Radial system is used when energy is to be produced on low potential.

Explanation:
A radial system is a type of power distribution system in which power flows in one direction, from the source to the load. It is called a radial system because it resembles the branches of a tree radiating from a central point. In this system, there is only one source of power, and it is connected directly to the load without any interconnections between sources.

Reasons for using a radial system when energy is to be produced on low potential are:

1. Simplicity: A radial system is the simplest and most straightforward distribution system. It consists of a single source of power, such as a power plant or a substation, that supplies electricity to multiple consumers. The power flows in a linear path from the source to the load, without any parallel connections or interconnections.

2. Cost-effectiveness: Radial systems are cost-effective in terms of installation and maintenance. Since there is only one source of power, the infrastructure required for interconnecting multiple sources is eliminated. This reduces the overall cost of the system.

3. Reliability: Radial systems are generally more reliable than other distribution systems. Since there are no interconnections between sources, a fault or disturbance in one part of the system does not affect the rest of the system. This means that if a fault occurs, it is localized and can be easily identified and repaired.

4. Load balancing: In a radial system, the load is distributed among multiple consumers, which helps in load balancing. Each consumer receives power directly from the source without any diversion. This ensures that the load is evenly distributed and prevents overloading of the system.

5. Flexibility: Radial systems are flexible and can easily accommodate changes in the load. If the number of consumers increases, additional branches can be added to the system to supply power to the new consumers. Similarly, if a consumer is removed from the system, the corresponding branch can be disconnected without affecting the rest of the system.

Overall, a radial system is suitable when energy is to be produced on low potential because it offers simplicity, cost-effectiveness, reliability, load balancing, and flexibility in power distribution.