Solar photovoltaic (PV) systems use ultra-violet light from the sun to generate electricity. When installed on or near a building they can be used to run appliances or stored in a battery for later use, for lighting or to charge an electric vehicle, for example.
A PV cell consists of a sandwich of a semi-conducting material, usually silicon, with layers of boron and phosphorous between layers of glass or flexible plastic. When light shines on the cell it causes electricity to flow around a circuit. The greater the intensity of the light, the greater the flow of electricity.
PV systems generate no greenhouse gases in use so saving, in central Scotland, up to the equivalent of 400kg of carbon dioxide emissions per year for each kilowatt peak (kWp*) installed, which is around 5.5m2 of PV modules. If it takes approximately 5 years in Scotland to generate the equivalent of the energy it took to manufacture the system, a typical 2.5kWp domestic system will save around 20 tonnes over its 25-year lifetime.
*kWp - PV arrays are rate in terms of the watts they can potentially generate under standard test conditions of irradiation and cell temperature, typically 250 to 300 watts per module (panel).
PV modules come in a variety of shapes and colours, ranging from grey 'solar tiles' that look like roof tiles to transparent panels that can be used, for example on conservatories, to provide shading as well as generating electricity.
You can install a PV system on a building with a roof that faces within 90 degrees of South, as long as no other buildings or trees overshadow it. If even a small part of the system is in shadow for parts of the day, the output may decrease significantly. The ideal in Scotland is between SE and SW with a slope of around 36O to the horizontal, but it makes little difference if within the range of 25 to 45O. A steeper slope aids cleaning by rain.
The roof must be strong enough to take the solar panels’ additional weight (around 15kg/m2) and the fixings must be substantial enough to withstand the effect of the strongest wind without weakening the roof structure. A structural engineer may be approached for advice if there is doubt.
Solar PV installations should always be carried out by a trained and experienced MCS-accredited installer (see later); they are required to verify that a roof is suitable.
Prices for PV systems vary with the size of the system to be installed, type of PV module used and the nature of the actual building on which the PV is mounted. Scaffolding can be a significant element in a building of more than a single storey. The size of the system is dictated by the amount of electricity required, the space available and of course the owner’s budget.
For a domestic system, a typical size is 4.2kWp which costs on average around £6,500. Panels integrated into a roof will cost more than those that sit on top unless installed as the roof is being built. Solar tiles cost around twice conventional panels.
As installation costs can vary greatly between installers and products, we recommend getting quotes from at least two MCS-accredited installers. Click here for information on finding an installer.
PV systems require very little maintenance, generally limited to ensuring that the panels are kept relatively clean and that shade from trees and other vegetation has not become a problem. The wiring and components of the system should however be checked periodically by a qualified technician. Inverters and, if used, batteries may need replacing before the modules, possibly every 7 to 10 years. The cost of these items continues to fall.
Cut your electricity bills:
In Scotland expect a typical yield of roughly 800 to 900 kWh per year for each kilowatt peak of capacity. A typical 2 kWp domestic system will thus produce around 1,700 kWh, which is around half the annual electricity consumption of a typical household (not electrically heated), but how it benefits financially will depend on how it uses power during the middle of the summer days.
The majority of generation takes place between 10am and 4pm between March and October. Units exported are worth much less than those displacing imported units, perhaps only 4-6p compared to 30-34p. This is a reason to install a smaller system to increase the proportion of power used on site.
For those who are away from home most days or have a larger PV array, or are not mains-connected, it is becoming increasingly attractive to install a battery system, typically with a storage capacity of 2 to 14 kWh, as these continue to fall in price. If you also use an electric vehicle (EV), charging it with stored power can make both even more cost-effective.
Cut your carbon footprint:
Solar electricity is a green, renewable energy and doesn’t release any harmful greenhouse gases or other pollutants. A typical home PV system could save around 1,000kg of carbon dioxide per year – that’s around 25 tonnes over its lifetime.
Sell electricity back to the Grid:
If your system is producing more electricity than you need, or when you can’t use it, your neighbours will use it – and you could receive payment from your supplier via the Smart Export Guarantee (SEG).
For more detailed information about the Smart Export Guarantee, click here.
Always check with your local authority about planning issues before you have a system installed. Most PV installations on roofs and some ground-mounted systems are Permitted Developments, meaning they do not need planning permission, but in conservation areas or on, or near, listed buildings, planning permission is required. Obtaining retrospective planning permission can be difficult and costly.
The Energy Agency is a registered charity established in 1999. We provide free and impartial advice to households, businesses and communities in south west Scotland on:
The Energy Agency is a “data controller” and this document explains how we process your information.
We manage a number of schemes. Please read the scheme below that applies to you.
For all of the schemes we gather your personal information which may include name, address, telephone numbers, email address, date of birth, age, sex, employment status, tenure, benefits, income, savings bracket, bank details, fuel expenditure, fuel type, how you pay your energy bills, third party details, number of dependent children under 18, signature.
Please read below to find out what other information we may collect for each scheme.
*some data is shared anonymously
If we process your information based on your ‘Consent’, you have the right to withdraw your consent at any time. Withdrawing your consent may mean that we cannot provide a service to you.
For the Home Energy Efficiency Programmes for Scotland Area Based Schemes (HEEPS: ABS) we process your information based on ‘Contract’. You will enter into a contract with the Energy Agency in terms of which the Energy Agency will employ and manage a contractor on your behalf. Either party can withdraw from the contract with one months’ written notice.
If you apply for an Energy Agency loan for HEEPS:ABS we process your information based on ‘Contract’. This agreement is between the Energy Agency (lender) and householder (borrower). The agreement is a standard Fixed Sum Loan Agreement regulated by the Consumer Credit Act 1974. You have the right to withdraw under the terms of the above Act.
We take information security seriously and regularly review the systems, policies and procedures we have in place to protect your information and ensure these are implemented.
We will not process your information without your consent. If your data includes “special category data” we will not process this without your explicit consent.
Where we pass information on to a third party, we ensure that this is passed securely and that they have adequate security measures in place to store your data.
We do not share your information with any third parties for marketing purposes.
We will keep your information for:
Schemes – 7 years
Monitoring - 1 year
Financial - 7 years
You have the right to request a copy of the personal information we hold about you. A request can be made verbally or in writing to Liz Marquis, Director, Energy Agency, Watson Peat Building, Auchincruive, Ayr, KA6 5HW
Proof of identity must be established before we supply a copy of your personal information. We will respond to your request within one calendar month of receiving it.
If you are asking about information relating to another person, a relative for example, we need to be sure you have the authority to act on that person’s behalf. Normally this can be done through evidence of a ‘Power of Attorney’ or similar document.
You also have the right to ask us to rectify, erase, restrict, object or withdraw your consent to processing the personal information we hold about you. You can also ask us to provide data in a suitable format to transfer to another organisation – portability. If applicable, we will comply within one calendar month.
If you would like to make a complaint contact:
Information Commissioner's Office
45 Melville Street
Edinburgh, EH3 7HL
Tel: 0303 123 1115
Cookies are text files placed on your computer to collect standard internet information and visitor behaviour information. This information is used to track visits to our website.
Our website contains link to other websites. This Privacy Notice only applies to this website so when you link to other websites you should read their own Privacy Notices.
We regularly review our Privacy Notice to ensure it is up-to-date. This Notice was last updated on 31/8/20.
Your use of the Energy Agency Web Site is subject to these terms and by using the Site you show your agreement to such terms. If you do not accept our terms, please do not use the Web Site.
Ownership of Web Site
This Web Site belongs to Energy Agency, Watson Peat Building, Auchincruive, Ayr, KA6 5HW
Headings used in these terms and conditions are for convenience only and shall not affect their interpretation.
The images, logos and names on this Web Site which identify Energy Agency or third parties and their products and services are proprietary marks of Energy Agency and/or the relevant third parties. Nothing contained in this Web Site shall be deemed to confer on any person any license or right on the part of Energy Agency or any third party with respect to any such image, logo or name.
Energy Agency reserves the right, at any time and without prior notice, to remove or cease to supply any product or service contained on this Web Site. In the event that such removal takes place we shall not be liable to you in any way whatsoever for such removal.
Phone Calls and Emails
Telephone calls using the telephone numbers provided on this Web Site and email correspondence with Energy Agency at the email addresses accessible through, or discernible from, this Web Site may be recorded or monitored. By using such communication methods you are consenting to the recording or monitoring of the same.
The price of calls may vary depending on your telecoms supplier. Please check with your operator for exact charges.
This Web Site is for non-commercial, personal use only. The services contained on this Web Site may be supplied on a commercial basis on payment to Energy Agency or its service or product suppliers of its charges from time to time. Please contact us on Tel: 01292 521896 | Email: firstname.lastname@example.org
In the event that you use any of the services contained on this Web Site for commercial use, Energy Agency shall be entitled to charge you at its applicable rates in respect of such commercial use.
The copyright in the material contained in this Web Site belongs to Energy Agency or its licensed source. Any person may copy any part of this material, subject to the following conditions:
the material may not be used for commercial purposes;
the copies must retain any copyrights or other intellectual property notices contained in the original material;
the products and technology or processes described in this Web Site may be subject to other intellectual property rights reserved by Energy Agency or by other third parties with no license granted in respect of those intellectual property rights); images on this Web Site are protected by copyright as its text by IPR and may not be reproduced or appropriated in any manner without the written permission of their respective owner(s).
Changes to Terms and Records of Agreements
We reserve the right to change these terms and conditions at any time by posting changes on the Web Site. It is your responsibility to review the Web Site terms and conditions to ensure you are aware of the latest terms and conditions. Your use of this Web Site after a change has been posted will be deemed to signify your acceptance of the modified terms and conditions. We recommend that you print off and retain for your records a copy of these terms and conditions from time to time and a copy of any terms and conditions relating to any product or service which you apply for online, together with any related application form completed and submitted.
Any amendment to terms and conditions must be agreed in writing by us, or, if appropriate, by the relevant company or individual supplier with whom you contract.
Whilst Energy Agency has taken due care and attention in the preparation of the contents of this Web Site, this Web Site and the information, names, images, pictures, logos, icons regarding or relating to Energy Agency or our products and services marketed on the site (or to third party products and services), are provided on an 'as is' basis without any representation or endorsement being made and without any warranty of any kind, whether express or implied, including but not limited to, any implied warranties of satisfactory quality, fitness for a particular purpose, non-infringement, compatibility, security and accuracy.
To the extent permitted by law, all such terms and warranties are hereby excluded. In no event will Energy Agency be liable, whether in contract or tort (including negligence or breach of statutory duty) or otherwise for any losses sustained and arising out of or in connection with use of this Web Site including, without limitation, loss of profits, loss of data or loss of goodwill (in all these cases whether direct or indirect) nor any indirect, economic, consequential or special loss.
Energy Agency does not represent that the information contained in this Web Site is accurate, comprehensive, verified or complete, and shall accept no liability for the accuracy or completeness of the information contained in this Web Site or for any reliance placed by any person on the information.
Energy Agency does not warrant that the functions or materials accessible from or contained in this Web Site will be uninterrupted or error free, that defects will be corrected or that this Web Site or the server that makes it available are virus or bug free or represent the full functionality, accuracy, reliability of the materials.
If any of these Terms and Conditions (or any terms and conditions relating to a product or service referred to in this Web Site) should be determined to be illegal, invalid or otherwise unenforceable by reason of the laws of any state or country in which such terms and conditions are intended to be effective, then to the extent of such illegality, invalidity or unenforceability, and in relation to such state or country only, such terms or condition shall be deleted and severed from the rest of the relevant terms and conditions and the remaining terms and conditions shall survive, remain in full force and effect and continue to be binding and enforceable. Nothing in these terms and conditions shall exclude Energy Agency's liability for death or personal injury resulting from negligence of Energy Agency.
Intellectual Property Rights
All Intellectual Property Rights (including, without limitation, all database rights, rights in designs, rights in know-how, patents and rights in inventions (in all cases whether registered or unregistered and including all rights to apply for registration) and all other intellectual or industrial property rights in any jurisdiction) in any information, content, materials, data or processes contained in or to this Web Site belong to Energy Agency or its licensed source. All rights of Energy Agency in such Intellectual Property Rights are hereby reserved.
Jurisdiction and Law
Energy Agency makes no representation that any product or service referred to on or through the Web Site is appropriate for use, or available in other locations. The information and other materials contained in this Web Site may not satisfy the laws of any other country and those who choose to access this Site from other locations are responsible for compliance with local laws if and to the extent local laws are applicable.
These Terms and Conditions and any terms and conditions relating to products or services described in this Web Site shall be governed by and construed in accordance with the law of Scotland. Disputes arising in relation to the same shall, unless otherwise expressly agreed, be subject to the exclusive jurisdiction of the courts of Scotland.
Links to other Web Sites
Certain (hypertext) links, advertisements or suppliers promotion will lead you to Web Sites that are not under the control of Energy Agency. When you activate any of these links, you will leave Energy Agency Web Site by opening a new window and we have no control over and will accept no responsibility or liability in respect of the material on any such other Web Site. By allowing links with third party Web Sites Energy Agency does not intend to solicit business or offer any security to any person in any country, directly or indirectly.
Every effort will be made to carry out the contract but its due performance is subject to cancellation by Energy Agency or to such variation as we may find necessary as a result of inability to secure labour, materials or supplies or as a result of any act of God, War, Strike, Lockout or other labour dispute, Fire, Flood, Drought, Legislation, or other cause (whether of the foregoing class or not) beyond the sellers control.
We have tried to make this website as accessible as possible and easy to use for everyone, regardless of circumstance or ability.
All our page templates comply with the WCAG Priority 2 checkpoints as a minimum requirement. And we make every effort to ensure that all the content on our site meets this standard too. We are making every effort to ensure that we don't exclude any users. For example:
We try to publish all our text content as accessible HTML rather than in other formats such as PDF. Where we do publish PDFs or other formats our policy is to make them as accessible as we can.