On-Grid Versus Off- Grid Solar Power

Solar energy has a lot of benefits, both residentially and environmentally. Solar energy is produced when sunlight strikes photovoltaic panels that cause electrons to flow, generating electricity.

Solar energy is maintainable and renewable; we will never run out of it as long as the sun exists and is able to produce light (so forever, basically). Solar energy is a silent, efficient, and smooth producer of electricity and you can even receive a tax credit for it (the Solar Renewable Energy Certificate).

When it comes to solar power, there are two main types: on-the-grid and off-the-grid, each with their own set of advantages and drawbacks.

Here are the top five key differences between on-grid and off-grid solar energy.

1.    Percentage of Electricity Produced

Solar power that is on-the-grid (also known as “grid-tied”) does not need to produce 100% of the solar power that is used by a building because it is linked to a commercial grid. Wherever the solar power falls short, it’s supplemented by an electrical company. By contrast, off-grid solar energy produces all the energy a building needs and it is not tied to a grid, meaning that it is a standalone system.

2.    Batteries

Off-grid solar power systems require batteries to store excess solar power that can be used on days where there is no sunlight. This way, you will always have a backup store of energy and aren’t left in the dark when it’s raining. On-grid solar systems, when there is no sunlight, rely on the commercial utility to grid to provide electricity. Therefore, they don’t need a storage system and no batteries are required.

3.    Power Outages

In the event of a power outage, solar power that is not tied to a grid has the upper hand. Even if everyone else’s power is out because of a grid malfunction or any other outage, a system that is off-the-grid will keep running and won’t go dark. Solar power that is on-the-grid will be shut off in the event of an outage for safety reasons.

4.    Monitoring Systems

Both on-grid and off-grid solar power has a monitoring system, but the purpose and function of each monitor are slightly different. Solar power models that are on-the-grid have a system that tracks energy production—this monitor is usually optional. Off-grid systems have a monitor whose function is to ensure that there is a balance between energy production and energy consumption.

This monitor is not optional. Off-grid systems also have a charge controller that protects the battery bank and prevents it from overcharging. Both systems still have the required safety gear (breakers, disconnects, fuses, et cetera) and, of course, they both require solar panels. There are just a few differences in how each is built and applied.

5.    Solar Renewable Energy Certificate (SREC)

This certificate is a tax incentive that is only received by solar power producers who are grid-tied. SRECs are given in states that have a Renewable Portfolio Standard requiring energy producers to generate part of their electricity from solar power. SRECs are doled out for each hour of solar energy that is produced. One SREC is equal to one MWh of solar electricity.

For reference, a 10 kW facility generally produces twelve SRECs annually. Off-grid systems cannot take advantage of these SRECs because their power does not flow to a commercial grid; therefore, they are not part of this exchange and cannot take part in these “environmental tradeable commodities.”

On-grid and off-grid solar technology differs in both construction and implementation, and each form of solar power has both advantages and disadvantages. In order to find out which is suitable for your home, consider undergoing an energy audit that will determine if solar power, either grid-tied or standalone, is right for your residence. Companies such as Bob Heinmiller Solar can assist you with converting your home to a solar power pad.

Lautaro Martinez, a green enthusiast is always looking for ways to incorporate solar energy into his home. If you would like to learn more about green living, you can check out Lautaro’s google+ profile.