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Category Archives: PV solar

Energy generation and usage is considered not only as a mark of progress of a nation but also security of a nation. That is why countries go to extraordinary distance to achieve such a security and everything else becomes secondary in the path of their goal. That is why countries with high oil and gas reserves enjoy good relationship and privileges with powerful nations of the world. Countries who do not have their own oil and gas reserves and who completely rely on import of oil and gas have no choice but maintain a good relationship with oil rich countries despite their difference in ideologies and policies. But with warming globe and changing climate the dependence on fossil fuels is fast becoming unsustainable and countries look for alternatives. It is good news for the whole world especially for nations who depend completely on import of oil and gas because they can develop their own renewable energy sources to lower their emissions. But there is one major difference. Countries who depend on import of oil and gas required to develop only an infrastructure to store and distribute oil and gas, But with renewable energy they have to develop an infrastructure to produce the hardware necessary to use alternative energy sources such as solar, wind, geothermal  but also energy storage such as batteries. The warming globe and changing climate have become a grave threat to the plant earth and a threat to lives of entire future generations. It is the greatest challenge of the industrialized world. One can view this as threat or as an opportunity. But it is time to act irrespective of our views and we must act now.

It is an opportunity for scientists and engineers to view energy sources and their applications in a new perspective. It is an opportunity to understand how human activities affect our environment and how not to damage them but preserve them for our future generations while developing new alternatives. Humanity is just a part of a larger environment and any damage to planet earth is at our own peril. It is an ancient wisdom, but we neglected them. When an aboriginal of Australia said “we belong to earth and earth does not belong to us” we failed to listen to them. We(people) became bigger than They (environment).

In pursuit of a new energy source one must be extremely careful in examining Nature and how she operates so that we do not make the same mistakes of the past. As we develop renewable energy as a potential energy source of the future, we should be aware of the life cycle of such a system and their impact on environment. Renewable energy requires hardware that uses exotic metals, catalysts, polymers, new Carbon sources and glasses. As we switch to Carbon free economy, we should make sure that there are no emissions in developing renewable energy sources and if necessary impose Carbon tax on such emissions and, to develop recycling technologies to recycle that hardware safely and environmentally friendly manner. It is critically important issue as we move forward. According to an article published in Chemical engineering News

“The potential quantities of waste are enormous. By 2025, waste batteries removed from electric vehicles will total 95 Giga watt hours, according to an estimate by Bloomberg New Energy Finance. That pile will weigh roughly 600,000 metric tons.

A similar amount of old solar panels will have accumulated by then, according to projections by the International Renewable Energy Agency. IRENA anticipates solar panel waste could reach 78 million metric tons by 2050. And Europe could see 300,000 metric tons per year of decommissioned wind turbine blades in the next two decades, says the trade association Wind Europe.

Each year, approximately 300,000 metric tons of lithium-ion battery waste is generated around the world, says Sheetanshu Upadhyay, an analyst with India’s Esticast Research & Consulting. Most of those batteries come from mobile devices, but that waste will soon be overshadowed by old electric car batteries. Sales of plug-in electric vehicles are expected to surpass 2.6 million in 2020, according to Navigation Research.”

The above data shows the amount of CO2 emission associated with implementation of renewable energy sources soon. There is a potential for large scale recycling industries on renewables, but it will come with a price and environmental issues. Right now, the main problem is the CO2 emission and the only way to tackle this problem is impose Carbon tax on emissions while encouraging industries with low emission technologies. It should be possible for UN to pass a unanimous resolution among the nations to address climate change by imposing Carbon tax uniformly across the nation. By such resolution UN can bring all those countries to the table who are currently reluctant to be a party to the Paris accord. Countries can use “Carbon rating” similar to “energy ratings” currently used for measuring energy efficiencies in appliances such as Heaters and air-conditioners. The lowest emitting technologies will get the highest Carbon rating while high emission technologies will get the lowest Carbon ratings. By using such a method country who are reluctant to act on climate change will be disadvantaged; they will not be able to compete in international market or export their goods to low emitting countries based on Carbon ratings.

 

Recycling PV solar panelsRecycling renewablesRecycling wind turbines

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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.

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.

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.

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