20 Dec 2010 10:12:03
What is solar PV?
The idea of solar panels has been with us for decades. For most people, solar panels are associated with holidays to the Mediterranean or the vast sun-baked expanses of the Nevada desert. As for the UK's overcast and cool temperate climate, the idea of solar panels in this country is a joke made by the silly green fringe, right? Wrong! Huge advances in technology have made the installation of solar panels in the UK a sensible and effective possibility.
There are a couple of types of panels: solar PV and solar thermal. Today, I'll have a look at the benefits and pitfalls of solar PV.
Solar PV is crucial to the global move towards renewable and non-polluting energy generation. To put it into perspective, solar PV is the fastest growing method of power generation in the world. Increases in design technology and economies of scale have seen a steady drop in price for solar PV units, placing them within the reach of regular domestic households for the first time.
Energy is produced by the conversion of solar radiation into DC electricity using an array of semiconductors laid out in a series of cells. Certain materials are used to manufacture these semiconductors, each of which displays the necessary photovoltaic effect necessary for the energy conversion. These materials include monocrystalline silicon, polycrystalline silicon, amorphous silicon, cadmium telluride, and copper indium selenide/sulphide.
There are numerous applications for solar PV panels. These include the powering of transport systems, power stations and even satellite-based power plants. However, solar PV panels are most commonly associated with domestic home use.
The most contemporary homes may be built with integrated panels on the roof's south side. More usually, panels are fitted retrospectively onto existing roofs or onto a separate free-standing array nearby. The most modern panels are extremely thin and unobtrusive, covering either a section of the roof or its entirety. New buildings may also have cells integrated into walls, although this option is unusual in the UK.
Once a solar PV system is installed, it may become either an ancillary power source for the home or its main generation system. Contrary to popular belief, the panels continue to produce energy even in cold or cloudy weather. However, under these conditions power conversion is reduced. In the UK, most solar PV systems form the primary energy generation system during sunny or warmer conditions, with other methods such as solar thermal or traditional fossil-fuel alternatives used in cooler or darker conditions.
There are a couple of major disadvantages in running domestic solar PV systems. The most obvious of these is that the system won’t work at night. This is significant since the very time that a household needs most energy is during a cold winter when daylight is at its shortest. The other disadvantage is the initial installation cost. Prices are dropping year on year as technology and take-up increases. However, with the UK government's confirmation of its Renewable Heat Incentive scheme, the initial cost of installation is more than offset by the long-term financial rewards available.