To figure out why it is neccessary for PV system to configure with battery energy storage battery, we have to know the definition of PV ESS.
What is PV ESS?
Figure 1. PV ESS compositions
PV ESS is the abbreviation for Photovoltaic Energy Storage System. There is instability in the conventional photovoltaic systems, while they can be upgraded to be new energy storage systems with a battery module for the immediate storage of energy. For PV systems, the energy storage technology is the key to effectively solving the high and low peak power, which can realize the tracking of the load and the control of the power quality. The energy storage system can take advantage of the power price gap between peak and valley to bring higher benefits, and can also effectively adjust the capacity of the system itself to solve the problem of the combined development of renewable energy and power grids.
How does PV ESS work?
There is a big difference in the working mode of photovoltaic energy storage system during the day and night.
Working mode in the day
Figure 2. Working Mode in the Day
The Energy Management System (EMS) works in self-consumption mode by default. Photovoltaic power will first be supplied to emergency loads and house loads, followed by batteries. Then, if the battery is fully charged, the excess will go to the grid, and the feed-in power should not exceed the limit value in the zero output setting during initial commissioning.
If the photovoltaic power is less than the load power, the battery will discharge and provide insufficient energy. If the power from PV and battery is less than the load power, the inverter will draw power from the mains.
Working mode in the night
Figure 3. Working Mode in the Day
The battery discharges to provide energy to the load. If the battery is dead or the battery system does not have enough power, the unsatisfied power will first be provided by the grid to emergency loads and household loads.
When the grid exists, the bypass function of the hybrid inverter works, and the emergency load will be directly connected to the grid through the bypass relay integrated into the inverter. Emergency loads are powered by photovoltaic or battery energy first and are supplemented by the grid when photovoltaic and battery energy is insufficient.
Why choose PV Storage System?
There are many benifits about PV ESS, although the cost of installing PV ESS cannot be ignored. Below we have listed some suggestions that may be helpful to you. According to our suggestions, you may be able to know whether it is necessary for you to choose PV systems with battery energy storage systems.
1.High Power Generation Efficiency and Low Cost
The photovoltaic equipment of PV ESS can absorb solar energy and convert it into electrical energy during the day, and the energy storage equipment will store this electrical energy, and then convert the stored electrical energy into AC power required by the grid and release it at night. To a certain extent, this realizes the self-use of photovoltaic power generation, which not only improves the efficiency of power generation but also converts solar energy into electric energy, which greatly reduces the cost of power generation and electricity consumption. With the outbreak of the worldwide energy crisis and the rise in energy prices, PV ESS can largely avoid such adverse effects.
2.Provide Clean Energy to Help Save Energy and Reduce Emission
The electrical energy provided by this system is converted from renewable and cleaner solar energy. As a result, this has played a role in saving energy to a large extent. In addition, the electricity generated by this power generation system has fewer harmonics and is purer electric energy. It can not only achieve energy saving and emission reduction but also improve the quality of the power grid.
The federal Investment Tax Credit (ITC), which allows any U.S. resident to deduct 26% of the cost of installing solar panels on their home from their federal tax bill. Many people don’t realize it, but the same tax credit also applies to solar battery storage.
The “Inflation Reduction Act” passed in August this year has significantly improved the economics of deploying large-scale battery energy storage projects in the United States. Standalone energy storage systems will be eligible for a 30% investment tax credit (ITC) and a tax credit free discount of up to 70%.
In addition to federal tax credits, every U.S. state offers some type of rebate or incentive to purchase photovoltaic panels and batteries.In Europe and other regions, various governments have also introduced corresponding tax incentives for photovoltaics.
4.Resilience During Outages
For areas with frequent natural disasters, power is often easily interrupted, affecting normal life order. Usually, gas generators can handle this situation, but generators are noisy, expensive, expensive to maintain, and harmful to the environment, making them not an ideal option. However, for areas with PV ESS installed, during the outages, the backup battery can still assure the normal operation of necessary electrical appliances and avoid the inconvenience caused by power outages to life.