Solar PV – Pros & Cons of Solar Photovoltaic Systems
The term solar PV (photovoltaic) refers to an array of cells containing a solar photovoltaic material that converts solar radiation into direct current electricity.
Photovoltaic research and development has been upped in recent years as the technology is considered a leading renewable consumer energy source.
In fact, reports claim photovoltaic production has doubled every two years since 2002 making it the world’s fastest-growing solar power and energy technology as a whole.
How do Solar PV systems work?
Solar PV systems work by converting light into electrical power. This is achieved using a thin layer of semi-conducting material, most commonly silicon, enclosed in a glass or plastic casing. These can range in size with small versions used on watches and calculators to a system of hundreds of square metres of solar PV panels linked up to make an array to power large buildings.
When exposed to sunlight the semi-conducting material causes electrons in the materials’ atoms to be knocked loose. The electrons that are knocked loose then flow through the material to produce an electric current known as a direct current (DC). The direct current is carried through wiring to an inverter which converts the current to alternating current (AC) so it can be connected to your property’s main electricity distribution board which either used within the home or fed back into the national grid.
Pros and Cons of Solar PV systems
Pros
- You can benefit from the Governments feed-in tariff which pays a set rate per kWh of electricity generated and an additional rate for any exported back to the national grid.
- The feed-in tariff is guaranteed by the Government for 25 years.
- Panels designed for European countries generate power even on cloudy days, they simply need light to produce electricity.
- Clean energy means you reduce your carbon emissions by up to 1 tonne per annum.
- Producing your own power protects against rising energy prices.
Cons
- A large area of unshaded south, south-west or south-east facing roof is required to maiximise payback. Smaller systems can be installed but payback will be longer.
- Panels degrade over time by approximately 20% over 25 years, this however is taken into account in most reputable suppliers calculations.
- It may be beneficial to replace the inverter after 10 years to optimise power generation, although this is not essential.
You can calculate potential earnings via our Solar PV Calculator or should you have any comments or questions about PV the please post them below.
Did you know that a 
The Government's 
How easy is it to fit PVs to a large area of felted flat roof?
how many days would it take for the installation of solar panels on a tiled roof? or is it possible to do so?
You say “The feed-in tariff is guaranteed by the Government for 25 years” which is totally untrue. The government have just slashed the tarrifs for everyone and what is to stop them doing it again and again. This is no longer a viable or trustworthy investment as has recently been proved. So after very nearly going ahead with PV we have now decided that the guarantees are not worth the paper they are written on.
In response to all of these comments, firstly, the PV panels can easily be fitted to clay or slate roof tiles, they just cannot project any further than 200mm off the tiles, they also are not allowed to go above the ridgeline of the dwelling.
The feed-in tariff is infact guaranteed at the rate of which you first apply, and will track the RPI from there on. The rates have been reduced to 21.0p / unit for all consumers who complete installations after 12th December 2011, all customers who get in before hand, will gain the higher rate for the 25 year period.
The feed-in tariff isn’t available to everyone, so this must be considered before installation, as the dwelling must already prove to have certain eco credentials.
In response to Neils comments: The overall proposition of PV installation is still financially viable, particularly when you consider the cost of modules has dropped on average 50% in 12 months. We now wait on the rest of the ‘Balance of System’ ie Inverters, mounting systems etc also reducing costs which will actually bring the rate of return to not far off where the FIT started when costs were much higher.
As Lloyd stated, the tariff is guranteed for 25 years and Index linked so dependent of when you sign up, you will be guranteed your ROI.
Unfortunately the reality is that most people are in it for financial gain alone where the whole idea of the technology was for a greener future….(understandable)…But, we have got to, at some point, look ahead to the bigger picture !