Mark Chewter of Plug In Solar explains why solar energy remains a great investment, and how a solar PV system can be used to help you meet Building Regulations, while saving money on your self-build home’s future bills
With an average of 4,000 solar panels being installed in the UK each month, and in an era of increased environmental awareness, it’s clear to see why solar energy is such a popular option for self-builders.
Solar energy, often termed ‘Solar PV,’ is an easy-to-install, cost-effective, clean source of energy, making it particularly suitable for those building their own homes. Solar PV is also a great investment as most installations have an average return on investment (ROI) period of between 6-10 years.
As the summer approaches, many self-builders will be turning their attention to solar energy as a way to help power their new homes, and reduce their carbon footprint.
CAN I INSTALL MY OWN SOLAR PV KIT?
Out-of-the-box solar PV kits can be delivered directly to site, and include everything required to complete a solar PV installation using on-site roofers and electricians.
Without the need for a specialised installation team, an off-the-shelf solar PV kit can typically be installed, and signed off, in under two days. This reduction of on-site labour results in simplified project management, increased construction speed and ultimately reduced build costs.
As with any other building materials, it’s paramount that self-builders only source solar PV equipment from reputable suppliers. Each piece of equipment must have the necessary MCS and G98 certifications to ensure all necessary legislative and regulatory requirements are met.
Moreover, it is compulsory that all work complies with the latest edition of the roofing and electrical regulations and the appropriate certificates are issued by the relevant contractors in order to meet Part L of the Building Regulations.
DO I NEED PLANNING PERMISSION FOR SOLAR PANELS?
In England, Wales and Scotland, the large majority of domestic solar panel installations will not need planning permission, as they fall under permitted development.
There are, however, restrictions for certain types of domestic solar installations, such as those mounted on the ground or on a flat roof, as well as constraints on installations over 4kW. In these instances, planning permission must be granted prior to an installation. Furthermore, if a self-build is to be situated in a national park, conservation area, World Heritage Site, or Area of Outstanding Natural Beauty (AONB) specific planning permission guidelines will need to be followed.
If you are in any doubt, contacting the planning department of your local authority or visiting the online planning portal is advised.
HOW MANY SOLAR PANELS WILL I NEED TO INSTALL?
There are four key areas to consider when choosing the correct size solar PV installation for your self-build:
HOW MUCH ELECTRICITY WILL BE USED
Each self-build home will require a specific amount of electricity to power all the appliances in the property each year. The latest OFGEM figures show that an average UK household uses 3,731kWh of electricity per annum. Based on the latest solar performance estimates from the National Renewable Energy Laboratory, a 2.25kW solar PV kit would generate enough electricity to cover 50 per cent of the average UK consumption each year.
THE SIZE OF THE AREA WHERE THE PANELS WILL BE INSTALLED
Solar panels can be installed on tile or slate pitched roofs, flat roofs, metal or wooden roofs, and on the ground. The number of panels a self-builder can install may be limited by the available area, but with well thought-out design, it is generally possible to achieve an effective solution. Generally, installing the solar panels on a south facing elevation at a 35-degree angle will result in optimal performance.
Ultimately, budget will dictate the size of the solar PV kit that can be installed. A lower budget will require a compromise on the number of panels that can be installed, resulting in less energy being generated. However, it is still possible to realise significant energy savings with small solar installations, if designed correctly.
Ideally, if the budget is favourable, it is worth increasing the number of solar panels. This will maximise the amount of solar energy generated, resulting in bigger financial savings and a faster ROI time. Some solar PV kits are modular in nature, making it possible to buy the kits incrementally, helping to spread the purchase cost across a few months/years.
PART L BUILDING REGULATIONS AND SAP CALCULATIONS
All self-builds have to meet Part L of the Building Regulations (‘Conservation of Fuel and Power’), part of which is passing the Standard Assessment Procedure (SAP) calculations. Along with equipment such as energy efficient windows, solar PV is a cost-effective method of meeting these requirements. As factors will differ from build to build, opening a dialogue with your SAP assessor regarding the use of solar PV is recommended at an early stage of the build process.
CAN I ADD BATTERY STORAGE?
The pairing of solar PV and battery storage is becoming more common practice in self-builds, and if implemented correctly, electricity bills can be reduced further using this method. Battery systems work by storing surplus electricity from the solar PV system, and allowing it to be used at a later time rather than exporting it back to the National Grid.
For homeowners who will not be at home during peak sunlight hours, battery storage can be worthwhile if specified and executed properly. However, at present battery storage technology is expensive, and when coupled with the fact a battery storage system may need to be replaced 5-15 years after installation (depending on the technology), doing a cost/benefit analysis is imperative before embarking on this approach.
Mark Chewter is managing director of Plug In Solar