For those who want to use solar energy in their homes, the cost of setting up solar panels is the crucial question. It is often believed that the investment in a solar energy set up is determined by the size of the house. This is not true. Factors such as geographical location, exposure to the sun, and the level of energy consumption in the house determine how much it will cost to set up a solar panel system in a house.

So, if you want to calculate how many watts of solar panels do you need to install in your house, follow this simple method. Divide the number of kilowatt hours mentioned in your electricity bill by 30. This will provide you with the amount of average energy consumed in your house in a day. Divide your daily average by the total number of full sun hours you receive everyday. Multiply that number with 1.15 and you will be able to figure out how many watts of solar panels you need to install in your house.

For people who are already using solar energy in their homes, the best way to judge the effectiveness of a solar cell is to check its dollar/watt ratio. This is because, according to scientists, no two identical solar cells are capable of generating the same amount of energy. They say that apart from the size, various other factors affect the performance of a solar cell. These include the quality of the cells; the technology used to produce them, and the duration for which they have been functioning. The good news here is, that scientists the world over, are of the view that solar cells will become extremely affordable in the years to come. According to a report published by Prometheus Institute, the prices of a silicon-based solar panel are likely to fall from $3.66 per watt to $2.14 per watt by the year 2010. Also, the prices of the thin-film photovoltaic cells are likely to go from $2.96 per watt to $1.81 per watt.

In case you want to further reduce your energy bill, you can use scrap solar cells. Scrap solar cells are cells that break during the time of manufacture. Solar cell manufacturers often give away these cells at very low prices. It has been estimated that using scrap solar cells can help you generate electricity at a rate lower than $3 per watt.