Hybrid solar systems are so-called because they employ two or more renewable energy collection methods.
The most common combination is solar panels and a wind turbine. This type of system, while more expensive than a single source collection system, provides considerable advantages.
In Australia, the term hybrid solar system is also commonly used to refer to a grid-connected solar system with a battery backup. In this article however, the term will also refer to a multi-source renewable energy system.
Keep your solar batteries fully charged for longer
Solar batteries are the most costly component of a renewable energy system. Therefore anything you can do to extend the life of a solar battery is a good idea that will save you money.
Battery lifespan is greatly affected by what is called ‘depth of discharge’. This means the amount a battery is allowed to discharge before recharging. When a battery drops to below 20% of its capacity, it is considered to be deeply discharged.
Allowing batteries to reach a deep discharge state before recharging is known as deep cycle recharging. Contrary to what many people believe, this practice will shorten the lifespan of the battery.
To maximise the lifespan of rechargeable solar batteries, shallow cycle recharging is recommended. This means trying to keep your batteries at 80% or more of their capacity at all times.
Using a hybrid solar system will help you achieve this goal more easily. Obviously solar cells don’t work at night, so if you have a wind turbine connected then your batteries will still be charging as long as there is some wind.
Conversely wind turbines don’t work in the absence of wind, but as long as there is some sunlight, the solar panels will take over the job of charging the batteries.
And of course when it is both sunny and windy, your solar batteries will be charging up to twice as fast!
Not just for off-grid systems
While hybrid systems are most commonly found in off-grid solar systems, they also have a place in grid connect solar systems. As stated above, hybrid solar systems give the advantage of one source being able to take over when the other source is not available, and when both sources are available, power can be generated up to twice as fast.
For the householder this has two advantages. Firstly, it extends the time that you can power your appliances before you need to draw energy back from the grid, and secondly it provides you more opportunity to sell energy back to the energy retailer when you are generating surplus electricity.
