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Category Archives: Regenerative Fuel cell

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.

Photovoltaic  solar energy  is becoming popular as a source of clean energy and an alternative to fossil fuels to combat climate change. Though the initial cost is expensive people have started realizing the potential of PV solar as  a real alternative to grid power, especially when they can export surplus power to the grid and earn some revenue. It is  a source of income for potential investors as the energy cost keeps rising steadily. The cost of solar panels, batteries and inverters are slowly coming down as the systems get more popular and more competition is created in the market. However, during cloudy days or when the solar hours are less, the power generation by solar panels is considerably low. Moreover, the ‘power in tariff ‘ system is not available in many countries especially in developing countries. Therefore, energy storage becomes an issue. Lead acid batteries serve as storage devices for smaller applications but it becomes expensive for lager systems. Operation and maintenance, replacement and waste disposal are some of the issues with battery storage.

Generating Hydrogen on site using solar power and storing Hydrogen under pressure in a tank is the best method of storing solar energy. The stored Hydrogen can be used to generate power using a Fuel cell as and when we need power. However, the amount of energy required to convert water into Hydrogen using Alkaline Electrolyzer or Solid Polymer Electrolyzer is still high, averaging 5-7 kwhrs/m3.When you calculate the economics of  Hydrogen storage versus battery storage using a computer modeling for a stand alone system, it is clear that Hydrogen storage is more economical and also guarantees an uninterrupted power supply using a Fuel cell.

One US company has developed a Carbon doped Titanium oxide nanopowder visible light photo catalyst to  generates Hydrogen using sun’s light energy. The company claims that it consumes only one-third of the power consumed by PEM Electrolyzer or half of an Alkaline Electrolyzer.It can be easily installed at roof tops and it can generate Hydrogen even at one-third of sunlight because it can effectively use short UV light and blue wave length of suns light because these energetic wavelengths penetrate cloud cover more effectively than the rest of sunlight. A 2mm modular solar panel can be installed on roof top or installed in multi-acre field installations. Even during the absence of sunlight the company claims it can use grid power to generate Hydrogen using its hybrid integral (MMO) Mixed metal oxide Titanium anode as efficiently as PEM Electrolyzer.

While a PEM electrolyzer generates about 1.3kg Hydrogen from a power input of 100Kwhrs, this model can generate about 2.5kg Hydrogen using MMO + TiO2 anode and about 3.8kg using TiO2 alone. (Based on higher heating value of Hydrogen at 39.4 kwhrs/kg).The panel consuming 26.7kwhr power at 1.0Volt DC current at Anode can generate 1.25kg Hydrogen with Electrolysis electrical efficiency at 148%.  This will make Hydrogen fuel a commercial reality because it will consume only 21.36 kwhrs of Dc power to generate 1 Kg Hydrogen. The generated Hydrogen can generate about 15 Kw power using a Fuel cell. This is an elegant solution to generate and store power using sun’s light than Photovoltaic power.

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