What is a Solar PV system?
Most electricity is generated by burning fossil fuels. This releases carbon dioxide and other gases into the atmosphere, which contributes to climate change. A Solar Photovoltaic (PV) system is one that converts light directly into electricity on your roof with no waste and no emissions. This electricity is used throughout your home in the same way as the electricity you currently buy from your energy supplier. Harnessing the sun’s energy and converting it into electricity will reduce your fuel bills and at the same time reduce your daily impact on the environment.
How does it work?
When light hits the silicon in a solar PV cell, electrical energy is created. The electricity flows through a cable and is collected at a central point, often located in your roof space. At this central point the electricity is converted from Direct Current (DC) to Alternating Current (AC) and carries on into your household electricity system. The electricity generated by your system works hand in hand with your own system for all your electrical needs. If not, your needs will be supplemented by your electricity supplier. If during the day you generate more electricity than you need this excess will flow out of your home and back into the main electricity grid.
What systems are available?
Some solar PV systems are available as roofing products that replace conventional roof tiles. They can be integrated into your roof without changing its shape or style. Not all roofs will suit all types of products. An integrated system is particularly suitable if you are building or re-roofing a property. If your roof does not need replacing, a framed system can be installed. This type of system is made up of a number of solar panels that fit into a frame that is then attached to your existing roof. These systems can be also be fitted on flat roofs, façade mounted or mounted on the ground.
What am I getting?
The electricity you currently buy from your energy supplier is sold to you in electrical units. You may pay less for units you consume during the night and more for units used during daylight hours. An electrical unit as itemised on your electricity bill is known as a kilowatt hour (kWh). When you invest in a Solar PV system you are buying a system that produces electrical units for use in your own home. Every unit you produce reduces the amount of electricity bought from your energy supplier and therefore the amount of carbon dioxide released into the atmosphere.
How much electricity can Solar PV panels produce?
A solar PV system is measured in size according to the number of electrical units it would produce in an ideal environment. The smallest system size usually installed on a domestic property is 1 kilowatt peak. In the UK, a 1kWp system is expected to produce at least 750 kilowatt hours every year. The average household in the UK uses approximately 3,300kWh per year. Therefore a 2kWp system will produce nearly half of your yearly requirements and avoid around 650 kilograms of carbon dioxide emissions. With a life span of at least 25 years, a 2kWp system will generate 37,500 kWh and avoid approximately 16 tonnes of carbon dioxide emissions in its lifetime.
What type of system is suitable?
The size and type of system suitable for your property depends on your available roof area and your budget. You should be matching your system to your daily electrical requirements to make best use of the electricity you generate. You should try and plan for any future electricity requirements, given that your system will be operating for at least 25 years. With very low transmission losses, clean electricity will continue to be generated efficiently and reliably.
What are the key considerations for installing Solar PV?
The ideal roof pitch is approximately 30-50 degrees. PV can be successfully installed on a flat roof as there is much scope for the ideal orientation. You will need at least 8m2 un-shaded, exposed roof area facing predominantly south. Chimneys, roof lights or nearby trees can all shade your PV and need to be taken into consideration when deciding where best to position it.
Feed in Tariff
The Feed-in Tariff is a new financial incentive to encourage the installation of micro-generation systems. It has introduced by the Department of Energy and Climate Change and will provide payments through your electricity supplier for each kWh that your system produces (whether you use it or not). For a 4kWp or less retro-fit system the FIT is paid at 12.03p per kWh generated. In addition the export rate will be 4.85p per kWh and you will also save on your bills by using the electricity directly. The tariff is in place for 20 years from installation and is inflation linked. The FIT scheme is subject to continuing changes by the Government so the figures quoted are correct as of November 2015 but the current figures may be different.
4.00kWP system (un-shaded, south facing and 450 pitch)
Generates: 3836kWh per year
FIT paid: 3836kWh x 12.03p = £461
Exported: 1918kWh (assumes 50% exported)
Export payment: 1918 x 4.85p = £93
Used Energy: 1918kWh (assumes 50% used)
Saving on bills: 1918 x 15p = £284 (assumes 15p paid per kWh)
TOTAL POTENTIAL PAYMENT/SAVINGS PER YEAR £838.00
In some instances, you may need to obtain planning consent for your system. This usually applies to listed buildings or those in conservation areas. It is advisable to contact your local planning authority for clarification.
Access to the distribution network
By producing your own electricity you essentially become a supplier yourself. As well as producing electricity for you own needs, there will be times when your system produces more than you need. In this situation, the surplus electricity will be fed into the local network. It is the responsibility of your installer to ensure your system is installed according to existing electrical installation regulations. It is also their responsibility to contact your local Distribution Network Operator to advise that a new solar PV system is being connected in their area. The connection of solar PV to the electricity grid has become standard procedure and your installer will deal with the paperwork.
To find out more call 01223 873640 or contact us through our website.