Solar Photovoltaic On Grid or Off Grid?

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The Grid - to be or not to be

Until recently, solar electricity has been very much a stand-alone system. Photovoltaic (PV) panels were usually installed at residential homes and were off-grid from the power plants. This meant that the power generated by these PV panels had to be consumed immediately or go to waste, unless it was stored in batteries for later usage. But even with the latter alternative, if the batteries are fully charged and there are no more electrical loads available, the solar power that is being generated is wasted. Also, the addition of battery packs to store this excess solar power increases the installation and maintenance costs in the long run. So how should this excess power be utilized?

One method that is quickly becoming a favorite among solar power enthusiasts is the grid-tied system. Also known as grid-direct or utility-interactive, grid-tied systems allows any excess electricity generated by your PV panels will be transmitted across the utility grid to the next available depot where electrical energy is required, such as to an office or to your neighbor’s home.  And if your home requires more electricity, the same exchange of power will be performed by a nearby PV system that is interlinked on the grid.

Sharing of excess electrical power gives you more than great savings and higher efficiency of your PV system. A grid-tied solar electric system also lessens the need to maintain the system. There’s no need to keep checking the system voltage or fear that electricity is being abused by your kids while you are at work. And you don’t need to worry about regularly refilling the battery packs with distilled water or feel fear of being entangled by lethal cables all around.

Another benefit of a grid-tied system is that your PV system size is irrelevant, unlike the off-grid systems where you have to compute various factors, such as availability of average solar, electrical requirements of premises and frequency of cloudy weather, to determine the number of PV panels required in your solar system installation. An off-grid solar system can be inconvenient when it is oversized or undersized.

A grid-tied solar system frees your PV size. Other more important considerations, such as your roof space and budget, can be deliberated on more carefully. A grid-tied system is more reliable than a stand-alone system that requires consistently good maintenance (especially for battery packs) to function reliably.

Last but not least, the benefit of a grid-tied PV system is its lower cost and components required. This translates to generations of better financial and energy returns. There is higher efficiency in the grid-tied PV system as the net energy or EROEI works for you.

EROEI is energy returned on energy investment, which refers to the energy profit from its generation process. An EROEI of less than three years means that the energy produced that uses all the available generation components would be generated within three years. This shows the efficiency of the grid-tied system over the off-grid system.

Some may consider installing a hybrid system known as