Light can be absorbed by certain materials to release electrons, creating a voltage. This is known as the photovoltaic effect, and it was first discovered in 1839. Therefore the method of converting energy from sunlight and turning it into electricity is known as Photovoltaics. Photons of light excite the generated electrons and they jump to a conduction band within the solar cells. Direct current electricity is produced. Photovoltaics (PV) is the method by which scientists harness the sun’s radiation and solar PV panels utilize photovoltaic material to create a renewable and abundant energy source.
Although it was Edmund Bequerel, the French Physicist, who noticed the photoelectric effect is 1839, it was not until Albert Einstein laid down the laws of light and the photoelectric effect in 1905 that photovoltaics had a foundation on which to be built upon. In 1954, Bell Laboratories succeeded in creating the first PV module.
Solar cell efficiency and photovoltaic arrays, made of a series of cells, have greatly improved since the technology was first discovered. As demand increases, the technology behind harnessing the abundant energy source has improved steadily. In fact there has been such demand that maximum capacity has gone up 60 percent a year since 2009. An increase in manufacturing scale and efficiency has also helped the technology improve. It has also caused prices to plunge, making the technology more affordable for the average consumer.
Satellites and spacecrafts were designed to use photovoltaics to power themselves. They were the first to benefit from this renewable energy source. The successful utilization of the new technology boosted public confidence in it. Presently, photovoltaic modules, better known as solar panels, are often connected to the city grid.
Off-grid power generation is also possible. This method is useful for powering homes, vehicles, and boats, as well as other applications. PV panels are often mounted ground level on farmland or grazing lands. Other times they are built into roof tops and walls, then called BIPVs. While only one panel is enough to power a household device like a telephone, an array would be needed to power house.
Photovoltaic power is calculated by testing to see the maximum energy input possible. In reality, the power generated is often less than the value stated. Factors such as weather conditions, location, and time contribute to the amount of energy harnessed. Actual performance is usually around 25% of stated output.
With a 20 percent annual increase, PV panels have become the fastest growing of all energy technologies. The United States has lagged behind other countries in embracing this renewable power. The US only installed 500 MV last year while forward-thinking countries like Germany have steadily increased the number and efficiency of PV panels in their country. Germany installed 3,800 MV in 2009.
Spain is currently leading the effort in switching to solar powered renewables but they have recently introduced a tax that will lower their encouraging numbers. Japan, Italy, France, and Germany are close behind. Greenpeace and other environmental organizations urge more countries to get seriously involved. They predict that if there were an international coordinated effort to support green technology, specifically solar PVs, by 2030 sunlight would satisfy up to 14% of world demand.
As newer technologies are discovered, and existing ones are improved, the world will surely see cheaper, more efficient solar PV panels. But in order for this to occur, demand and public interest must continue to grow.