Solar Panels for home – some more Questions

The more you search for information about Solar Panels for home the more questions will arise and for these questions you will need answers. We have covered the initial questions and some additional questions a home owner may have the moment (s)he decides to install a solar panel on the roof of his home.

We will try to answer some more questions which may arise during your quest for the most suitable solar panels for your home.

Charge Controller

Does your Solar Panel Installation need a charge controller? If yes, what is charge controller why is it needed? These and many other questions arise when someone mentions the charge controller for the Photovoltaic, PV, solar panels.

As the name implies, a charge controller is a device which controls the charging and by charging we refer to the battery charging. So every system which charges batteries needs a controller. So if you have installed batteries and connected them to your Solar Panel system so as to store electricity produced during the day, you need to install a charge controller so as to avoid reverse current. The basic role of charge controller is to protect our batteries form reverse current conditions which may result to a slight discharge of the already fully charged batteries and therefore result to loss of power and thus money.

In addition charge controllers prevent battery overcharging, a factor which is not desired since it damages the batteries. During the day PV solar panels produce electricity and they send the electrical current in one direction. At night, when electricity is not produced, solar panels may push the current in the reverse direction thus drain the charged batteries.

It should be noted that every renewable energy source, RES, system like wind, solar, hydro and others which produce electricity and charge batteries need the installation of a charge controller. Charge controllers protect the batteries and extend their lifecycle. The cost of charge controllers is neither high nor prohibitive when compared to the total cost of the system so homeowners should not hesitate to install charge controllers along with their solar panels.

Inverters

Inverters are essential and basic components of every photovoltaic Solar panel installation.  The inverter converts the Direct Current, DC, electricity produced by either the system directly or by the batteries which store DC, to Alternate Current, AC, electricity which is usable and useful since all our electricity devices operate on AC.

The Inverters are definitely not simple devices and have an efficiency of 85% to 95%. This means that some of the electricity produced by the solar panels is lost during the conversion from DC to AC.

There are many factors which affect the usage of an inverter and you should therefore have all parameters in mind before selecting the right Inverter for your installation. You should always have in mind that Quality pays and in the case of the Inverter this is absolutely relative and correct.

Even though the Inverters are both complex and certainly important, making the right choice is just a matter of following certain selection criteria which will help you choose the right Inverter for your installation. These criteria can be summarized easily in the following paragraph.

• Define the application Environment. You need to define where the inverter will be used.
• Conformance with the electrical regulations of the area where your installation is.
• Power Capacity. You need to define the loads the system will handle. Inverters have different ratings and there are three different ratings you should have in mind when selecting the right solar panel inverter. These ratings are: continuous rating, a limited-time rating and surge rating. All have their importance.
• Power Quality. Is power quality critical for you? Clean power implies pure sine wave AC. Anything else may be considered as not so clean and may be called as Modified Sine Wave power. The selected inverted should be the appropriate one.
• Efficiency. Selecting a very efficient inverter implies better exploitation of the electricity produced but it also implies that you pay a higher price for the inverter.
• Size and weight. Does size and weight matter? If yes then these two parameters should be in your selection criteria table.

One important and a requirement by law feature, is  that a grid-tie inverter should have  the anti-islanding function which is the function that protects utility workers when there are power cuts.

Solar Panel Mounts and Trackers

When it comes to the mounting of solar panels there are different solutions depending on the space and structure availability. If mounted on the roof the mounts are called roof mounts and if on the ground, ground mounts. If not mounted on the roof or on a roof-based structure then solar panels may be mounted on the top of a pole and for this reason the mount is called pole top mount.

Mounts which allow the panel to move with movement of the sun are called trackers since they have systems which track the movement of the sun thus maximizing the exposure of the solar panel to the sun. As you may understand trackers cost and this is a parameter which should be considered during the evaluation of the right system to be installed.

With this article, which is the third of the series, we believe that we have covered the basic questions a homeowner should answer before selecting a solar panel for his home. This and the other two articles, Solar Panels for Home – the initial questions and Solar Panels for Home – the next questions  we have shed some more light to the new and exciting world of photovoltaic, PV, solar panels.