Solar Power Plants
Basic System Description:
Solar Photovoltaic power generator consists of solar modules in series and parallel connections; these convert solar radiations into DC electrical power at the pre-determined range of Voltages whenever sufficient solar radiation is available. The individual crystalline cell panel connected together of a 10 module (in series connection), which are hermetically sealed to survive in rugged weather conditions and ensures optimum performance during its ling life
In order to achieve a higher system voltage, modules are installed in a row arrangement, called a string. A higher system voltage has the advantage of lesser installation work, higher efficiency of the entire plant and usage of smaller cross section cables.
Modules are connected to strings in parallel by cables in Junction Boxes. These junction boxes not only act as a junction point but also monitor each string output which will be fed to the central monitoring and analysis system. Outputs from many such junction boxes are connected in parallel in the Main Combiner Box (MCB). This Main Combiner Box output is fed to the central inverters/Power Control Unit (PCU) to invert solar generated DC power in to conventional 3 phase AC power.
Central inverter or PCU operate on MPPT (Maximum power point tracking) mode to ensure maximum output from the solar generators at different ambient conditions. Central inverters use higher system voltages to reach very high plant efficiency.
Furthermore, installations can be expanded with additions of more modules without problems. AC power from inverters will be fed to existing 415 V, L.V panel which in turn will supply power to factory.
Operation Philosophy:
Solar panels mounted in the field generate DC electric power. The DC electric power generated by the solar panels cannot be fed directly in to the rice mill. The charge controller with inverters invert the direct current output from the solar array into grid compliant AC voltage, feeds it in to the utility power system with proper protection and control. The system automatically starts up in the morning and begins to export power to the rice mill, provided there is sufficient solar energy and the grid voltage, frequency is within the range.
If the sun energy goes out of range the inverter will be immediately disconnected and reconnected automatically at a pre-determined time after the sun comes back within range.
Benefits of Solar PV Power Plant:
- Power from the sun is clean, silent, limitless and free
- Photovoltaic process releases uninterrupted power at no fuel cost, and no pollution of SO2 or NO2 gases which are normally associated with burning finite fossil fuel reserves and don’t contribute to global warming.
- Photovoltaic’s are now a proven technology which is cheaper than using DG sets during day time. Solar power is inherently safe as opposed to other electricity generating technologies.
- No fuel is required for generation, so fuel cost of power generation is zero.
- Solar power shall augment the needs of peak power needs
- Increase in reliability i.e., voltage and frequency.
- Good possibility of REC & MNRE benefits.
(a) Amorphous type
(b) Crystalline type
(c) Thin Film (CIGS/CdTe) type
The efficiency of amorphous is less than crystalline. So, more area is needed to setup same capacity solar plant with amorphous type cells. Polycrystalline solar cells are used in proposed solar power plant.