Solar Thermal Heating
What is Solar Thermal Heating?
Solar Thermal heating systems are a proven and well-developed technology, which has been used for decades alongside conventional water heating systems. They work by capturing the sun's radiation and transferring this heat for use in heating water for households and businesses. With an average of 3-4 kilowatts (kW) hours per square meter of solar energy falling on the UK everyday, it is considered to be one of the simplest and economical ways to utilise solar energy in the UK, especially when you consider that water heating accounts for over 26% of a typical household energy costs.
Average daily light energy through a year for the UK and Eire. Source: World Irridation Centre.
Types of Solar Thermal Panels
The two main types of collectors that can be used in cold climates are flat plate collectors and evacuated tube collectors.
Flat plate collectors
These can either be integrated into a roof or mounted onto the roof or other structure. They consist of a transparent, glazed, insulated and weatherproofed panel Flat plate collectors are less expensive and slightly less productive than evacuated tube collectors, but they are a proven technology.
Evacuated tube collectors
These feature parallel rows of transparent glass tubes that each use a partial vacuum to assist with heat transfer. Evacuated tubes are slightly more efficient, however, they are more expensive, more susceptible to breakage, ineffective after a snow shower. Also, to some people they are less visually pleasing.
How Does it Work?
All Green Energy Doctor solar thermal systems consist of three main components:
Solar Panels (Collectors): are mounted on the roof or other structure. The surface within the panels is coated with a special material made from aluminium oxide. When light strikes the coating it causes the molecules of the substance to vibrate, this is designed to occur in all types of light conditions as well as in below freezing weather conditions. That vibration causes friction, which produces heat, which is absorbed through the collector. In the collector is a system of pipes filled with a heat transfer fluid.
Heat Transfer Loop: The heated fluid is now transported through the pipe work that forms a closed heating pipe that connects to a coil in your domestic hot water cylinder. This is managed by means of a digital controller, which is connected to a pump.
Hot Water Cylinder: The heat transfer system goes straight into the domestic hot water circuit by methods of a second coil in the Hot Water Cylinder. There is a primary coil that is connected to the boiler as a form of back up when solar energy is low or insufficient. The Hot Water Cylinder stores the hot water that heated during the day and supplies it for use later.
Solar Thermal systems produce heat, which is captured and transferred to be used for water heating. 1: Sun Rays, 2: Solar Panel (Collector), 3: Hot Water Cylinder, 4: Boiler, 5: Pump, Controller and Heat Transfer System/Loop
Is It Suitable For My Requirements?
Which system is most suitable for your property or project depends on a number of factors that Green Energy Doctor will take into account prior to designing a solution.
In the meantime, the following gives a good indication of some general principles that should be taken into account when deciding if the technology is suitable, and if so, designing a cost effective Solar Thermal system:
Collector Location
These systems work equally well in any environment (urban or rural) as they can be easily installed on the roof of just about any building. Panels can be roof or ground mounted. Ground panels can be oriented due south, and can easily have snow swept off of it to maximise efficiency, but many buildings lack the ground space needed; in an urban setting, the roof is usually a better option.
Suitable Space
Mounted panels range in size, but for the average three to four bedroom house you would ideally need 4m2 for a flat plate collector or 3m2 for an evacuated tube collector.
Orientation of the Panels
Ideally the collector should be on a roof within 45 degrees of South and with a pitch between 30 degrees and 60 degrees to allow it to absorb the most light.
Shading/Obstructions
Roofs that are shaded for much of the day or are obstructed may not be suitable for Solar Thermal systems. A solar shading analysis would be done by Green Energy Doctor to assess the roof's suitability.
Hot Water Cylinders
It is often necessary to install a twin coil hot water cylinders that forms part of the solar system. With Green Energy Doctor, this will be included in the price of the solar system. These cylinders are generally taller/narrower than single coil cylinders With this in mind it is important to consider additional space required or alternative locations for the cylinder may need to be located.
Pipe Insulation
It is very important that great attention is given to fully insulating the pipelines within the solar loop to prevent unnecessary heat loss when transporting the heat transfer fluid to the cylinder.
Please feel free to call us, send us an email or send us a drawing of your specific project.
What Are The Benefits?
Reduce Your Energy Bills By Up to 19%
In a domestic installation, a well-designed solar thermal system will provide 100% of a households hot water during the summer months and deliver an annual average contribution of approximately 70%. In winter months Solar Thermal can still contribute significantly to your domestic water requirements.
Reduce Your Impact On The Environment
With almost 40% of all UK carbon emissions coming from 24 million dwellings in the UK there are many opportunities to install solar thermal systems to help reduce these emissions. Fossil fuel use has a particular detrimental effect to the environment as when these fuels are burned, carbon dioxide is released into the atmosphere contributing significantly to global warming. Energy from the sun is environmentally friendly. It's clean, it doesn't pollute. A typical domestic solar thermal system will generate 1500kWh of useful heat per year. This equates to a CO2 reduction of between 325kg and 700kg per year depending upon your current fuel type.
Lower Maintenance And Servicing Costs
The technology used is proven and established. The solar collectors are very durable and have no moving parts and as such there is very little that can go wrong with them. Unlike fossil fuel systems there is no need for regular servicing and maintenance is minimal. This means that the actual running costs are reduced further when compared to fossil fuel systems.
Reduce Your Dependency On Fossil Fuel Imports
The sun is a plentiful and free source of energy and is estimated to be secure for the next 4 billion years. This can provide you with the peace of mind that a significant proportion of your energy is under your control and will not increase in price as a result of foreign government actions or the prevailing economic climate.
Easy To Use As A Fossil Fuel System
A modern solar thermal system dovetails seamlessly into your existing hot water heating system and is self regulating, meaning that when the sun is shining it is silently contributing to your energy requirements without you having to lift a finger.
How Much Does It Cost To Install?
The typical cost for a professionally designed and installed domestic flat plate system would cost between £3,500 and £6,000 depending on the system requirements. This system would include the solar water cylinder, piping, insulation, digital controller, pump and commissioning.
The typical cost for a evacuated tube system would cost between £4,000 and £5,000.
Once the technical survey has been carried out, all Green Energy Doctor prices will be given as fixed prices.
How to Get Started...
To organise a no obligation site visit or to start moving your project forward contact the Green Energy Doctor today on:
T: 0845 009 5652
E: info@greenenergydoctor.co.uk