Understand PV, Energy Storage, and Inverters in One Article: From Principles to Industry Trends, A Comprehensive Guide to the New Energy Power Loop

This article explains photovoltaic (PV), energy storage, and inverters clearly.

Photovoltaic (PV) systems convert solar energy into electrical energy, generating power for our use. Since the sun is not always available—PV generation stops on cloudy days or at night—energy storage devices are needed, acting like large-scale batteries. They charge when there is sunlight and supply stored power when there is not.

PV systems produce direct current (DC), which must be converted to alternating current (AC) by an inverter before it can be used in households. Common PV panels are installed on rooftops or the ground. Their raw material comes from sand in deserts, which is purified into silicon material. This silicon is the same as the raw material for chips, but with a key difference in purity: silicon used in solar cells has a purity of 99.999% (five 9s), while silicon for chips is much purer, reaching a purity of 99.999999999% (eleven 9s).

Traditional energy storage, such as hydropower stations, works by pumping water to a higher elevation when sunlight is abundant, then releasing the water to generate power using gravitational potential energy when there is no sunlight. However, hydropower stations are limited by geographical conditions—they require abundant water resources, height differences, and large land areas. This makes them difficult to promote widely and only suitable for local use. Unlike hydropower stations, energy storage batteries can be installed in household distribution rooms, making them accessible to every household. Currently, lithium-ion batteries are the mainstream for energy storage, with a future trend toward solid-state batteries. Solid-state batteries have larger storage capacity, higher safety, and are non-flammable and non-explosive; the only issue now is their high cost, and enterprises are working to reduce it.

Inverters serve two main roles: first, they act as a "translator" by converting DC to AC for household use; second, they intelligently distribute power. Their intelligent regulation works as follows:

• When sunlight is sufficient: Priority is given to powering the household, with any surplus used to charge the battery. Once the battery is fully charged, excess power is fed into the grid to generate profit from selling electricity.
• When sunlight is insufficient: The system first uses power from the battery. When the battery is depleted, it draws power from the grid.

In short, PV converts sunlight into electricity for household use; energy storage stores PV-generated power for emergency needs; and inverters not only convert DC to AC but also enable intelligent power distribution to generate revenue from selling electricity.