Scientists tackle grid integration problem with smart technologyNew study finds solution to unpredictable solar power output

The transition to renewable energy sources is reducing our dependence on fossil fuels and providing a more sustainable alternative. However, this change also brings about new challenges.

One such challenge is the variability in power output from solar photovoltaic (PV) plants, which is subject to the unpredictable nature of weather and other environmental factors.

According to Prof. Mahesh Bandi, director of the Nonlinear and Non-equilibrium Physics Unit at the Okinawa Institute of Science and Technology (OIST), and Prof. Golan Bel of Ben-Gurion University of the Negev, there is a pressing need to find a way to anticipate changes in the amount of energy generated from solar photovoltaic systems. Their recent study, published in Physical Review Applied, presents a new approach to studying fluctuations in power output from solar PV plants over time, taking into account the unique power fluctuations observed in different regions.

Our electricity grid relies on a blend of energy sources to provide a consistent supply of electricity, yet the demand for electricity varies throughout the day. The challenge lies in balancing the fluctuations in power generation with the ever-changing demand for energy. To achieve this balance, gas turbines and energy trading are used to stabilize the supply and demand, which is crucial for critical facilities such as hospitals and data centers. However, the limited storage capacity of electricity grids means that energy production and consumption must be in sync to avoid blackouts.

The integration of variable renewable energy sources, such as wind and solar, into the power grid presents what is known as the "grid integration problem." These sources pose unique challenges due to their unpredictability and uncertainty in comparison to traditional energy sources. One possible solution to this problem is the use of smart grids equipped with sensors that can monitor supply and demand and make adjustments as needed. However, the design of such a network requires a deep understanding of different energy production scenarios, as renewable energy sources require careful analysis to balance supply, demand, and technology.

Scientists use a concept called the power spectrum to study changes in solar photovoltaic power output. This tool helps measure fluctuations in power generation across individual solar plants over different time scales, aiding in the effective planning and operation of solar PV systems. However, comparing measurements across different solar plants is challenging due to the changing environmental conditions, such as cloud cover and dust particles, which can cause intermittent and uncertain energy production.

In their study, Prof. Bandi and Prof. Bel built upon their previous research from 2019, in which they used the clear-sky index to calculate changes in solar power generation in different locations. The clear-sky index measures the amount of total solar radiation that reaches the Earth's surface under clear-sky conditions, providing insight into how deviations from ideal clear-sky conditions are affected by factors such as clouds, aerosols, and other atmospheric conditions.

Prof. Bandi explains, "With wind power, we have the advantage of a theory of atmospheric turbulence to help us understand these fluctuations. This is because the power generated by a wind turbine is directly related to the cube of the wind speed. However, for solar power, no such relationship exists. This means we do not have a systematic way or a theoretical framework to forecast changes in solar power output."

The researchers focused on analyzing the global radiation intensity measured at the Earth's surface to understand how it changes over time and how it is affected by factors that cause deviations from the predicted clear-sky conditions. This type of study had not been done before, and it provides a baseline to compare solar radiation across different geographic regions. The results showed that frequent changes in solar radiation were linked to unpredictable environmental changes, while intermediate changes were associated with clear-sky patterns.

In the future, this new method can be used to investigate how the size of solar PV plants and specific factors affecting energy absorption influence solar power generation in different locations. This could potentially shed light on why energy fluctuations vary across sites. While some intermittent changes in energy levels become less extreme when considering different locations, others may persist. By collecting and comparing data from solar PV plants in various locations, scientists can gain a better understanding of these fluctuations.

Ann Castro
Ann Castro Author
Ann Castro carries a total of 7 years experience in the healthcare domain. She owns a Master’s of Medicine Degree. She bagged numerous awards by contributing in the medical field with her ground-breaking notions. Ann has developed her own style of working and known for accuracy in her work. She loves trekking. She visits new places whenever she gets free time.