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Battery 8hrs and Hydrogen 2 months autonomy24hrs batery storage modelBattery 10hrs and Hydrogen 17hrs autonomyBattery 8hrs and Hydrogen 2 months autonomy172 hrs (one week) battery autonomyAfrica- Australia conference

Most of the renewable energy projects that are now set up around the world are grid connected with feed-in power tariff arrangement. People can generate their own electricity by solar/wind to meet their demand and supply the surplus power to the grid at an agreed power rates. They can also draw power from the grid if there is any short fall in their production of renewable energy. It is two-way traffic. There is an opportunity for people to generate revenue by sale of surplus power. It is an incentive for people to invest on renewable energy and that is why the investment on renewable energy has steadily increased over a time. But this is not the case with many developing and under developed countries. The situation is still worse in many islands where there is no centralized power generation at all or power distribution through grids. They depend on diesel generators. Even to transport diesel from mainland they have to use diesel operated boats. They have no drinking water even though they are surrounded by sea. I happened to visit a remote island in PNG few years ago and saw the plight of those people first hand. They live in absolute poverty and nobody cares to offer them a solution. Their voices are never heard and permanently drowned in the deafening roar of the sea.

The problems of supplying clean power and water to these remote islands are not only political but also technical and commercial in nature. One has to use only commercially available systems and components which are meant for a single or three-phase grid connected power supplies. Even though renewable energy sources basically generate only direct current (DC), one has to convert them into alternate current (AC) for easy distribution and to use appliances which are designed for AC operations. Isolated communities like islands can use direct current and also use DC operated appliances because they are commercially available and they are more efficient. Anyhow most of the house appliances need DC supply and AC/DC converters are commonly used for this purpose thus sacrificing efficiency in the process. They also need better storage solutions because they are not connected to the grid and they have to necessarily store power for several days. Some of these islands are connected with inefficient wind turbines backed by diesel generators. It is an absolute necessity to incorporate a long-term storage capabilities in the system if one has to offer a continuous power and clean water. If the wind velocity is not enough (during off seasons) or if there is no sun (cloudy) for days together and if there is not enough storage capacity, then all the investment made on the project will be of no use. Any half-baked solutions will not serve the real purpose.

There are also commercial problems because a well designed system will cost more, which will eventually increase the power tariff. Unless the Government subsidizes the power   sufficiently, people cannot afford to pay for their electricity or water. It requires a careful planning and community consultations to set up a ‘stand alone renewable energy projects in islands’. Governments in the pacific islands should act with great urgency because there is also a risk of inundation by sea level rising due to global warming.

We are in the process of designing a solution to provide such islands with clean power, clean drinking water and even wireless connectivity for schools so that children can get education. It may sound ambitious but it is the first step one has to take into long journey of sustainability and self-reliance by these isolated communities. There is a good possibility that such island may one day become completely independent and self-sufficient with clean power and water.

The same solution can be implemented in other countries too. Many countries have necessary infrastructure to generate and distribute power yet they suffer regular power cuts and black outs due to inefficiencies in their system.

Our proposed solution can provide uninterrupted clean power and water because the system will have long duration centralized energy storage. We have made a detailed analysis of various alternatives available for the above purpose using Homer hybrid solution software. The solution proposes a PV solar with storage solutions using battery bank as well as Fuel cell back up. The solution also proposes a long duration of storage ranging from few hours up to a fortnight .It is a standalone system with complete energy management and suitable for remote operations. The solution can also incorporate wind turbine in addition to PV solar depending upon the site and wind velocity profile.

The model is to supply clean power and drinking water for 600 families with an average 3 people in a family. The system will supply power at the rate of 1.50kwhrs/day/person (1800 x1.5 = 2700kwhrs/day) and drinking water at the rate of 200 lits/day/person (1800 x 200 lit/person= 360,000 lits/day).The power for a desalination plant will be 1980 kwhrs/day. The system is designed for a total power generation capacity of 4680Khwhrs/day.

The model is based on battery storage as well as based on Hydrogen storage with varying durations. Comparative analysis is shown in the figures.

The first window is based on PV solar with  2 months Hydrogen autonomy.

The third window is based on PV solar with battery storage 5 days and Hydrogen 17hrs autonomy.

The fourth and fifth window is based on PV solar with battery 12hrs and Hydrogen 17hrs storage autonomy with varying panel costs

The sixth window is based on PV solar with 172 hrs (one week) battery autonomy.

The resulting analysis indicates that a centralized Hydrogen storage with Fuel cell back up offers the most economical solution even though the power tariff is higher than a system with battery storage. The investment for long duration battery storage is almost double that of Hydrogen based solution. The cost can further be reduced if and when the Electrolyzers as well as Fuel cells are manufactured on mass scale. The added advantage with this system is it can also provide Hydrogen fuel for Fuel cell cars and boats substituting diesel. One day it may become a reality that these isolated islands can become completely self sufficient in terms of water, fuel and power with no greenhouse gas emissions. This solution can be replicated to all the islands all over the world.

Note:

The above system can also be installed in many developing countries in Africa which is an emerging market. An Africa-Australia Infrastructure Conference  will be held in Melbourne, Australia on 2-3 September  2013 and it will offer a platform for Australian companies to invest in Africa on infrastructural projects.

Do you use a generator that runs on diesel or gas to power your business due to frequent power outage from the grid? Are you running an air-conditioner with the grid power? Then you must look for waste heat recovery system to improve your energy efficiency and save your fuel cost. You can also use roof top solar hot water to supplement waste heat recovery. The savings may be real and you may be able to recover your investment in a short period and also contribute for the reduction of greenhouse emissions.

The diesel or gas engine converts only most 30% of fuel input in the form of thermal energy into mechanical energy to run your generator, and the balance heat is wasted in the form of greenhouse gas. You can recover this heat and increase the efficiency of the system. This means for the same amount of diesel used, you will get much higher output in the form of heating or cooling or in the form of additional electricity.

The exhaust temperature from a gas engine is about 420C.You can also recover extra heat from jacket cooling. Let us assume that you have a natural gas-fired engine to generate 100kw electricity for the premises. The efficiency of such spark ignited reciprocating gas engines are typically about 30%, which means a natural gas input of 1.145 mm Btu/hr. Let us assume the cost of piped natural gas at $10 per mm Btu; the fuel cost will be about $ 11.45/hr.

The exhaust heat from the engine will be about 801,500 Btu/hr; with waste heat recovery efficiency at 75%, the heat recovery will be 601,125 Btu/hr.You can air-condition premises with an area of 35-40 square meters using this recovered waste heat. If you use grid power   at the rate of $0.10/kwhr, to run the air conditioning system for the above area, you will be spending about 30,000kwhrs of electricity per month, costing about $ 3000 per month. By installing an absorption chiller to air-condition your premises using engine exhaust heat, you will be saving about $36,000 per year towards air-conditioning. The air-conditioning system may cost about $130,000, and with the above savings you will be able to get a return on your investment in less than 3 years.

If you have a roof-top solar water heater then you can supplement it with your engine exhaust heat water so that the capacity of the air-conditioning can be increased. It is one of the best methods by which an energy efficiency of a fossil felled engine can be increased. If the capacity of the engine is much higher, there are other methods by which the efficiency can be increased.

For example, the hot water from the exhaust system can be used to generate some extra power using an ORC, organic Rankin cycle. It is similar to a steam turbine. An organic liquid with low boiling point will be evaporated into vapor by a low heat source such as hot water from engine exhaust, which runs a turbine, generating some extra power and condensing back into the liquid, and then the cycle continues. You will be able to generate an extra electricity of about 15-18% making the total electrical efficiency of the system  to 45-50%, which is similar to a Fuel cell system, but at a much lower cost.

Heat recovery system with an absorption chilling and using low heat source to generate extra power using ORC, are best methods to improve energy efficiency of an existing system with little investment. The purpose of such integration is to increase the energy efficiency of the existing system, so that you will be getting more output of energy from the same input of fuel.

 

 

 

There are many ways to increase the energy efficiency of an existing system which also helps invariably to cut 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 used. 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 show 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 make sure that they don’t lose customers who may insist on green power.

You can check various power tariffs in your place 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 when 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 and not 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 cut 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 achieve these goals.

Renewable Hydrogen is the key that can offer us energy independence in the twenty-first century. Fossil fuel usage will still continue for some more time because the world has already invested massively on fossil fuel infrastructures. The stacks are too high for them to switch over to renewable over night. It is the Mother Nature who provided us coal, oil and gas all these years using her manufacturing process under the earth over millions of years. But we human beings exceeded her tolerance limit by emitting greenhouse emission by our rapid growth in population and industrialisation.We failed to discover an alternate fuel in time and continued with an age-old technology with all its inefficiencies. Inefficiencies breed pollution. We were keen to use the heat of combustion by burning a fossil fuel to generate electricity or drive our cars, but paid no attention to the gases released during such combustion. We learnt Thermodynamics and the relationship between heat and work, but failed to understand the consequences of gases of combustion and its impact on our environment.

There are two issues involved in burning a fossil fuel to generate electricity. The heat of combustion is an exothermic reaction and we get a certain amount of heat. Then we convert this heat energy into electrical energy and the overall efficiency of such conversion is about thirty-five percent. Only thirty-five percent of the heat input energy becomes electrical energy and the remaining sixty-five percent heat along with gases of combustion are released into atmosphere. Of course part of this heat is recovered in a commercial plant, but the bulk of heat is released into the atmosphere as greenhouse gases. We failed to understand the potential of Hydrogen even though we used Hydrocarbon for several decades. We even discovered Urea, the fertilizer that caused ‘green revolution’ in agriculture, using the same Hydrogen present in the Hydrocarbon feedstock. It is time for us to make best use of a fossil fuel to its most potential when we burn each kilogram of fuel. We should burn coal not just with air but also with steam so that we can generate Hydrogen rich gas that can run a gas turbine in a combined cycle or run our cars on roads. Such a conversion will lead to a substantial increase in energy efficiency as well as in greenhouse gas emission reduction. Governments in industrialized countries should make it a mandatory to convert all their power plants to syngas generation as described above. They should also discourage new plants using fossil fuels with punitive power tariffs and encourage renewable energy projects with higher tariffs. Governments can also impose similar tariffs for transportation depending upon the fuel used such as fossil fuel or Hydrogen.

Governments should encourage renewable energy projects such as solar and wind   to generate Hydrogen from water as centralized power plants and distribute DC (direct current) by rural electrification. If the country side is electrified using this system then, agriculture, business and industries can thrive in rural areas. Direct current (DC) distribution net work can be installed in rural areas and encourage people to use energy-efficient appliances such as Direct current air-conditioners with energy star ratings and tariffs. Governments can bring about these changes by adopting a ‘carrot and stick ‘policy to encourage renewable and discourage fossil fuels.

Solar energy is the key from which all other forms of energy emanate such as wind, geothermal and ocean thermal energy conversion system.  It is of paramount importance to increase the efficiency of renewable systems and improve energy efficiencies of appliances we use. It is simpler to use LED bulbs using a Direct current generated by Renewable Hydrogen. It is once again the Mother Nature that can come to the rescue of human beings through solar, wind and water to generate clean energy for the twenty-first century.

Energy generation and distribution is no longer a business or revenue issue but a moral and ethical issue for Governments. It is only people who can bring about such sweeping changes by electing the right Government who can care for the environment. The future generation will judge us only based on what kind of environment we leave them behind.

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