Solar photovoltaic panels produce energy only while the Sun shines, but lighting is required mainly during night. So, the solar energy needs to be stored, which is now generally done through lithium-ion batteries.
The lithium-ion batteries have some limitations. For one, cost of lithium-ion batteries is increasing year after year, so these are suitable for high-priced mobile items like vehicles and smartphones only. For stationary applications we need to find alternatives.
Second, lithium-ion batteries can handle a few thousand charge/discharge cycles only. This means the batteries need to be replaced after about five years of use.
Third, re-cycling of lithium-ion batteries is challenging and expensive. Also, India does not have lithium mines, so we are completely dependent on imports.
Fourth, lithium-ion batteries also use metals like nickel and cobalt. Therefore, these batteries are not environment-friendly. Besides, lot of mining is required to get these metals.
Hence, it becomes important to explore other devices for energy storage. Here we will explore use of supercapacitors for energy storage for low power but widespread applications.
This project will be published in a few weeks. If you want to access it now, refer to Electronics For You’s February 2023 Issue–print or ezine edition.
Thanks for the design of Low Power Standby or Backup Battery using Super Capacitor and Solar Panel. Is this economical enough? As a Super Capacitor costs from Rs.200 up to Rs.7500 and Solar Panel costs from Rs.100 up to Rs.3500, is this the right alternative for Li Ion or Alkaline Batteries? Or, are there suitable means to increase the overall storage capacity so that they can replace conventional Primary or Secondary Batteries? Although a Super Capacitor holds charge in the range of tens of Farads, their delivery of power over a long period is still below the actual field requirements.
“This is a good observation.
Demand for energy storage devices is increasing exponentially. Following are broad guidelines through which we can try to meet the demand.
1) Explore all types of storage devices.
2) Try to take advantage of their unique features. For example, supercapacitors can be charged and discharged 100000 times. So, it has 3 times more life than a lithium-ion battery even after charging several time in a day. Also, supercapacitors are environment friendly.
3) The cost issue can be tackled by increasing production. For that, we have to identify applications which are low lying fruits. This way, we can generate initial demand which will result in reduced price. In turn it will open up newer applications and improved capacitors.
With above points in mind, the clock power supply circuit has been designed. Even though it is a very small power application, it has the potential to eliminate crores of AA batteries. Thereby reducing hazardous waste.
Lastly, use of lithium-ion batteries for stationary applications is a waste of precious resource.
As far as solar panels are concerned, they have a long life of >25 years. Problem is the initial cost. That is the reason the government is offering subsidies. ”