On Grid Vs Off Grid solar PV systems

On Grid Systems

On Grid Solar Systems (also known as ‘grid tie systems’ or ‘integrated systems’) are connected to the mains power supply just like a regular home. This means that mains power can still be used any time your solar panels generate less electricity than is needed, e.g. at night. In many countries, solar homes can also capitalize on times when the panels generate more electricity than is needed by selling the surplus back to the electricity company -usually at a nice profit.

On Grid Systems usually require:

• Solar panels and an appropriate mounting system,
• Grid tied solar inverter(s) and monitor(s),
• Solar cables and MC4 connectors,
• AC and DC safety isolator switches, and
• Grounding earth cables and clamps.

Off Grid Systems

The problem is that in many countries it is either not permitted or not practical to connect on grid solar power systems to the mains utility grid.

Off Grid Solar Systems do not need to be connected to mains power. As there is no ready source of reserve power, they rely on generators or storage batteries to provide electricity on days when the solar panels generate less electricity than is required, e.g. on cloudy days or at night time. The idea is that at times when the system provides more electricity than required the surplus can be used to recharge the batteries.

Off Grid Systems normally require:

• Solar panels and a suitable solar mounting system,
• Off grid solar inverter(s),
• Solar power controller and batteries,
• Solar cables and MC4 connectors,
• AC and DC safety isolator switches, and
• Grounding earth cables and clamps.

Which do I need?

In many cases this decision will be made for you. If you are unable or not permitted to connect to your local mains electricity supply, you only choice is an off grid system.

If you are in the lucky position of choosing, we would advise that, in most cases, an on grid solar power system will be the most reliable and cost effective choice.

On grid systems do not require batteries, which can be expensive and require frequent replacement, and require fewer panels, as you don’t need to generate extra power for cloudy days. This cuts down the initial cost and reduces the payback time considerably. When coupled with payments from the utility company for surplus generation, these systems can often pay for themselves in seven years or less.

If you have the opportunity to install an on-grid system, you owe it to yourself to research your options. Get in touch with your local grid operator or your current electricity provider to find out if you could be saving money with solar.

If you have any questions related to designing and installing on grid solar power systems, we would love to help. Feel free to leave your question or comment below.