Pros and Cons of PWM and MPPT Controllers

PWM Type Solar Controllers	MPPT Solar Controllers
PROS
- PWM controllers are built on a time tested technology. They have been used for years in Solar systems, and are well established - These controllers are inexpensive, usually selling for less than $350 - PWM controllers are available in sizes up to 60 Amps - PWM controllers are durable, most with passive heat sink style cooling - These controllers are available in many sizes for a variety of applications	- MPPT controllers offer a potential increase in charging efficiency up to 30% - These controllers also offer the potential ability to have an array with higher input voltage than the battery bank - You can get sizes up to 80 Amps - MPPT controller warranties are typically longer than PWM units - MPPT offer great flexibility for system growth - MPPT is the only way to regulate grid connect modules for battery charging
CONS
- The Solar input nominal voltage must match the battery bank nominal voltage if you're going to use PWM - There is no single controller sized over 60 amps DC as of yet - Many smaller PWM controller units are not UL listed - Many smaller PWM controller units come without fittings for conduit - PWM controllers have limited capacity for system growth - Can't be used on higher voltage grid connect modules	- MPPT controllers are more expensive, sometimes costing twice as much as a PWM controller - MPPT units are generally larger in physical size - Sizing an appropriate Solar array can be challenging without MPPT controller manufacturer guides - Using an MPPT controller forces the Solar array to be comprised of like photovoltaic modules in like strings

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Wind power pros and cons facts

Wind Energy Pros and Cons discusses the advantages and disadvantages of using Wind as an renewable source of Energy.

Wind Energy Pros
Residential Wind Generators

Wind Power is free and in abundance in certain areas. The Wind Speeds are always higher on the shoreline, at the top of a hill, and in places free of obstructions. Obstructions such as trees (forests), mountains, buildings, silos, and other natural and man made structures.

Wind Power does not generate "Pollution", or radioactive waste. It does not consume any of the non-renewable resources such as coal, natural gas, or oil. It is a renewable energy.

Wind Power can generate enough energy for large numbers of people. By using larger turbines connected to an electrical grid it allows people the benefit of wind power without owning their own wind system.

It is a "permanent energy". The wind will exist until the end of the sun. About 5 billion years.

Wind becomes "A Source of Power" during times when the electrical grid is out. For example, hurricanes, power outages, brown outs. Using wind power can provide you with the needed electricity.

With new technology, the cost of a residential wind power turbines have decreased significantly while increasing in their efficiency. It is reported that costs have decreased well over 60% since the 1980's. Wind power has no hidden costs, and it has become more cost-effective with each new round of technological advancements.

Wind is an excellent supplement to other renewable resources. For example, solar or hydro power.

Installing Residential Wind Power to your home can gain you tax credits and/or rebates from the Federal Level as well as possibly your state's level.

Wind energy is readily available around the globe, and therefore can lessen the dependence for energy for any country.


Wind Energy Cons

The main "con" of wind power is the reliability of wind. You cannot expect the "same amount" of wind power to be generated by your wind turbine. If the Wind speed varies by only 10% (from 12 mph to a little under 11 mph, the production of wind power from the turbine can vary up to 25%!).

Wildlife can be endangered. Birds, especially Migrating Birds, are known to try to fly between the running blades, and they get hit by the blades.

Lightening causes the most damages to Wind Turbines. Mostly in part because of the tall thin steel shapes. Areas in warmer region are hit the most frequently.

Some people don't like the design of wind turbines. Long steel bars, or many of them that make up Wind Farms as pictured here.

Wind energy can only be stored with a battery.

Possible Noise Pollution -There is a low 'swoshing' sound from one home wind turbine. However, the noise from commercial wind turbines or from 'wind farms' is similar to the sound of a small jet engine.

The Site possibilities of the Turbine may be limited. You may live in a windy area, but the only place you can install it may be on your rooftop - which is next to a neighbors garage redirecting the wind. Or want to start a wind farm and all real estate is priced accordingly to how much wind energy the land has. A general idea of how much 'wind' is needed to power a small wind electric turbine is an "annual average speed" greater than 9 mph.

Additional "Wind Energy Pros and Cons"

(Issues listed below could fall into either "pros" or "cons" or neither....depending on the situation.)

Before installing any Renewable system, wind, solar or hydro, Check with your local government for any zoning regulations or laws.

Check out your neighborhood with the area you intend to place the wind turbine and be mindful of placement. Let your neighbor know ahead of time.

Look at the landscape of the possible wind turbine site and see what may change in the next 10-15 years you have your investment. Will your 'Home made wind power' be affected. Land for sale? New construction that may block the wind? Trees growing?

Design is the key to building successful Wind Generators for the Home. Be sure to take into account the list of "Wind Energy Pros and Cons".

Wind Energy Pros and Cons
Advantages
1) Green and Clean Energy

Among the wind energy pros and cons collection, the most primary and weighted advantage that can outrun the most shortcomings of the wind energy is that this prolific source of energy is “green and clean” that means wind can be deployed to produce energy without any pollution, toxic materials and fossil fuel generation. Due to the increasing industrial concentration in the world, the alternative energy resources accompany with the primary disadvantage of the pollution because renewable energy resources cannot be used without the production of toxic materials but wind energy offsets the pollutants in the air. According to a study, wind energy plants located at California contributes to an offset of around 2.5 billion pounds of carbon dioxide, and 15 million pounds of other pollutants that would have been very detrimental for the human and animal life. The on shore wind energy production resources can produce electricity without emitting any kind of pollution and this is the most exigent feature of this energy resource. Wind energy harnessing can be done without any green houses gases production, toxic wastes and carbon by-products.
2) Amazing Potential That Can Satisfy All the Energy Needs

Whenever the wind energy pros and cons are discussed, the abundance of potentiality factor can also add a great weightier to the usability of wind energy resources because according to an estimate, the wind energy resources have the potential of producing a power of around 400 TW (terawatts). As the wind is available everywhere on the earth so the wind energy can be harnessed and deployed for the human uses literally everywhere excluding the feasibility factors and risk assessment. The elevation of the magnitude of the wind energy potential can be perceived from the study that took place in Palo Alto, California in which the scientists said that he wind energy can suffice for the energy needs of the whole civilization and if a 100 more wind mills can be installed, this can do tricks beyond imagination of the humans. They said that the wind energy can be effectively harnessed to produced trillion of watts of power that can fulfill the energy needs for the humans all around the world. According to government estimates wind mills produced around 7TWh of energy  that is more than a quarter of the electricity provided by British renewable energy resources and are enough to save six million tones of CO2 throughout UK.
3) Economical Energy

Another important advantage of wind energy is its cost effectiveness. In the era of depletion of the energy resources, the scientists are looking into the most economical renewable energy source that they can use in order to satisfy the industrial and day to day energy needs of the human beings. The experts throughout the world, after assessing the wind energy pros and cons have come to the conclusion unanimously that the wind energy is definitely the most economical renewable energy resource that can be used effectively to carry out the energy needs. With increasing coal and gas prices, the wind energy resource is the most exigent source of energy to suffice the needs of human kind because of intense monetary benefits. The Colorado Public Service Commission started a 161-megawatt (MW) wind project in Lamar in order to complete the local energy needs and they were amazed to know the fact that wind energy generation was one of the most economical way to generate energy and Colorado, the commission determined that wind energy provided the lowest cost of any generation resource of energy production submitted to a solicitation bid by Xcel Energy. Wind energy is so profitable that in America, due to the 47,000 megawatts of wind energy capacity outlets, each mega watt gives a total of $11,000 income to state.
4) Agricultural and Rural Development

Rural and agricultural development is another important advantage of wind energy. Wind farms located in rural areas can generate a lot of Energy and this energy can be transmitted to load centers in urban areas using the regional utility grid outlines that are normally available readily. Rural areas can sustain the land lease revenue and many farmers can rent the spaces and outdoor capacities and gain incomes. Wind energy also provides an increased and augmented local tax base for rural areas. Prowers Count which is a home to the Lamar project, increased its local tax base by $32 million and a 912 MW of new wind power installed in Texas in 2001 produced $13.3 million which was used in the schools and social work.
Disadvantages

Wind energy pros and cons article turning into a “wind energy pros article”? No! As we are about to tell you about the cons of the wind energy so that you may remain vigilant and can know the potential short comings and threats of this energy resource.
1) Unstable/ Unreliable Energy Resource

As wind is one the most low density energy resource, efficiency is decreased of the wind mills farms if a very large number of wind mills are not placed. There should be great amount of distance between the wind mills because of the requirement of harnessing energy and turbulence problems. Due to the low density, the intensity of the wind does not remain constant and there are halts and closes for the wind mills which can really cause damage to the electricity output and all the appliances that are used to harness this energy. The winds are not constant all the time and the onshore wind harnessing cost can increase exponentially.
2) Threat to Wild and Human Life

Due to barotraumic noises and turbulence, the wild life can be at danger. In North America, around 300,000 in one cave alone was dead because of the white noise problem caused by the wind mill noises and turbulence. Humans living around the areas where wind mills are placed can also be upset due to the sounds produced because of the wind mills. The birds are killed in great numbers due to the sharp blades of the wind mills.
3) Limitation of Deployment

Wind energy is only suitable for the coastal regions where the wind mills can be made with optimal feasibility. The hilly areas are also very suitable for the wind energy harnessing but what about those parts of the world where the wind speed is very low? Certainly this energy source fails in those areas and this is one of the most prominent drawbacks of wind energy. The alternative energy resource which is being searched by the scientist should be constant and readily available all the time in order to increase the homogeneity of the productivity of the industry but wind energy sources lack this factor. Similarly the coastal regions are not very abundant in perspective of the areas and the numerous wind mills cannot be built on coastal region otherwise it will decrease the scenic beauty of these regions.
Conclusion

Wind energy pros and cons must be assessed in a balanced way and the world energy experts should inculcate this fact that no alternative energy resource can be perfect. We have to combine the pros of diverse and multifarious energy resources in order to satisfy the augmenting and elevated energy needs of humans. The wind energy resources have a capacity to fulfill the energy needs but at the same time the disadvantages must be inculcated at the planning levels to optimally exploit the productive resources.

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The Advantages of Car Power Inverters Article

The Advantages of Car Power Inverters

Travelers in cars, trucks, recreational vehicles, scooters, and even boats can take advantage of car power inverters to power a wide range of appliances and electronics. Most consumers, in everyday situations, will find that the 12 volt inverter for the cigarette charger is fine. Some of the advantages of power inverters:
Multimedia

Entertainment while traveling is a big advantage of car power converters. While many newer vehicles come equipped with a DVD player, these upscale models are expensive, and many older cars are not capable of internally installed multimedia devices. Instead, people can use the inverter to plug in laptops, DVD players, CD players, and stereos. Game systems are portable and can receive power from the inverter. As far as power output, the standard cigarette connection easily powers all multimedia devices. Laptops use about 75 watts and DVD players use about 35 watts. Even game consoles only use about 100 watts.
Charging

People who are on the go often run out of cell phone, laptop, tablet, and music power for portable devices. The car power inverter solves this problem, as cell phone car chargers use about 20 watts of power. For just cell phone charging, consumers can buy extremely small inverters or adapters that store in the glove box, pocket, or purse. For laptops, consider getting a larger unit with higher output. Purchasing inverters with most power that still fit in the cigarette charger and do not attach to the battery is wise because they have a high range of device powering capabilities. Also, consider an inverter with two, three, or four electrical plugs in order to have compatibility with the highest number of devices. However, keep in mind the total amount of power each device is drawing as the standard inverter only gives about 160 watts total.
Recreational

People engaged in recreational pursuits like camping, stargazing, and sports tailgating could really use the advantages of the inverter. These types of activities often require kitchen appliances, heaters, air conditioners, and refrigerators. For instance, while planning a night of stargazing, a person could easily find a converter to attach to the car battery that would support a space heater. Tailgaters, those that cook out and entertain at sporting events and concerts, can power a wide variety of appliances like a refrigerator, a microwave, or a blender. Campers can eat in style with a coffee maker, waffle iron, frying pan, and any number of appliances. They can even power a clothes washing machine.
Working

While working outside or inside at locations without electrical power, the car power inverter is useful for powering a wide variety of tools including saws, welders, and pumps. For instance, while working at a location cutting down trees, the person could use a high watt inverter connected to the battery in order to use a hacksaw and cut down trees. Inside locations may also be advantageous for an inverter. For instance, a long cord attached to the inverter can be stretched inside to illuminate a house with no power.
Purchasing and Using a Car Inverter

Because the inverter has two sides to the equation, consumers need to consider the input side (from the car battery) and the output side (the appliance). For most car batteries, a 12 volt inverter is sufficient. A 24 volt inverter is more efficient. Since every battery is different, the consumer needs to consult the battery manufacturer to estimate exactly how much power the inverter draws and how long the battery will run the inverter before being drained. To plug in appliances or devices that draw more than 162 watts, the inverter needs to be attached directly to the battery.
Inverter Size and Position

The size of the inverter depends on the amount of power it puts out. More power equals a larger bulkier inverter, due to the increasing amount of components. Also, older inverters will be larger than newer ones due to improved technology and miniaturization. The inverter usually takes a rectangular form and weighs one to three pounds.

The inverter slips easily under the car seat as it needs to be on a flat surface, but better air circulation makes the car floor a better location. Most inverters will come with a long cord extending from the cigarette socket so the inverter can lie on the floor, but some of the smaller inverters will just stick straight out from the socket. Avoid exposing it to water or other liquids and avoid placing it near any heat sources, including direct sunlight and flammable materials. The ideal temperature for an inverter is between 50 to 80 degrees

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How to Calculate Battery Amp Hours Article

Learn to estimate the capacity of a battery, in amp-hours, to know how much charge it needs for a specific task. Engineers frequently must determine the total available charge a battery must have to power a specific electronic device. It's important to note that the unit amp-hour indicates an amp multiplied by hour. Electrical current, in amps, represents an amount of current flowing past a given point each second, hence the amp-hour is a unit of charge.

Instructions

        1. Convert the electrical current needed by the device the battery will power into amps. For example, assume a device needs 550 milliamps of current. One amp contains 1,000 milliamps, so the conversion is achieved by dividing by 1,000. Performing this step, for the example, you have 550 milliamps divided by 1,000 milliamps per amp, or a current of 0.55 amps.
        2.  Change the total time the device needs to run on a single battery change into hours. Divide the minute portion of the time by 60, then add it to the hour portion. For example, assume a run-time of 15 hours, 40 minutes. Continuing the example, you have 40 minutes divided by 60 minutes per hour, or 0.67 hours. Adding 0.67 hours to 15 hours you arrive at 15.67 hours for the run-time.
        3. Multiply the current draw required by the run-time to arrive at the battery capacity needed in amp-hours. Completing the example, you obtain 0.55 amps times 15.67 hours, or a battery capacity of 8.62 amp-hours.

Tips & Warnings

    Dividing amp-hours by the current drawn, in amps, yields how long a battery will stay charged in hours.

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How to Calculate AH for a Battery Article

Based on an appliance's wattage and the voltage of the attached battery, the appliance will draw a specific amount of current through the connecting wire in order to run properly. Because a battery is designed to maintain peak voltage throughout its life, the standard measurement unit of how long an appliance can run on a given battery is amp-hours or "AH." While manufacturers put an amp-hours rating on a battery, this value is based on a one-amp appliance. To determine the amp-hours rating of a battery for a specific level of current, you need to use Peukert's formula.
Instructions

        1.  Check the battery's label for the published amp-hours rating.
        2. Check the battery's label for its voltage.
        3. Check the appliance's owner's manual for its power rating (in watts). If you don't have this manual, visit the manufacturer's website and search the "Support" section for technical information.
        4. Divide the appliance's wattage (from Step 3) by the battery's voltage (from Step 2). The result is the current (in amps) that the appliance draws from the battery.
        5. Determine the "Peukert's number" for the battery. See "Resources" for a link to a table of Peukert's numbers for common batteries.
        6. Calculate the current draw (from Step 4) taken to the power of the Peukert's number (from Step 5).
        7. Divide the battery's published amp-hours rating (from Step 1) by the result from Step 6. This value represents the actual amount of time (in hours) for which the battery can support the appliance.
        8. Multiply the result from Step 7 by the appliance's current draw (from Step 4). This will given you the actual amp-hours rating for the battery when used with that particular appliance.

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How to Calculate Battery Capacity Article

The capacity of a battery relates to the time you can expect it to last and is measured in milliamp hours (mAh), not to be confused with voltage, which is the force of electrical power the battery produces. The mAh you can expect to get from a fully charged battery is often marked on the battery label, but if it isn't on the label, then you can obtain it from the battery manufacturer's website. The mAh declines as the battery gets used, so by using a multimeter you can calculate your battery capacity.

Instructions

        1. Read the fully charged capacity of your battery on the battery label or look on the manufacturer's website for your specific battery. For example, a nickel cadmium battery is likely to state 600 mAh and a lithium battery 2,400 mAh. Make a written note of the battery's mAh.
        2. Turn on your multimeter and set it to measure mAh. Either turn the knob to the correct setting or press the appropriate button.
        3. Place the metal tab on the end of the red wire from the meter onto the positive terminal of your battery; it's labeled "+." Place the sensor on the end of the black wire onto the negative terminal of your battery, labeled "-."
        4. Read the meter display panel and make a written note of the measurement. If the battery is fully charged, it is the same as the figure you wrote down from the battery label. If the battery is not fully charged, the figure is less than the one from the battery label.
        5. Use a calculator to divide the figure you wrote down from the meter by the figure from the battery label; then multiply the answer by 100 to get the percentage capacity in your battery. For example, if the meter reading is 600 mAh and the battery label is 2,400 mAh, 600 divided by 2,400, multiplied by 100, equals 25, so your battery capacity is 25 percent. If the two figures you wrote down were the same, then your battery capacity is 100 percent.

Tips & Warnings

    Use the figure you calculated earlier and you can work out how long your battery is going to last. Read the label on the device your battery powers to get its mAh rating. Divide the reading you got from the meter by the mAh rating on the electrical device, and multiply the result by 60 to get the minutes your battery will last. For example, if the meter reading is 600 mAh and the rating on the label of the device is 1,200 mAh, 600 divided by 1,200, multiplied by 60, equals 30, so your battery will last 30 minutes.

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