SOLAR POWER BATTERIES

12:58 AM 1 Comment

Last time I briefly introduced the solar generator and what it entails.I also mentioned that one of the most essential stuff  we need for a solar generator is a battery.Battery is very fundamental in a solar power system.Without battery you cannot store energy for a later use especially when there is no sunshine.Today I am going to explain what kind of battery you need and also tackle how to connect the battery to get to the solar panel in order to get a  high power output.
There are many types of batteries available outside there in the market.However,the battery that is widely used in Photovoltaic system is the lead acid batteries.Other types of batteries such as nickel-cadmium battery may be used but the advantages of lead acid batteries ensures that it is still the most poplar choice.
Battery types
There are two main types of lead acid battery;starting battery and axillary power battery.The two battery types are constructed in completely different ways; having different plate thicknesses etc. The number of times a battery can be discharged is called cycle life.This is what determine its suitability for use with solar cells.The most common type of lead acid battery is car batteries.  A car battery is an example of starting battery.It can survive only 5-10cycles and will be damaged if it is deeply discharged.Therefore not appropriate for use in Photovoltaic system.A car battery is designed to provide a very large amount of current for a short period of time.This surge of current is needed to turn the engine over during starting.Once the engine starts,the alternator provides all the power that the car needs,so a car battery may go through its entire life without ever being drained more than 20% of its total capacity.To achieve a large amount of current,a car battery uses thin plates in order to increase its surface area.On the other hand a deep cycle battery that is highly used in solar cell system  is designed to provide a stead amount of current over a long period of time.A deep cycle battery can provide a surge when needed ,but nothing like the surge a car battery can. Deep cycle battery is also designed to be deeply discharged over and over  again something that would ruin a car battery very quickly. To accomplish this, a deep cycle battery uses thicker plates.


Leisure battery  

Exide G80 Gel leisure battery 80Ah

A leisure battery is an auxiliary power battery designed to provide a steady rate of power over a period of time. A deep cycle leisure battery is designed to perform a high number of discharge/recharge cycles without loss of battery health.They are the cheapest deep cycle battery.They look similar to a car battery but have a different plate construction. Their capacity is normally in the range of 60 to 120 Ah at 12 Volts, making them most suitable for smaller systems.Essentially,the higher the Ah the longer it will last between charges.The higher the Ah figure,the physically larger the battery.To main capacities are the 85Ah leisure battery and the 110Ah leisure battery.The cycle life of leisure batteries is limited to a few hundred cycles, meaning that they are most suitable for systems which will not be used every day, such as those in caravans or holiday homes.The vast majority of leisure batteries are wet lead acid/flooded type batteries as they are cheaper to produce and extremely easy to look after.They are Lead acid batteries that have caps to add water. Many manufacturers make these types for Solar Energy use. Trojan, Surrette, and Deka are probably the most well known. All flooded batteries release gas when charged and should not be used indoors. If installed in an enclosure, a venting system should be used to vent out the gases which can be explosive.You also have to handle wet lead acid batteries carefully due to their acid content;you have to keep them upright for example.Gel batteries such as the Exide G80 80Ah Gel leisure Battery have no liquid content so can be stored in any orientation and are safe to handle.The picture of Exide G80 Gel leisure battery 80Ah is shown above.
Gel Leisure batteries are extremely low gassing so can be safely installed inside the cabin of a motorhome. Downsides to gel are that they can be expensive and you have to be very careful not to overcharge them. AGM(Absorbed Glass Mat) batteries  are the latest technological development in leisure and caravan batteries that blurs the distinctions of the various types, combining all the best features.IT IS THE BEST AVAILABLE BATTERY FOR SOLAR POWER SYSTEM USEHL.Instead of using gel, AGM batteries use a fibreglass type material to hold the electrolyte in place, making them spill-proof and extremely vibration resistant. The AGM battery can be constructed with extremely thin separators which keep the internal resistance low. This means that you can leverage high power from a small volume which makes the AGM battery ideal as a starter battery as well as auxiliary battery. The AGM battery has one drawback which is that the amount of acid is limited. All acid must be absorbed by the separator paper and when the small amount of acid has been converted into lead sulphate, this signals that the "petrol tank" is empty. To deal with this problem, the AGM battery often have a somewhat higher acid weight. This means that an AGM battery can, and often should, be charged using a voltage that is a little higher. Again, you must be careful not to overcharge AGM batteries.

Traction battery 

The term traction battery relates to all batteries used to power electric vehicles. This can mean anything from a mobility scooter to a fork-lift truck, so encompasses capacities from 30 or 40 Ah to many hundreds. The smaller traction batteries are usually 6 or 12 Volt units, where the largest are single 2 Volt cells. Traction batteries are ideal for solar power applications, as they are intended to be fully discharged and recharged daily. The larger traction batteries can withstand thousands of discharge cycles. There are also batteries known as semi-traction batteries, which can be thought of as higher quality leisure batteries, exhibiting a greater cycle life. Marine,cart golf and RV batteries also fall into this category.Traction batteries generally operate in very harsh operating environments and must withstand wide temperature ranges ( -30°C to +65°C) as well as shock, vibration and abuse.A very popular battery for small systems is the Golf Cart battery. They are somewhat more expensive than deep cycle recreational batteries but are probably the least expensive choice for a small system on a budget.

Sealed Lead Acid batteries  

There are many types of sealed lead-acid batteries, ranging from those of 1 or 2 Ah to single cell traction batteries of hundreds of Amp-hours. The advantages of sealed batteries are obvious; they need no maintenance and are spill-proof. They do have disadvantages however; they are more expensive than other battery types, they require more accurate charging control and can have a shorter life, especially at high temperatures. Sealed batteries are most appropriate where the solar power system will need to operate for long periods without maintenance.Examples of Sealed Lead Acid Batteries are absorbed glass mat and Gell cell that I explained above.

Battery Maintenance 
 Deep cycle batteries such as those used in solar power systems have much thicker lead plates to make them last longer. Deep cycle batteries should never really be discharged to below 20% of their full capacity, because internal resistance causes heat and damage when they are recharged. Renewable energy systems usually use a low-charge or low voltage warning light or a low-voltage cut-off switch to prevent the type of damage that will shorten the battery's life.
 Battery shelf life can be extended by storing them at a lower temperatures, because the chemical reactions in the batteries are slower. However, in order to reach their maximum voltage, batteries must be returned to room temperature. Therefore, most battery manufacturers do not recommend refrigerating batteries.

Battery safety, explosions and hazards
A battery explosion is caused by the misuse or malfunction of a battery, such as attempting to recharge a non-rechargeable battery or short circuiting a battery. Explosions are most likely to occur when a short circuit generates very large currents. In addition, deep cycle batteries can release hydrogen when they are overcharged (due to electrolysis of the water in the electrolyte). Normally the gas dissipates quickly. However, this gas can be ignited by a nearby spark (for example, when removing the jumper cables).
Attempting to charge a battery beyond its electrical capacity, ie overcharging, can also lead to a battery explosion, leakage, or irreversible damage to the battery. It may also cause damage to the components in which the overcharged battery is used.
When a battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting. In extreme cases, the battery acid may spray violently from the casing of the battery and cause injury.
Battery explosions can also occur in maintenance free lead-acid batteries if the valves fail or are blocked. The pressure rises within the cells until a short-circuit ignites the hydrogen-oxygen mixture. Such explosions can cause severe injury. The problem can be detected in most batteries if the sides appear swollen, or if the battery feels hot to touch.
I hope this helps you learn more about batteries to use in you Photovoltaic system!In my next posting I will explain how to build your own  large battery bank by connecting the batteries in parallel or series.




typical battery bank
This is a typical of a battery bank by free sun power . These are 12 volt 105 AmpHour AGM lead acid batteries wired in parallel. With 1575 total AmpHour capacity and using 125 to 200 AmpHours per day,He uses around 300 to 350 AmpHours before he recharge to increase the battery life.With this technique the battery can last longer.That means without recharging it can last 2 to 3 days.For people who live in places with less sun supplementing the system with a mid sized AC generator to charge the battery during the period with less sun will be advisable.Replacing power hungry appliances with with alternative energy source of energy such as natural or propane gas.Examples of power hungry appliances include dryers,heaters,electric stoves e.t.c.It is better to replace or buy appliances that consumes less power to around 1,000watts at most.

Read More

WW3

1:26 AM No Comments

I was just reading this famous quote by Einstein "I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"  and it got me thinking,Is there a possibility of WW3 in the near future.In every corner of the world there are a lot of ongoing military wars that have resulted into tremendous causalities and  violent deaths.Just a few of them worth mentioned are the Gaza war,Yemeni Civil war,Syria revolution,Libya war for democracy,the never ending Somali piracy and civil unrest ,war against terrorism and last but not least the Mexico drug war. Due to this wars many people have lost their loved ones.people have lost their lives,some have lost eyesight ,some have been raped and deflowered,it has showed us the inhumanity of human beings towards others human beings.Nevertheless there are too far from being called WW3.This is because a World War is a military conflict spanning more than 2 continents, in which at least 20 major countries participate in an attack against a common enemy, and which has the attention of the man-in-the-street due to the significant loss of life.

 At this time,with human being venturing into the world of sophisticated weaponry  and technology advancement  they have developed enough powerful weapons and chemical weapons that could wipe out the entire planet a number of times and put us right back to the stone age, where we would have to start all over again. And I think this is what Einstein was trying to preach to us.If we can have WW3 tomorrow  the whole mother nature  and human race in it will be wiped out such that if someone happen to remain alive he will have to start over from the stone age and agrarian period.And that is what Lord Louis Mountbatten also sad "If the Third World War is fought with nuclear weapons, the fourth will be fought with bows and arrows." When would this WW3 be?A friend of mine  told me that the only thing stopping WW3 from happening is mutually assured economic destruction. For example,If China nukes the US, they will be economic downtown in China because the US won't be able to consume their junks anymore, and then the rest of the world will fall like dominoes. All of the major world economies are linked together at this point.However some people think otherwise.Some things  that the WW3 has already started unofficially.They believe  that the WW3 is about Oil and the dance partner is China.China is already a significant power in Asia and day by day it keeps on increasing its global influence with its economic policies in Africa ,Latin America and Europe.It's future global prowess both in economic and military is indisputable.It is commonly referred to the "emerging superpower".But few decades to come there is a likelihood that it will make that one small step from emerging superpower to superpower well all the world is watching.At that time i can not tell how the world will be shaped with China being the superpower but u can imagine how it will be.So if people say that China will play a greater role in ww3 I definitely agree with them.

but wait....Is it WW3 that we should be worried about?how about the Armageddon;the war that will end all wars.The coming of Jesus Christ and the end of the world.Whether you will be part of a new world.It is a another long story so lets keep it for another day but really JUST THINK ABOUT IT

Read More

The Great Comeback

11:08 PM No Comments

But Peter, standing up with the eleven, raised his voice and said to them, “Men of Judea . . . heed my words.” —Acts 2:14

We like to read about comebacks—about people or companies who face near disaster and turn things around. The Ford Motor Company is an example of that. In the 1940s, a reluctance by leadership to modernize almost destroyed Ford. In fact, the government nearly took over the company lest its demise threaten the US war effort. But when Henry Ford II was released from his military duties to run the company, things turned around. Ford became one of the biggest corporations in the world.

Occasionally, we need a comeback. We need to correct wrong directions or compensate for wrong decisions. In those times, we have an example in Peter. He had failure written all over him. First, he nearly drowned when his faith faltered (Matt. 14:30). Then he said things that were so wrong Jesus called him “Satan” (16:22-23). And when Jesus needed Peter the most, he denied that he even knew Him (26:74).

But that’s not the end of the story. In the power of the Spirit, Peter made a comeback. On the Day of Pentecost, he preached and 3,000 people came to faith in Christ (Acts 2:14,41). Peter returned to effectiveness because his faith was renewed, he guarded what he said, and he stood up for Jesus.

Struggling? If Peter can come back, so can you. —Dave Branon

Today Christ calls, “Come follow Me!”
Do not look back to yesterday;
Fresh grace He’ll give to do His will,
His joy you’ll find as you obey. —D. De Haan

To become whole, yield to the Holy Spirit.

Read More

PV in the Developing World--A ‘Cell Phone‘ Model for Microgrids Driving New PV Adoption

6:59 AM 1 Comment

The PV industry is exploding--or is it? European PV leaders are cutting tariffs, reducing incentives, and instituting caps for PV development; the U.S.A. has no clear federal drive for PV; and Japan is enduring a catastrophe that will undoubtedly have serious impacts on its economy and PV investment capability. Spain is a distant memory for PV, and Italy has now come and gone. The global PV market cannot currently depend on these countries to increase their PV demand and expand the market. Developing countries are in a unique position to step in and pick up the slack, and it may well be in the context of the microgrid. Bottom-up electrification initiatives are happening in the developing world, and are proving to be efficient and cost-effective entry level strategies. Microgrid applications in rural areas represent the largest number of microgrids currently operating globally. While many systems have historically featured diesel distributed energy generation, the largest growth sector opportunity is for PV, with ‘small wind’ playing a significant role as well. By Shannon Fulton, Andy Skumanich Developing Countries: Microgrid Can Be Similar to the Cell Phone Model The cell phone model for microgrids is a low-cost, limited-resources approach to energy delivery on a limited scale and targeting small localities. Original implementation of cell phone technology and subsequent expansion of coverage occurred very rapidly, at comparatively low cost, with limited infrastructure and without overburdening the existing telecom infrastructure. In fact, more people own cell phones in developing countries than own refrigerators. Just as cell phones are helping to lift the poor out of poverty, microgrids could help shoulder developing countries’ growing thirst for electricity without overburdening aging transmission lines or investing massive amounts of capital and time to construct traditional power plants to meet this demand. The technological development that distinguished the early cell phones was the use of multiple cell sites and the ability to transfer calls from one site to the next without the need for costly landline infrastructure and maintenance. Similarly, a single microgrid or aggregate of localized microgrids may operate independently of a centralized grid by transferring between diverse power sources. This is especially important in developing countries such as Lebanon and India where the population endures episodes of prolonged power outages. Not only is the grid unreliable, but grid transmission can cost upwards of US$1million per mile, so extending the grid is too expensive. The cell phone model allows for staged implementation of energy provision. Why is the Microgrid Important? Grid-connected PV is a major global energy source with almost 40 GW installed, primarily in the last 10 years. SolarVision Co. provides guidance for PV clients in several developing countries, and our analysis shows that the rate of PV implementation by developing countries will accelerate dramatically as a result of decreasing costs of PV, rapidly growing populations, and expanding middle class. This surge in PV installations in developing countries derives demand for PV microgrids, which may be implemented at lower cost and with added flexibility and reliability. Furthermore, a microgrid’s capability to switch to off-grid mode power generation provides a bridge between common and often prolonged blackout gaps. SolarVision Co. estimates microgrid PV potential in developing countries alone will be greater than 5 GW in the next few years, especially as growth in current PV leader countries continues to slow. In our engagements with numerous clients, we are seeing an increase in interest for PV in microgrids which does not show up in typical market analysis as it is ‘off-the-books’ and financing is still in exploratory stages. Key Issues: Affordability and Reliability The affordability of PV is improving as module costs drop and the incentive increases with rising oil prices. Further price decreases will come, and as new modes of energy storage become viable, the PV-integrated microgrid becomes increasingly realizable by developing countries with resources that must be prioritized. The key advantage of a microgrid is its use of dispersed generation sources and its inherent reliability--the ability during an electricity grid outage to isolate itself from the grid seamlessly with little or no disruption to the loads within the microgrid. Combining a variety of distributed resources enables a community to generate sufficient electricity in the event of a prolonged power outage in order to operate emergency services, such as a police station or hospital, and ensures that citizens have sufficient power to meet their essential needs. Likewise, when the electricity grid disruption ceases, the microgrid reconnects flawlessly to the grid without impacting the quality of power. Microgrids are completely compatible with a centralized grid and serve as purposeful components of grid expansion. The selection of particular micro-grid technology can have far-reaching consequences for the sustainability of the services. Technical failures of even the most perfectly matched microgrid system may result from an absence of indigenous capability. Community involvement (of both men and women) is necessary for successful operation whether the system is locally or regionally maintained. Locally trained staff members often migrate to urban areas to exploit their new skills. As such, a consistent, reliable source of power from any micro-grid system depends on selection of trainees, particularly women, who are likely to remain in the area. What Is a MicroGrid and How Is PV a Part? Solar PV plays an important role in meeting the energy needs of the developing world, however, those needs are growing quickly while resources remain few. These conditions are perfectly suited to a PV microgrid solution, which provides reliable, lower comparative cost power in a more amenable timeframe. A microgrid is a concentrated web of distributed energy sources, energy storage, and loads that normally operate connected to an electricity grid. The various energy sources are tied together on their own feeder, which is then linking to the grid at a single point of common coupling. A microgrid may be viewed as peer-to-peer transmission of energy, which is more networked and symmetrical, without a master controller or central storage unit that is critical for operation. Its reliability hinges on its diverse generation sources and ability to function and be controlled independently as needed (i.e. during a brownout or blackout). Microgrid energy sources may consist of an evolving mix of standard and renewable options. In a manner similar to the early hybrid cars, the beginning stage may have more fossil fuel utilization, but this would decrease with time. Standard power-supplying sources in a microgrid may also utilize novel equipment such as a microturbine to maximize efficiency while being augmented by PV. Over the course of time, the energy mix would become dominated by PV and possibly other renewables. A set of examples of rural electrification solutions with mixed sources are shown in Figure 1. Standard generators may be replaced by microturbines, which make efficient (possibly up to 80% efficiency) use of byproduct heat for local process heating or space heating, allowing flexible trade off between the needs for heat and electric power. Microturbines are small combustion turbines approximately the size of a refrigerator with outputs of 25 kW to 500 kW. A microturbine produces both heat and electricity on a relatively small scale and offers several potential advantages over standard energy generators, including relative low capital costs, limited moving parts, compact size, greater efficiency, lower emissions, lower electricity costs, and flexible fuel options. Solar combined cycle, a system that provides solar power during the day and standard power via natural gas combustion in a microturbine at night or under cloudy conditions, is currently under development by HelioFocus and Capstone. Examples of several Capstone microturbines are shown in Figure 2.   Case Studies and Discussion SolarVision Co. has been providing guidance to a range of rural electrification customers in developing countries including India and Latin America countries, such as Panama, Cuba, and Chile, as well as Azerbaijan, Indonesia, and some clients in Africa. There are common points of note which develop from these engagements. It is possible to establish key points of learning, evaluate critical considerations, and provide technology guidance. Many of the clients are trying to understand the various technologies of PV, as well as CPV, and CSP along with wind and storage.1) The complexities of financing and maintenance are also points of note. SolarVision Co. is seeing increasing interest, which is gaining momentum. Our analysis comes from both the specific client support as well as detailed market analysis for this segment. SolarVision Co. is now actively involved with a solar project in India which will provide up to 14 MW. A Few Case Studies Highlight Some of the Key Learning Points: One of the authors traveled to Cuba to examine and provide guidance on their use of PV in microgrids for rural electrification.2) As recently as 12 years ago, Cuba’s energy situation was bleak. The country had 11 large and quite inefficient plants generating electricity for the entire island. Most of the plants were 25 years old and only functioning 60% of the time, setting the stage for frequent blackouts, especially during peak demand periods. Cuba’s transmission grid also saw typical high percentage of transmission losses. In addition, 75% of the population was cooking with kerosene, and low residential electrical rates discouraged conservation. Extended power outages following subsequent hurricanes in 2004 and overarching drivers of peak oil and climate change sparked Cuba’s ‘Energy Revolution‘-- the country’s commitment to prioritizing development of reliable energy sources. The Cuban populace in general expressed a broad depth of awareness of PV as a energy solution and were interested to have more inputs.1) The results have been impressive. Cuba has leap frogged to the top of the list of countries with strong energy utilization and low carbon footprint. In 2009, the World Wildlife Fund (WWF) declared Cuba to be the only country globally that is approaching sustainable development. The solutions to Cuba’s energy needs were not easy. Severe economic constraints in Cuba has historically prevented significant government and private investment in energy infrastructure; however, the ‘Energy Revolution’ provided the foundation for Cuba to succeed through various measures, including energy conservation and implementation of small-scale renewable energy projects. One of the gating factors associated with successful executing the ‘Energy Revolution’ is cost. Installed costs are low, in the range of about US$2.50/W; however, wind power production appears to be even more economical. As such, the Cuban micro-grid model utilizes a mix of energy sources, with PV being a significant part of the overall portfolio. The most appropriate scenario for Cuba appears to be a mix of PV, solar thermal, wind, and bio-gas generation.  Figure 3 shows a PV installation at a Renewable Energy Center micro-grid supplying a total of ½ MW to the community in the eastern part of the island near Bayamo . India boasts a much stronger economy and solar implementation strategy than Cuba, however, it has undergone much criticism of its perceived reluctance to move away from fossil fuel burning and faces immense challenges in rural electrification due to its rapid population growth, poor electricity infrastructure, and lack of political commitment and government resources. India’s Solar Mission represents one of the world’s largest renewable energy plans to date; a project aimed at expanding India’s solar capacity from 3 MW to a target of 20 GW by 2020 and 200 GW by 2050. This immense undertaking forms the centerpiece of India’s National Climate Change Strategy and will cost upwards of US$100 billion to implement even part of this ambitious plan. These challenges make India an ideal candidate for reaping the benefits of the cell phone-microgrid model. SolarVision Co, has had various clients in India looking at the considerations for PV in microgrids, as well as supporting clients currently installing PV. Microgrid installations are a reality in Japan, and it is surprising that micro-grid applications were not a part of the safety design for the nuclear power generation facility in Fukushima. The Sakura at Sendai Microgrid electrical generation and distribution system was constructed to serve a small local area in Sendai, Japan. The microgrid system is connected to the main electrical grid, but includes its own solar PV and gas-powered generators and serves a high school, medical school, and a water treatment plant. Key Learning The key point of learning from Cuba is that high-level government support and commitment of the populace are necessary for a successful energy revolution of any appreciable scale. Cuba created its own path towards a new energy paradigm by applying concepts such as distributed generation, efficiency, education, and the gradual expansion of solar energy across the country. India’s ambitious, long-view strategy for expanding its solar capacity is another key strategy to consider. Such a strategy shows the intent of government support and specifically targets opportunities for entrepreneurial investment. India also intends to request both monetary and technological backing from developed nations in order to meet its Solar Mission objectives. Without such an ambitious plan, this type of support could not be won. Financing of solar PV projects, whether microgrid scale or large utility scale, remains a limiting factor. As there are still limited financial resources, there is pent-up demand for PV in the microgrid context. However, the prices are dropping and the urgency for energy is increasing to the point where these developing countries are at a cross-over point and seriously looking at how to implement some modes of microgrid. The broader view is that they are interested in hybrids of solar with co-generation. It is dramatically lower up-front cost to buy diesel generators; however, operational costs are increasing. Indeed, in some regions the cost of petrol is even higher because of transportation (e.g. Nepal) and the microgrids are in fact financially attractive. The hybrid mode combines a mix of PV, diesel and other elements. Various SolarVision Co. clients are eager to understand better how these moving parts work and how to get started. PV is well suited to be a key component in microgrids. The global grid-connected PV capacity is rapidly approaching 40 GW with most of this growth in the last 10 years. Microgrid and off-grid segments are showing strong potential to become major components in the PV market. SolarVision Co. estimates the opportunity for micro-grid installations over the next several years at levels approaching 5 GW. Indeed, as the leading developed nations scale back on incentives, and even on the actual installations, it is possible that the micro-grid market will ramp up into a position that will provide a major demand market for solar. The worldwide movement from fossil-fuel-based energy sources to renewables is a trend based on the desire for energy independence, reduction of Greenhouse Gas (GHG) emissions, and limited fossil fuels resources. HSBC’s senior global economist, Karen Ward, recently reported in a research note that there could be less than 49 years of oil supplies left, even if demand were to remain flat.Fossil fuel reserves are finite. Derived from this movement away from fossil fuels is recognition among industrialized and developing countries of the need for non-standard energy provision options. This is especially true in developing regions which lack the basic infrastructure. Further, even where an electric grid exists, there are often problems of intermittency and power outages. Micro-grid power production could easily range between 1 MW to an aggregation of 10s of MWs and have the ability to evolve and expand or decrease with local needs, as those needs evolve and become recognized. The electricity generated by PV and PV-integrated microgrids is clean, renewable and reliable. Microgrid implementation is urgently needed to move rural populations away from burning wood and fossil fuels, which has a disproportionate impact on the global carbon levels and is ruinous for the physical and human landscapes exposed to such measures.

Read More