Energy: Two Different Types Of Solar Energy

SOLAR ENERGY

Solar energy is energy harnessed by the radiant light and heat of the sun by using technologies such as photovoltaic, solar thermal energy, solar heater, and solar charger. It is the most readily and abundant source of energy .It is also the most important non-conventional source of energy as it’s non-polluting and hence helps in tackling the greenhouse effect.

Solar systems are powered by energy from the sun. Two generic types of solar-electric systems are solar photovoltaics and solar thermal electric. Photovoltaics use a quantum process to convert solar radiation directly to electricity. A solar thermal electric system uses a working fluid that is heated by solar energy and expanded through a turbine or heat engine.

Solar radiation

Power conversion unit efficiency is dependent on load. It is usually in the range of 95% to 97% at above 25% load but falls off sharply below that level.

Instantaneous system performance can easily be calculated manually given insolation data and module manufacturer data. Annual performance is best estimated using a performance computer model such as PVFORM (Menicucci and Fernandez). PVFORM reads insolation data (for example, TMY data) at hourly increments and computes temperature-corrected module efficiency and other efficiency factors based on user input. The codes steps through each hour of the year and provides daily, monthly, and annual summaries as requested by the user.

Research and development on PV technology is aimed at increasing module efficiency and decreasing module cost. A chief contributor to PV module cost has been the semiconductor-grade crystalline silicon used in the manufacture of a large number of PV cells. Not only the material is expensive, but also traditional wafer slicing and trimming approaches have resulted in significant material waste. Many development efforts are aimed at crystal growing techniques to reduce the waste, at using lower grade materials or at using thin film techniques.

SOLAR THERMAL

It prevents overcharging and may protect against overvoltage, which can reduce battery performance or lifespan, and may pose a safety risk. It may also prevent completely draining (deep discharging) a battery, or perform controlled discharges, depending on the battery technology, to protect battery life.

What is the need of charge Controllers?

Solar cells are very useful things. Unfortunately, they are not very smart. Neither are batteries - in fact batteries are downright stupid. Most PV panels are built to put out a nominal 12 volts. The catch is "nominal". In actual fact, almost all "12 volt" solar panels are designed to put out from 16 to 18 volts. The problem is that a nominal 12 volt battery is pretty close to an actual 12 volts - 10.5 to 12.7 volts, depending on state of charge. Under charge, most batteries want from around 13.2 to 14.4 volts to fully charge - quite a bit different than what most panels are designed to put out.

There are two types of charge controller –

1. Stand-alone charge controller

2. Integrated charge controller