The Power of Inverters

Should you decide to use your Solar Array to power your electronics and appliances, you are going to need an inverter.  An inverter simply takes the DC (Direct Current) power produced by your solar panels or battery bank and inverts it into AC (Alternating Current) power.  While this seems easy enough, there are items you need to be aware of when selecting an inverter.  Here is a short list for you:

1)      Inverters come in different output types.

The two most common types of inverters are Pure Sine Wave and Modified Sine Wave.  Pure Sine Wave inverters best emulate your existing Utility Grid.  In most cases, the power from a Pure Sine Wave inverter is cleaner than the Grid.  This type of inverter is best suited when sensitive electronics are going to be used.  A Modified Sine Wave Inverter does not produce as clean of power as a Pure Sine Wave inverter.  However, a Modified Sine Wave can be more economical when power is your sole focus.

2)      Inverters are rated by Power Output

You need to select an inverter with at least the same output wattage as your maximum wattage needs.  The inverter Wattage Output is the maximum power you can get from that inverter.  For example, a 2000W inverter will output up to 2,000 watts worth of power continuously.  If you need more power than the output wattage rating, you need to choose a bigger inverter.

3)      Input DC Voltage

 The Input DC Voltage of the inverter must match the output voltage of your battery bank.  If this is not the case, the inverter will never run properly and cause damage to the inverter or the battery bank.  If your battery bank is 24 volts DC, than your inverter must have a 24 volt DC input rating.

4)      Inverter verses Inverter/Charger

Even though your goal is to solely charge the battery bank using your solar array, you may need an inverter/charger.  This type of inverter will allow you to utilize Grid power to charge your battery bank when the solar array isn’t producing energy.

Planning your project will allow you to choose the right products to meet your needs.  

Micro-Inverters and the Apocalypse

For those fans of “The Walking Dead”, you may have noticed a micro inverter in last night’s episode.  Therefore, we felt that it is a good time to talk about what a micro-inverter is.

In order to use the power from your solar panels for appliances and household electronics, you have to utilize an inverter.  An inverter inverts the DC power from the solar panels into AC power.  Currently, in the residential market, there are two types of inverters.  There is the string inverter and there is the micro-inverter.  While they both serve the same function in the end, they both do it in different ways.  With a string inverter, the groups of solar panels are wired together in series to form a string.  With a micro-inverter, each solar panel is connected to one micro-inverter.

Why the two options?  Both inverters have their merits and there downfalls.  A string inverter is the most cost effective way to go solar and if the string inverter fails, it is easy to replace.  The downside to a string inverter is that any shading on one solar panel in the string can seriously hurt the power production of that string.  A micro-inverter doesn’t have the shading issues of a string inverter.  If one solar panel is shaded, only that panel and inverter are reduced in power production.  The remaining solar panels will still perform.  With this same idea, if one micro-inverter fails, it doesn’t affect the rest of the solar panels and their production.  The downside to micro-inverters is both their cost and replacement.  Since micro-inverters are installed under the solar panels, it can be difficult to replace them.

In the next article, we will discuss how shading impacts a solar array in more detail.  At least now, you know what a micro-inverter was doing in the apocalypse.