Grid Tie Inverters for Solar Energy

Having a solar system at home to convert sunlight into electrical power for domestic use is very beneficial to a person in several ways. Apart from having an uninterrupted power supply that is very much reliable, you get to save costs that would be used to foot electricity bills thus an appropriate source of power.

Connecting the solar to a power grid is one of the most common ways of configuring it at home because it ensures surplus power does not go into waste as well as producing extra power when the sunlight levels are low and at night when there is completely none. Owing to the benefits it comes with, this article will take you through the main steps of wiring grid tieinverters for solar energy at home to ensure you do not seek professional help when installing yours.

Getting Tools of Trade Ready

To begin with, you will be required to have all the necessary materials and equipment for wiring well in place and in advance. Make sure the solar panels, combiner box, direct current breaker box, grid disconnects and power inverter is ready and in good working condition. Once all that is ready, wire each string of the solar panels into the combiner box and make sure the circuit breakers are also in place. The number of solar panels you are using will determine the type of box and size of breakers that you require and this is vital for consideration to ensure you do not use wrong ones.

At the exact point where cables running from the panels enter the house install the direct current disconnect switch and then fix a metal oxide variator to the point where connections from several devices meet. This will be helpful in preventing circuits from any effects occasioned by excess currents or voltage thus minimizing chances of fire outbreaks in case of faults within the electrical system.

You can then install the breaker box which plays the role of a cutoff point because it acts swiftly to open the circuits whenever power leakages are detected. Do the same to the power inverter and this is important since it changes direct current that comes from the solar panels into alternate current which is the most common one in many homes. This furthermore makes sure the voltage of the current that comes from the panels is neutralized in a way that it is well suited for use with all the electrical apparatus like iron box, TV, radio and heaters you have.

Since there are times when you will not be willing to use the power or it is not necessary at all you will have to install the main service disconnect. This will enable you to cut the power supply between the system powered by the grid and the solar panels when not in use. Once you are through with all that, it is time to connect the main device disconnect to the power grid meter as well as the distribution panel. You will have tied together the solar system, utility lines and the power outlets in your house to enjoy uninterrupted power supply for free.

Caution while Wiring Your Grid Tie Inverters

Solar energy can be very dangerous like normal electricity especially when there are a lot of sunlight therefore you have to be extra careful when making the connections. Never leave any cables naked and seek advice from a qualified and experienced electrician before doing connections to avoid making wrong configurations. Also, take note that the entire system is connected together and the failure of one will lead to the failure of the rest which means you have to be cautious when using any.

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How to Build a Solar Power Windmill?

With the harsh economic period that is being witnessed in the entire world, it is important that you derive ways in which to handle this situation. It is believed that human activities have greatly contributed to the economic crisis as well as to the harsh climate conditions that have caused unpredictable weather conditions. This is because these human activities affect the environment thus to reduce these effects, it is good to consider some of the activities that are harmful. One such way to protect the environment is to use solar power windmill. This is possible in that it will save lots of energy as well as costs. It is possible to build solar panel on your own.

How to Build a Solar Power Windmill?

The first thing that you need to do is to plan your system. Here are some ways to attain this;

You need to plan your system: This is the initial step when it comes to building a solar power windmill. In this step, you need to know how much energy you consume on daily basis or per month and also look at the monthly bills. You also need to cut wasting electricity in that you have to switch off lights when not in use also ensure some of the electronics in your house are put on power strips. You the need to add the entire wattage used on daily basis and also the amount that is used by your appliances. This is advised in that you will know the exact output of solar power windmill that you need in your home.

With this information, you need to research the market so as to find out the available solar power windmills as well the price. In this case, look at the features of these windmills such as battery durability which is important in that it will help establish the amount of energy that will be saved. Consider a battery that saves energy in at least two consecutive days.

You also need to evaluate solar output as well as the wind speed. This in most cases has to be done with the location in mind. Consider the wind turbines diameter so as to know the right turbine and solar to opt for. You can decide to purchase a kit or Build a Solar Power Windmillon your own. This is a decision that you need to regard.

Putting together the items

• After you have determined what you need and shopped for the right products, it is time to build a Solar Power Windmill.
• You need to install the solar panels on a designated place on your roof. This place should be where the sun hits so much. Consider the southwest facing side.
• Erect windmill tower in a location where wind can easily reach the turbine blades without any form of hindrances from the environment. In order to boost performance, it is good to raise the tower.
• Fix the turbine to the tower and during this process, ensure that the blades are of adequate length and that they have been pitched so as to catch prevailing wind and enhance free turning.
• You then have to attach the windmill to a generator or alternator which is mandated to change wind power into electricity.

Finally, you have to wire the solar panels, generator as well as the battery to the electrical system. You need to be aware that the solar panels that you will install only generate electricity when light strikes onto them hence the amount of energy produced can vary from time to time. In case of temperature change, production of electricity will also be affected.

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How to wire a Solar Cell into an Electrical Circuit?

The role of solar cells, in other words the main parts of the solar power panels, is to absorb photons and convert them into electrons. We already know that activation of electrons produces electricity.

The electricity produced by the solar cells cannot be used directly in everyday electronic devices because of the difference in voltage. Most of the solar cells sold today have a 6V - 12V - 24V output, whereas electrical appliances function with a mains voltage requirement of 115V - 240V AC input voltage. For this very reason the energy produced by solar cells cannot be connected to any system without using an agent electronic device.

Regulation of the Voltage of Solar Cells

As mentioned above, DC (direct current) has to be converted to AC (alternating current) which is used in network structure and is convertible. The device used for this purpose is called an Inverter.

An inverter is a device that converts a direct current with a specific voltage to alternative current. In the image below you can see how voltage is converted by an Inverter.

Electrical Circuit Connection Options

1.) Direct Connection: Some home electronics need 12 - 24V DC voltage, although this is quite rare. It is possible to connect solar power panels to these devices. However, it is important to be aware that the output power solar energy cells provide is unstable. The calculations are generally done as 1000W solar power/1m2 with °90 Angle. However, this is not the case for all day. A decrease of performance and voltage occurs in early mornings and at sunset. In the diagram below you can see the amount of energy acquired depending to the angle of the sun.

In the above mentioned situation, what is required to connect the solar cells to an electronic device is to stabilize the voltage with the help of a battery, or by preparing an electronic regulation circuit. You should know that the regulation circuit cannot equalize the power while raising the voltage of the regulation circuit.

2.) With the Help of Inverter: In this phase the solar power panels are connected to the inverter module and the inverter outputs are connected to the inputs of the device that we want to use. What we have to pay attention to is that both the inverter output and device input has the same levels of voltage. There is another point you should pay attention- the drop of voltage applied to the input of the Inverter will cause a power loss as we mentioned above in the previous item. For this reason, the specific solution is to attach a battery unit to the solar panel.

The Connections of an Electric and Possible Problems

The main problem when connecting solar cells to electric circuits is voltage inconsistency. We talked about it above and offered some solutions. Now let’s move on to other possible problems and solutions.

Question: How can I connect the system without risking the solar panels if the circuit is using a different source?
Answer: In this kind of scenario you should isolate the solar cell system and the electric circuit with the help of diode. We ensure the protection of test current by connecting the solar cell’s one end to a diode and other end to the electric system. Otherwise, an inverse current would pass through to destroy the solar cells.

Question: I have a number of solar cells with different power and voltage; can I connect them all to the same electric system?
Answer: the most important thing that you should know is that you can connect two devices with different voltages in series and raise the voltage. However, you cannot do this by shunting. The basic rule of shunt is that the devices must have similar voltages. Therefore you have to connect the solar cells that have similar voltage. If you just want to raise the voltage then you can connect them in series. We will soon bring out a detailed study on this.

Question: Is there any possibility that the solar cells could harm electric circuits?
Answer: It can definitely harm the circuits. Any connection that is made recklessly or miscalculated, may harm the electric circuits.

Question: Are the variety and structure of the cables used in interconnection important?
Answer: Although not as important in smaller frames, the variety and structure of the cables are quite important in larger frames. A 200W panel, whose output voltage is 12V, has 17A output current. For this reason, the cable you chose should resist heavy currents. Imagine you are using 10 panels at the same time, in this case the output current would be around 170A and you have to choose the cable for transferring this kind of current carefully.

Dictionary of Technical Terms

• Inverter: It is the device used to change AC voltage to DC voltage.
• Electron: It is a particle that enables voltage generation in accordance with its speed in metals and it carries current. It moves from (+) --> (-).
• Diode: It is a particle that lets electrons go over it in a one-way direction. In other words, it has (+) and (-) poles and it stops the transition of electrons.
• Solar Cells: These are the most important parts of the Solar Panels. It is a chemical mechanism that converts reflected photons into electrons.

You now have the information required on how to connect solar panels to electrical circuits. In upcoming articles we will discuss series connection and shunt with illustrations.

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Solar Heaters for Swimming Pools

Whether fixed or portable, swimming pools can be found in the gardens of many houses throughout the world. Most people begin using their pool in the spring or beginning of summer. Although the air temperature may be pleasant enough, the temperature of the pool water is usually below desired levels at the beginning of the summer. To raise the temperature of the pool, solar heaters that use solar energy and grid tie heaters can be used.

The most important thing about solar heaters is that they are energy-saving and environment-friendly. These two terms are very important these days. The more we use renewable energy sources, the more we can help safeguard our planet's future.

There are two types of solar heaters: ones that are roof-attached and ones that are located pool side. The roof-attached solar heaters are the more commonly used.

Renewable Energy and Solar Swimming Pool Heaters

The use of renewable energy sources such as wind, solar and geothermic energy lessens the release of harmful gases in to the atmosphere and will help leave us a habitable world for future generations. Solar heaters for swimming pools may be a small solution to this problem, but they are a popular one nonetheless.

In the States, many houses with pools use this system. Thanks to this system, we can make use of the solar energy which is both cheap and clean. In this article we will try to inform you about the system's advantages in terms of energy-saving and how much we could save.

Solar Pool Heating System Parts

Solar Collector: We already mentioned about its basic function and how it works in a previous article. Briefly though, it is a component that provides the user with hot water by transferring the sunlight it absorbs to the water within it by means of a specific device. There are different sizes that can be used, depending on the size of the pool in question.

The solar collector is a device that converts the cold water it takes in into hot water; it has to different types of units: BTU and MJ.

Pump: It carries the cold water from the pool to the solar collector and carries warm water back to the pool. There many types of pumps in terms of performance, and they are chosen according to the amount of water that need circulating and the transfer rate. For larger swimming pools, pumps with greater power are obviously chosen. There are two ends to these pumps: the intake and outlet.

Filter: This helps the pool stay clean and prevents it from clogging the system by cleaning the debris before the pump takes the water to the collector. These filters should be cleaned regularly.

Check Valve (Wave): When the manual check valve is shut, the solar collectors heat the water in the swimming pool to the maximum temperature allowable and deactivate all the temperature check systems.

Flow Control Valve (Wave): The flow control valve is connected to a sensor which checks the temperature of the system and when the desired level is reached the solar panels prevent the swimming pool from getting hotter by stopping the water transfer. The check valve should always be open for this valve to function.

Sensor: This is the device that controls the Flow Control Valve in order to keep the pool temperature regulated as well as measuring the temperature on both the panels and pool.

How Solar Swimming Pool Heaters Work?

We talked about the different components and the roles they play above. Please see the picture below to understand how the system functions and how the parts are related to one another.

Let us detail the way the system functions:
1.) The solar collectors heat the water by using the sunlight. As mentioned before, the important aspect of this is transferring the heated water to the pool and taking the cool water to the collectors.
2.) The water taken from the pool by the pump is sent to the filter unit to eliminate debris.
3.) The cool water cleaned in the filter unit is directed to the solar collector by means of the pipes and simultaneously directed to a secondary pipe system which is also shunt to the collector unit. The role of the second pipe system is to protect the temperature of the pool.
4.) If the system is programmed to heat the pool, the secondary pipe system will be turned off for the water to pass through. So, the cool pool water taken from one end is heated by the collectors and unloaded as hot with the help of the pipes to the swimming pool.
5.) When the pool is warm enough, the secondary pipe system starts to pour the water to the pool by using the pipes other than the collectors. This means the water comes back to the pool without being heated. The cycle continues in this way.

Above you can see the main working principles of the solar heaters. We need to add that we turn the secondary pipe system off by manually turning the Check Wave unit off.

Installation Details

Before installing a solar swimming pool heater you should make sure you research all your options; otherwise you could encounter not only high costs, but degradation issues as well. Things to consider when researching:

1.) The Sunlight Receiving Capacity of your House: The main principle of the solar collectors is to collect solar energy and heat the water passing through. For this reason the sunlight receiving capacity of the region where your house is situated is really important. In southern regions the insulation time longer than the northern regions. Because of this, you need to define the collector and its capacity according to the region you reside.

2.) The Location of the House: If your house is located in the shadow of a hill or tall building you wouldn't be able to get constant sunlight. This is the reason why the location of the house is very important for the capacity of the system.

3.) The Location of the Collector: The solar collectors are generally located on the south side of the roof. If not, there will be degradation meaning you are not exploiting all the available solar energy.

Installation of such systems is usually carried out by professionals in the region you live, so the necessary calculations and research will be done by these people.

The capacity of the solar collector is dependent on many variables.

Pool Size: The size and depth of the pool is very important. Since large sized pools are harder to heat, a larger system should be mounted. The preferred calculation is:

Surface area of the pool / the size of the system = 1 or 2, which means the surface area of the collector should be at least the 50% of the surface area of the pool.

Average Temperature: As mentioned above, southern regions usually have higher temperature levels. So the average regional temperature is an important variable.

Pool Temperature: The desired temperature of the pool is a factor influencing the capacity is the system. For those who prefer a higher temperature, larger sized collectors that heat the pool faster is advised.

Collector Location and Tilt: We mentioned that the installation should be done on the southern side. The solar collectors are generally mounted on roofs. Sometimes they are mounted near the pool (using portable collectors). Wherever they are mounted, the collectors should be located facing south otherwise sunlight exposure would be lower and there will be degradation.

It is very important that the same collectors should face the sun. To take full advantage of the sun they should be installed with a 90 degree angle. For this reason, the panels are also mounted at a 90 degree angle.

Collector Type: Some solar collectors transform more energy as they are made from better quality material and components of a more advanced technology.

Pool Covers: It is important to install systems for preventing the energy being wasted. Pool covers are therefore an important consideration. These can be used to keep the pool warm.

10–20 % of the energy in swimming pools is lost due to the bottom and side walls. 60-70% of it is lost due to evaporation. In these cases a pool cover prevents much of the evaporation.

The evaporation rate depends on the rate of humidity, the speed of the wind and difference in temperature between the pool and environment. When you choose a pool cover therefore, consider these variables.

Energy Efficiency and Solar Pool Heaters

We have explained the main parts of the solar pool heaters and other things that you should know so far. Now, let's take a look at the performance of the solar collectors and the factors influencing the performance.

The main unit used for the solar collectors is BTU (British thermal unit). BTU = 1 pound (0.454 kg) is needed to raise the heat of the water 1 °F more. It is calculated as 1 BTU = 1055.07 Joules.

The main unit value is BTU/ft2. The higher the BTU value, the more efficient the solar collector is. For example, a solar collector having 18 BTU/ft2 value works more efficiently than a solar collector whose main unit value is 12 BTU/ft2. The advantages highly efficiency provides are:

1.) Using less space (ft2): The highly efficient collectors can absorb the same amount of energy in a smaller place.

2.) Lowering the cost: The collectors, which take up smaller places and heat more quickly, have less operating costs.

3.) Heating more quickly: The collectors with high efficiency heat more quickly in the same space.

Although high efficiency solar collectors are more expensive, they are cheaper to run in the long term.

Advantages and Disadvantages

Advantages

• Heating the pool with less energy
• Causing less damage to the environment by using renewable energy
• A risk free heating method.

Disadvantages

• Costly installation
• Annual maintenance expenses
• The blot on the landscape that the solar collectors cause

Frequently Asked Questions

Question: My pool is 40 ft x 45ft. What capacity should my collector system have?
Answer: The size of the area where solar collector will be mounted is defined by the efficiency of the solar collectors you would use, the insolation conditions of your house and the location of your city. If solar collectors with high or medium efficiency are used by placing them facing south and there are no high buildings and is located in a southern area:

Total pool range = 40 x 45 = 1800 square feet. If we use minimum 50% parameter, the solar collector size you have to use is:
1800 x 0.5 = 900 ft2

Question: How much does Solar Pool Water Heaters cost?
Answer: The average prices range between $2000 - $10000 and may increase according to the size of the pool.

Question: How can I calculate Price/Performance value?
Answer: There should be a note on each solar collector defining how much BTU it can produce. For example, think that each solar collector has = 30.000 BTU and think that you use 8 collectors. The total BTU value is calculated = 30.000 x 8 = 240.000 BTU/day.

If the cost of each panel is $500, 8 panels would be calculated as $4.000. Daily performance value would be Total BTU/Total Price = 240.000/4.000 = 60 BTU/day-dollar, which means you save 60 BTU/day for each day. The higher this rate is, the more advantageous you are.

Question: I would like to get a solar collector system mounted to the pool in my garden. What should I do?
Answer: You should receive quotes from experienced companies in your city. What is important when you choose the company is their experience. You should evaluate references and the terms of guarantee in your region.

Question: How long is the life expectancy of Solar Swimming Pool Heaters?
Answer: An average system has 10-25 years of use, depending on the quality of the collector.

Question: How long will it take to provide a payback?
Answer: The recycling period changes between 1- 8 years and the parts you choose have a great influence on this period.

Question: The region I live has very cold winters with ice and snow. What should I do to protect the system?
Answer: There is a method called Freeze Protection. You should set up a loop system for this system to function. The first cycle is between the collectors and heat transfer box, the second cycle is between the pool and heat transfer box. So the heat transfer occurs in the specially designed heat transfer box. The freezing temperature is lowered by pouring antifreeze to the system in the first cycle. There is no problem in the second system as there is no water.

Question: How can I install Solar Pool Heating?
Answer: You are better leaving the installation to the professionals as mounting on the roof and placing the pipes in the proper fashion, as well as all the calculations, have to be done correctly. A transfer pump is mounted between the collector on the roof and the pool, and the installation is complete after the whole system is connected altogether with the pipes.

Solar Pool Heating systems are widely used today. If you live in an area with high insolation levels, and have no high buildings around your premises, you can contribute to a cleaner environment by using solar power.

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