For many people, installing solar power is about becoming more self-sufficient. They want to be able to rely on their own power production, not the city grid. However, most homes installing solar are still connected to the city grid and may not be permitted to disconnect completely. For these situations, many solar users are designing zero-export solar power systems that rely entirely on self-consumption. What does this mean, and why would you want such a system? Keep reading to learn more.
What Is Zero Export?
As the name implies, “zero export” means that your system does not export any of its excess power to the city grid. In grid-tied systems, most inverters will default to feeding any energy you don’t use to the grid, typically for a credit on your utility bill. That sounds like a good idea, right? Why not sell the energy you’re not using? This is a great solution for many solar users.
But some people simply don’t want this. They want as little interaction with and reliance on the city grid as possible. Additionally, in some parts of the world, exporting power to the grid actually isn’t permitted due to local laws so a zero-export system may be the only option available.
How Do You Create a Zero-Export System?
Now that you understand a bit of zero-export systems and why people might want to build a solar power system in this way, here are a few ways that it can be done:
- Direct self-consumption with zero export – This design requires an intelligent PV inverter to be installed in your system. The inverter must be configured for zero export. It can then dynamically limit the power production if you are not consuming the energy in your household at the time that it’s generated. Essentially, if the inverter senses you’re not currently using as much power as your panels are producing, it will reduce the panels’ power production to whatever amount you’re currently consuming. Obviously, this is not a highly efficient solution, as it does not allow you to maximize your panels’ power output.
- Self-consumption with battery storage and zero export – The more effective solution for battery storage with zero export is to equip your system with a solar storage system. This allows you to rely more on what your system produces by storing any excess energy for later use instead of filtering it into the city grid. This also requires an intelligent inverter to regulate power.
- Retrofit for self-consumption with zero export – If you have an existing PV system, you can retrofit it for zero consumption. You’ll just need to add a storage system. Any PV inverter can be used in the system in combination with a compatible lithium-ion battery.
So, suppose you want to upgrade to a zero-export system without sacrificing your system’s productivity. In that case, you’ll want to add a modular battery system, like the Power Cell from Generac to create a battery storage system sufficiently sized for your needs.