Solar Panels derive energy in the form of light and heat directly from the sun, and in turn may provide a useable, renewable and environmentally friendly source of energy. Their use today is predominately associated in providing electricity for small appliances, particularly in the MEDC's (More Economically developed Countries) supplementing the energy consumption of the average home.
Currently as oil and gas prices increase, the need to use alternative sources coupled with Government grants makes this increasingly a viable option for homeowners, particularly those with low energy requirements.
Solar Panels are increasingly becoming a viable option, particularly PV Panels as described below, which presently cost around £12,000 and have a payback of 7 years.
As technology improves, their efficiency in turn allows greater financial benefits to be obtained, offsetting the fairly high initial capital cost.
There are currently two main types of systems currently in use today. These are:
- Thermal (Hot Water) Solar Panels
- Photovoltaic Panels (Solar Cells)
Thermal (Hot Water) Solar Panels
Thermal Solar panels utilise the energy from the sun, transferring this through convection and radiation to piped water circulating within glass panels.
Panels such as the "Thermomax" are able to work in relatively low lux intensities and cloudy, overcast conditions, typified by the UK's temperate climate, due to their ability to absorb Infra Red light (invisible to the human eye).
Thermal panels can save substantially on hot water bills, as it is known that spatial heating is the most energy demanding within the average home, particularly during the winter months.
Thermal solar panels are generally used as an accompaniment to other renewable energy sources, due to their relatively low energy outputs attainable.
Integrating these panels with other sources will allow maximum energy saving gains to be obtained. It is recommended to consult an expert before undertaking any installation.
Photovoltaic Panels (PV, Solar Cells)
Photovoltaic Panels consist of an array of semi-conducting units, usually silicon, fitted on a mounting system, which convert direct sunlight into useable and transferrable form of electricity.
PV panels work by inducing a positive flow of electrons, through a combination of elements such as silicon and boron; generating electricity through a process of photon displacement.
These systems are flexible whereby several units may be combined, in different arrays providing varying quantities of electricity to suit individual user requirements. These can be tailored to suit traditional slate, concrete tiles to use of transparent cells for conservatories and glass.
If sited and used correctly, an average 3.4Kw/Hr PV panel has the potential to deliver substantial energy savings, with a payback of approximately 7 years. Larger units may produce up to 50% of the average homes electricity demands.
PV panels are ideal for remote locations where it would be too costly to install adequate infrastructure for electricity connections.
Advantages of Solar Panels
- A good solar water panel system can reduce the average homes annual water bills by 50-70%. Significant reductions in running costs and overall long term living costs may be attained through installation of such a system.
- By combining both systems simultaneously, greater cost benefits can be achieved, providing both reductions on water bills and a direct source of electricity to run small appliances from.
- A number of grants are available to supplement expenditure on Solar technology, these can vary depending on the extent and size of system to be installed.
- Solar panels provide positive environmental benefits, reducing the 'Carbon Footprint'. Introduction of such systems will assist to strengthen their reputation and existing public impression, whilst contributing towards achieving sustainability.
- Excess electricity may be stored in lithium ion batteries or if connected to the national grid, they may be sold back, providing additional revenue.
Disadvantages of Solar Panels
- Both thermal and photovoltaic panels still remain a fairly costly system to purchase and install.
- There is however, ongoing research into reducing the manufacturing costs through development of "plastic cell technology" which are essentially a thin film able to be mass produced at a much lower rate. These require minimal installation, able to be simply sprayed on or rolled out as required. However these still remain unviable, as they currently are only able to convert 6% of direct sunlight energy.
- Solar Panels have a limited useable lifespan of approximately 20 years, due to a process of degradation caused by light emitting photons and UV and IR radiation.
Installation of Solar panel systems may be a difficult and costly process; it is advised that a specialist surveyor and or contractor be appointed to assess your predisposition.
Prior to commencement of such a system, it should be worth identifying whether your home is suitable, whereby is there sufficient unobstructed sunlight, is the roof structure sufficiently capable, and consider complications with regard to planning permission.
There are two different means of installation of solar panels. These may sit on top or incorporated into the existing tiles (which are usually more expensive initially, but cheaper to replace and or maintain).
Costs for installing a solar panel system are approximately 50% of the overall price of solar panels, which can be anywhere in the region between £5,000 and £18,000 depending on size and type specified.
Once these have been installed, it should be noted, that solar panels are transferrable, whereby, they can be used by different tenants/ users, and or sold with the property.
Alternatively, homemade, solar panel kits or 'DIY' solar panels may be the preferred choice, which can provide substantial savings. A good solar panel kit can cost from as low as £1,000, but installation would not be included. Be sure to read how to make solar panels.
A number of DCLG and Local Authority funded grants are available to supplement the initial capital expenditure. PV and Thermal panel grants are available, providing up to £2,500 and £400 towards the cost of purchase and installation for each home.
Business may profit from Enhanced Capital Allowances (ECA) enabling 100% first year capital allowance on their initial expenditure. The capital cost may be written off against the taxable profits during the period of investment.
Home owners can earn substantial revenue by selling excess electricity back into the national grid, utilising Feed In Tariffs at a rate of approx 50p/KWhr. These are to be reviewed in 2012, however those already in or entering now, are entitled to these rates for at least 25 years.
Under the BERR funded Low Carbon Programme a 30% DTI solar grant is available for non profit organisations, (encompassing schools, hospitals, housing associations etc).