Brief description about equipment’s of a Solar PV system.
Solar Panel or Photovoltaic (PV) Module is the heart of a solar system. It consists of multiple solar cells joined together within a aluminium frame and glass casing. When placed in light, cells generate electricity. Solar Panels are rated for their output power. For rooftop system, typically power rating used is 250W or 300W. Multiple panels are put together to generate the desired amount of power. For example if we use 4 panels of 250W we get 1000W or 1kW power. Typically 1kW worth of panels require space of ~ 80 – 100 sq. ft.
Panels are long life item. They last for more than 20 years.
If panels is the heart of Solar PV system, inverter is the brains. Inverter’s main function is to convert DC power generated by solar panel in to usable AC power (to run our appliances and equipment). It also ensures that Solar power is used in priority over other available forms of power via grid, battery etc
The inverters we use are transformer-less and hence practically silent. They require very little space and can be wall mounted at a convenient location (typically close to solar panels). Inverters are typically warrantied for 5 to 10 years. You can easily expect a working life of around 15 years.
Solar inverters are essentially of following types-
1) Grid Tied
- These are directly connected to the grid supply.
- There is no limitation to the size and type of equipment than can be run
- With net metering, excess power can be exported and used later when required
- Suitable for cases with reliable power supply
- These are connected to specific loads to be run
- These have to be sized based on connected loads and their surge requirement
- Power cannot be exported as mains and loads are isolated
- Suitable for areas with load shedding problem
Inverters are extremely critical to the performance of the system. Hence we only use equipment from European or Taiwanese manufacturers to deliver maximum output.
To get the maximum output, the panels should be facing south at a certain angle depending on the geographic location. The ensure that panels remain fixed to the roof in the desired orientation, mounting structures are used. They have to designed to suit the type of roof. Typically there are two types of mounting structures –
- Triangular Mount: for flat roofs
- Flush Mount: for inclined roof
We use mounting structures made of Galvanized Iron or Aluminium to ensure they are able to last long term without any maintenance. This is even more critical in demanding Indian conditions. These structures are warrantied for 10 years.
Our design keeps in mind appropriate provision for access and cleaning of panels in the future.
Balance of System
The remaining part of Solar PV system consists of electrical components such as-
- AC & DC Cable
- Circuit Breakers
- Safety Equipment: RCCB, Surge Protectors, lightening arrestors etc
– SPD (Surge Protection Device) protects the equipment fromfrom surge voltages created during lightening and grid fluctuations.
– RCCB (Residual Current Circuit Breaker) protects against current leaks which may lead to shock or fire.
The electrical equipments have to be designed according to the technical specifications of panel and inverter. It is important to install safety equipments since PV systems are designed for long life. Electrical surges or short circuit can damage the equipment which are much more expensive to replace than standard safety devices.