If you are one of the many people considering a home solar system, then you need to carefully assess your situation first, so that you are able to pick an adequate number of solar panels and use them in the most efficient manner possible. A photovoltaic solar energy system is definitely a move towards the future of energy, which is eco-friendly and green. Moreover, it will considerably add to the real estate value of your home.
Calculate The Solar Radiation
As a rough estimate, it can be said that a residential solar system can generate 4 to 5 kWh/m2/day in most areas. In some cases, the power generated can be as high as 8 even. You can easily find out the exact output for your area by running an online search in many of the solar energy calculators, regarding your geographical location. To break down the kWh/m2/day delineation so that it is easy to understand, the kWh is kilowatt per hour and the m2 is the surface area of the photovoltaic cell in square meters. On average, solar panels work at an efficiency of between 7 to 17 percent.
Determine Your Need
The next step is to assess how much you will be using every day. A good way to go about doing that is to look at your previous energy bills, so there is no room for error. The state averages for energy consumption vary drastically, so look for information particular to yours before deciding upon a final number. According to a residential energy consumption survey, by the U.S. Energy Information Administration in 2009, the following is the breakdown for how energy is used in homes:
- 42% for space heating
- 30% for electronics, lighting and other appliances
- 18% for water heating
- 6% for air-conditioning
- 5% for refrigeration
- Calculate the Number of Solar Panels
With the knowledge that you have gathered in the above-mentioned steps, you should now be able to gauge how many solar panels you need to power your home. Whichever manufacturer you are considering should be able to provide comprehensive literature regarding the sizes of the solar cells on offer, so you can make a decision easily. The following equation can be of help in making this calculation as well:
- Surface area of the panel x Solar radiation in the area x 0.07 (7% solar panel efficiency) x Average days per month
- Once you have made this calculation, divide your energy usage per month by the end product, obtaining the total amount of panels you require.
Consider Your Costs
The upfront costs of installing a photovoltaic system can be considerable, but many government run incentive programs allow you to significantly cut down on this cost. Apart from that, the long-term savings on utility bills are also a blessing. With ever increasing costs of fossil-fuel energy, it makes good economic sense to invest in an independent source of energy. If you choose a grid-tied solar system, then you also have the option of selling surplus energy to a utility company in most states.
Plan The Placement
Perhaps the most crucial step, as without proper placement your home solar system is virtually useless. It must be placed so that it is exposed to an adequate amount of sunlight, preferably on the south-facing side of your home. The most optimal position in on the south of your roof, at an angle equal to the latitude.