Renewable energy is the need of a sustainable society, as it allows us to stop depending on fossil fuels. But renewable energy sources are irregular and may not be available during periods of high demand. This is where battery technology plays the important role of storing the energy generated for future use.
By Megha Rawat
Stored renewable energy plays a crucial role in creating a more flexible and reliable grid system by balancing the supply and demand for power. Future homes and businesses are set to have their own batteries, and this will change how the entire power sector operates. These customers at homes and offices will be able to store electricity, and use it when its price is the highest. According to various analysts, this possibility could increase the demand for, and the interest in energy storage batteries. In the renewable energy sector, particularly, the development of long lasting, reliable and more efficient batteries is crucial.
The battery options available
There are many options available for renewable energy storage but finding a technology that can address challenges like an unstable grid, heavy cycling and irregular full charging, is very important.
Deepak Omar, general manager, Okaya Power Pvt Ltd, says that the manufacture of lithium-ion batteries (LIBs) is being seen as the next big opportunity in India’s renewable energy market, as researchers and manufacturers are experimenting with new technologies for storage batteries.
About the current battery manufacturing scenario, Sunil Bhatnagar, country head (energy division), Micromax Energy Ltd, says, “India is doing very well in the renewable energy field and there is very good scope for battery manufacturers. There are ample opportunities to supply batteries for solar home lights, solar streetlights, rural electrification programmes, etc. The main technologies are lead-acid tubular and VRLA, but now lithium technology is making inroads very fast. Till 2020, the potential for all battery manufacturers in India is excellent.”
“Technology is the most important factor now as lithium-ion and lithium-ferro phosphate batteries are coming up fast, for most applications. Carbon and graphene technologies are also evolving, apart from vanadium and other flow batteries. Fuel cells are also evolving fast,” he adds.
There are many options available in the market, but every type of battery has some advantages and disadvantages. A few challenges that need to be overcome in order to produce the right batteries for renewable energy are listed below.
- High prices: Bhatnagar says that a big challenge for the battery industry is the high price of metal, which is driven mainly by the London Metal Exchange (LME), but local factors also play a part. In the case of lithium, battery pack assemblies are currently not available in India. He says that lithium cell manufacturing may come up by late 2019. Foreign currency fluctuations are another major challenge these days, Bhatnagar adds.
- Short life cycle: Longevity, or the life cycle of a battery, plays an important role in deciding whether it is appropriate for storing renewable energy or not. Li-ion batteries do not last as long as required. There is an urgent need to improve the life cycle of batteries and to ensure that more energy can be stored for a longer period of time, without affecting performance.
- Low charging capacity: Charging capacity differs in every battery technology. For renewable energy storage, the charging requirement is very high as a huge amount of energy can be obtained from the energy sources. Battery technology has not yet advanced to the level where the charging capacity matches the pace and volume of the renewable power generated.
- Recycling woes: The batteries used for renewable energy storage have a low life cycle, which means that these become permanently dead after a few years. Recycling of these dead batteries is a major issue and, as of now, there is no viable, sustainable and eco-friendly solution to dispose them. This takes us to the environmental concerns and hazards linked to the materials used in manufacturing these batteries.
- Lack of a manufacturing ecosystem: India has no major producer of renewable batteries at present and lacks state-of-art facilities with adequate capacity. The cost of the batteries can be reduced if the battery packs can be built from the cells imported into India.
- Low availability of testing equipment: Every battery that is manufactured must go through several tests to check its capacity, longevity and charging/discharging time. To successfully test these parameters, testing equipment is needed. There are issues regarding the availability of testing equipment as well as the knowhow to conduct the tests. And there is lack of transparency on whether the tests are being conducted or not.
With differing requirements, the selection criteria for batteries also change. There are certain specifications that should be kept in mind while selecting the best battery option for energy storage.
- Capacity and power: Both parameters should be in sync so that you do not have to compromise either on the amount of energy stored or in the usage time.
- Efficiency: Batteries should be efficient enough for you to recover your investment in them. If a battery gives back only 70 per cent of the total energy, then it cannot be considered as highly efficient.
- Life cycle: With time, the quality and efficiency of a battery degrades and after ten years or so, it becomes useless or permanently dead. So, a battery with a higher life cycle is more valuable.
Bhatnagar says, “In the case of some batteries, the initial capex is low but the opex is high, so select a battery where we get the best value for money. The efficiency of a battery should be good, and its round-trip efficiency should be the best. It should also perform well and last long in high temperatures.”
Other parameters that should be kept in mind while buying a battery are energy density, power requirements, temperature, safety, maintenance, cost, charger requirements and environmental considerations.
|The pros and cons of different types of batteries|
|Lithium-ion||Cobalt oxide, lithium, phosphate, nickel, manganese, iron||
The future of battery manufacturing in India
There is no doubt that India is going to witness a boom in the battery manufacturing industry. As battery prices fall and the market for energy storage takes off, distributed solar power that is off-grid, in residences and in the commercial sector, is set to flourish.
Omar from Okaya says that with the market for EV batteries alone pegged at US$ 3 billion to US$ 5 billion, the manufacturing of lithium-ion batteries (LIBs) is set to gather pace in India in the coming days. Bhatnagar states that the future is bright despite a fall in power cuts as the energy storage segment is evolving into a big industry. Rural electrification, grid balancing, electric vehicles, battery swapping stations, smart cities and many more applications are emerging in the renewable energy sector. “There is a great future for batteries, but the technology may change from pure lead-acid to lead-carbon, fuel cells, vanadium, lithium, etc. Also, the domestic inverter battery market could go down due to an improved grid and increased use of renewables,” adds Bhatnagar.
Omar concludes, “It is high time we look ahead at new technologies in storage batteries, so that these offer more running time and weigh less. LIBs will address this challenge and several manufacturers are focusing on manufacturing them in India. Currently, LIBs are imported or assembled in India by importing cells from China, but several Indian manufacturers are gearing up to produce them indigenously.”