The Power Inverter
Unless you plan on using battery power for everything, you will need a Power Inverter. Since the majority of modern conveniences all run on 220 volts AC, the Power Inverter will be the heart of your Solar Energy System. It not only converts the low voltage DC to the 220 volts AC that runs most appliances, but also can charge the batteries if connected to the utility grid or AC Generator as in the case of a totally independent stand-alone solar power system.

Square Wave power inverters :
This is the least expensive and least desirable type. The square wave it produces is inefficient and is hard on many types of equipment. These inverters are usually fairly inexpensive, 500 watts or less,Don't even consider one of these types of power inverters for a home system.
Modified Sine Wave power inverters :

This is probably the most popular and economical type of power inverter. It produces an AC waveform somewhere between a square wave and a pure sine wave. Modified Sine Wave inverters, sometimes called Quasi-Sine Wave inverters are not really expensive and work well in all but the most demanding applications and even most computers work well with a Modified Sine Wave inverter. However, there are exceptions. Some appliances that use motor speed controls or that use timers may not work quite right with a Modified Sine Wave inverter. And since more and more consumer products are using speed controls & timers, I would only recommend this type of inverter for smaller installations.

True Sine Wave power inverters :
A True Sine Wave power inverter produces the closest to a pure sine wave of all power inverters and in many cases produces cleaner power than the utility company itself. It will run practically any type of AC equipment and is also the most expensive. Many True Sine Wave power inverters are computer controlled and will automatically turn on and off as AC loads ask for service. I believe they are well worth the extra cost. The Xantrex 2500 watt power inverter has a search feature and checks every couple of seconds for anything that wants AC, then it powers up automatically. You just flick on a light switch (or whatever) and it works. When you turn off the light or the refrigerator kicks off for example, the power inverter shuts down to save battery power.
While the Modified Sine Wave inverter (sometimes called a Quasi Sine Wave inverter) is nearly half the price of a True Sine Wave inverter, I would still recommend using a True Sine Wave inverter if you want to supply automatic power to a normal home using a wide variety of electrical devices. Also, most appliances run more efficiently and use less power with a True Sine Wave inverter as opposed to a Modified Sine Wave power inverter.
Grid Tie Power Inverters
If you are connected to normal Utility company power and just want to add some Free Sun Power electricity to reduce your electric bill and you do not need a totally independent system, it is possible that a Grid Tie power inverter will suit your needs. With a Grid Tie power inverter, whatever electricity that your solar panels produce will reduce the amount supplied by the utility company, in effect lowering your bill. And, if you are producing more power than you are using, you can actually sell the extra power back to the utility company! For this type of setup a much smaller battery bank can be installed just to cover short term outages from a few minutes to an hour or two. In fact, if you don't have frequent long term power outages and don't need back-up power, then you will not need any batteries at all. (But, really, what utility company never fails?

Input voltages. Should I use a 12, 24, or 48 volt inverter?
The main consideration when deciding on the input voltage (from your battery bank) of your Inverter is the distance between your solar panel array and your battery bank. The higher the voltage, the lower the current and the smaller the (expensive) cables need to be. Of course, when you decide on a system voltage, the Solar Panels, Inverter, and Battery Bank all need to use the same voltage. More detailed information on voltage & current will be explained in the next tutorial on Power & Watts.

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Selecting an Inveter - Solar and Backup

The long list of many types, sizes, brands, and models of inverters are available, Choosing which one is best from such a long list can be a chore. Power output is usually the main factor, but there are many others.

There are many factors that go into selecting the best inverter (and options) for your application, especially when you get into the higher power ranges (800 watts or more). This should give you the information you need to get your selection down to what will work best for you.

Some Basics First...
Watts

The poor watt is often misunderstood. Watts are basically just a measure of how much power a device uses when turned on, or can supply. A watt is a watt - there is no such thing as "watts per hour", or "watts per day". If a something uses 100 watts, that is simply the voltage times the amps. If it draws 10 amps at 12 volts, or 1 amp at 120 volts, it is still 120 watts. A watt is defined as one Joule per second, so saying watts per hour is like saying "miles per hour per day".
Watt-hours. One thing to be careful of when choosing an inverter is the rating. Is is rated in Kva or Wattage

A watt-hour (or kilowatt hour, kWh) is simply how many watts times how many hours that is used for. This is what most people mean when they say "watts per day". If a light uses 100 watts, and it is on for 9 hours, that is 900 watt-hours. If a microwave uses 1500 watts, and runs for 10 minutes, that is 1/6th of an hour x 1500, or 250 WH. When you buy power from your the utility(PHCN) (look at your last bill), they sell it to you at so much per kWh. A kWh is a "kilowatt hour", or 1000 watts for one hour (or 1 watt for 1000 hours).
Amps
An amp is a measure of electrical current at the moment. (Amps do not come in "amps per hour" or "amps per day" either). Amps are important because it determines what wire size you need, especially on the DC (low voltage) side of an inverter. All wire has resistance, and amps flowing through a wire makes heat. If your wire is too small for the amps, you get hot wires. You can also get voltage drops in the wire if it is too small. This is not usually a good thing. An amp is defined as 1 Coulomb per second.

A Coulomb is the charge of 6.24 x 1018 electrons. Therefore, 1 Amp is equal to the charge of 6.24 x 1018 electrons passing a point in a circuit in 1 second.
Amp-Hours
Amp-hours (usually abbreviated as AH) are what most people mean when they say "amps per hour" etc. Amps x time = AH. AH are very important, as it is the main measure of battery capacity. Since most inverters run from batteries, the AH capacity determines how long you can run. for more detailed information you can contact me on 08030675746
Watts - Or What Size do I Need?
Peak Power vs Typical or Average

An inverter needs to supply two needs - Peak, or surge power, and the typical or usual power.

Surge power is the maximum power that the inverter can supply, usually for only a short time - a few seconds up to 15 minutes or so. Some appliances, particularly those with electric motors, need a much higher startup surge than they do when running. Pumps are the most common example - another common one is refrigerators (compressors).



Typical power is what the inverter has to supply on a steady basis. This is the continuous rating. This is usually much lower than the surge. For example, this would be what a refrigerator pulls after the first few seconds it takes for the motor to start up, or what it takes to run the microwave - or what all loads combined will total up to. (see our note about appliance power and/or name tag ratings on demand).


Average power would usually be much less than typical or surge, and is not usually a factor in choosing an inverter. If you run a pump for 20 minutes and a small TV for 20 minutes during a one hour period, the average might be only 300 watts, even though the pump requires 2000. Average power is only useful in estimating battery capacity needed. Inverters must be sized for the maximum peak load, and for the typical continuous load.

Power Ratings of inverters

Inverters come in size ratings all the way from 50 watts up to 50,000 watts, although units larger than 11,000 watts are very seldom used in household or other PV systems. The first thing you have to know about your inverter is what will be the maximum surge, and for how long. .

Surge: All inverters have a continuous rating and a surge rating. The surge rating is usually specified at how many watts for how many seconds. This means that the inverter will handle an overload of that many watts for a short period of time. This surge capacity will vary considerably between inverters, and different types of inverters, and even within the same brand. It may range from as little as 20% to as much s 300%. Generally, a 3 to 15 second surge rating is enough to cover 99% of all appliances - the motor in a pump may actually surge for only 1/2 second or so.

General Rules: The inverters with the lowest surge ratings are the high speed electronic switching type (the most common). These are typically from 25% to 50% maximum overload. This includes most inverters in the market, and nearly all the inexpensive inverters in the 50 to 5000 watt range. The highest surge ratings are the transformer based low-frequency switchers. This includes most Xantrex, Magnum, and Outback Power. Surge ratings on these can range up to 300% for short periods. While high frequency switching allows a much smaller and lighter unit, due to the much smaller transformers used it also reduces the surge or peak capacity.

To be continued. for any enquiry you can talk to us on 08030675746