Did you know that today’s photovoltaic cells are based on a lucky finding by Alexandre Becquerel way back in 1839? He placed an electrode in a conductive solution, and when it was hit by sunlight a current was generated. The first solar cell, however, wasn’t produced until 1883, Charles Fritts produced a 1%-efficiency (!) selenium-on-gold photovoltaic panel.

The photovoltaic effect was then followed by the discovery of the photoelectric effect, which Albert Einstein would publish a paper about in 1904. A flurry of photoelectric advances followed, until eventually, in 1954, AT&T Bell Laboratories created the first modern silicon solar cell. Bell Labs also produced the solar cells used in early space satellites like the Vanguard 1. Soyuz 1, in 1967, would also use solar cells, and would become the first manned spacecraft to do so.

Between the 1950s and 70s, solar power fell out of grace. Producing solar cells was still prohibitively expensive ($250 per watt), and their efficiency still hadn’t broken past the 10% mark. As the semiconductor industry flourished, however, and as the size of silicon boulesand the integrated circuit market boomed, the cost of solar panels plummeted. By 1973, solar panels had reached 15% efficiency, and could be produced for around $10 per watt.

Today, the solar power industry is very healthy indeed. The price per watt is down to around $3 and at-home installations (and government subsidies!) are becoming increasingly common — and just take a look at the number of photovoltaic power stations that opened in 2010! Indeed, you have to look no further than President Obama himself to see how popular solar power is becoming: in 2010, he ordered the installation of solar panels and a solar hot water heater at the White House. Now it’s just a matter of when solar power will overtake coal in terms of cost and efficiency, which could occur in the next few years.

For more information on the history of solar technology, check out the infographic below, or read more about the history of solar power on Wikipedia.

Infographic by SunRun – Home Solar Leasing Made Easy

Install a solar panel on your rooftop to generate energy and sell it to the distribution company through the grid for money.

To encourage green energy, the Centre is planning a programme under which it will provide incentives, either financial or through a subsidy, to home owners installing a rooftop solar panel for own energy consumption, and who will sell the extra power to the grid during daytime.

The programme also contains a proposal in which a building owner can rent his rooftop to investors to set up a solar power plant.

The plan, which is still in a preliminary stage, says the electricity distribution companies can buy the power from households, either by paying money to the seller or giving subsidy in the seller’s electricity bill.

To introduce the system in India, which is prevalent in many European countries including Germany, there is a need to modify the current Electricity Act as well as develop locally suited technology, Union Minister of Power K C Venugopal told Deccan Herald.

Delhi to be first

The Delhi government is likely to be the first to implement the scheme as the government has started working on the issue. As per the Delhi Government’s proposed policy, residents can get solar power plants installed on their rooftops by signing a power purchase agreement with the company supplying power in their respective areas.

The cost of setting up such a plant in an area of 200 square metres will be between Rs 8 lakh and Rs 9 lakh.

According to the policy, house owners can either lease out their roofs to a developer, who will then set up the unit, or pay 30 per cent of the cost of installation.

The remaining 70 per cent will be financed through banks. The cost of generating each unit of power from the rooftop plant will be Rs 17.50 which the owner of the rooftop can sell to any of the power supplying companies.

The plants will be set up using the solar photo-voltaic technology as they can be easily mounted on rooftops, said an official in the Power Ministry.

The Centre which aims to produce 10,000 MW of solar energy in the 12th five year plan ( 2012-2017) with an investment of Rs 50,000 crore, has already set up 61 solar energy monitoring units across the country.

The government has started collecting radiation data from these monitoring centres and accordingly it will encourage setting up solar plants, he said.

While Gujarat and Rajasthan are ahead with installed capacity of 3,000 MW and 1,000 MW solar energy, the Centre wants other states to follow suit.

Power is money

* A house owner can install solar panel on the rooftop to meet his power needs

* He can then sell the extra power generated to distribution companies

* The owner can also rent out the space for setting up a solar power plant

* In return, discoms will either pay in cash or give subsidy in the seller’s electricity bill