What is the difference between a grid-tie and an off-grid solar system?

The grid-tied solar system is when you connect solar panels interactively with the power grid;
they work as one so that when the sun shines, you use the energy that you produce from your
panels, but when the sun goes down, you rely on the grid for your energy. With an off-grid
solution, you also use what you produce while the sun shines, but you store excess energy in
batteries. Therefore when the sun isn’t shining, you can use that stored power until the sun
shines again.
Grid-tie systems are primarily used in urban areas to save on electricity costs. However, off-grid systems are regularly used in rural areas where the grid isn’t present, and you
independently create your energy.

Which is better: a grid-tie or an off-grid solar system?

They are different systems; therefore, there isn’t one that is better than the other but used for
various reasons. Grid-tie systems such as SolarEdge or the Enphase microinverters help you either counter the use of energy from the grid,
reducing a percentage or all your costs. The disadvantage of a grid-tie connected system is
that they are connected directly to the grid, meaning that when there is a power outage, they
shut down all the power within the system because any worker attempting to work during the
outage could get electrocuted if it was still connected. That means even if the sun is shining,
you can’t have power unless you install a battery backup system in conjunction. This type
would have a transfer switch separating the grid-tied portion with a panel strictly for when the
power is out.
The off-grid system such as Victron or the Magnum, is a is a stand-alone system that’s always separated from the grid; therefore,-
you use what you produce and store what you don’t use later, such as when the sun goes
down. With this system, batteries are connected as a storage solution. In turn, they are used
in conjunction with an inverter to produce AC power, just like what the grid provides in your
home.
The stand-alone off-grid system using batteries in the form of storage from your solar panels
gives you energy when the sun shines and when it doesn’t. In areas with no grid, such as rural
areas, the cabin, or boat, these systems are worth every penny if you want everyday luxuries
at home or in a grid-style situation. You can have lighting, run your television, charge your
mobile devices or use your power tools at any given time, night or day. Obviously, it depends
on your system’s size. In some locations or on vacation, you may be able to power a septic
pump or a water pump with electricity. You can power appliances, hair dryers, toasters, and
security systems in addition to cameras.

Do you need batteries for an off-grid solar system?

Yes, you need batteries. As the solar panels produce power, they are not a regulated source
or in a consistent form of power and fluctuate with various voltages and amperages. This is
where the solar controller comes into play, which takes that sun-produced energy and
regulates it, controls it in a way as to properly distribute this energy. It also charges and
protects your battery better than conventional battery chargers in 3 to sometimes 4 separate
stages and can rejuvenate dying or almost dead batteries. The controller lets your battery
bank be used in a DC form or connected to an inverter to create an AC voltage like what you
have in your home. This controller cannot be turned on to do its job without a battery.

How many batteries do you need for an off-grid solar system?

It depends on what you are looking to energize. The whole system in itself is a balanced
system to be able to create energy, store it, and re-use that energy. Suppose it isn’t balanced
so you can correctly power the device or load you want to be powered. In that case, you will
eventually drain your battery’s storage to zero and no longer have a working system.
The best way to describe how many batteries you need is to ask yourself what it is that you
want to power, for how long, and when would you like to power it again: this gives you the
amount of energy you need for that particular device or load, for how many hours you want it
on, and depending on the point that you can produce with the sun to store into your battery,
how much storage would you have for when the sun goes down to continue to power such a
device until you can replenish that battery again.
Sometimes, on darker or cloudier days, gas or propane generators are used to help replenish;
therefore, to avoid wasting fuel, that balance must be struck. Otherwise, using the generator
would counter-benefit the solar system altogether. Each solar system is designed to work as
one so that the number of panels is adequate to charge the battery bank properly with the
loads you are energizing. Some factors come into play when you set up an off-grid system,
including the wire sizes, fuses, breakers, and cables. A proper balanced solar system is key
to a long-lasting off-grid design.