The function of any cable is to transport electricity. It takes electricity generated at one point to different points in any given system. The main function of a solar cable is in photovoltaic power generation. It acts as an interconnecting cable, connecting electrical components, like solar panels, in a photovoltaic system.
Photovoltaic cells and systems are an important part of solar and wind power generators. As suppliers of an important component of alternative energy sources, solar cables manufacturers are now under increased demand. Because of their function, solar cables are not to be confused with ordinary cables. This is why their manufacturing is also done by specialist manufacturers.
As explained above the demand for solar cables is linked with the rising demand for alternative energy sources. India faces a massive crunch in energy generation. With increasing population and urbanisation, this crunch is only expected to get much worse. As a consequence, it is important that alternative sources of energy are found and utilised to ease our dependence on fossil fuels as a source of energy.
Fossil fuels are not just non-renewable, they are also more expensive. Alternative natural sources are the most viable alternative. One of the abundant natural sources that we have is sunlight. Under the Government’s Jawaharlal Nehru National Solar mission, solar power generation is expected to reach 100 GW by 2022.
The demand is not limited to the public sector. As awareness of finding alternative sources increases, the demand in the private sector is also increasing. Solar PV systems are increasingly cropping up across the landscape. We have both stand alone units as well grid systems.
Solar cable application
The solar cables are required to connect the photo voltaic arrays to storage batteries. In the process it transmits photon energy from the arrays to the battery. The energy is received in the form of DC current, which is then converted into AC form through an inverter. The conversion of DC to AC is necessary because AC current is the more accepted form in India.
In a typical unit, there are four main components that are connected together. These are:
— Solar panels,
— Charge controller
The solar panel absorbs the sun’s energy. The charge controller helps in preventing the batteries from overheating and the inverter converts DC power to AC, which is a more commonly used form of electricity.
Solar cables can be solid or stranded. The latter is used when more flexibility is required. Stranded cables also have better conductivity. The other consideration here is between aluminum and copper cores. Copper is stronger and has a greater conductivity than aluminium, but it is more expensive.
Some requirements for solar cable manufacturers are:
All the components of the PV system are laid in outdoor conditions. Hence, the cable that connects these parts is exposed to harsh environmental conditions. This is why solar cables must be weather resistant. They must be able to withstand high heat, moisture and other elements. One of the critical requirements is resistance to UV radiation and high temperatures.
The cables have a wide temperature range and can be laid in almost any condition. The standard here is single-core cables that have a temperature range of –40°C to +90°C. The maximum permissible DC voltage is 1.8 kV.
Apart from the insulation, the cables also have a metal mesh that encase it to improve its resistance to environmental conditions. The insulation itself is required to withstand thermal as well as mechanical loads. This is achieved by cross-linking plastics. In addition to UV and moisture, the cables are also required to be resistant to salt water, acids and alkaline solutions.
PV units are usually stipulated to survive a minimum of 25 years before thermal ageing sets in. The solar cables must, therefore, have the same durability. This requires excellent resistance as explained above. Without the durability, the unit will fail in a short time.
In any cable application, size is important. Selecting the right size ensures that there is minimum energy loss and no chances of overheating. This is critical because overheating can cause a fire breakout.
The cables attached to solar panels must have flexibility because the panels move along with the sun. This requires high tensile strength. Flexibility ensures that the cable will not crack over time as it is moved around.
Solar cables manufacturers must have the proper certifications, including compliance with ISO standards. Since a small error can cause a major mishap and damage to the entire PV unit, it is important that this criteria is always checked.