Frequently Asked Questions
- General FAQ
- Photovoltaics FAQ
- Solar Thermal FAQ
- Air Source Heat Pump FAQ
- Wind Turbine FAQ
- Wood Pellet Stoves
What is the Building Energy Rating?
The Building Energy Rating, BER in its most basic terms is the amount of energy required per meter squared of property to bring it up to a required level. Sustainable Energy Ireland has developed a method of rating a property using what they call the Dwelling Energy Assessment Procedure (DEAP), where they go through a series of tests to determine the overall energy requirement for the entire property would be. The BER is determined based on the energy required per meter squared compared against the BER-chart
New regulation states that all dwellings that apply for planning permission after 1st January 2007 need a Building Energy Rating (BER) certificate before they are offered for sale, BER certificates are valid for 10 years and all dwellings will require this certificate if offered for sale or rent after 2009.
Photovoltaic FAQ
- What does photovoltaic stand for?
- How do photovoltaic (PV) panels work?
- Does PV work in Ireland?
- Isn't solar power expensive?
- Why should I use photovoltaics (PV)?
- What are the components of a photovoltaic (PV) system?
- How do you know that the system is taking power from the panels and not the grid?
- What maintenance and cleaning do the systems need?
- What is the lifetime of PV modules?
- What is the output of the PV modules?
- How can PV affect the Building Energy Rating (BER) of my home?
- What effect will a Photovoltaic installation have on the BER?
- What effect does PV have on the energy rating of a domestic home?
- How much electricity does a standard domestic house use?
What does photovoltaic stand for?
First used in about 1890, the word has two parts: photo, a stem derived from the Greek phos, which means light, and volt, a measurement unit named for Alessandro Volta (1745-1827), a pioneer in the study of electricity. So, photovoltaic (PV) could literally be translated as light-electricity. And that's just what photovoltaic materials and devices do; they convert light energy to electricity. This phenomenon is known as the Photoelectric Effect.
How do photovoltaic (PV) panels work?
Sunlight is made up of photons, and when it hits the semi-conductor metal of the PV panel, electrons are released; these electrons form a direct current. People have been using PV for years; your pocket calculator for example typically has a number of PV cells. NASA has been using and developing this technology for years, satellites and other space going bodies rely on this technology to produce the power in order to run.
Does PV work in Ireland?
There is an opinion out there that Solar technology would not work in Ireland, this stems from people thinking that we don't get enough sunlight in the Summer, never mind the Winter.
This however is not true, photovoltaic cells work on sunlight as opposed to the heat from the sun. In fact, Ireland has the same annual Irradiation levels as many parts of Central Europe, ranging from 1200 kWhr/m2/yr in the South of the country to 1000 kWhr/m2/yr in the North of the country, a good average for the entire country is 1100 kWhr/m2/yr.
If you consider our typical winters would not be as bad as many parts of Central Europe, Irelands mild climate is ideal for Solar installations, as we never get too hot or too cold and we have good light levels for a large part of the year.
Isn't solar power expensive?
A solar installation adds as little as 4% to the build cost of an average three bedroom home, but over 10% to its final value when sold. It also helps 'future proof' a home against rising fuel prices making properties doubly attractive to price conscious house buyers; as fuel prices continue to rise, energy efficient renewably powered homes will continue to sell at a premium.
Although the initial investment may seem quite large, once the system is installed it would provide free electricity for the life of the product.
Why should I use photovoltaics (PV)?
The number of PV installations is fast increasing in Ireland due the many advantages associated with this technology.
- Meet new regulation - From January 2008 new legislation states that 40% of your energy requirements must come from renewable sources in order to be granted planning permission. Installing PV will allow you to meet this new legislation.
- Increase the value of your property - for new builds PV can add as little as 4% to the cost of your home but once installed can increase the value of your property by up to 10%
- Environment - PV systems create no pollution and generate no waste products when operating.
- Maintenance - PV systems require no maintenance.
- Durability - Our PV modules are based on a proven technology, as a subsidiary of CareyGlass International we work hard to protect our reputation and always offer only top quality products and stand over all of our installations.
What are the components of a photovoltaic (PV) system
A PV system is made up of Photovoltaic Modules, usually roof mounted. Wiring from the PV array to an Inverter, this changes the PV generated DC current to AC current, matching the ESB grid supplied electricity. It is because of these inverters that we can grid connect seamlessly, without a need to switch from one power source to another. The inverter then connects directly into your Distribution (Fuse) Board to be used by your domestic appliances.
How do you know that the system is taking power from the panels and not the grid?
The system will take power from the PV panels "first" naturally and will only draw power from the grid if there insufficient power available from the PV panels. The flow of electricity in a system is determined by the electrical potential at all points in the system. The simplest analogy is to think of the flow of electricity in a network of conductors connected to the grid as being like the flow of water through a network of pipes connected to a water main. If there is more pressure in the network of pipes than in the water main, water will flow out into the water main - and vice-versa.
What maintenance and cleaning do the systems need?
Solar photovoltaic systems have no moving parts and require no maintenance whatsoever.
What is the lifetime of PV modules?
PV modules have a manufacturer's warranty of 25 years and a working lifetime of 40 years and beyond. As the photovoltaic effect is a naturally occurring phenomenon, there is nothing to say that the panels will not continue to create electricity for as long as they are in sunlight. A PV system that is designed, installed, and maintained well will operate very efficiently for at least 25 years. The best way to ensure and extend the life and effectiveness of your PV system is to purchase quality components from a reputable company who will guarantee that your system is correctly installed and commissioned.
What is the output of the PV modules?
The CareyGlass Solar standard module is 165 watts, our installed arrays are typically producing 1,100kWh per kWp per annum.
How can PV affect the Building Energy Rating (BER) of my home?
Market research in the UK has shown that properties with a good energy rating and using renewable energy sources achieve better market value. With the recent introduction of the Building Energy Rating Scheme by the Irish government, this trend is without a doubt going to be reinforced. With current trends in the Irish property market the installation of renewable energy and having a good BER rating may be the deciding factor between one house and the next.
What effect will a Photovoltaic installation have on the BER?
The SEI have stated that introduction of micro-generation has the single greatest effect on the energy rating; it is also considered one of the only ways to get up to an A1-rating. The reason it has such a great effect is because when micro-generation is introduced into the building envelope it reduces the Primary Energy rating of the building. The Primary Energy is the amount of energy that the energy supplier, in this case the ESB, has to produce in order to supply the dwelling.
Grid electricity has a very high energy and greenhouse gases content due to the inefficiency of centralized power plant using fossil fuels like peat, coal, oil, etc. and high distribution losses. So for every 1 kW of electricity used in your home 2.7 kW of electricity needs to be produced by the ESB, this 2.7 kW is passed directly onto your homes BER. Conversely the introduction of 1 kWp of PV has a minus 2700 on the DEAP result, which makes up the BER.
By comparison, photovoltaic energy is produced on site using sunlight, a free clean and inexhaustible source of power. Investing in PV is one of the best ways to reduce the carbon footprint of your property.
What effect does PV have on the energy rating of a domestic home?
As mentioned above, PV has a hugely positive impact on the Building Energy Ratings of a house. The primary energy rating of the house is greatly affected.
Consider the new regulations for Fingal County Council where the maximum allowable energy requirement per meter squared is 60 kWh/m2/yr on a dwelling of 120 m2. So the building energy rating for this dwelling is A3.
The introduction of a Photovoltaic array of size 1.65 kWp will result in a new BER rating of A1.
How much electricity does a standard domestic house use?
An average house is considered to be 150m2 /1,614sq ft and uses approximately 3,300 kWh of electricity per annum. An energy efficient house uses approximately 1,960kWh per annum. A 1kWp system generates 1,100kWh of electricity per annum (statistics from CareyGlass Solar's existing installations in Ireland).
Solar Thermal FAQ
- How are hot water requirements calculated and how is the solar water heater sized?
- What is the average size of a solar panel?
- What percentage of the hot water requirements will be covered by the solar panel?
- Is the location of the solar panels (orientation, tilt, visual aspect) appropriate?
- Is there any disruption of the building structure required to install the system?
- How is back up heating provided?
- Can the solar collector heat water to a high enough temperature? What happens when there is negligible solar power available?
How are hot water requirements calculated and how is the solar water heater sized?
The hot water requirements are calculated by taking into account the number of people living in the house and the size of the hot water cylinder. Each person living in the home is calculated at 50 litres per day. The solar panel is then sized to heat the size of the cylinder, taking into account the average climate conditions and the orientation of the roof; south, south east or south west.
What is the average size of a solar panel?
In general the size of a solar panel in based on the number of people in the household.
What percentage of the hot water requirements will be covered by the solar panel?
Up to 70% of the annual hot water requirements will be delivered free of charge and 100% in summer time.
Is the location of the solar panels (orientation, tilt, visual aspect) appropriate?
Yes. The panel should be mounted at 40% (typical roof tilt) and be south, south east or south west facing. If the house has a flat roof a special mounting kit is provided to ensure the correct tilt. The panel is surface mounted.
Is there any disruption of the building structure required to install the system
Minimal disruption is caused on the roof as the unit is fitted on the surface. A Dual coil cylinder is sited in the house unless the existing cylinder is used. This will require some pipe work. The entire installation takes approximately one day.
How is back up heating provided?
Back up heating is provided by any other means such as gas or oil boiler, heat pump or wood pellet stove. The cylinder is fitted with an immersion heater for use when the boiler is not required.
Can the solar collector heat water to a high enough temperature? What happens when there is negligible solar power available?
Yes, the solar collector can heat the water to a high enough temperature. In good weather it can even bring water to a boiling point. Generally this is not necessary and so the system should be designed to provide a daily temperature rise of around 25-30oC (45-54oF) in the summer. Sizing a domestic system that can bring the cold water up to 60oC / 141oF in a single day is not logical, because if hot water is not used for one day, the following day the system will be boiling and dumping hot water via the temperature relief valve. This is both a waste of energy and water! If the external conditions are overcast the water in the cylinder will be automatically heated by the alternative heat source to the required temperature.
Air Source Heat Pump FAQ
- How do air source heat pumps work?
- The benefits of air source heat pumps
- What are the environmental aspects to a heat pump?
- Can I use a Heat Pump with radiators / under floor / air blower heating?
- Can you produce hot water?
- How noisy are heat pumps?
- If the temperature drops below zero will my Air Source heat pump work?
- What is the COP?
- Does my heat pump need servicing?
- Can a system be placed in an old building?
- Is an air source heat pump a viable option for me?
How do air source heat pumps work?
An air source heat pump extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can extract heat from the air even when the outside temperature is as low as minus 15° C.
The benefits of air source heat pumps
One Bill – An air source heat pump runs on electricity, so there's no need to pay for gas, oil or solid fuels to heat your home. You eliminate the standing charge for mains gas supply, delivery charge for oil and solid fuel, etc.
Save space – An air source heat pump system is compact, and requires no storage space for fuel.
What are the environmental aspects to a heat pump?
Heat pumps are very environmentally friendly, they have no emissions and up to 80% of the energy is renewable. If you decide to use a heat pump in conjunction with a Solar PV or Wind system as your electric source up to 100% of the energy that you will be using will now be renewable.
Can I use a Heat Pump with radiators / under floor / air blower heating?
Standard radiators operate with water temperatures of 60°C to 70°C. Under floor heating and air blower systems can operate at temperatures as low as 40°C. Heat pumps are far more efficient when operating at these lower temperatures however you can still use an air source heat pump to contribute greatly to the energy requirement of the heating system when using radiators.
Can you produce hot water?
Just like your standard oil or gas system your Heat Pump will heat the hot water cylinder in conjunction with the home heating.
How noisy are heat pumps?
Heat pumps are generally very quiet, noise levels equivalent to that of a fridge. As the pump is outside it is very rare that this is noticed in the house at all.
If the temperature drops below zero will my Air Source heat pump work?
Yes, CareyGlass Air Source heat pumps can operate efficiently down to temperatures as low as -15°C.
What is the COP?
The COP or coefficient of performance is a term used to measure the efficiency of a heat pump. It is the ratio of heat delivered by the heat pump and the electricity supplied to generate this heat. A normal COP would be in the region of 3:1 to 4:1 meaning 1kW of electricity to get 3/4kW of heat.
Does my heat pump need servicing?
No. We recommend that you monitor the control unit to ensure that it is operating within normal parameters but usually there is no need for regular servicing.
Can a system be placed in an old building?
Yes, systems have been installed into all types of building that are working effectively. More engineering design is required on older and complex buildings than newly constructed buildings and we will be happy to specify the system best suited to you.
Is an air source heat pump a viable option for me?
Air source heat pumps are easier and cheaper to install than other heat pumps. Usually the COP of an air to water heat pump can be a little lower than ground source. However with the advances in the technology together with the Irish climate people should expect to see average COP's of 3.3 to 3.8.
Wind Turbine FAQ
- What speed does it need to achieve to produce maximum output?
- Do I need planning permission for a wind turbine?
- What cleaning and maintenance does the turbine require?
- Where should I position my turbine?
- How much electricity does a standard domestic house use?
- What are the components of a Wind Turbine system?
- What effect will a Wind Turbine have on the BER?
- What effect does a Wind Turbine have on the energy rating of a domestic home?
What speed does it need to achieve to produce maximum output?
For the Vertical Wind Turbine: Cut in speed: 4 m/s (9mph), to produce full output: 10.3 m/s (23 mph) and will continue to produce up to 71.1 m/s (159 mph) (Grade 2 hurricane).
For the Horizontal Wind Turbine: Cut in speed: 2.5 – 3.5 m/s (5.6 – 7.8 mph), to produce full output: 12 – 13 m/s (26.8 – 29.1 mph) and will continue to produce up to 39 m/s (87.2 mph).
Do I need planning permission for a wind turbine?
All of the CareyGlass Wind Turbines meet eh following planning exemption regulations:
- Height below 13m
- Noise level less than 43 dbA
Taking the above into account, as long as the turbine is placed 13m or more away from the nearest boundary of the property then planning permission is not required.
What cleaning and maintenance does the turbine require?
Our turbines do not require any cleaning. We recommend a full turbine check and maintenance every 5 years.
Where should I position my turbine?
The Wind Turbine should be installed not only in a high-wind area, but also far enough from buildings, treetops, fences, etc.
The image below shows how wind obstructions may act and the way to avoid them.
How much electricity does a standard domestic house use?
An average house is considered to be 150m2 /1,614sq ft and uses approximately 3,300 kWh of electricity per annum. An energy efficient house uses approximately 1,960kWh per annum. A 3kW Vertical Axis wind turbine system generates 6.6kWh of electricity per annum (statistics from CareyGlass Solar's existing installations in Ireland).
What are the components of a Wind Turbine system?
A Wind Turbine system is made up of the wind turbine itself, installed on a concrete base. Wiring from the turbine to an Inverter, this changes the turbine generated DC current to AC current, matching the ESB grid supplied electricity. It is because of these inverters that we can grid connect seamlessly, without a need to switch from one power source to another. The inverter then connects directly into your Distribution (Fuse) Board to be used by your domestic appliances.
What effect will a Wind Turbine have on the BER?
The SEI have stated that introduction of micro-generation has the single greatest effect on the energy rating; it is also considered one of the only ways to get up to an A1-rating. The reason it has such a great effect is because when micro-generation is introduced into the building envelope it reduces the Primary Energy rating of the building. The Primary Energy is the amount of energy that the energy supplier, in this case the ESB, has to produce in order to supply the dwelling.
Grid electricity has a very high energy and greenhouse gases content due to the inefficiency of centralized power plant using fossil fuels like peat, coal, oil, etc. and high distribution losses. So for every 1 kW of electricity used in your home 2.7 kW of electricity needs to be produced by the ESB, this 2.7 kW is passed directly onto your homes BER. Conversely the introduction of 1 kW of Wind Generated power has a minus 2700 on the DEAP result, which makes up the BER.
By comparison, wind energy is produced on site using wind, a free clean and inexhaustible source of power. Investing in wind power is one of the best ways to reduce the carbon footprint of your property.
What effect does a Wind Turbine have on the energy rating of a domestic home?
As mentioned above, wind generated energy has a hugely positive impact on the Building Energy Ratings of a house. The primary energy rating of the house is greatly affected.
Consider the new regulations for Fingal County Council where the maximum allowable energy requirement per meter squared is 60 kWh/m2/yr on a dwelling of 120 m2. So the building energy rating for this dwelling is A3.
The introduction of a Wind Turbine of size 1.6 kW will result in a new BER rating of A1.
Wood Pellet Stoves FAQ
- How does a wood pellet stove work?
- What are Wood pellets?
- What are the benefits of wood pellets?
- Where will I store my wood pellets?
- What are the running costs of a wood pellet stove?
- What size stove will I need for the area am I heating?
- Where will I locate my stove or stove with back boiler?
- What about the flue/chimney?
How does a wood pellet stove work?
Our stoves burn small wood pellets at a regulated rate to produce space heating and\or hot water. The pellets are loaded into the stove by pouring them into the tank behind the hearth. This tank can hold over 15kg of pellets. The pellets are collected by a worm screw and fall freely into the combustion chamber where ignition is carried out with an electronic trigger. So there is no need for matches or firelighters. The stove is controlled by a microprocessor on a circuit board, which is connected to various sensors and probes within the heater and which adjusts the air flow and the fuel feed in order to optimize combustion.
What are Wood pellets?
Wood pellets are small pellets of compressed saw dust.
Simply put saw dust is a by product of other more lucrative wood processing. This saw dust is dried to specified moisture content, and compressed by a very high pressure machine. Generally no glue or binding agent is required other than the sap from the timber itself.
What are the benefits of wood pellets?
- They are easy to transport
- They are clean
- They comply with standards
Where will I store my wood pellets?
It is best to store your pellets in a dry enclosed area. This applies to all fuels. Generally your garage or outside shed will be sufficient.
What are the running costs of a wood pellet stove?
The unit is electrically ignited which consumes a small amount of power. The fan also running consumes a small amount of electricity. Wood Pellets currently cost around 1/3 less than oil and gas on an annual basis.
What size stove will I need for the area am I heating?
The following points must be determined before a stove size can be recommended. Ideally, it’s important to know the area of the room or house in square feet or metres. In addition, an approximate idea of the ceiling height would also be helpful. Factors such as very high ceilings or large open plan rooms do affect the calculation of the area you are intending to heat. This is important as it is needed to determine what output you will require for the stove or combination stove and back boiler.
Where will I locate my stove or stove with back boiler?
For a stove you can locate it in any room in the house. Remember that it has a glass front, so usually it’s located in a living room or kitchen.
For the stove with back boiler, these also have a glass front, giving heat to the room that they’re located in, so again keep this in mind. There will be some plumbing works to consider also when choosing a location for this stove. Both of these will also need a power point.
What about the flue/chimney?
According to current building regulations, a flue outlet must be located a minimum of 1.6 meters from a door or window.
For a stove you have the option of either going up an existing chimney with flexible flue liner, or making a hole in the wall and erecting a ‘low-level outlet’ flue here. It’s important to keep in mind the proximity to a window or door of the top of this outlet, because of the current building regulations. It may be necessary as a result to take this erected flue up past the eave of the house.
Head Office: 1890 252 412
Dublin Office: +353 (0)1 6642876
Cork Office: +353 (0)21 4355790