Solar photovoltaic (PV) systems are used all over the world to supply power to households, businesses and remote installations such as communication towers.
There are 3 main solar PV system designs; Grid Connect, Hybrid and Stand-Alone.
In this blog, the experts at Valen take a brief look at these 3 system types, explain the differences between them, and where each system is most effectively used.
Grid Connect Solar Systems Explained
These PV solar systems are definitely the most popular choice in Australia with around 1 in 5 households today having grid connected solar panels on their roofs.
The electricity generated by these solar panels is generally used to run the household during sunlight hours with any excess returning to the grid for a rebate (feed-in tariff) from either the government or the electricity network provider.
During the evening, or when the sun isn’t shining, power is supplied to the home from the mains grid.
Industrial business premises often use grid connect solar systems as well because the majority of their power requirements are needed during sunlight hours.
Grid connect systems do not include battery banks or any form of secondary power backup. When there is demand for additional power, the grid will “cut in” to supply the demand.
Government rebates on solar panel installations have assisted to make grid connected systems attractive, particularly for the average homeowner.
Hybrid Solar Systems Explained
Hybrid solar systems work pretty much the same way as a grid connect system but offer some additional advantages. These systems are still connected to the main power grid, however they also use a special hybrid invertor and utilise deep cycle battery banks to store excess energy.
These batteries basically act as a UPS (Uninterruptable Power Supply) if the panels are unable to draw power for some reason, for example during solar drought (long periods of cloud cover). The battery systems can also be drawn on for power supply during the night when electricity is in peak demand and prices are higher.
For the residential market, hybrid systems are still relatively high in price compared to the savings they incur. Therefore, it makes more economical sense for most average sized households to go with the standard grid connect system.
However, installers will often suggest that homeowners make their system ‘battery ready’ to allow for the addition of battery banks at a later date for a number of reasons, including:
- The option for a hybrid system becomes more affordable.
- In the event the price of grid connected electricity skyrockets.
- When the solar ‘feed-in tariff’ becomes obsolete.
Stand-Alone Solar Systems Explained
Stand-alone solar systems are just that...they stand completely alone off the main power grid. These systems are mostly used in remote areas where grid power cannot be connected to or it would be cost prohibitive to do so.
A typical stand-alone power system setup consists of PV solar panels, mountings or frames, an invertor, a solar charge controller and a system of connecting batteries.
The batteries in stand-alone systems act as the main power source. These systems require regular maintenance and, in some cases, can be monitored remotely.
As the batteries are the main power source, it is essential that the correct type of batteries are installed. Stand-alone solar systems place cyclic pressure on batteries due to regular use and other factors such as solar drought. This means that such systems must utilise batteries designed for cyclic use, rather than standby use.
VRLA Gel type batteries have the unique ability to recover from deep discharges, heavy cycling and cyclic abuse which would otherwise damage a VRLA AGM type battery. Gel batteries are also well suited for use in remote locations as they are capable of performing well in hot operating temperatures.
So by design, Gel batteries are ideal for handling the demands of stand alone solar systems.
Want to learn more about Grid Connect, Hybrid and Stand-Alone solar systems?
Talk to the team at Valen. We’d be happy to answer any questions you have and make recommendations about which type is best suited to your needs.