Bookmark Us!About Solar PV
Solar photovoltaic production is the worlds fastest growing energy technology. As the technological innovation of solar PV advances, production increases and as a result of this increased production, the cost of solar PV panels has steadily decreased each year since the first solar cells were manufactured.
This is good news for those looking to invest in solar energy for their homes and unlike solar thermal systems which require direct sunlight to heat water, solar PV converts solar radiation (also known as daylight) into direct current electricity. Contrary to popular belief, solar PV does work admirably on cloudy days, even this far north!
Ideally, solar PV panels are best installed on a south facing roof, which will maximize electricity generation throughout the day. However south-east and south-west facing roofs still receive plenty of sunlight to generate solar power. Another consideration is nearby trees, which may put all or part of your roof in shade and various times of day, or during the winter months when the sun is low in the sky.
Solar PV cells come in a variety of shapes and colours, from the common solar panels which sit on top of your roof tiles and come in a variety of sizes, to solar roof tiles designed to blend in with your existing roof tiles and even transparent solar PV cells which can be used on conservatories. For more information on which solar system is best suited to your home and budget, contact Solar Panels 4U.
How to Size Your Solar Array
Many people would like to be able to power a conventional all-electric home with solar modules. Sadly to go ALL electric would be cost prohibitive, however it is possible to make great savings on current electricity usage by installing PV panels.
Today's solar modules can convert approximately 18% - 20% of the solar energy they receive into electricity under ideal conditions. This means the more square-feet of solar array you have, the more power you will generate. However, outdoor temperatures, cloud-cover, site elevation, and shadows from nearby objects will reduce this electrical power output substantially.
Bearing in mind there are many different outputs available. Basic array sizing using an average output, will take between about 12-16 square metres of solar array/panels for a 2kW of solar output required, (depending on the module output chosen).
Ideally, you should use a module count that is in multiples of two, since most modules have a nominal voltage of 12 or 24-volt. For example, if you intend to install a solar array in the 2 kW size range, you should install 12 modules at 170 watts each (2,040 watts total), but should not use 13 modules just to make it match a nominal output goal. This approach will enable equal division of the voltage and current among other system components, such as array circuit fuses, charge controllers, and cable runs etc.
When selecting the mounting site for your array, keep in mind there should be no shading of any part of the array between 9:00 am and 3:00 pm. Even narrow shadow from a nearby tree partially covering only one module can potentially reduce the total array output by up to half!
The highest yearly total output will be achieved if the array is on a south facing roof, with a roof slope equal or greater than the latitude for your location. However, it is possible to mount solar arrays in all orientations from almost due east to due west, and with all roof-mounting angles from vertical to flat, to accommodate unusual local site conditions or design requirements; so don't rule it out if your preferred location is less than perfect.
Yes, the sun shines all day (we hope), but at the lower sun angles before 9:00 am and after 3:00 pm, a typical solar array will have a much lower power output. During shorter winter months this "solar day" is even shorter.
