distribution Constraints: Widespread deployment of renewable energy generation (notably solar and wind) can create significant transmission and distribution (T&D) constraints. Renewable power is often generated where wind and solar resource potential are high; the power demand typically concentrates in urban centers.
Conventional fossil fuel power plants would be constructed near cities and urban centers with the fuels moved there and burned to produce power. This mismatch between generation and demand can create transmission problems because power must transmit long distances from renewable generation sites to where it’s needed.
Storage of Energy: One of the unique ways to overcome this intermittency is through the storage of energy. When renewable energy generation is high (on sunny or windy days, for example), battery storage devices can capture surplus energy and then release it when generation is low.
Large-scale storage, above all batteries, is still expensive, however. In addition to batteries, other storage technologies such as compressed air energy storage and pumped hydro storage are also being explored. Those systems, however, have their drawbacks, including high capital costs and geographical constraints.
The Need for Change
As the share of renewable energy sources in our power mix increases, the old ways of managing the grid simply don’t work anymore. Real-time data, predictive analytics, and advanced forecasting can be tools that can help grid operators better understand and plan for patterns of renewable energy. Equipped with smart meters, sensors, and distributed energy resource (DER) data, operators can seamlessly respond to fluctuations in supply and demand.
Adoption of smart grid innovations that employ sophisticated sensors, communications networks, and data analytics to automatically detect and optimize the flow of electricity. Furthermore, smart grids can stabilize intermittent renewable generation by giving grid operators greater visibility and control over the management and distribution of power, allowing the integration of energy to optimize generation and enable fast response to imbalances.
Demand response systems, which incentivize consumers to change their energy consumption based on grid conditions, are flexible solutions for grid management that can work very well. For example, it might encourage users to draw more power when more renewable energy is coming online and to draw less power when less renewable energy is available to avoid stressing the grid.