Solar
Solar Panels, also known as "collectors", can be fitted to a building’s roof. They use the sun’s heat to warm water, or another fluid, which passes through the panel. The fluid is then fed to a heat store (e.g. a hot water tank) and helps provide hot water or a source of hot water for central heating for the building. Solar panels work throughout daylight hours, even if the sky is overcast and there is no direct sunshine. Solar panels can also be used to contribute to space heating demand. The cost of a professionally installed solar system for heating hot water can vary greatly. If you are considering investing in this technology you should do sufficient research to ensure that you are getting the best system for your needs and value for your money.
Location - The optimum location for solar panel collectors for all year round energy collection is roughly south facing and at a tilt angle of 30°- 45° to the horizontal (however angles between 15° and 60° are also acceptable). It is also important that the collectors are positioned so there are no shadows on them during the middle of the day. Shading can be from the collectors themselves, or from trees, chimneys, part of the building or adjacent buildings.
Cylinder – An appropriately sized cylinder should be chosen for the house. The volume of your solar hot water cylinder is related to the maximum cylinder temperature. It is recommended that at a maximum cylinder temperature of 60°C, 70 litres per square metre of aperture area is supplied and at a maximum cylinder temperature of 80 – 90 °C, 50 litres per square metre of aperture area is supplied. Smaller capacities will limit the benefit from the system and may lead to frequent overheating of the solar circuit. Generally Dual Coil cylinders should be used, having the coils at the top and bottom of the cylinder. The solar collector circuit should be connected to the bottom coil and the auxiliary circuit to the top coil, which will enable the solar system to pre-heat in bad weather. Your installer will be able to help you choose an appropriately sized cylinder.
Thermal Mixing Valve (Anti-Scald Valve) - Best practice calls for the fitting of a thermal mixing (anti-scald) valve. This applies to all hot water systems and not just solar heated water systems. With the current recommendation to store hot water at 60°C to prevent the growth of legionella bacteria it is becoming more of a consideration to install thermal mixing valves. A thermal mixing valve mixes cold and hot water together to ensure the water temperature is safe for people to use.
Controller – After commissioning, a permanent power supply should be provided for the solar controller to ensure circulation in the solar loop.
A solar water heater is composed of:
A solar collector (flat plate or evacuated tube) which absorbs solar radiation (sunlight) and changes it into heat;
A pump which transfers the heat from the collector to hot water in a storage tank;
The storage tank accumulates the hot water produced by solar energy so that it can be stored for use when needed;
A number of accessories which ensure the regulation and the safety of the system;
A back-up heater (gas, oil, or wood fuelled boiler, immersion heater or heat pump) which will bring the hot water to the temperature required when there is not enough sunlight to do so (mostly in winter).
In Ireland, solar collectors alone cannot provide all the hot water for a household’s needs throughout the year. Correctly sized they will supply 60% of heat / domestic hot water needs. They are normally installed in conjunction with a conventional back-up heating system.
Planning Permission for Solar Panels
The installation of solar panels in your home is exempt from planning permission up to 12m2 or 50% of the total roof area as per Statutory Instrument No. 83 of 2007 Planning and Development Regulationssigned and implemented by Dick Roche, the Minister for the Environment, Heritage and Local Government on the 28th February 2007. Contact you local planning authority if you are unsure of the local planning requirements.
Click here to download our brochure on Solar Water Heaters
Click here to download our brochure on Solar Central Heating
Click here to download our Buyers Guide to Solar Water Heaters
Click here to download our Homeowners Installation Guide for Solar Panels
Click here to download the Solar Products List