How Is Solar Energy Stored ? 9 Storage Methods
Storing any form of energy in an efficient and effective manner is crucial to ensure its continuity and dependability. The same holds true for solar power. The infinite nature of this renewable energy resource becomes of no use if one is not able to tap into it, as and when required. So, how is solar power stored? What are the most viable storage methods? And, what is the nature of technology behind different storage methods? These, and many more such questions will be addressed in this article in a comprehensive manner. Read on, to know more.
Different Solar Power Storage methods
At present, there are nine storage methods when it comes to harnessing solar power. These can be clubbed under four broad categories. These include:
1. Battery Storage
Batteries are by far the most common way for private and public establishments to store solar power. When sun’s energy is transferred into a battery through solar panels, a chemical mechanism among the battery components secures the storage of the same. The reaction is reversed when the battery is discharged, permitting current to exit the battery.
1. 1 Lithium-ion batteries
Lithium-ion batteries are most commonly utilized in solar-based applications. They have ended up as the industry standard due to their high energy density, long life expectancy, and moderately quick charge and release rates. These batteries are compact, making them reasonable for domestic establishments where space is restricted, and their efficiency often surpassing 90% ensures that most of the put away vitality is recoverable.
1.2 Lead-acid batteries
Although they are older and less effective, lead-acid batteries, are still used especially in off-grid applications where cost is a major factor. They are more cost-effective upfront but come with disadvantages such as shorter life expectancies and lower energy density.
1.3 Flow batteries
On the cutting edge of battery innovation are flow batteries, which offer an interesting advantage which is the capacity to decouple energy capacity from control yield. This makes them especially reasonable for large-scale vitality capacity arrangements where duration and scalability are significant. Flow batteries work by circulating fluid electrolytes through a cell stack, empowering vitality to be put away in outside tanks, hence permitting simple scaling by expanding the estimate of these tanks. Whereas right now more costly and less compact than lithium-ion batteries, flow batteries hold massive potential for future utility-scale solar based storage applications.
We can say that solar-oriented storage batteries are fundamental in bridging the gap between energy generation and utilization, guaranteeing that solar power remains accessible when the sun isn’t shining and subsequently upgrading the steadiness and unwavering quality of renewable energy systems.
New battery innovation is growing at a rapid pace, which guarantees to provide cheaper, more adaptable battery capacity arrangements. In fact, U.S. energy storage capacity is anticipated to reach about 7.5 GW every year by 2025, a sixfold development from 2020, representing a market worth $7.3 billion.
2. Solar Thermal Energy Storage
Thermal storage methods capture and store sun based vitality as heat, which can be converted into electricity or utilized straightforwardly for heating purposes.
2.1 Concentrated solar power (CSP)
Molten salt storage is a broadly utilized thermal storage strategy in concentrated solar power (CSP) plants. It includes warming a blend of salts to high temperatures, which can afterward be utilized to generate steam and drive turbines when daylight isn’t accessible.
This method is especially useful in large solar power plants where the sun’s energy is concentrated to create high temperatures like Concentrated Solar Power (CSP) systems. Melted salt storage or heating a mixture of salts to temperatures as high as 600°C (1112°F) is one of the most popular thermal storage techniques. Typically the salts used are potassium and sodium nitrate. Power generation can continue even after sunset or during cloudy periods because these salts can hold heat for prolonged periods of time with little loss. In order to ensure a steady supply of power from solar energy the stored heat is used to create steam which powers turbines to generate electricity.
2.2 Phase Change Materials(PCMs)
Phase Change Materials(PCMs) are another thermal capacity strategy, where materials assimilate and discharge energy as they alter from one state to another, such as from solid to fluid. PCMs are utilized in both industrial applications and private heating systems, offering a productive way to store and discharge energy.
Utilizing Phase Change Materials (PCMs) which absorb and release thermal energy during their transition from solid to liquid states is another cutting-edge method. Large amounts of energy are stored at a constant temperature during the phase transition which makes PCMs exceptionally efficient. They are therefore perfect for spaces-constrained applications like small-scale industrial operations or home heating systems. Thermal energy storage can also be incorporated into construction materials to create passively heating and cooling structures which eliminates the need for active HVAC systems.
Thermal energy storage helps make solar power more reliable lessens reliance on fossil fuels and is essential to the wider uptake of renewable energy technologies by efficiently controlling the timing of energy use.
3. Mechanical energy storage
A reliable and tried-and-true technique for storing extra solar energy is mechanical energy storage which transforms solar energy into mechanical energy that can be transformed back into electricity when needed.
3.1 Pumped hydro storage
The most well-known type of mechanical energy storage is pumped hydro storage which is widely utilized worldwide. It functions by pumping water uphill from a lower reservoir using excess electricity produced during periods of maximum solar production. Water that has been stored is released through turbines when energy demand increases producing electricity.
This technique can store a lot of energy for a long time which makes it perfect for grid-scale applications. Its round-trip efficiencies typically range from 70 to 85%.
3.2 Compressed Air Energy Storage
Compressed Air Energy Storage (CAES) is another promising mechanical storage technique that stores air in large underground tanks or caverns by compressing excess energy. Compressed air is released heated and expanded via a turbine to produce power when electricity is required. Large-scale energy storage can be achieved with CAES systems albeit they are not as efficient as pumped hydro and need appropriate geological formations.
3.2 flywheel energy storage
Another creative mechanical method is flywheel energy storage which uses a rotating mass (the flywheel) to store kinetic energy.
The extra electricity accelerates the flywheel and when the flywheel slows down the kinetic energy is transformed back into electrical power. For applications requiring brief high-power bursts of energy like regulating grid frequency or supplying backup power flywheels are a good choice because of their quick reaction times and exceptional durability. Large-scale dependable renewable energy systems must include mechanical energy storage systems due to their scalability and longevity especially as solar and other intermittent energy sources gain traction in the world energy mix.
4. Hydrogen storage (P2G)
Emerging and extremely promising hydrogen storage is a great way to store solar energy, especially for large-scale long-term uses. This method also known as Power-to-Gas (P2G) is electrolyzing water to separate it into hydrogen and oxygen using excess electricity produced by solar panels. The produced hydrogen can be kept in a variety of media such as liquid compressed gas or chemical carriers like ammonia. One of the main benefits of hydrogen storage is that it can store enormous amounts of energy for long periods of time without suffering significant losses. This feature makes it perfect for adjusting for seasonal variations in solar energy production.
Fuel cells which combine hydrogen with airborne oxygen to produce electricity water and heat without emitting any harmful emissions can be used to transform stored hydrogen back into electricity when energy is needed. Because of this hydrogen is a clean and adaptable energy source that can be used to heat power industrial processes drive vehicles and generate electricity. Further improving its usefulness and acceptance is the ability to incorporate hydrogen into the current natural gas infrastructure either by mixing it in with the gas or by turning it into synthetic methane.
Notwithstanding its present drawbacks—such as comparatively high expenses and a lower overall efficiency when compared to direct battery storage—hydrogen storage is becoming increasingly recognized as a crucial technology for facilitating the energy systems’ deep decarbonization. It is anticipated that ongoing developments in fuel cell technology hydrogen storage methods and electrolyzer efficiency will reduce costs and increase the viability of hydrogen as a key element of a sustainable renewable energy future.
All of the abovementioned solar storage methods have their unique capabilities and their utility to different users. As we progress more there will definitely be more innovations in solar energy storage methods which will help in making it a common source of energy.
Final Thoughts
Increasing solar energy storage capacity is crucial in maximizing the effectiveness and availability of this clean, feasible control source. Building huge solar infrastructures will not be feasible unless and until we manage to store the energy produced so that we can ensure a steady supply of energy to meet all of our demands.
As the entire world is understanding and building consensus on the squeezing issue of climate change, the significance of renewable sources has become progressively clear. Among the different renewable alternatives, solar energy stands out as one of the foremost promising and rapidly growing arrangements.
Harnessing the sun’s inexhaustible vitality offers a feasible elective to fossil powers, making a difference in decreasing carbon emissions and fighting climate change.
Frequently Asked Questions
Charles Fritts invented the solar panel in 1883. He coated a thin layer of selenium with an extremely thin layer of gold and the device had an efficiency of only about 1%.
Before installing solar panels at home, complete knowledge about the system, the budget, technical aspects, and site inspection should be considered. Despite a DIY guide being available, seeking a professional for some help is recommended. To get a rough idea of how to go about it, you might want to check out this article :
How to install solar panels at home in india
The solar panels need to be cleaned at least once or twice a year to maintain their outstanding performance. Using a hose and a bucket of soap water would be the most effective method employed for cleaning.
A 3kW solar panel can generate 12–15 units of electricity/day. This energy can run multiple appliances like TV, Refrigerator, Air conditioners, Lights, Washing machine, and Fans except for a 2-ton Air conditioner.
