For most areas, energy production from solar is typically the most during the daytime and the least during the nighttime. In contrast, for most residential homes, energy consumption is the least during the daytime, and the most during the nighttime. With this, if the local utility of a homeowner has poor sell-back rates, if at all, a solar PV system may be rendered useless because it is incapable of offsetting energy consumption when it is needed.
Thus, a battery-backed system would be advantageous to not only offset your consumption when you are actually consuming but also mitigate hefty utility rates, like that of homeowners under Time Of Use (TOU) rates.
For example, as shown above, battery storage would be a great option for discharging during the “peak” times and charging during “off-peak” and “partial-peak times”.
Another strong reason for having a battery backup system is energy resilience to grid outages. For areas highly susceptible to grid-outages, a battery backup system would allow end-users to continue energy consumption, regardless of grid presence. Among many other reasons, this can be extremely important for end-users who need continued operability of vital equipment or for business owners who need the energy to maintain business operations.
Currently, the most common reason for adding battery backup is for off-grid applications, where there is no grid at all. Since a solar PV system will not produce power at all times, it is crucial that all unused energy is being stored for later use when the weather permits little to no solar power production. In other words, battery-backed systems allow for a constant power supply.
Battery-backed systems are usually composed of the following main components:
In summary, here are the main advantages of having battery-backup:
- Increased independence from the utility-grid
- Eliminates or reduces utility rates
- Constant power supply even without the utility-grid
For more information on how to set up a DC-Coupled or AC-Coupled batter backup system, please see here.