Electricity is essential to modern life, but its production does not always match the times when it is needed most. Electricity demand may increase during the evening, while solar power generation is often highest around midday. This mismatch presents a challenge for electrical power engineers, particularly as renewable energy sources become more widely integrated into power systems.
Battery energy storage systems offer a way to address this challenge by storing electricity for later use. However, an important question remains: How can we determine the best times to charge and discharge batteries to make the most efficient use of stored energy?
Why Do Power Grids Need Energy Storage?
Solar and wind power generation depend on weather conditions, which means their output varies throughout the day. Battery Energy Storage Systems (BESS) help manage these fluctuations by storing surplus energy and supplying it when needed.
For example, consider a solar power system that produces 50 kilowatt-hours (kWh) of surplus energy during the day. If this energy is stored in a suitable battery system with a round-trip efficiency of 85%, approximately 42.5 kWh can be recovered for use in the evening, assuming sufficient storage capacity and appropriate operating conditions.
This example illustrates an important principle: batteries do not generate additional energy. Instead, they allow energy to be used at a different time, while some energy is lost during the charging and discharging process.
Energy storage systems can also help reduce peak demand and support grid operation. However, achieving these benefits depends on effective energy management and compliance with the technical limitations of the batteries.
How Can Artificial Intelligence Support Decision-Making?
Some energy management systems operate according to predefined rules, such as charging batteries when surplus solar energy is available and discharging them when electricity demand increases.
But what happens if demand is expected to rise significantly in the evening, or weather forecasts indicate lower solar generation the following day? In such situations, retaining some stored energy may be more beneficial than discharging the battery immediately.
This is where Reinforcement Learning (RL), a branch of artificial intelligence, becomes relevant.
Reinforcement learning enables an algorithm to learn how to make sequential decisions by evaluating the outcomes of its actions. An RL algorithm can be trained in a simulated environment using information such as the battery's State of Charge (SOC), forecast solar generation, electricity demand, and energy prices where time-varying tariffs apply.
Based on these inputs, the algorithm can learn to select suitable charging and discharging actions while respecting the battery's operating constraints.
For instance, it may learn to preserve stored energy during periods of low demand and release it during peak hours when doing so provides greater operational or economic benefits.
However, reinforcement learning does not automatically outperform conventional control or optimization methods. Its performance must be tested and compared with established approaches.
Scientific Example: How Can Batteries Reduce Peak Demand?
Consider an industrial facility with an electrical demand of 70 kilowatts (kW) during a two-hour peak period.
Suppose a battery energy storage system can supply 15 kW continuously throughout this period. The power drawn from the main electricity supply could then be reduced from 70 kW to 55 kW, assuming the facility's demand remains constant.
To achieve this reduction, the battery system must deliver at least 30 kilowatt-hours (kWh) of usable energy over the two hours, with additional consideration given to conversion losses and operating limits.
An energy management algorithm can determine when to discharge the battery based on load forecasts and available stored energy. This process, commonly known as Peak Shaving, helps reduce the maximum power demand placed on the electricity supply.
It may also provide economic benefits under electricity tariffs that include time-dependent pricing or peak demand charges. However, the actual financial savings depend on the applicable tariff structure and operating conditions.
Can Artificial Intelligence Help Extend Battery Life?
Battery performance depends on more than the amount of stored energy. It is also influenced by temperature, charging and discharging currents, State of Charge (SOC), cycling patterns, and operating conditions.
Repeated operation under unsuitable conditions can accelerate battery degradation and reduce its available capacity over time.
Artificial intelligence-based energy management algorithms can consider these factors when making operating decisions, aiming to balance the benefits of using stored energy against the long-term effects of battery degradation.
However, it is important to distinguish between an AI-based Energy Management System (EMS) and a Battery Management System (BMS).
The BMS monitors essential battery parameters, including voltage, current, and temperature, and implements the necessary protection functions. An AI-based EMS, on the other hand, may support higher-level decisions about when and how much energy should be stored or released.
Artificial intelligence can therefore improve energy management decisions, but it cannot replace essential battery protection systems or guarantee a longer battery lifespan without supporting experimental evidence.
What Challenges Does This Technology Face?
Although research and simulation studies have produced encouraging results, applying reinforcement learning to real-world battery energy management still presents several challenges.
These include data quality, changing operating conditions, computational requirements, and the difficulty of ensuring safe decisions under unexpected circumstances.
An algorithm may perform well during training but produce less reliable results when faced with unfamiliar electricity demand patterns or unexpected changes in renewable energy generation.
For this reason, researchers are investigating approaches that combine reinforcement learning with conventional control and optimization techniques, while enforcing strict operational constraints to protect batteries and electrical networks.
Any proposed algorithm should be evaluated using measurable criteria, including operating costs, energy losses, compliance with technical limits, and the effects of charging and discharging decisions on battery degradation.
Research Opportunities in Electrical Power Engineering
This field offers valuable research opportunities for electrical engineering students and researchers.
A simplified power system consisting of a solar photovoltaic (PV) array, a battery storage system, and an electrical load can be developed using software such as MATLAB or Python.
Three energy management strategies could then be investigated: rule-based control, conventional mathematical optimization, and reinforcement learning.
Their performance can be compared using indicators such as energy utilization, operating costs, energy losses, and battery State of Charge. The evaluation should also consider different load profiles and weather conditions to assess how reliably each strategy performs.
Such research is becoming increasingly important as renewable energy systems, battery storage technologies, and smart grids continue to develop. These technologies create a growing need for flexible and reliable methods of managing electrical power systems.
Towards Smarter Energy Management
The future of electrical power systems depends not only on increasing electricity generation but also on improving how energy is stored, managed, and utilized.
Reinforcement learning represents a promising research direction for developing more flexible energy management strategies. Nevertheless, its practical value must be demonstrated through rigorous comparisons with conventional methods, while maintaining battery safety and power system reliability.
The central question remains: How can artificial intelligence be used to manage stored energy more effectively without compromising battery lifespan or the reliability of electrical power systems?
Addressing this question could contribute to the development of more efficient energy management systems and open new opportunities for research and innovation in electrical power engineering.
Al-Mustaqbal University — The First University in Iraq.