Energy is essential to our lives, but it is a finite resource that needs to be used efficiently. Various energy storage technologies are the key to solving this problem and will play an important role in building a sustainable energy system of the future.
Energy is the ability to do work, and it is utilized in many forms in our daily lives. Examples include electrical energy to power our smartphones, chemical energy to move our cars, and thermal energy to generate electricity. Energy is essential to human life, and it’s a vital resource in the modern world. The energy we use doesn’t just make our lives easier, it also has a direct impact on the economy, industry, and the environment. Therefore, using energy efficiently has a significant impact not only on our personal lives, but also on the future of our country and the planet as a whole.
However, the resources for energy production are limited, so we need to use energy efficiently and conservatively. Energy conservation is not just about saving money, it’s about protecting resources and preserving the environment. Furthermore, the nature of energy generation facilities is such that once they are operational, they provide a certain amount of energy over their lifetime, which can lead to an imbalance in supply and demand. For example, there may be a shortage of energy during the day when energy usage is high, and a surplus of energy at night. To solve these problems, energy storage technologies that allow us to save in times of surplus and borrow when there is a shortage are essential, just like saving and withdrawing money from a bank. These technologies play an important role in helping us design a more sustainable future.
Energy storage methods can be categorized into mechanical, electrical, thermal, biological, and chemical storage, depending on their principles. Each storage method can be compared by energy conversion efficiency and energy density. Energy conversion efficiency refers to how much of the stored energy can actually be utilized, while energy density refers to the amount of energy generated per unit weight or unit volume. These two factors are important criteria for evaluating the efficiency of an energy storage method. For example, storage methods with high energy conversion efficiency can minimize energy losses, while high energy density allows for more energy to be stored in less space.
Mechanical storage is a method of storing excess energy by converting it into mechanical energy. Examples include pumped storage dams and compressed air storage. A pumped storage dam releases excess water from a hydroelectric dam to store energy during times of low energy consumption. Pumped storage dams pump the discharged water back up to a higher water level and use it to generate power during peak consumption periods. Although this method has a low energy density, it can store large amounts of energy and is already practical and widely used. Compressed air storage is a method of storing gas by pressurizing it to reduce its volume and then releasing it through a narrow gap when needed, using the pressure to turn a turbine to generate power. In layman’s terms, it’s like blowing up balloons to store excess energy and then using the compressed air when needed. This method mainly uses underground cavities to store air, which requires airtight technology to prevent air leakage, and has the disadvantage of emitting a lot of pollutants during the process.
Thermal storage uses excess energy to heat an object and utilize the stored thermal energy again when needed. For example, when heating in winter, a thermal storage wall can be constructed to absorb excess solar energy during the day, and when the temperature drops after the sun goes down, heat can be released from the thermal storage to heat the house. Similarly, a tank wall can be used to store solar energy during the day and use it to heat water at night. The disadvantage of thermal storage is that it is difficult to convert the stored heat into other forms of energy, meaning that the energy stored through thermal storage cannot be converted into electricity and used, but can only be utilized as heat. However, thermal storage plays an important role in sustainable building design, especially as it can significantly improve the heating and cooling efficiency of buildings.
Electrical storage involves storing excess electrical energy in lead- or lithium-acid batteries, which are then used when needed. This method is most often used for small-scale power supply rather than large-scale power supply. A typical example is the battery in a portable electronic device. The disadvantages of this method are that it’s easy to discharge and difficult to store electricity on a large scale. However, electricity storage is becoming increasingly efficient through continuous technological development and innovation, and it is expected to find more applications by connecting with renewable energy. The largest electricity storage system currently in operation is a large-scale electricity storage system in Fairbanks, Alaska, USA. It is capable of providing 26 MW of electricity for 15 minutes and 40 MW for 7 minutes in case of emergencies such as power outages.
Biological storage is the use of plants to store energy, or in other words, growing plants. Plants store solar energy through photosynthesis, and this stored energy can be used when needed. When plants grown in this way are dried and burned for energy, they are called biomass, and when the sugars stored in them are used to replace fossil fuels through chemical processes, they are called biofuels. While these biological storage methods have gained a lot of attention for their environmental friendliness, they have the disadvantage that it is difficult to artificially control the amount of energy in a short period of time. In addition, the resources and time required to produce biomass and biofuels, as well as their environmental impact, need to be taken into account, and more research and improvement is needed to make them truly sustainable.
The most famous chemical storage method is hydrogen. When energy is surplus, hydrogen is generated using methods such as electrolysis or pyrolysis of water, and then stored and used. This hydrogen is often used as an energy source for fuel cells. However, hydrogen has a low energy density compared to natural gas (methane), which is currently used in large quantities. The low energy density of hydrogen also means that a lot of technological development is needed to store and transport it. However, as an environmentally friendly energy source, hydrogen has the potential to play an important role in future energy systems, and research and investment in this area is continuing.
So far, we’ve covered a variety of energy storage methods. We need to use energy to survive, and the energy we get comes from limited resources, so we need to use it wisely. However, large-scale production of energy cannot be done immediately to meet our needs. Therefore, energy storage technologies are essential, allowing us to balance the supply and demand of energy. There are many different energy storage technologies being developed and researched, and the more advanced they become, the more sustainable energy systems we will be able to build. Research and investment in energy storage technologies will continue to be a major challenge for our future.
