The working principle and function of distributed photovoltaic with energy storage
What are the working principle and functions of distributed photovoltaic systems with energy storage?
As the grid-connected photovoltaic (PV) installation capacity continues to grow, the demand for flexible and adjustable resources within the power grid becomes increasingly urgent. For example, during peak electricity consumption periods, the grid often becomes overloaded, or during widespread power outages, users face the dilemma of having "no electricity available." These challenges pose significant issues for self-consumption distributed PV systems. This is where energy storage becomes essential. It allows electricity to be stored and released when needed, ensuring stable household power supply and alleviating the pressure on the power grid.
Working Principle:
Under sunlight:
The direct current (DC) generated by the PV system is converted into alternating current (AC) for household use.
Any surplus electricity is first converted to DC and stored in the battery.
If there is still excess electricity, it is sent to the grid for revenue generation.
During brief outages caused by thunderstorms or other disruptions:
The PV system cannot generate electricity.
Stored energy in the battery becomes a contingency reserve, supplying power during grid outages.
At night or on cloudy/rainy days:
The electricity stored in the battery is converted into AC to power household appliances.
During peak usage periods, both the grid and the battery work together to provide electricity for the home.
During off-peak hours, such as early morning, the grid can recharge the battery at lower electricity rates.
During prolonged outages caused by adverse weather like snowstorms:
When the PV system, grid, and battery are unable to supply power, a diesel generator can step in.
A hybrid inverter integrates the generator and storage system to prevent long-term power interruptions.