Grid-Tied Solar Energy SystemsUpdated June 22, 2022 Solar
Grid tied solar, (also known as grid connected solar systems, grid intertied photovoltaic systems or on grid solar systems) produce solar energy for your home in the day and since you are also hooked up to the grid, they take electricity from the power company as it is needed at night or in times of rainy or cloudy weather.
The Grid Tied Solar System Set Up
Typical grid intertied solar systems consist of solar panels (to collect the power), an array DC disconnect (to be able to cut the power from the PV panels), an inverter (to convert it from DC to AC), an AC breaker panel (to accept and distribute power to your household loads, the kilowatt per hour per meter and to the grid) which also sends power back.
These types of grid connected solar systems use no batteries but they do have a system controller that automatically decides whether to draw power from the solar panels or from the utility grid based on how you set it. If it's sunny, it draws power from the solar panels, but if it's cloudy or dark, it will draw from the electric company's supply.
Get Paid By Your Power Company
If you produce more solar energy in the day than you use, it gets fed back into the grid and you can receive an energy credit on your electric account with what's known as "net metering". Therefore if your solar panel array produced enough electricity your power meter would actually begin to turn backwards.
Since the energy you produce with on-grid solar systems counts against the energy your home uses, you are in essence, getting paid by the power company to produce energy for them.
In this way, grid intertied solar systems (with no battery bank) sort of use the utility grid like a battery bank. Also, by eliminating the use of storage batteries, the total costs for your PV system decrease dramatically.
However, grid connected solar systems with no battery bank are also subject to loss of power during solar system maintenance and in blackouts or power shortages.
Why Should I Use a Grid Connected Solar System?
Implementing a grid connected solar electric system onto your home or business can help you save money on energy, reduce your dependency on utility company electricity, and minimize the production of environmentally harmful greenhouse gases.
Eventually, on-grid solar systems will pay for themselves and keep saving you money. Larger grid connected solar systems may even make you money by giving you perpetual credit with your local utility company.
On Grid Solar Systems Are Easier To Set Up
Another plus is that these grid intertied photovoltaic systems are the easiest (and most affordable) to build, purchase or maintain. Since batteries are usually the most expensive component, having no batteries takes a lot of the risk of "losing money by accident" away and you don't have to be careful not to damage them by over or under-charging.
With a lower initial cost, grid connected solar systems can pay for themselves faster and continue saving you money for many years to come.
Grid connected solar systems can also add considerable value to your home. If your solar system is big enough, you can even make money from your utility company in the form of a perpetual energy credit.
Although grid tied solar systems make it possible for you to have a more affordable, lower maintenance, and more worry-free solar energy system, it is a good idea to still add a small battery bank capable of storing enough power to cover your minimal energy needs, just in case of a power outage, or other similar emergency.
Grid Tied With Battery Solar Systems
The grid tied with battery backup solar system is very similar to the grid tied solar energy system type.
It makes power from the sun for use in your home when there's sunlight, takes it from the grid when it needs to (during clouds/night) and feeds surplus energy back into the grid accumulating an energy credit on your electric bill.
The only difference is, the grid tied with battery backup system also uses a battery bank to store energy as a backup, eliminating the need to use utility power at night and thus saving you even more money.
Additionally, a battery bank ensures that you will always have a constant source of power and that your family will still have power in a blackout or power failure.
Big or Small Battery Backup?
Often people with grid tied solar systems only require a very small battery bank since they only use it for emergencies.
Others prefer to have enough storage space in their battery bank for enough energy so that they can go without using utility company power for many days of no sunlight. This way, they can accumulate a bigger energy credit on their bill (instead of using the power) and thus have even more reserve energy available in the form of a huge unused electric company power credit.
Whether you decide to go big or small with your battery bank for your grid tied with battery backup system, implementing one will require additional photovoltaic components as well as slightly different wiring than with a simple grid tied solar set up.
The Grid Tied With Battery Backup Set Up
A typical grid tied with battery backup solar system consists of the following components:
- Solar panels (to collect the power)
- Array DC disconnect (to be able to cut the power from the PV panels)
- Charge controller (to regulate the charge to the battery)
- Battery bank (to store power)
- System meter (to monitor power usage and status)
- Main DC disconnect (to cut power to battery bank/inverter)
- Inverter (to convert it from DC to AC)
- AC breaker panel (to accept and distribute power to your household loads and to the grid – which also sends power back)
These types of solar systems use a system controller that automatically decides whether to draw power from the solar panels, from the battery bank, or from the utility grid based on how you set it. So you can set it to draw from your battery if there's no sun, and from the grid if there is no battery power. This way you use as little (expensive) utility energy as possible.
Grid-Tied Solar Energy Systems
The grid tied with battery backup system sends surplus electricity back into the grid (using net metering) if you produce more solar energy in the day than you use. This results in an accumulating energy credit on your electric account. If your solar panel array produced enough electricity your power meter would actually start to spin in reverse.
Since the energy you produce with a grid-tied with battery backup solar system counts against the energy your home uses, you are in essence, getting paid by the power company to produce energy for them.
And since you now have a battery bank, you can use less of the utility company's power and bank it instead.
A huge surplus of grid energy is a great thing to have stored and ready when you need it, possibly during system maintenance, replacement, or repair.