On-Grid or Grid-Tie Solar Systems are the commonly used type of solar systems for residential as well as business requirements. They do not require a battery to be installed and are directly connected to the public electricity grid. The excess power that is generated by your system is sold to the public power system and you are paid for the same.
Quite often, people are confused as to which type of solar system to choose. The correct type of system that you need depends on your various power requirements as well as your budget. If your requirement is to have no electricity bill along with the least maintenance, and if the power cut off in your area is usually less than two hours, then On-Grid Solar System is what you need.
Why choose the On-Grid system?
On-Grid Systems are usually preferred over Off-Grid and Hybrid Systems due to their financial and power advantages. In On-Grid Systems, the electricity generated during the daytime is sent to the grid and it’s used to meet the power requirements. Any excess electricity that is produced after meeting the energy needs can be sold and is a great investment to generate income. In areas where frequent power failures occur, it’s advisable to add an extra inverter/ battery.
India has great potential for solar power generation as it has an average of 300 sunny days a year and a high rate of 4–7 kWh/m solar installation. The Government of India hopes to have a huge share of the country’s power generation from renewable energy sources.
The photovoltaic cells in the installed solar panels will start producing electricity as soon as the sun’s rays fall on it.
The cells produce Direct Current(DC) which has to be converted to Alternating Current(AC).
The function of an on-grid solar inverter is to convert the DC current produced from the solar panel into AC current which is used for our energy needs. This form of electricity is consumed by electrical appliances and these appliances are classified as electric loads.
When solar power generation begins, the power needs of the appliances are first met and the excess energy is sent to the power grid. And on a cloudy day, to meet the energy requirements, electricity is exported from the grid to run the appliances in residential or commercial buildings.
Let’s see an example. Suppose the power requirements of the building is 1800kW, and on a rainy day the solar panels produce 1000 kW, the remaining 800kW will be supplied by the public electricity grid. This is not the case with Off-Grid systems and can even cause voltage fluctuations and might cause damage to the appliances.
In the on-grid Solar Systems, since energy is not produced during the nighttime due to the unavailability of rays from the sun, electricity is imported from the grid. The energy that is consumed will be recorded as import and the excess energy that is fed to the grid is recorded as export.
As we can see, now you have the basic idea of the working of the On-Grid Solar System. Now let’s see the requirements for a 1kW Solar power plant. It takes 100sqft of shade free area. And about the cost, it costs nearly Rs 75,000–85000 as the price is greatly determined by the quality of the products chosen. It’s better to choose medium quality solar power plants for residential property as higher quality ones might take longer periods for the return on the investment. But if you choose quality and are ready to invest, you should totally go for it. But commercial buildings should definitely opt for higher quality ones as it’s a long term investment and also since the price drops with the capacity of the solar plant.
To have more knowledge about solar power plants, let’s see the components required for the On-Grid Solar System. The main four components are the panels made of photovoltaic cells, inverter, the net meter and the grid.
These are made up of multiple photovoltaic cells (PV cells) made from silicon. They produce DC (Direct Current) when the sun’s rays fall on them. These PV cells are all linked together inside the solar panel and are connected to nearby panels with the help of DC cables. It should be noted that its not the heat from the sun that produces the electricity. It is the light energy or irradiance responsible for the generation of electricity. The solar panels connected and installed together are called solar array. Among the four components, Solar panels are the costliest ones.
The inverter is responsible for converting the DC(Direct Current)power generated by the solar panels to AC(Alternating Current). This step is essential as we need power in the AC form to run the appliances and also to connect with the grid system of the power sector. Various types of inverters are available depending on the requirement with ratings ranging from small kVA to larger kVA. The MPPT(Maximum Power Point Tracking) enabled inverters comes with a wider input Vdc range.
The two types of inverter systems used are the string inverter system and the microinverter system.
When the solar panels are linked together in series, it’s called a string inverter system and here the DC is given to a single inverter and the conversion from DC to AC takes place. Whereas when every panel is fitted with its own micro inverter on the backside of the panel, it’s called a micro inverter system. The panel produces DC and is covered to AC on the roof and is then directly fed to the load.
Net meter :
The net meter plays a very important role in the profitability of the solar system. There will be a meter that records the import as well as the export of the energy. This is a bidirectional net meter. For billing, the difference in the imported and exported electricity is considered. i.e., import minus export. If there is any credit, it’s carried over for the subsequent billing.
Whenever excess electricity is produced by the solar panels, it’s sent to the grid and is available for usage by other consumers. But when the solar system is producing lesser energy than your requirement, or if it’s not working( during the night time), the needed amount of energy will be supplied from the grid.There is another important component that plays a major role in solar power plants. That is the DC and AC disconnect. They are in the form of boxes and their function is to separate inverter form the electrical grid. It can be considered as a circuit breaker.
The advantages of going On-grid
- • Can reduce power bills by as much as 90%!
- • Is a great source of investment due to faster returns.
- • As the On-Grid inverters are highly efficient, there will be the least loss of electricity.
- • The load amount is versatile. Any amounts of load will do.
- • That will be enough and a stable electricity supply.
- • Cost of operation is minimal.
- • Cost of maintenance is very less.
- • Excess energy generated is not wasted as it’s exported to the grid.
- • Can save on costly batteries as it requires no storage.
- • Helps in reducing carbon footprint as it uses solar energy which is available in plenty and is renewable.
- • It adds value to your property.
- • Helps you to relax and stop worrying about the hefty electricity bills that are always going up.