By: John Gibbons

When most of us think of solar panels, we think of warm sunny Continental climates rather than our own dull and rather damp Irish weather. However, the amount of solar energy reaching Ireland is roughly the same as other countries in Northern Europe.

This means Ireland is just as suitable for solar heating as Germany and Austria, which are two of the largest markets for solar in Europe.

So what is solar heating and how does it work?
Solar heating can provide up to 60% of domestic hot water throughout the year. A widely-held misconception about solar systems is that they will heat your home as well as providing hot water. This is not true. Solar systems are designed to provide domestic hot water only to your home. If you also want to heat your home, you will have to use a solar system in conjunction with other systems such as heat pumps, wood pellet boilers etc.

Almost everyone is familiar with the large solar panel “collector plates” which are situated on the roofs of many homes in Continental Europe. The idea of being able to heat our domestic hot water supply in this country using energy from the sun seemed almost a Utopian concept until the Irish Government introduced grant aid for the installation of renewable energy heating systems.

There are two main types of solar collector:

• Evacuated tubes
• Flat Plate Collectors

Solar heating is potentially suitable to almost every home in Ireland and can be installed with minimum disruption. For domestic hot water there are three main components to installing a solar heating system; solar panels, a heat transfer system and a hot water cylinder.

First, solar panels – known as collectors – are fitted to your roof. They collect heat from the sun’s radiation. The heat transfer system used the collected heat to heat domestic hot water. The hot water cylinder stores the water that is heated during the day and supplies if for use later.

If you want to install a solar heating system, ideally you will need  2-4m square of southeast to southwest facing roof receiving direct sunlight for the main part of the day. You will also need space in your hot press/utility room for a hot water cylinder.
The typical installation cost for a solar heating system varies greatly, but you could expect to pay anywhere from 3.000 to 5.000 euros to have the complete system installed.

If you are considering a solar system, make sure to log onto the Sustainable Energy Ireland website (www.sei.ie) website to see a list of registered installers in your area. If your solar system is not installed and commissioned by an SEI-registered installer you will not qualify for Government grant-aid,

Solar heating system usually come with a 10-year warranty and require very little maintenance. The householder will usually be required to carry out a yearly check on the collector plates, and more detailed checks will generally be carried out every three to five years by the installer. However, our temperate Irish climate means that very little is likely to go wrong with the system.

When considering a solar heating system, it is worth remembering that, by 2009, all residential properties for sale or rent on the Irish market will be required to have a building energy rating. By installing a solar heating system you will automatically have a higher energy rating which will increase the value of your home.

Installing a solar system is worth considering, but bear in mind that it will not provide the complete solution to all your home heating needs. Yes, you will have free hot water all summer long (after paying the initial installation costs) and you will get around 15% of your domestic hot water heated by solar energy during the winter.

However, you will also have to explore all the other options, and part with a lot more of your hard-earned cash, to ensure that you have heat in your home – as well as in your taps – during those long cold Irish winter nights.

Sustainable Energy Ireland was up until September 2007 grant-aiding solar heating systems to the tune of 300 euros per square metre of solar panel. Given that a standard system will typically have two panels on your roof; a 300 litre insulated tank and a pump between the two, this amounted to 1,200 to 1,500 euros off the cost of installation.

However, in the revised Greener Homes scheme just announced, the grant has been reduced to 250 euro per square metre for panels.

Did you know?
Sustainable Energy Ireland (SEI) has calculated that one square metre of solar collector is the equivalent of more than 100 litres of free oil every year. This means that a typical installation is the equivalent of between 400 and 500 litres of free oil over the course of a year! Apart from the cash savings, that’s quite a lot of CO2 that you won’t be emitting as a result of your new solar panels.

In a typical Irish summer, a solar heating system can heat all the water you use at no extra cost. This means you can turn your boiler and immersion off between April and September. In the winter it will heat around 15% of your water and you will need to use a boiler or immersion to heat the rest.

The average person uses between 40 and 60 litres of water per day. The size of the solar heating system you use will therefore depend on the number of people in your house and the demand for hot water. A 300 litre water tank with two solar panels would be sufficient for up to approximately six people.

Smaller water tanks can be used, but it is worth remembering that solar heating is most efficient when it has a large supply of water in which to store the energy.