18th November 2019
The gross development of any country is directly measured by its per capita energy consumption. Now with almost each nation trying to fall under the gamut of developing and further developed nation, the energy demand of the world is poised to increase. Estimates from the major research organization suggest that the world energy demand shall increase by more than 100% in the next 15~20 years (refer Figure 1). This means that the energy generation need to be ramped up in a similar fashion. However with the world focussing on renewables as a potential generation source and with the every altering energy requirements, both generation and consumption patterns around the world are changing at an imprecise rate.This directly means that the local and/or federal grid(s) may not always be able to accommodate such changes and the utilities need to source/dump additional energy to bridge the generation and demand gap. Additionally with various government(s) around the world focussing on secure and reliable supply of electricity 24x7x365, the stage is set for energy storage (batteries to be more appropriate).
Figure 1: Growing energy requirement of the world (Source: International Energy Agency)
A battery in the simple terms could be defined as a device which stores and delivers electrical energy when required. It basically comprises a positive and a negative electrode separated by an electrolyte (a liquid/semi-solid medium).The electrodes are usually two dissimilar metal (or metal polymer) where chemical reaction takes place when the battery is in use. During discharging, the electrode with the high electron affinity will release electron (which is known as anode) and the electrode with the low electron affinity will gain electron (which is known as cathode). This electron would travel through the load and thus allowing the battery to supply energy (refer Figure 2). Since the discovery and initial development of battery in the 18th century, various chemicals have been utilized to create batteries, which indirectly led to various compositions. Out of all those variants, use of lead acid and lithium ion battery have been prominent. While lead acid have been dominant, the energy storage market is now observing a significant shift to lithium ion battery. For a novice, it is hence necessary to understand the basics of both the battery technology and their implied advantages. Further it is also necessary to have a complete understanding about the indicators which led such shift.
Figure 2: Typical working of a battery (Source: Google)
Invented in early 1859 and put to commercial use in the early 19th century, Lead acid battery utilizes lead as a base material with the anode and cathode made up of lead & lead oxide respectively and mixture of sulphuric acid & water as an electrolyte.The battery utilizes chemical reaction between electrolyte and the cathode & anode to generate electricity. The amount of charge stored in/delivered by the battery depends on the concentration of the electrolyte and the area of the plate. While this was the basic chemistry, there were lot of variants of lead acid battery as mentioned below:
While the applications of the lead acid battery were ubiquitous, the ever increasing need of energy in the late 19th century required the amount of storage to increase exponentially. The batteries while cheap had various shortfalls which led the world to explore alternative technologies:
Figure 3: Typical limitations of lead acid battery
While this article dealt with Lead acid batteries, its types, applications and their advantages, the next article would focus on lithium ion battery explaining its variants & advantages over lead acid battery which has enabled a steep shift towards the technology. Further it would also give readers an overview of the market scenario for lithium ion battery and its applicability in Indian scenario. Keep looking at this space for our next article.
Let us all pledge to make solar energy the primary source of energy in the near future.
RAHE ROSHAN HAMARA NATION