Solar Photovoltaic System
The solar cells used in the PV Voltaic systems are made of a single crystal or poly-crystalline silicon materials, to form p-n junctions. Certain impurities like boron and phosphorus are added to silicon wafers that enables them to generate current when exposed to sunlight.
Specifications and Ratings
The standard capacities available in India varies from 5Wp to 120Wp. Here, Wp stands for peak watt which can be defined as the maximum power output the module delivers. The solar cells are connected in series to get corresponding voltage. Generally, 36 solar cells when connected in series, produce a usable direct current (DC) voltage of about 16.5V that can be used to charge a 12V battery.
A typical solar photovoltaic system consists of:
- Inverter (to convert DC into AC)
- Electronic charge controller
- Storage of electricity (battery banks are used to supply power to loads during cloudy days)
- Since PV systems have no moving parts, they can avoid unnecessary wear and tear.
- As we all know, solar radiation is available in most parts of India even all the way in the North where climate conditions are extreme. Hence, the SPV system can be used anywhere in the country.
- SPV modules don’t require heavy maintenance.
- As solar radiation is free, no running costs can be associated with the SPV system.
- SPV systems can be expanded as required for small, medium, or large apps.
- A PV system has an effective life span of 15-20 years.
- This kind of production of electricity is eco-friendly and pollution-free.
- Since the PV systems are pre-fabricated, they don’t require much time to be installed.
The only problem with the solar rooftop systems is that the initial cost of setup of the system is very high which is only a small hurdle. So keeping this in mind, the technological advancements have got you covered. There are some cost-effective alternatives that one can use if the solar rooftop system seems to be heavy on the user’s pocket.
Cost Effective Alternatives
In this section, I am going to discuss some cost-effective alternate solar appliances that the user can experiment with.
1. Solar Street Lighting System
An outdoor lighting system that can be used to light up an open area or a street. A solar PV module is mounted on the top of the pole, facing south, to receive solar radiation throughout the day. The solar street lighting system is provided with a battery, that is sufficient to operate the light for 10-11 hours.
- Automatic ON/OFF time switch for dusk and dawn operations.
- 11 Watt CFL lamp, along with fixture
- 74Wp solar PV module, 12V, and 75 Ah tubular plate battery with battery box.
- Charge controller cum inverter (20-35 Hz)
- Weatherproof meter mild steel lamp along with paint and mounting hardware.
The cost of a single SSLS is INR 19,000 along with some financial assistance provided by MNRE (Ministry of New and Renewable Energy) and GoI (Government of India).
2. Solar Lantern
A portable lighting system that can be used both indoors and outdoors. It can give light up to 3-4 hours everyday.
- PV module of 8Wp – 10Wp capacity.
- Compact fluorescent lamp (CFL) of 5W – 7W ratings.
- A sealed maintenance-free battery of 12V, 7 Ah capacity.
The cost of a single SL is INR 3000 – 3300. Low-cost models with smaller modules and batteries are also available.
3. Solar Home Lighting Systems
These systems can run a small DC fan or a 12V DC television. They are useful in non-electrified rural areas or areas with erratic power supply.
The Solar Home Lighting Systems (SHLS) are designed in such a way to give a working time of 3-4 hours everyday with a fully charged battery. Along with this, the system also provides buffer storage for 1-2 non-sunny days.
- Solar PV modules along with charge controller and battery.
- Lightning system (lamp and fan).
- The capacity of the PV module can be 18, 37, or 74Wp.
- CFLs 9W or 11W rating.
- A sealed, maintenance-free, or flooded lead-acid battery system of 12V and 20V or 75 Ah capacity.
- Model I (One 9W CFL) = INR 6,000
- Model II (Two 9W CFL) = INR 10,000
- Model III (One 9W CFL and One Fan) = INR 11,000
- Model IV (Two 9W CFL and fan/TV) = INR 18,500
The economics of these systems is very attractive. Suppose you buy a Model IV for your office, you just have to pay a one-time payment of INR 18,500 and as discussed earlier, the life span of PV modules is 15-20 years. So let’s go through some calculations.
|Years||Years in Month||Cost/Year||Cost/Month|
|15 years||180 months||INR 1,240||INR 102.77|
|20 years||240 months||INR 925||INR 77.00|
Table 1: Yearly and Monthly cost of Module IV (Two 9W CFL and A fan/Tv) system
These prices can decrease further if the demand for solar PV systems increases which would help ease the pocket of the consumer. We are lucky to be living on a solar-powered planet. Everything on this planet traces it’s source to the sun. We can use the power of the Sun to power our houses and the planet. The applications are immense – we just need to know and encourage people to adopt solar practices. I believe knowledge is power. So people remember, together we can and we will Save the Planet.
SOURCE: Solar Photovoltaic Technologies for Domestic Applications (IGNOU)