Skip navigation

Tag Archives: Lithium-ion battery

Renewable energy is one of the fastest growing energy sources of our times. But still there are many obstacles to overcome, before it can substitute current methods of electricity generation using fossil fuels, or substitute petrol in cars. The main obstacle is, the intermittent and unpredictable nature of renewable energy sources, such as wind and solar. Wind blows only certain seasons of the year and then wind velocity fluctuates widely in a day. Similarly sun shines only certain hours in a day and the intensity of radiation varies widely in a day. The wind velocity and sun’s radiation intensity are critical components in designing a reliable energy system. It is an anomalous situation, when we need power, there is no sun or wind; when sun shines or wind blows, we may not need any power. How to overcome this anomaly? That is the key, in successfully deploying renewable energy technologies.

Currently we are using batteries to store the energy. When there is a wind with reasonable velocity or sunshine with reasonable radiation intensity, we can generate power and store them in batteries. The wind velocity should be above certain threshold limit, say such as, a least wind velocity of 3mts/sec for amount of hours, while designing a wind based energy system. The same principle applies to solar energy and we need certain minimum solar   intensity and several hours. But in reality, we don’t get these minimum operating parameters, which make the design of a renewable system more complicated.

Batteries can accumulate these small energy generations by intermittent sources of wind and sun, and store them. But these batteries have certain life between 3-5 years and requires regular maintenance, replacements.They also have certain charging and discharging cycles and limitations. At the end of its life, it has to be disposed carefully because these batteries are made of lead and acid, which are toxic materials. Many companies are trying to introduce better technologies such as ‘flow batteries’. But experience shows that such batteries are confined to only smaller capacities. Large scale storage is expensive and sometimes it is not economically feasible. Lithium-ion batteries are more efficient than Lead-acid batteries, but they are more expensive so the renewable energy projects become expensive and cannot compete with conventional fossil fuels, in spite of higher tariffs offered by Government as incentives. Moreover the demand for Lithium-ion batteries will increase substantially in the future, as more and more Electric cars are produced. But lithium sources are limited and it is not sustainable.

The best option to develop renewable energy systems is to generate Hydrogen using renewable energy and store them, instead of storing them in batteries. We can use stored Hydrogen to generate power, or use as fuel for the car, as and when we need. There are no maintenance or disposal problems with Hydrogen storage, when comparing with batteries. Hydrogen generators (electrolyzers) can generate Hydrogen when the intermittent power flows from wind or sun. They can run from a range of capacities from 5 to 100% of rated capacity and they are more suitable for renewable energy sources. But there will be a loss of energy, because the amount of power required to generate Hydrogen, is more than the power generated from the resulting Hydrogen by a Fuelcell.The initial cost will be higher, but it will give operational flexibility with least maintenance, and even adoptable to remote sites. Technology is improving to cut the cost of fuel cells and electrolyzers so that Hydrogen based renewable energy will become a sustainable source of energy in the future. Hydrogen is the only solution that can solve both power generation and transportation problems the world is currently facing.

There is a myth that electric cars will eliminate Greenhouse gas emission and reduce the global warming. Electric car will not reduce the greenhouse emission because; you still need electricity to charge your batteries. Companies promoting electric cars are now planning to set up their own battery charging stations because, customers have to charge batteries of these electric cars every now and then. Otherwise, they will not be able to drive their electric cars continuously.  There is no battery currently in the market that can last more than 28 hours between the charges, though many companies are trying to develop superior batteries. One company claims a Battery(electricity) of 300whr/kg, for their LLithium-ion polymer battery, much superior than other batteries, which can run 600kms, with 6 minutes charging. Though, new batteries such as semi solid Lithium-ion battery, based on the principle of ‘flow batteries’, are promising, it is still, a long way to commercialization. President Obama  has set a set a target of 1 million electric cars in US roads, by 2012.It is estimated that US has to produce about 40 billion dollars worth of domestically produced batteries. A lithium-ion battery which weighs less and stores more energy is the promising technology. But Lithium resources are limited. Battery is the heart of an electric car. These electric cars do not emit smoke, or make noise like petrol cars. But, these two factors alone are not sufficient to substitute traditional fossil fuel powered international combustion engines.

It is also true, that electric cars can cut green house emission to an extent, where fossil fuel consumed cars are replaced with electric cars. To that extend, the fossil fuel consumption by these cars are reduced. But the power to charge the batteries will still have to come from the common grid. Unless the power generation technology using fossil fuels is changed, there will be no dramatic greenhouse gas emission reduction by introducing electric cars. Alternatively, if cars are built on Hydrogen based fuel either using a conventional Internal combustion engine, or by using Fuel cell, then a substantial amount of greenhouse emission can be eliminated. However Hydrogen generation should be based on Renewable energy source only. Whichever way one looks at it, renewable energy is the key. Those Governments and companies who do not invest in renewable energy technologies and systems, now, will have to pay a heavy price, in the future. But even those companies investing on renewable energy technologies, should look beyond current technologies and systems. The best starting point for these industries will be to substitute ‘storage batteries’ with ‘stored Hydrogen’.

It is much simpler to install PV solar panels or wind turbines, and to generate Hydrogen on site, from water. One can store Hydrogen in fuelling stations, and fuel the cars. Honda was the first entrant into this market, who was focusing on fuel cell technology, using compressed hydrogen gas. Alternatively such Hydrogen can be generated from ‘Biogas’ generated from biological wastes and waste treatment plants. All necessary technologies are currently available to make it happen. Governments can try to promote small townships with Hydrogen fuel stations, and show case such models to the rest of the country or other nations to follow. This will help nations to reduce their greenhouse emission and at the same time, they can become self-sufficient in their energy requirements. They no longer have to depend on polluting oil and gas, from few Middle East countries. Countries like India with impressive economic growth heavily depend on oil imports and any slight fluctuation in oil prices can easily upset such growth. It is time Governments around the world take a serious look at Hydrogen, as their alternative energy source. It is just not good enough to promote renewable energy technologies, but they have to develop generation, storage and distribution technologies for Hydrogen. What is needed at this hour is, ‘will, determination and leadership’ on the part of the Governments, like US, China and India, that can set an example for the rest of the world by investing in Hydrogen economy.

%d bloggers like this: