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Author Archives: ahilan@cewt.tech

Professional chemical engineer,specializing on clean energy and water technologies.He has more than 35 years of industrial experience in various process industries.Bulk of his experience were in R&D and commercialization.He has few innovative National and International patents on desalination and power generation. His latest patent is to store renewable energy such as solar, wind and geothermal in the form of SNG (synthetic natural gas) to generate base load power. You can eliminate the usage of fossil fuel and substitute with SNG with Zero Carbon emission. He is also a writer on Eastern philosophy, especially on Advaita Vedanta. He believes that science and Vedanta are two sides of the same coin. Science applies to this physical world, and it has its limitations. However, spirituality transcends science and the physical realm. It is your TRUE NATURE. Please check my LinkedIn profile.

Can we duplicate Nature’s photosynthesis for Hydrogen production?

One of the wonders of Mother Nature is her ability to sustain life on earth with sun light, water and Carbon dioxide from the atmosphere producing food. No toxic chemicals, no polluting gas emissions and no noise. We can only admire the majesty and power of Nature with our  fragile knowledge of science and try to duplicate Nature to satisfy our growing energy needs. Nature produces Carbohydrates C6H12O6 using sun’s light, Carbon dioxide from atmosphere and water by a chemical reaction as shown below:

6H2O + 6 CO2  ———–   C6H12O6 + 6O2

The same Carbon dioxide from the atmosphere is now threatening the globe with warming. Can’t we grow more trees so that all the carbon dioxide emissions from our power plants and cars can be converted into more carbohydrates? It sounds very simple and logical but is it feasible? The carbon dioxide in the atmosphere before industrialization was about 280ppm but it has now increased to 392ppm which is almost double. It has grown roughly 2.2% exponentially in the last decade. It is the highest in the past 800 years and likely higher than in the past 20 million years. (Ref: Wikipedia). Couple of things happened during this period. The industrial and population growth increased rapidly building up carbon dioxide level in the atmosphere and at the same time displacing tropical and rain forests with people and industries; it resulted in the buildup of greenhouse gases to a level, which scientists say are unsustainable. We don’t have enough forest to absorb so much of carbon dioxide.

Alternatively, scientists are now trying to interfere with Nature’s photosynthesis process using micro algae called chlamydomonas reinhardtii that will support the production of Hydrogen instead of Oxygen in a normal photosynthesis reaction. This was based on the discovery that if an algae growing culture medium is deprived of Sulfur, it will generate Hydrogen instead of Oxygen. They also found out that such an algae can thrive in a Carbon source such as Carbon dioxide or even in  Acetic acid medium. They tested the process using a pilot Photo bioreactor and concluded that the cost of producing Hydrogen by this route will be about $ 42/kg.The cost is high compared to the target cost of Hydrogen by DEO  (Department of Energy,USA) at $2.80/kg which is fifteen times lower. However scientists are still working to cut the cost.

Meanwhile scientists are also working on Hydrogen production using Photoelectrolysis.The water electrolysis using Direct current is a known process but the cost of energy in this process is still high. The high cost is due to several stages involved. In the first stage, one has to generate power using PV cells. In the second stage the PV generated electricity will be used to split water electrolyticlly.But scientists are now trying to substitute both the above steps with a single step of utilizing direct sun light to split water into Hydrogen and Oxygen.Thie requires a catalyst known as Photocatalyst which will use light energy instead of electrical energy to split water into elements. Using TIO2 (Titanium dioxide coated electrode) and ultraviolet rays of the sun they believe that a 20m2 PV solar panel can generate about 5m3 of Hydrogen ad 2.5m3 of Oxygen in 24 hours, equal to a power generation capacity of 15kwhrs or roughly about  2.01 gallons of Gasoline from 4 liters of pure water.

Scientists are now  hoping that light energy, more precisely ultraviolet rays from the sun will come to the rescue of human beings in solving one of the greatest  energy crisis  in the history of mankind. At last we can hope to see some ‘light’ at the end of the tunnel.

Why should you choose Photovoltaic Hydrogen over Photovoltaic battery?

 Photovoltaic (PV) power is becoming popular worldwide as an alternative to grid power for various reasons. It gives an energy independence and freedom, it helps reduce greenhouse gas emission and combat global warming, it helps people taking advantage of various Government subsidies and incentives, and it also generates some revenue by selling surplus power back to the grid. At the end of the period you own the system and claim depreciation and some tax benefits. All these compelling factors may motivate people to opt for PV solar power. But you should also do some math and make a cost benefit analysis to choose a right system for you.

When there is a good sunshine day after day and throughout the year, PV solar is good proposition and can be really rewarding. Unfortunately that is not the reality. There may be many cloudy, rainy and fogging days in a year and your PV solar capacity may be overestimated or underestimated. You know the real data only after one or two years of life experience. It is a long-term financial and ethical decision one has to make and the decision should be absolutely right. You can make such a decision by carefully examining all the factors, not just by looking at the first cost but looking at operating and maintenance costs and all the costs and benefits associated with them.

Storage batteries are inevitable in PV solar systems, especially for grid independent systems. Even with grid connected PV solar system the design and installation of a correct battery bank, controllers and rectifier are important issues. In this article we will discuss about grid independent system because many developing countries in Africa and Asia do not have 24×7 uninterrupted grid power supplies. Many people living in islands have to manage their own power by using diesel generators. This is the stark reality.

Let us assume that you design a system assuming a daily average power consumption of 25,000 kwhrs/day, which is suitable even for a medium size family in US. We made an optimum design study between two  systems; first  containing PV solar,battery,controller for grid independent power supply; and second  system with PV solar, battery, water Electrolyzer,Hydrogen storage  and PEM Fuel cell and a rectifier for grid independent system,  based on the same power consumption of 25,000kwhrs/day. You can clearly see the difference between the two systems by the following data.This financial analysis was made assuming there is no Government subsidies and incentives.

Grid independent system with battery storage for 25,000kwhrs/day power:

Total NPV (net present value):$ 342,926

Levelized cost of energy: $2.94/kwhrs

Operating cost/yr: $22,764

Grid independent system with Hydrogen storage for 25,000kwhrs/day power:

Total NPV (net present value): $ 169,325

Levelized cost of energy : $ 1.452/kwhrs

Operating cost/yr: 8,330

The number of batteries required in the first case is 17 numbers. In the second case, number of batteries required is only 2.Obviously,  the levelized cost of power using  PV Hydrogen (storage) is less than 50% of the power generated using PV battery (storage) for the same energy consumption of 25,000kwhrs/day. The operating cost is only one-third for PV Hydrogen system compared to battery system. Batteries are indispensable in any renewable energy system but reducing their  numbers to the lowest level is important, when the life of the system varies from 25 years to 40 years. The numbers and the cost of batteries and their maintenance cost  will make all the difference.

 

Sustainable Hydrogen from bio-waste

It is clear substituting fossil fuels with Hydrogen is not only efficient but also sustainable in the long run. While efforts are on to produce Hydrogen at a cost in par with Gasoline or less using various methods, sustainability is equally important. We have necessary technology to convert piped natural gas to Hydrogen to generate electricity on site to power our homes and fuel our cars using Fuelcell.But this will not be a sustainable solution because we can no longer depend on piped natural gas because its availability is limited; and it is also a potent greenhouse gas. The biogas or land fill gas has the same composition as that of a natural gas except the Methane content is lower than piped natural gas. The natural gas is produced by Nature and comes out along with number of impurities such as Carbon dioxide, moisture and Hydrogen sulfide etc.The impure natural gas is cleaned and purified to increase the Methane content up to 90%, before it is compressed and supplied to the customers. The gas is further purified so that it can be liquefied into LNF (liquefied natural gas) to be transported to long distances or exported to overseas.

When the natural gas is liquefied, the volume of gas is reduced about 600 times to its original volume, so that the energy density is increased substantially, to cut the cost of transportation. The LNG can be readily vaporized and used at any remote location, where there is no natural gas pipelines are in existence or in operation. Similarly Hydrogen too can be liquefied into liquid Hydrogen. Our current focus is to cut the cost of Hydrogen to the level of Gasoline or even less. Biogas and bio-organic materials are potential sources of Hydrogen and also they are sustianable.Our current production of wastes from industries business and domestic have increased substantially creating sustainability isues.These wastes are also major sources of greenhouse gases and also sources of many airborne diseses.They also cause depletion of valuable resources without a credible recycling mechanisms. For example, number of valuable materials including Gold, silver, platinum, Lead, Cadmium, Mercury and Lithium are thrown into municipal solid waste (MSW) and sewage. Major domestic wastes include food, paper, plastics and wood materials. Industrial wastes include many toxic chemicals including Mercury, Arsenic, tanning chemicals, photographic chemicals, toxic solvents and gases. The domestic and industrial effluents contain valuable materials such as potassium, Phosphorous and Nitrates. We get these valuable resources from Nature, convert them into useful products and then throw them away as a waste. These valuable materials remain as elements without any change irrespective of type of usages.Recyling waste materials and treatment of waste water and effluent is a very big business. Waste to wealth is a hot topic.

The waste materials both organic and inorganic are too valuable to be wasted for two simple reasons. First of all it pollutes our land, water and air; secondly we need fresh resources and these resources are limited while our needs are expanding exponentially. It is not an option but an absolute necessity to recycle them to support sustainability. For example, most of the countries do not have Phosphorous, a vital ingredient for plant growth and food production. Bulk of the Phosphorus and Nitrates are not recovered from municipal waste water and sewage plants. We simply discharge them into sea at far away distance while the public is in dark and EPA shows a blind eye to such activities. Toxic Methane gases are leaking from many land fill sites and some of these sites were even sold to gullible customers as potential housing sites. Many new residents in these locations find later that their houses have been built on abandoned landfill sites. They knew only when the tap water becomes highly inflammable when lighting with a match stick. The levels of Methane were above the threshold limit and these houses were not fit for living. We have to treat wastes because we can recover valuable nutrients and also generate energy without using fresh fossil fuels. It is a win situation for everybody involved in the business of ‘waste to wealth’.

These wastes have a potential to guarantee cheap and sustainable Hydrogen for the future. Biogas is a known technology that is generated from various municipal solid wastes and effluents. But current methods of biogas generation are not efficient and further cleaning and purifications are necessary. The low-grade methane 40-55% is not suitable for many industrial applications except for domestic heating. The biogas generated by anaerobic digestion has to be scrubbed free of Carbon dioxide and Hydrogen sulfide to get more than 90% Methane gas so that it can be used for power generation and even for steam reforming to Hydrogen generation. Fuel cell used for on site power generation and Fuel cell cars need high purity Hydrogen. Such Hydrogen is not possible without cleaning and purifying ‘ biogas’ much. Hydrogen generation from Biogas or from Bioethanol is a potential source of Hydrogen in the future.

Will Bioethanol and Hydrogen replace Gasoline?

Many universities, research and development institutions and industries are studying various biological processes to produce Hydrogen using different sources of organic materials such as Starch, Glucose, Bioethanol and cellulosic materials. However many of these technologies are at an early “proof of concept’ stages.  Moreover these processes depend upon site and availability of specific raw materials in these locations. For example, Brazil has been very successful in the production of Bioethanol from sugar cane molasses and using it as the fuel for cars. Brazil has also successfully used Bioethanol as a substitute for Naphtha as a feedstock for the production of ethylene, a precursor for a several plastics such as PVC and Polyethylene and Glycols. Bioethanol is a classic example of biological process than can successfully substitute Gasoline .Many industrial raw materials are also derived from Sugar cane and Corn Starch. The main issue in substituting Gasoline with bio-chemicals is political, in many countries. India has produced industrial alcohol from sugarcane molasses for  number of years but they were not be able successfully substitute Gasoline with Alcohol. They have to fix the price of Alcohol in relation to the price of Gasoline or Naptha.This pricing mechanism is critical.

We have been using coal as the raw material for several decades not only to generate power but also to produce host of organic chemicals and fertilizers such as Urea, coal-tar chemicals such as dyes and pharmaceuticals. These industries later switched over to oil and Gas. Now the world is facing depletion of fossil fuels at a faster rate. Greenhouse emission and global warming threats are looming large. There is a clear sign that the energy prices will sharply increase in the near future. Renewable energy projects are at early stages and their first costs and cost of productions are much higher compared to fossil fuel based power generation. However biological processes and biofuels offer a glimpse of hope to get over the energy crisis and also to mitigate greenhouse gas emissions.

Production of   Biohydrogen using bio-organic organic materials such as starch, glucose and cellulosic materials are under development, but it may be a decade before they can be successfully commercialized. But production of Bioethanol and Biogas are well-known technologies. Generation of Biogas from agricultural waste, food waste and municipal solid waste and waste water are known technologies. However Methane the major constituents of biogas, is a potential greenhouse gas. The Biogas can be easily cleaned from other impurities such as Carbon dioxide and Hydrogen sulfide and can be readily converted in Hydrogen gas by steam reformation. This will substantially increase the energy efficiency of Biogas plants.

Many developing countries can adopt these technologies on a wider scale and promote Bioethenaol and Biogas generation to substitute petroleum oil and gas. They can convert Gasoline cars into 100% Bioethanol (anhydrous) or blended with gasoline fuels for cars. These technologies are commercially available. Some countries in Asia, Africa and South America produce various starches such as Tapioca starch for industrial applications. Vegetable oils such as Jatropha and Castor oils are excellent for bio-fuels and lubricants. Though it is theoretically possible to substitute most of the petrochemicals with bio- organic materials, it is important that food products such as corn should not be diverted for commercial applications such as fuel.

The coming decade will be a challenging one and Hydrogen generation from various biological organic materials can substitute fossil fuels at a much faster rate. A judicial mix of bio-energy and renewable energy such as solar and wind should help the world to overcome the challenges.

Hydrogen is the choice of Nature as a source of clean energy

There is so much discussion about Hydrogen as a source of clean energy because, it is the choice of Nature. Nature has provided us with fossil fuels which are Hydrocarbons, chemically represented by CxHy, Carbon and Hydrogen atoms. In the absence of Hydrogen in a Hydrocarbon, it is nothing but Carbon, which is an inert material. The Hydrocarbon gets its heating value only from the presence Hydrogen atom. The natural gas, now considered as the cleanest form of Hydrocarbon is represented by the chemical formula CH4, containing 25% Hydrogen by weight basis. It represents the largest Carbon to Hydrogen ratio at 1:4.This is the highest in any organic chemicals. In aromatic organic compounds such as Benzene, represented by C6H6, the Hydrogen content is only 7.69%.Even in Sugar which is an organic compound from Nature, represented chemically as C12H22O11 has only 8.27% Hydrogen. But Bioethanol, derived from sugar represented by C2H5OH has almost 13% Hydrogen.  Ethyl Alcohol known as ‘Bioethanol’ derived from sugar is blended with Gasoline (Hydrocarbon), for using as a fuel in cars in countries like Brazil. Brazil is the only country that does not depend on imported Gasoline for their cars. The same Bioethanol can also be derived from Corn starch. But the starch should first be converted into sugar before alcohol is derived; that is why it is more expensive to produce Bioethanol from starch than from cane sugar molasses. The climatic conditions of Brazil are more favorable for growing Cane sugar than corn.  Brazil is in a more advantageous position than North America, when it comes to Bioethanol. US is one of the largest consumer of Gasoline.US has imported 11.5 million barrels/day of oil in 2010.It has used 138.5 billion gallons of Gasoline (3.30billion barrels) in 2010) according to EIA. (US Energy Information Administration) It is estimated that Brazil’s sugar based Alcohol is 30% cheaper than US’s corn-based Alcohol. Brazil has successfully substituted Gasoline with locally produced alcohol .They also introduced ‘flexible fuel vehicles’ that can use various blends of Alcohol-Gasoline. Most of the Gasoline used in US has 10% Ethanol blend called E10 and E15, representing the percentage of Alcohol content in Gasoline. Brazil is the largest producers of Bioethanol in the world. Both Brazil and US account for 87.8% of Bioethanol production in the world in 2010 and 87.1% in 2011.Brazil is using Bioethanol blends of various proportions such as E20/E25/E100 (anhydrous alcohol) (Ref: Wikipedia). Almost all cars in Brazil use Bioethanol blended Gasoline and even 100% anhydrous Bioethanol are used for cars. Brazil has set an example as a ‘sustainable economy introducing alternative fuel’ to the rest of the world. The ‘bagasse’ from cane sugar is also used as a fuel as well in the production of ‘Biogas’, which helps Brazil to meet sustainability on renewable energy and greenhouse gas mitigation. The above example is a clear demonstration of sustainability because natural organic material such as sugar is the basic building block by which we can build our Sustainable clean energy of the future. The same Bioethnanol can easily be reformed for the production of Hydrogen gas to generate power and run Fuel cell cars. Many companies are trying to use chemicals such as metal Hydrides as a source of Hydrogen. For example, one company successfully demonstrated using Sodium Borohydride for Hydrogen production. Many companies are trying to find alternative sources of Hydrogen generation from water, including Photo-electrolysis using direct solar light and special photo catalyst materials. We know Nature produces sugar by using sun’s light, water and carbon dioxide from air by photosynthetic process. Can man duplicate this natural process and generate Hydrogen at the fraction of the cost by simply using water and sun’s light? The race is already on and only time can tell whether our pursuit for cheap and clean Hydrogen can become a commercial reality or just stay as an elusive dream.

Hydrogen is the choice of Nature as the source of clean energ

There is so much discussion about Hydrogen as a source of clean energy because, it is the choice of Nature. Nature has provided us with fossil fuels which are Hydrocarbons, chemically represented by CxHy, Carbon and Hydrogen atoms. In the absence of Hydrogen in a Hydrocarbon, it is nothing but Carbon, which is an inert material. The Hydrocarbon gets its heating value only from the presence Hydrogen atom. The natural gas, now considered as the cleanest form of Hydrocarbon is represented by the chemical formula CH4, containing 25% Hydrogen by weight basis. It represents the largest Carbon to Hydrogen ratio at 1:4.This is the highest in any organic chemicals. In aromatic organic compounds such as Benzene, represented by C6H6, the Hydrogen content is only 7.69%.Even in Sugar which is an organic compound from Nature, represented chemically as C12H22O11 has only 8.27% Hydrogen. But Bioethanol, derived from sugar represented by C2H4OH has almost 11.11% Hydrogen. That is why Ethyl Alcohol known as ‘Bioethanol’ derived from sugar is blended with Gasoline (Hydrocarbon), for using as a fuel in cars in countries like Brazil.

Brazil is the only country that does not depend on imported Gasoline for their cars. The same Bioethanol can also be derived from Corn starch. But the starch should first be converted into sugar before alcohol is derived; that is why it is more expensive to produce Bioethanol from starch than from cane sugar molasses. The climatic conditions of Brazil are more favorable for growing Cane sugar than corn. That is why Brazil is in a more advantageous position than North America, when it comes to Bioethanol. US is one of the largest consumer of Gasoline.US has imported 11.5 million barrels/day of oil in 2010.It has used 138.5 billion gallons of Gasoline (3.30billion barrels) in 2010) according to EIA. (US Energy Information Administration)

It is estimated that Brazil’s sugar based Alcohol is 30% cheaper than US’s corn-based Alcohol. Brazil has successfully substituted Gasoline with locally produced alcohol .They also introduced ‘flexible fuel vehicles’ that can use various blends of Alcohol-Gasoline. Most of the Gasoline used in US has 10% Ethanol blend called E10 and E15, representing the percentage of Alcohol content in Gasoline. Brazil is the largest producers of Bioethanol in the world. Both Brazil and US account for 87.8% of Bioethanol production in the world in 2010 and 87.1% in 2011.Brazil is using Bioethanol blends of various proportions such as E20/E25/E100 (anhydrous alcohol) (Ref: Wikipedia). Almost all cars in Brazil uses Bioethanol blended Gasoline and even 100% anhydrous Bioethanol are used for cars. Brazil has set an example as a ‘sustainable economy introducing alternative fuel’ to the rest of the world. The ‘bagasse’ from cane sugar is also used as a fuel as well in the production of ‘Biogas’, which helps Brazil to meet sustainability on renewable energy and greenhouse gas mitigation.

The above example is a clear demonstration of sustainability because natural organic material such as sugar is the basic building block by which we can build our Sustainable clean energy of the future. The same Bioethnanol can easily be reformed for the production of Hydrogen gas to generate power and run Fuel cell cars. Many companies are trying to use chemicals such as metal Hydrides as a source of Hydrogen. For example, one company successfully demonstrated using Sodium Borohydride for Hydrogen production. Many companies are trying to find alternative sources of Hydrogen generation from water, including Photo-electrolysis using direct solar light and special photo catalyst materials. We know Nature produces sugar by using sun’s light, water and carbon dioxide from air by photosynthetic process. Can man duplicate this natural process and generate Hydrogen at the fraction of the cost by simply using water and sun’s light? The race is already on and only time can tell whether our pursuit for cheap and clean Hydrogen can become a commercial reality or just stay as an elusive dream.

 

 

 

The changing chemistry of our oceans

Seawater is the largest source of Fresh water as well as the source of Hydrogen energy.However; Seawater cannot be used directly for these applications and it requires further treatment. Seawater has a number of dissolved salts and the TDS, total dissolved solids, of seawater is about 35,000ppm (parts per million).The commonly used industrial desalination process is by RO (reverse osmosis) as well as by multi flash distillation (MFD). Both these processes are energy intensive.RO process requires electrical energy and MFD requires thermal energy. Most of the countries in Pesian  Gulf use desalination process to convert seawater into drinking water as well as industrial water. These oil rich countries depend on the desalinated seawater as their main source of drinking water supply. In the desalination process by RO, the TDS level of seawater is reduced from 35,000ppm to 500ppm, meeting the WHO (World Health Organization) specifications for drinking purpose. The advantage with reverse osmosis process is it can remove even the smallest bacteria and virus, during the desalination. The water can further be disinfected by the injection of Chlorine before distributing for drinking purpose.

Majority of Desalination plants use RO process because it is economical. There is a worldwide shortage for safe Drinking water and more and more SWRO plants are coming up in various parts of the world. The technology of RO has advanced so much that the cost of desalinated seawater can compete with surface water in many parts of the world, especially in Gulf region where the energy cost is low. The rapid increase in population and industrial growth has created a greater demand for fresh water.

In conventional SWRO process, only 35-40% of fresh water is recovered and the balance 60-65% is discharged back into the sea as a highly saline brine, with TDS levels exceeding 65,000pm, almost double the salinity of seawater. Similarly most of the power plants located on sea coasts are using seawater for cooling purpose. In once through cooling system, the seawater is circulated into the power plant to condense steam in turbines and returned back to the sea. The temperature and salinity of the returning water into the sea is always higher than the intake water. Some oceanographers feel that such slow increase in salinity of seawater affects the temperature of the sea and the climate.

However, discharge of highly saline brine into the sea has become routine and EPA (Environmental and Pollution Authority) of various countries routinely approve such discharge, claiming it does not affect the marine life much. The environmental impact study conducted in one country is routinely followed by many countries and invariably conclude that such discharge has a very little or no impact to the environment. Human beings are concerned only with their environment and not with the Ocean environment where variety of marine species live. Our oceans have been heavily polluted from the time of industrial revolution by oil spills, toxic industrial effluent discharges, desalination and power plant discharges. The TDS levels of seawater in Gulf region has considerably increased in the past few decades. The TDS levels are about 50,000 ppm against conventional levels of 35,000PPM.The oceans are acidified by absorption of excess carbon dioxide from the atmosphere due to greenhouse gas emissions.

The power required to desalinate seawater is directly proportional to the osmotic pressure of seawater. The osmotic pressure increase as the TDS level increases, which in turn increases the energy consumption by desalination plants. A recent report from US government says that fresh water will become a serious issue after a decade and even wars may be waged between countries for the sake of fresh water. The human activities not only cause global warming but also changing the chemistry of our oceans. Steadily dwindling fish population is a clear sign of changing chemistry and biology of our oceans. In the absence of a proven scientific evidence to show that  human beings cause these changes in the ocean, we will carry on our business as usual until we reach a point of no return.

If you add salt to the water, it will not boil at 100C at 1 atmospheric pressure but slightly at a higher temperature. It is high school physics. When the salinity of the ocean increases from 35,000ppm to 50,000ppm, does it not affect the evaporation of the sea, which condenses into a cloud and come back as a rain? Does it mean there will be less precipitation in the future? Even if the ocean is under constant circulation, the overall salinity level keeps increasing.

Why PV solar is still considered expensive?

Photovoltaic  solar industry has started expanding in recent years in US and Europe and the rest of the world also started following. Still solar energy is considered expensive in many parts of the world for various reasons. In most of these countries, energy is predominantly managed by Governments with age-old technologies and transmission systems. Coal is still the major fuel used for power generation and distribution and their infrastructures are old and inefficient. Transmission losses, power pilfering, subsidized power tariffs and even free power for farmers, are some of the issues that compounds the problems. Energy and water are considered more of social issues rather than business issues. For example in India, frequent power failures are common  and sometimes people do not have power even up to 8 to 12 hours  a day, especially  in country sides. Standby diesel generators are integral part of an industry or business. The heavily subsidized power supply by Government from coal-fired power plants is  underrated. The average power tariff in India is still less than $0.07/kwhr.But the reality is they will be using diesel generated power for equal several hours in a day  and the cost of diesel power varies from  $0.24 up to $0.36/kwhrs, almost in par with solar power. The average power cost will amount to $0.18 to $0.20 /kwhrs.

Any slight increase  in oil price will have a dramatic effect in energy cost in India and their balance of payment situation.Governments are in a precarious situation and they have to make a balancing act between subsidizing the energy cost and winning the elections. They often subsidize the power resulting in heavy revenue losses for Government run electricity boards. Most of the electricity boards in India are in red. People are used to low power tariffs for several decades and any increase in the tariff will make the Government unpopular. Greenhouse effect and global warming are secondary issues. With an average economic growth rate at 7% year after year, their energy requirements have gone up substantially. They may need several hundred thousands of MW power in the next 5 to 10 years. They have opened up energy sector to private only in recent years.

Renewable energy industry is relatively new and there are very few large commercial-scale solar and wind power plants in India. Majority of residents and businesses cannot afford high cost of PV solar installation. Even if they install, there is no ‘power- in tariff’ mechanism by Government where consumers can export surplus energy at a higher tariff to the grid. With current power failures lasting 8-12 hours/day, such mechanisms will have no value. The situation is the same in many Asian countries.

The solar panel costs are high due to lack of local production of silicon wafers, batteries and inverters and most of them are still imported. State electricity boards do not have funds to buy power at higher tariffs. Import duties and taxes on imported components are still high making renewable industries uncompetitive against cheap coal-fired,  subsidized power cost of $0.07/kwhrs .India requires massive investment on renewable energy industries. But most of the power projects which are under planning stage or under implementation are based on either coal or oil or LNG.There is no sign that India will soon become a major player in renewable energy.

In PV solar projects, the cost of storage batteries are higher than the solar panel during the life cycle of 25 years. If the life of a battery is 8 years then you will need 3 batteries during the life cycle. For example, if you use 100 watts solar panel with a life span of 20 years, the initial cost of solar panel may be $300 which will generate an average power of 140 watt.hrs /day. If you plan to store 5 days energy using a battery, you will enquire 5x 140= 700 watt.hrs battery, costing about $175.If you have to replace batteries 3 times during the life span of 20 years then the cost of battery is 3×175= $525.You have to add operation and maintenance cost, in addition to it. Therefore, your investment on batteries is 1.75 times more than solar panels. This cost will substantially add up to your energy cost.

In most of the Asian countries where they cannot export surplus power to the grid, they have to rely only on batteries. This high cost of stored energy is not remunerative because they cannot export this surplus to the grid at a higher tariff. This situation is not likely to change at least in the short-term.

Solar energy storage with Battery or Hydrogen?

Renewable energy industry has slowly but steadily started expanding in many parts of the world in spite of  high cost of investment and high  cost of energy. Countries like US, Germany and China are now investing on large-scale solar and wind technologies, opening new avenues for investments and employment opportunities. Many of these technologies will undergo several changes over a time before it can completely substitute fossil fuels. How long this process will take will depend upon number of factors; but the single biggest driving force will be ‘the issue global warming and its consequences” and also on uncertainties over oil reserves in the world. Nothing dramatic will happen in the near future except that the concept of alternative source of energy will expand rapidly. It is also an opportunity to discover new forms of fuels, power generation and distribution methods.

The concept of solar energy is now well-recognized as an alternative source of energy because, it is abundantly available, it is clean, generates no pollution and it is silent. The major raw materials such as Silica  and Gallium Arsenide  are  also available but some of the rare earth materials used in PV industries and batteries  are available only in certain parts of the world.  China is endowed with many such rare earth resources. For example, Lithium has limited resources and now bulk of it is produced from natural brines similar to the one at Atacama deserts in South America. It is also available in the form of minerals and ores which many countries are now trying to exploit commercially.

The storage of energy from  solar and wind is  done using deep cycle batteries, most of which are Lead-acid batteries. Bulk of the used Lead acid batteries are recycled but the demand for such batteries keeps increasing. As I mentioned in my previous articles, the sheer weight of these batteries, space required to install them, capacity use, capacity constraints, regular need for  maintenance and life cycle are some of the issues that are critical for renewable industries. In deep cycle batteries, discharging stored energy below certain levels dramatically reduces the life span. Hot climate conditions have certain impacts on maintaining such batteries.Life of a battery is critical because when you calculate the cost of energy over the life cycle of 25 years,the several replacements of battaries and their cost will have a dramatic effect on the cost of energy.

Batteries are indispensable tools in energy industries but their usage can be minimized  to a great extent by using Hydrogen as a storage medium. Let us analyze a simple example of a PV solar system for power generation. We made a computer simulation on three  different  scenario for a PV solar system for a small residence with power consumption at 15,500kwhrs/day. First simulation was based on PV solar, direct grid connect, without  storage batteries but connected directly to the grid, assuming the grid power tariff  is at $0.10/kwhrs and sale to grid tariff at $ 0.30/kwhrs.The second simulation was based on grid independent system  using battery  storage for 8 hrs autonomy. The third simulation is also grid independent, but solar power is connected to an Electrolyzer to generate Hydrogen and store it in a tank. We used a small capacity battery, less than twenty percent  of the capacity used in the earlier case and a Hydrogen storage with Fuel cell along with an inverter. The stored Hydrogen was used to generate power to meet the requirement of the residence, instead of supplying power directly from the battery. The cost of energy using direct grid connect was the lowest $$0.33/kwhrs, while Grid independent with battery storage ,the cost of power was $1,20/kwhrs.In third  scenario with Hydrogen and Fuel cell the cost of power was $ 1.90/kwhrs, but there was surplus Hydrogen in the storage tank. With Hydrogen as a storage medium, the cost of power is high due to initial investment but it is maintenance free and ideal for remote locations.

The Hydrogen and Fuel cell solution though expensive, has a several advantages. The power generated by PV solar is stored in the form of Hydrogen instead of storing in batteries. A single battery is used to keep up a steady current to Electrolyzer but bulk of the energy is stored in the form of Hydrogen. Another advantage with this system is that stored Hydrogen can also be used as a fuel for residential heating as well as to fuel your car.

How to generate your own Hydrogen?

It is amazing that highly combustible Hydrogen is a constituent of cool water. As long as it remains a part of a water molecule we are able to handle it easily. Water is always in a state of ionization with H+ and OH- ions in a dynamic equilibrium. The electrical conductivity of pure water which is completely free from any other ions is almost zero. In a solid polymer electrolyzer, which is the reverse of Fuel cell, water is decomposed into Hydrogen and Oxygen while passing a Direct current. Electrolyzer is an electrolytic cell similar to battery, containing an Anode, Cathode and Electrolyte. In a solid polymer Electrolyzer, the electrolyte is a polymer membrane. Water is decomposed as shown in the following reaction:

At Anode of electrolyzer:               H2O——– 0.5 O2 + 2e + 2H†

At Cathode of electrolyzer:             2H† + 2e —— H2

The purity of water is critical in the above process of electrolysis. In conventional electrolysis, water with addition of potash lye (KOH) acts as an electrolyte. But in the above process there is no need for any addition of lye. Moreover, Hydrogen can be generated at high pressure so that further compression becomes easier. In cases of power generation using Fuel cell, the Hydrogen pressure from Electrolyzer is sufficiently high, obviating the usage of an additional compressor.

The electrical conductivity of water increases as the concentration of dissolved salts increases. That is why the electrical conductivity of seawater is much higher than your tapwater.But this salt can be removed by the process of desalination using ‘reverse osmosis’ systems.

When you separate pure water and salt water using a semi permeable membrane there is natural tendency for pure water to pass across the membrane to pure water side. This process is called ‘Osmosis’. The process continues till the concentration of water on both side of the membrane becomes equal. Nature does not like disparities between strong and weak and always tend to make both equal. By reversing this principle of osmosis, we can separate salt water into pure water and highly concentrated salt water known as brine. This process is called ‘Reverse osmosis’. We will discuss about this process later.

If your tap water is not very hard, say such as, total dissolved solids TDS is around  500ppm (Part per million), then the osmotic pressure is not high, which means you do not need to use a high pressure pump. Higher the TDS level, higher the osmotic pressure and higher the power consumption will be. You can install a reverse osmosis system based on your water analysis. You have to use a pure water with low conductivity 10-15 micro Siemens/cm.The reverse osmosis system can be connected to your tap and  store pure water while draining the salt water into the drain. You can use this pure water to an Electrolyzer to generate Hydrogen. The Hydrogen can be stored in a tank made up of Carbon composite materials that can withstand high pressure and approved by regulatory authorities.

This article is only to understand how Hydrogen can be generated using your tap water. The actual implementation of the system requires knowledge and experience in installing such a system. But we will release an eBook, a step by step guide to set up your power generation system as well fuelling your Fuel cell car, using Hydrogen. An independent power generation and fuelling system using only solar power and water will soon become a commercial reality because, it is a clean and sustainable solution for all our energy problems. The PV solar industries are already expanding at a faster rate and solar Hydrogen will soon become a final solution.