Are you thinking of installing a solar energy system for your business or residence but are undecided as to whether to go off grid or grid tied? If this is the case read on to learn what these terms mean, what components are needed for each, the pros and cons of each system and then make an informed choice to suit your interests best.
What is Grid Tied Solar System?
Grid-tied means your solar system is tied to the GRID of the local utility. Most residential homes will use this as it will cover if your solar system under-produces or over-produces depending on your varying energy requirements. In such cases, your utility system will be behaving like your battery space. So when your solar panels or system is producing more energy than your requirement, the excess energy is sent to the grid’s power company. This allows the building of credit which you can cash on later at the end of the year and this process is known as net metering. While if your panels are under-producing, you can get the rest of your requirements from the local grid.
Living with a grid-tied system is quite alike as living with utility electricity, only that some or all of the energy comes from the sun. Grid-tied solar systems need a power meter and Grid-Tie Inverter (GTI) or Micro-Inverters for functioning.
What is the Off-Grid Solar System?
In the off-grid system, it requires that the solar panels can produce enough electric power to cover the entire need of your household. This system means your solar panel or system is in no way connected to the grid’s power system or utility company. It allows you to store and save the produced solar power in batteries. This power can be used later when the power grid goes down.
This shows that this system is entirely self-sustaining. The off-grid solar system needs battery bank, off-grid inverter, solar charge controller, DC Disconnect (additional) and Backup Generator (optional).
What are the benefits of Grid Tied Solar System?
Grid tied solar, i.e. on-grid solar is beneficial as you need not buy an expensive battery back-up system to store the excess energy. It is more economical and very easy to install. It will pay for itself and you will be able to offset bills in 3 – 8 years. It will add money to your pocket in the long run. This is your way of reducing your electric bill. Also, you will be reducing the carbon footprint. It benefits the community as a whole.
It has fewer upfront costs. Also, it is more flexible as you don’t need to install all the solar panels needed for your total energy consumption at one go. You can add more panels, if needed, with the availability of financial resources later on.
What are the Disadvantages of grid-tied solar?
The biggest demerit of this system is, it does not provide power during a grid outage. Some think that when a power outage takes place, the panels will behave as backup generators. But this is not true. This is because they are connected to the greater power grid. Also, it is very expensive to install power lines to connect your solar system to the grid if you are living in rural areas.
What are the Benefits of Off grid solar?
With the off-grid system, you can store and save solar energy in batteries to be used later when the grid goes down. Thus this is entirely self-sustaining. Also, such a system can provide power for critical loads when the power grid is down. This means that your refrigerator, pump, and a few lights will get power while the TV and air conditioners and other non-essential loads can be put on hold.
You will receive no bill from the power company and will be independent of it. This is particularly beneficial in remote areas, where the installation of traditional power poles is pretty expensive. With off-grid in such areas, your worries are saved. The off-Grid system gives you a measure of the amount of energy you are expending in a day and is bound to make you more energy conscious. Such systems are especially useful for use in RVs, remote agricultural pumps, traffic signs or boats.
What are the Disadvantages of off-grid solar?
The off-grid system needs you to buy a back-up battery. This is not only expensive but also bulky and not at all environment friendly. As a consequence, the entire purpose of going solar is defeated. Also, the off-grid system is not able to cater to the energy demand of all your loads due to the volume and cost of batteries. Again these systems need lots of specialized equipment for functioning. A central/string inverter and a charge controller are required in addition to the batteries. Also, the installation of this system is complicated.
Maintenance and periodic replacement of expensive high amp batteries is another demerit. It is more complex and less flexible. Further here, you cannot depend on the power company for backup. So, before choosing this system, you should be sure that your property can sustain without power by itself at certain intervals.
Which to choose – Grid-tied or off-grid solar?
Off-grid systems are not ideal for the average homeowners as this particular system is not at all economic. Also, maintenance and installation are not easy. An off-grid system will need 3 to 4 times the cost for a similar on-grid system. It would be wise to install an on-grid solar system and go for a backup DG if necessary. Also, off-grid is difficult to install.
But, for remote areas, the off-grid solar system is a better alternative as in these areas the grid is unreliable or unavailable.