Grid-tied VS Off-grid Solar PV systems

 

Grid-tied VS Off-grid Solar PV systems

AS the adoption of PV solar solutions around the world grows, one of the leading questions we get asked is: do we stay connected to the grid or go off grid completely?

If you are concerned about the environment and want to go off the grid completely. For most people who are concerned about environmental issues, they might feel that to go off grid completely truest form of sustainable living. However, here at NSE we like to provide all the facts

To start, let’s quickly look at the difference between the two systems.

Grid-tied PV system1

In the Grid-tied PV system setup your property is still connected to the utility grid, power is generated by the Solar PV system in the form of DC that is converted to AC by the inverter and then used directly in your property. In the event of no power being created by the Solar PV System power is drawn from the grid. In some situations when possible excess power generated by your Solar PV system can feed back into the grid.

Off-grid PV system2

Off-grid is exactly that, off the grid completely. There is no connection to the utility and you are reliant on the power generated by your Solar PV solution, battery backup and the generator.  The power created by the Solar PV system is in the form of DC which feeds through a charge controller and is stored in the battery bank when the power is needed it flows through and inverter to change it to AC for use in your property. When there is no longer power in the battery bank and no power being produced by the Solar PV system the generator will kick in to provide power.

A Benefits Comparison

Off-grid System Pros and Cons

Pro Con
Ideal for more remote situations where power is expensive to bring in.

 

– Batteries and generator are expensive and require maintenance.
– Lifetime for the batteries and generator(10 – 15 years) is less than for the solar array (35+ years) and wind turbine (20-25 years).
– No power bills. No seasonal storage.  Batteries can only store power for a few days and have a maximum capacity.  When they are full, the rest of the power is wasted unless you can find an immediate use for it.
– No power outages. Power use must be carefully planned.
– Self-sufficiency on a clean, renewable energy source.

Grid-tied System Pros and Cons:

 

Pro Con
Easy backup from grid power.  You still have to pay the basic utility bill, just not for whatever power you’ve produced.
Eliminates need for batteries and /or generator (which also requires fuel). you are still using non-renewable resources when there is no solar or wind
Provides seasonal storage if a net metering or Feed-in Tariff program is available.
Maintenance free  for a solar power system
Internet monitoring available with inverters designed to be used for individual solar panels
You are providing clean energy to the grid