Solar panels can be used without batteries in certain types of systems. Solar panels generate direct current (DC) electricity when exposed to sunlight. Without batteries, this electricity is consumed in real-time as it is produced. There are several applications and setups where solar panels are directly connected to the electrical grid or used to power specific devices or equipment without the need for battery storage. Some common setups where solar panels are used without batteries include:

1. Grid-tied Systems: In grid-tied solar systems, the solar panels are connected directly to the utility grid. The electricity generated by the solar panels is used to power the electrical appliances and devices in the building. If the solar panels produce more electricity than is currently needed, the excess can be fed back into the grid, often resulting in credits or payments from the utility company.
2. Solar Water Pumping Systems: Solar panels can be used to directly power water pumps, especially in remote areas where there is no grid connection. These systems can operate during daylight hours when the sun is shining, pumping water directly from a water source without the need for batteries.
3. Solar-Powered Ventilation Systems and Outdoor Lighting: Solar panels can be used to power outdoor lighting systems or ventilation fans without the need for batteries. These systems operate during daylight hours, utilizing the electricity generated by the solar panels immediately for lighting or ventilation purposes.
4. Solar-Powered Electronics: Solar panels can be used to power small electronics and devices, such as calculators, small radios, or solar chargers, without the need for batteries. These devices use the electricity generated by the solar panels in real-time to operate or charge the connected devices.

In these applications, the use of batteries is not necessary because the electricity is either immediately consumed or fed directly into a grid or used for specific applications during the period of sunlight exposure. However, for applications that require continuous power supply even when sunlight is not available, such as off-grid homes or remote installations, the use of batteries or other forms of energy storage is essential to ensure a continuous power supply.