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Sunday, March 11, 2012
There are many ways to increase the energy efficiency of an existing system which also helps invariably to reduce your carbon footprint. The inefficiencies breed pollution. Such inefficiencies can emanate from power generation methods or from power distribution methods. Energy cannot be stored but has to be utilized. That is one of the main reasons why the power companies look for large consumers and offer them the lowest tariff. Some industries like Caustic soda plants and Aluminum smelters, consume large power. If you are using power from the grid then you can discuss with your service provider and check whether you can switch over to green power. The tariff may be slightly higher than a standard tariff but certainly helps you to reduce your carbon footprint. Some service providers indicate your carbon foot print by way a chart in their monthly energy bill. Most of the energy providers supply green power such as solar and wind as part of their energy mix to ensure that they don’t lose customers who may insist on green power. You can check various power tariffs in your location such a peak tariff and off-peak tariffs and you will be surprised at the difference. The peak tariff is when everybody use power , normally 9am to 5pm.The usage of air-conditioners during peak hours in tropical countries is high They can use rooftop solar panels with batteries and inverters because many counties in Asia do not have feed-in tariff method by which you can export your surplus solar power to the grid. Moreover they do not have a choice in selecting a service provider because power generation and distribution are mostly runs by Governments or by very few service providers. The best method for such users is to store the solar energy in batteries and use them whenever they want. Even consumers who use grid power can store electricity during off-peak period using batteries and then use them during peak period using an inverter. This is an ideal solution for Asian countries where the power outage is frequent and unexpected. The best method will be to use an Electrolyzer to generate Hydrogen using off-peak power and tape water and store them under pressure. You can generate your own electricity using small Fuel cell .This electricity can be a Direct current that can be readily connected to a host of Direct current operated appliances including your air-conditioners and refrigerators. If your electricity load is relatively high then you can integrate both solar panels and grid power in such a way that you can store enough electricity by way of Hydrogen or in a battery and use them during peak period. By this method you can be certain of an uninterrupted power supply and at the same time a reasonable power tariff. You can reduce your carbon foot print substantially by utilizing solar power with Hydrogen storage. You can choose energy efficient appliances by looking at their star ratings.A star rating of 6 and above is considered very energy efficient. You can choose LED bulbs for lighting and I would suggest using Direct current for LED bulbs directly from Fuel cell or battery rather than from grid supply using an inverter. You can also check the type of refrigerants used in air conditioners and Refrigerators and their star ratings. If you have a roof top solar panel as part of electricity supply then I will recommend to use Direct current operated Air-conditioners and regfigerators.When you choose these appliances you can look for the type of motor, compressor and fans used, because these are the main parts that use electricity. An energy efficient motor and the type of compressor used are critical components in determining the capacity, airflow and noise levels. The energy ratings are based on these factors only. You can save energy and reduce your carbon footprint in every step of the way if you are keen to do it. The most important factor in achieving energy efficiency is an understanding of your contribution to the environment and the prudence with which you can accomplish these goals.
Friday, March 2, 2012
Seawater is an inexhaustible source of Hydrogen but the cost of generating Hydrogen from seawater is much higher compared to normal tap water. The quality of water should have a minimum electric conductivity at 0.1 micro Siemens/cm for electrolysis. Even our tap water is not up to this purity and it requires further purification. The electric conductivity of seawater is about 54,000 micro Siemens/cm.The conductivity increases due to the presence of dissolved salts. But seawater can be desalinated using the process of distillation or by the process called ‘reverse osmosis’. In both the above processes, desalination requires a large input of energy in the form of thermal or electrical. Currently the source of such energy comes from fossil fuels, which is one the biggest emitters of greenhouse gas emission. Many countries in the Middle East have shortage of fresh water and most of these countries depend on desalination of seawater for their fresh water requirements. The cost of desalinated water varies from $ 1.00 to $ 1.75/m3 depending upon the capacity, location and the cost of energy. The fresh water for potable purpose normally has a TDS (Total dissolved solids) of 500ppm (parts per million) or less and this can further be lowered to a required level using reverse osmosis. Currently Hydrogen is generated as a by-product on an industrial scale by electrolysis of saturated sodium chloride brine during the production of Caustic soda. Chlorine is another by-product in the above process. Most of Caustic soda manufacturers use Hydrogen as a fuel or for the production of Hydrochloric acid. But there is an opportunity in caustic soda plants to use Hydrogen to generate more electricity using PEM (Proton exchange membrane) Fuel cell suitable for their electrolysis. This will assist these industries to reduce their energy consumption, which is one of the highest in Chemical industries. Alternatively, offshore wind turbines can be installed to generate power for seawater desalination and Hydrogen production. Offshore wind turbines generate 50% more energy than onshore wind turbines. An integrated process to generate fresh water, Hydrogen using wind turbine is an interesting renewable energy application. The stored Hydrogen can used to generate electricity in remote islands where diesel is used as a fuel. Most of the island in Pacific use diesel predominantly for boat as well as for power generators at exorbitant costs. The wind velocity in such islands is good to generate cheap and clean electricity. For example, the island of PNG has a severe power shortage and it is well located near Coral Sea, which has one of the highest wind velocities in Pacific Ocean. An average wind velocity of 7mts/sec and above is an ideal location for wind turbines. Since these islands are small with less population, wind generated Hydrogen is an ideal solution for their power problems. They can also desalinate seawater to supply drinking water using wind generated power. In fact they can also use Hydrogen as a fuel for their boats and generate power for their cold storage for fisheries. International financial institutions and local banks should come forward to fund such projects instead of funding diesel boats and generators. These islands have pristine water and abundant fish and their main income is only tourism. Sun, Sand and wind is an ideal combination to generate renewable power all round the year and for tourism industry. It is an opportunity these islands cannot afford to miss. The author is personally involved in a wind based Hydrogen solution for a small island in pacific. The people of this island welcome such projects because it guarantees them an uninterrupted supply of clean power and drinking water. Otherwise they have to sell most of fish catches in a nearby city to buy diesel and drinking water just to survive!