Solar PV Systems: Exploring the Difference Between Grid-tie, Hybrid and Off-Grid Solar PV
All solar PV systems work on the same basic principles. Solar panels absorb and convert energy from the sun into Direct Current (DC). This is achieved via the photovoltaic effect. The DC energy is then either stored in batteries or converted into usable Alternating Current (AC) through the use of an inverter. Depending on the type of system, excess solar energy that is produced can be fed back into the utility grid to provide credit and reduce electricity costs.
There are 3 main types of solar PV systems:
- Grid-Tie
- Off-Grid
- Hybrid
Grid-Tie
A grid-tied solar PV system is simply a system that is connected to the electrical grid. Solar panels capture the sunlight to produce Direct Current (DC) electricity. This electricity is passed through a grid-tie inverter that converts the DC electricity into AC electricity. The energy produced by the system is utilised during the day and switches back over to grid supply during the evening. This offsets your energy usage.
Off-Grid
Being off-grid means you are not connected in any way to your grid’s power system. It works by generating DC electricity from solar panels and using it to charge a solar battery via a charger controller. That electricity is then converted to AC electricity using an inverter so that it can power the home or business appliances. By saving the electricity in a solar battery, it is possible to run a household with solar energy, even at night or during times when there is less sun exposure. An off grid system also includes a generator as backup incase of periods of extended rainy days or a system failure.
Hybrid
Hybrid solar systems generate power in the same way as a common grid-tie solar system but use special hybrid inverters and batteries to store energy for later use. This ability to store energy enables most hybrid systems to also operate as a backup power supply during load shedding, similar to a UPS system.
The Bottom Line
If you are about to embark on a PV solar system, choosing the correct inverter type is critical to your return on investment. The entire system needs professional consultation. At Thula Moya Energy our goal is your energy independence. We will determine the most suitable options for you as well as talk you through all of the shortcomings and advantages of the different options.