How does a solar hybrid system work?
What does the word hybrid mean? To understand this, know that a mule is a hybrid between a horse and a donkey. A hybrid car is actually a hybrid engine car. It is driven by an internal combustion engine, or by an electric motor. Similarly, a hybrid solar system is a solar system working together with (supplementing, or being supplemented with) another power source. To learn more: https://sinovoltaics.com/learning-center/consumers/solar-hybrid-system-vs-grid-tied-vs-standalone-choose/
The other source can be a wind turbine, a diesel generator, or the grid. The control circuitry, if intelligent enough, will always utilize the cheapest source available.
To understand the usual implication of the solar hybrid term, consider the two choices: A grid tied solar system (without batteries), or an off-grid solar system (with battery backup). A grid tied solar system will feed excess power to the grid at the fixed feed-in tariff (FIT) which may be quite low compared to the grid electricity rates, read more here https://sinovoltaics.com/learning-center/basics/feed-in-tariff-fit/.
At night you buy from the grid at much higher rates. Also, the grid fails your system will be disconnected from the grid by design for safety reasons. If it happens when the sun is not shining, you are left without power. An off grid system will have its own storage and will consume the stored power when the sun is not there. You do not buy from the grid. But how much storage can you provide? If the sun does not shine for many days your batteries will be depleted and you will be without power.
A hybrid solar system combines the advantages of both the above choices. First of all it ensures uninterrupted power supply (UPS) to your load. During the day, it supplies the local load, charges the batteries, and feeds any excess power to the grid at FIT rates. The stored energy can be utilized at times of day when the grid rate is high. If the solar output is not sufficient to run the load and charge batteries, battery charging can be postpone till conditions are right, or when the grid is offering off-peak rates.
Systems may even be programmed to lay off some low priority loads under preset conditions, e.g. when the load demand tends to incur high demand penalties by the utility. The basic idea is to utilize the cheapest source of power at any time, and under any conditions.
With these advantages, the hybrid solar system is likely to become the standard solar system in the future.