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Tag Archives: Electricity generation

Fuel cell- a new concept in power generation

Power generation using fossil fuels is a well established technology dating back to 1839, when Michael Faraday invented the principle of Electro-magnetism. There was not much of a change in this technology all these years. But recently greenhouse emission and global warming has become an issue; and the world started looking for an alternative source of energy and method of power generation. However it is not an easy task to develop completely a different technology as well as a fuel in a short span of time, while an unabated man-made greenhouse gas emission continues. Scientists  are now warning  catastrophic consequences if we do not curtail greenhouse gas emissions with great urgency.Untill now the world was able to avert some of the potentially  catastrophic events happening, like ozone layer depletion, pandemic bird flu etc.But global warming is a new thereat  that demands an entirely a new solution and a swift action. But most countries in the world are not is a place to curtain greenhouse emission gas, simply because there is no alternative fuel known, except fossil fuels. Renewable energy is relatively a new concept. Though we knew about solar and wind energy sources, we did not persuade  them seriously because they could not compete with conventional fossil fuels. But the time has come for new emerging technologies that can not only compete with fossil fuels but also eliminate greenhouse emissions. The world has invested massively on fossil fuel infrastructures and still investing heavily on oil and gas explorations. Obviously there is no end in sight as far as fossil fuels are concerned and the world is carrying on business as usual.

Meanwhile a new technology based on fuel cell is emerging as an alternative for power generation. Fuel cell is a known concept and it has been successfully deployed in ‘Apollo space programme in space shuttle. This old version of alkaline fuel cells was replaced with PEM (proton exchange membrane) fuel cell or (PEMF) Polymer electrode membrane fuel cell. This new version was used in Gemini’s space programme in sixties. Fuel cell is an electro chemical device that uses Hydrogen gas as a fuel and it operates at ambient temperature. It is like a battery cell. The difference between fuel cell and batteries is the Fuel cell will keep generating power as long as fuel is supplied unlike a battery, where energy is stored in the form of chemical energy and converted into electrical energy when used by connecting through a conductor. Battery needs recharging but Fuel cell requires refueling. The fuel used in Fuel cell is invariably Hydrogen. Conventional power generation involves combustion of fossil fuel (heat energy) which drives a turbine (mechanical energy) to run an alternator to generate power (electrical energy).In fuel cell; Hydrogen gas reacts with oxygen from the atmosphere (electrochemically) to generate power. It produces water as by-product. The efficiency of Fuel cell is about 50-60% compared to 35-40% by steam or gas turbine. In regenerative fuel cell, we can split water into Hydrogen and oxygen using same proton exchange membrane elecrolyzer.We can use the resulting Hydrogen as a Fuel to the PEM Fuel cell to generate power, thus recovering  water. It is a closed circuit system. There are no mechanical moving parts, no combustion, no smoke or no noise. It is a quiet and clean operation. It is a very promising technology that can revolutionize the way we produce fuel and generate power. The Hydrogen and fuel cell combination is used in cars. Honda FCX (fuel cell model) cars work on the same principle and they are already on roads!

One problem with Hydrogen generation is it requires more power to split water, into Hydrogen and oxygen, than the power generated by resulting hydrogen, using Fuel cell. However, this technology will change the future of power generation by eliminating greenhouse emission completely. But how long it will take to become a commercial reality is something we have to wait and see! If political leaders and Governments around the world recognize the potential of this technology and take bold decisions together with swift actions, probably our future generation can breathe a clean air.

Hydrogen-the key to sustainability

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.

Can Electric cars eliminate greenhouse gas emission?

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.

Water and Energy

We know from the famous equation  of Albert Einstein , that a tiny amount of mass is a vast storehouse of energy. But even the molecular Hydrogen as a result of water decomposition, is a promising energy source of the future. However, the amount of energy we use to split water into Hydrogen and Oxygen is higher compared to the amount of energy that Hydrogen can generate using Fuel celll. But we can mitigate this problem by using Renewable   energy such as PV solar, Solar (thermal), wind energy, geothermal energy, and Ocean thermal energy conversion. The cost of renewable energy is still expensive for two reasons;

  1. We are used to cheap energy from fossil fuels for decades, and we have already recovered most of these investments.

2. A complete switch over to renewable energy technologies will require massive new investment. Unlike the investments we made on fossil fuel infrastructures over several decades, we have to invest on renewable Energy development on a massive scale, and we have to deploy them in a shorter span of time, simultaneously all over the world. Currently there is no such infrastructure in renewable energy industry in existence.

Meanwhile the unabated emission of carbon dioxide by fossil fuels is causing global warming. There are many skeptics on the science on global warming. Such skepticism does not stem from the fact that they have a concrete proof but, ‘such skepticism’ serves their vested interest. Politicians who are in power do not want any increase in the cost of energy, which becomes unpopular among people may eventually, throw them out of power. They say they want to serve people with low cost energy but, neither politicians nor the common man understands the consequences of such measures.

It will be our future generations who will face the brunt of this skepticism, by facing fuel shortage or unaffordable cost of fuel, erratic climate change, and frequent natural catastrophies.It is time for the world to act decisively and swiftly and move towards renewable energy, by massive investment and creation of new skills and jobs on a very large scale.

The companies who have massively invested in fossil power plants, and the governments who depend on the support of such companies and who want to keep the energy cost low, because of its popularity, are the major list of scientists opposing main stream scientific assessment of global warming. The hidden cost of environmental challenges and its consequences is much higher than the savings, due to cheap fossil fuels. It requires a paradigm shift and a sense of social justice, in the minds of Governments and companies. It is not all that difficult to switch over to cleaner technologies. In fact most of the technologies are already available and it requires only a ‘will, bold decision and leadership’ by Governments.

Any clean energy solution should be sustainable in the long run. Hydrogen can meet not only the sustainability but even the transition from fossil fuel to Hydrogen will be smooth. To start with all existing fossil fuel infrastructures can be modified towards Hydrogen generation, and fuel cell based Electricity generation  infrastructures. Of course this will require large investment but compared to a complete shift to renewable energy, it will require only a relatively smaller investment. For example, all fuel stations can be converted into Hydrogen stations by simply installing steam reformers, including LNG based fuel stations. All gasoline based automobiles can be either fitted with Hydrogen IC engines, or converted to fuel cells cars similar to Honda FXL models. If the Governments all over the world can agree for such conversion and a complete shift to Hydrogen economy then, it can become a reality in the next decade. We have to focus on ‘Renewable Hydrogen’, which can come from seawater, a waste source of Hydrogen using renewable energy sources, and Biohydrogen  using from waste organic matters. The future generation will not only have a cleaner and affordable fuel but, a more sustainable future!

Distributed -energy- systems

Distributed  generation system, is a system that generates power at the point of usage; unlike the centralized electricity generation, where power is generated at a remote place and then distributed to various locations using Power transmission  grids. The centralized systems became popular, due to its convenience, to transmit large power over long distances, under high voltage. However, there are several disadvantages, in centralized power generation and distribution. Most of these power generation plants are using fossil fuels, like coal, oil and gas, whose efficiency is only about 40%; which means, only about 40% of the heat value of the fuel used is converted into electricity, and the balance is a waste heat, discharged in the form of greenhouse gases, into the atmosphere. That is why; power station are the largest emitters of greenhouse gases, in the world. These plants are  not only the biggest emitters of greenhouse gases, but also a very inefficient, because bulk of the fuel is simply combusted and discharged into the atmosphere. With ever-increasing cost of oil and gas, these power plants are ‘white elephants’ that drain the oil and gas resources in the world and turn them into greenhouse gases. Such inefficiencies drive the cost of power high, and also increase the pollution levels. This unabated emission of greenhouse gas has to be curtailed.

At this juncture of global warming, and increasing energy cost, Governments and companies, should encourage distributed energy systems. The advantage with distributed energy systems is, when we generate energy  on site using a fuel, we can use the waste heat  in a productive way, thus increasing the power efficiencies from 40% up to 80-85%.This increase in efficiency, will result, is the reduction in the cost of energy. The power savings from distributed energy system varies  from 10% up to 80%. Industries and business who use continuous processes (24×7) and whose energy bill is substantial, are the ideal candidates for distributed energy systems. It is easier to adapt distributed energy system, with gaseous fuels, like natural gas and Hydrogen, than with liquid fuels such as diesel or solid fuel such as coal.

Distributed energy system can even be installed, using ‘Biogas’, where large quantity of  organic waste or waste water is available throughout the year, like dairy plants, breweries, municipal sewage systems etc.The power generated in DES system, is invariably a direct current (DC), which is usually converted into alternating  using rectifier,   before usage. But, part of this DC load, can be used directly in the form of Dc current, wherever necessary. For example, many consumers are using Light-emitting diode bulbs for lighting, to save energy. In distributed energy system, it is possible to use direct current for these applications because you can save a certain amount of energy in the process of converting DC to AC, and then again AC to DC.In fact, we can connect number of appliances directly  to  direct current.

In addition to the above advantages, we can utilize the waste heat  to generate steam, hot water, chilled water or space airconditioning.For example, if a distributed energy system generates  500 kw Electric power using natural gas, with an efficiency of 30%, the gas consumption will be about 1666 Kws.The remaining waste heat available is about 1166 Kws, which is equal to about 300 TR chilling capacity. This chiller can be used to air-condition an office space. The total efficiency of such system can be as much as 80%.We can reduce the cost of energy as much as 60% or more, in some cases.

Distributed energy system, is the best and cost-effective system to cut energy bills as well as to reduce Greenhouse gas Otherwise the power for air-conditioning has to come from the grid. It is a win situation, for everybody involved. Such system can also be used, with Hydrogen. In fact, the heat value of Hydrogen is much higher than any other fuel, such as coal, oil or gas. Hydrogen is the energy of the future that is not only clean but also sustainable.

” Water and Clean Energy -Two sides of the same coin”

Why I say “water and clean energy, are two sides of the same coin?” At the outset, it may sound odd, but in reality, these two are closely interconnected. Let us examine, step by step, how they are connected, to each other, and what are the implications, in terms of cost, and environmental issues.

Take for example, power generation industries. The two basic materials, any power plant require, are, fuel and water. It does not matter, what kind of fuel is used, whether it is a coal based power plant or liquid fuel based plant like Naphtha, or gas based plants, like piped natural gas or LNG Of course, this statement is applicable only, for existing, conventional power generation technologies, and not for PV solar or wind energy, technologies. Let us consider, only power generation, involving conversion of thermal energy, into electrical energy. Today, more than 80% of power generation in the world, is based on thermal power, including nuclear plants. What is the usage of water in power plants? All thermal power plants use steam, as the prime motive force, to drive the turbines, (gas turbine is an exception, but, even in gas based plants, the secondary motive force,  is steam, using waste heat recovery boilers, in combined cycle operations). The quality of water for conversion into steam is of high quality, purer, than our drinking water. The second usage of water is for cooling purpose. The water consumption by power plants, using once through cooling system is 1 lit/kwhr, and by closed circuit cooling tower, it is 1.7lit/kwhr .Only about 40% power plants in Europe, for example, use closed circuit cooling towers, and the rest use only ‘once through’ cooling systems. The total power generated in 2010, by two largest users, namely US and China, were 3792Twhrs and 3715 Twhrs  respectively. The total world power production, in 2008 was 20,262 Twhrs, using following methods.

Fossil fuel: Coal 41 %, Oil 5.50%, Gas 21%, Nuclear 13% and Hydro 16%.

Renewable: PV solar 0.06%, PV thermal 0.004%, Wind 1.1%, Tide  0.003 %, Geothermal 0.3%, Biomass &others 1.30%.

(1Twhrs is = 1,000,000,000 kwhrs)

The above statistics, gives us an idea, on how much water, is being used, by power generating plants, in the world. Availability of fresh water, on planet earth, is only 2.5% (96. 5% oceans, 1.70% ground water, 1.7% glaciers and ice caps, and 0.001% in the air, as vapor and clouds).The world’s precious water source, is used for power generation, while millions of people, do have water, to drink. The cost of bottled drinking water is US$ 0.20 /lit, in countries like, India. This situation is simply unsustainable.

The prime cause, for this situation, is lack of technology, to produce clean power, without using water. The power technology, we use today, is based on the principle of electromagnetism, invented, by Michael Faraday, in the year 1839. That is why, renewable energy, is becoming critically important, at this juncture, when the world is, at the cross road.

In order to overcome, the shortage of fresh water, many countries are now opting, for seawater desalination. Desalination, again, is an energy intensive process. For example 3-4 kwhrs of power is used, to desalinate 1 m3 of water. This  power has to come, from fossil fuel fired, thermal power plants, which are often co-located, with desalination plants, so that, all the discharge, from both the plants, can be easily pumped into the sea. Since, the world is running out of fresh water, we have to look for attentive source of water. In countries like India, the ground water is being exploited, for agricultural purpose, and the ground water is getting depleted. Depleting water resources is a threat to agriculture production. It is a vicious circle.

That is why, distributed energy systems, using Hydrogen as an alternative fuel,  is an important step, towards sustainability. One can generate Hydrogen from water, using renewable energy source, like solar or wind, and store them, for future usage. The stored Hydrogen can be used to generate power, as and when required, at any remote location (even where there is no grid power).The water is regenerated, during this process of power generation using Fuelcell, which can be recycled. There is no large consumption of water, and there is no greenhouse emission. It is a clean and sustainable solution. The same stored Hydrogen can also be used as a fuel for your car! Therefore; (The above statics are based on Wikipedia data).