Solar panels have been touted as a green alternative to traditional energy sources for decades, but how do they work? Amongst all the hype it can be difficult to know if solar panels are right for your home, and which type would be better suited to your property and the needs of your household. With savings ranging from 40% to 70% off annual energy requirements, solar energy is becoming more and more popular.
It is estimated that efficient solar PV systems could produce up to 80% of the energy needed for a household - however this doesn’t necessarily translate to an 80% saving off electricity bills. There is no escaping standing charges and the PSO levy if you are connected up to the electricity network. Here at Selectra we’ve done the needful and delved deep into the world of solar panels to come up with some answers for you.
It’s always best to keep in mind that if you are looking to lower your energy bills, the easiest and fastest way is by making sure to switch energy provider every twelve months. After that, energy efficiency measures (such as insulation), many of which also benefit from grant support from the SEAI, should be considered
Finally, after such measures have been put in place is really when you should be researching adding a solar panel system, along with fomenting healthy energy habits. In addition if you own an electric car, consider the fact that you can also use solar-powered electricity to charge it by installing solar panels on a car port.
PV Solar Panels
PV (photovoltaic solar panels), convert light into electricity by using material which exhibits the photovoltaic effect. PV solar panels produce electricity, although this electricity can also be diverted to heat hot water cylinders.
What is the photovoltaic effect?The photovoltaic effect is a well-studied phenomenon in physics and chemistry where electric current is created by exposing certain materials to light. Basically when enough light is absorbed by the material, it then becomes “excited” and electrons move around inside the material, releasing energy.
In Ireland, PV solar panels can cost upwards of €4000 for quality system including panels, batteries,and installation, before taking into account any government grants or tax incentives. The more panels you buy, the cheaper each panel is. Electric Ireland’s solar PV offering is priced at €4480 to install 6 solar panels (covering 10 square metres) with a diverter to heat hot water costing €510 (all prices quoted are inclusive of VAT).
The Pros of PV Solar Panels
- We will never run out of solar energy in our lifetime.
- Solar energy is a renewable, green, clean energy.
- Solar power can be harnessed anywhere in Ireland and doesn’t depend on connection to an existing network (such as the electricity and gas networks).
- Solar power can reduce, and depending on your set up, even eliminate your electricity bill (as long as you’re not connected to the grid).
- Solar power should become cheaper as installation and technology costs drop.
- Solar energy can even make you money if you feed in your excess electricity to the grid.
- Panels are normally installed on roofs to make the most of the unused space, but can be installed anywhere that gets regular sunlight.
- Solar panels can last for up to 40 years.
- Solar panels are quiet, unlike generators.
- Maintenance of solar panels is minimal, just ensure they are kept free of debris and that nearby or overhanging trees are trimmed back to keep them from shading the panels.
Fun Fact!According to NASA the sun is going to be around for at least another 6.5 billion years.
- Although initial costs of installing solar energy systems are high, switching to solar should be considered an investment given the longevity of the panels and the potential savings.
- Switching to solar energy will help make Ireland more independent and and reduce the need to import fossil fuels.
- A solar panel system should increase the resale value of your house, as home buyers become more aware of BER (Building Energy Rating).
- The cost of installing a solar panel system could be recovered within 5 - 10 years, or less if grants and incentives have been applied.
- Solar panels are easy to install without causing structural damage to houses.
- Due to the majority of solar panels being located on roofs, they are very unobtrusive.
- Solar panels systems can be easily scaled up as energy requirements increase or decrease, by adding additional panels.
- No planning permission is necessary to install PV solar panels unless your house is a listed property.
- If you don’t have a battery to store surplus energy and are unable, or unwilling, to divert it to the electricity grid, never fear. You can also install a diverter that will send excess electricity to heat your hot water cylinder.
The Cons of PV Solar Panels
- Initial installation of solar PV panels is extremely expensive and can range from €4000 up to €10,000.
- Solar panels cannot produce energy at night time.
- Solar energy is inconsistent and intemperate weather and longer winter nights can mean that being connected to the electricity grid, or having a backup generator, is necessary for when demand is greater than supply.
- Batteries for storing solar energy are expensive.
- PV Solar panels only manage to convert about 20% of the sunlight that falls on them to electricity, so there is definitely room for improvment regarding their efficiency.
- Solar energy is a clean green energy but the process used to make solar panels still emits greenhouse gases.
- Older solar panels are not recyclable, although this may change in the future as they become more commonly used.
- If too much of Ireland’s energy production came from solar power, which by nature fluctuates, a means would need to be found to resolve any instability of supply to the electricity grid.
- Additional equipment, such as inverters, is required to connect up residential solar panels to the electricity grid.
- PV panels are relatively fragile and could be damaged, for example by debris during a storm.
- Considering the size of the initial financial outlay, this makes it imperative to get insurance, further increasing the costs of your PV solar system.
Thermodynamic solar panels
Thermodynamic panels, also known as Solar Assisted Heat Pumps, are designed to produce hot water, unlike PV panels which produce electricity. Thermodynamic panels work by circulating extremely cold (-22°C) liquid refrigerant through the panel. This liquid them absorbs ambient heat from the air outside the panel, and from the infrared rays emitted by the sun.
Once the liquid refrigerant has absorbed enough warmth to increase its temperature by ten degrees, it turns into gas, and exits the panel. This gas is then compressed in the compressor, which produces heat, and is sent through a heating element. The heating element distributes the transferred heat energy into the water in a storage tank. After the heat energy has been transferred, the gas cools and becomes liquid again, and the cycle repeats.
Thermodynamic solar panel system installation can cost from approximately €4500 upwards for panels and installation.
The Pros of Thermodynamic Solar Panels
- Thermodynamic systems tend to come with large storage tanks for hot water and can provide up to 100% of hot water needs.
- Due to the fact that thermodynamic solar panels can absorb heat from the environment, they can be placed anywhere, even in the shade, although for optimal performance it’s best that they are in direct sunlight.
- Thermodynamic panels can continue to heat water even at night, as long as the temperature outside is above -15°C.
- Thermodynamic units will switch off once the stored water has reached a predetermined temperature, usually set to 55°C, in order to prevent dangerously hot water and scalding.
- Thermodynamic solar systems require no maintenance.
- Thermodynamic systems can last for up to 25 years.
- If multiple panels are to be installed, they can be racked to save space.
- Installed thermodynamic systems should add resale value to a house.
- In some cases, thermodynamic heating systems can also be uninstalled and moved to a new house.
- No planning permission is necessary to install thermodynamic solar panels unless your house is a listed property.
The Cons of Thermodynamic Solar Panels
- Unlike combi boilers, which heat on demand, thermodynamic panels require large tanks to store heated water in, which can be quite tricky if space is at a premium.
- It can take approximately 3-4 hours for water to be heated sufficiently from when the unit is turned on. However once achieved, the optimal temperature is then maintained, for a constant supply of hot water.
- In cases where a pump is needed, these hot water systems will require a small amount of electricity, and will cost a household approximately €45-75 a year to run.
- Warranties usually only run up to 5 years so insurance is a must, given the large initial financial outlay.
Solar Thermal Panels
Solar thermal panels directly collect heat from the sun, working on the principle that black surfaces attract heat. Somewhat similar to a dark car, where the heat inside the car can far surpass the temperature outside upon significant exposure to sunlight.
Heat generated in the solar “collector” panel is then transferred to a hot water cylinder. There are two types of these solar collector type panels, evacuated tube solar panels and flat plate panels. Evacuated tube solar panels are up to 20% more efficient than flat panels due to less heat loss and greater efficiency at collecting heat from the sun at different times of the day
Flat plate thermal solar panels start from around €3000 while the more efficient evacuated tube panels can be had for around €2800.
The Pros of Thermal Solar Panels
- Thermal solar panels use no electri+city to run a compressor, unlike thermodynamic panels, and as such have much lower running costs.
- Your water heating bills could be reduced by 70%.
- Some thermal solar panel suppliers provide warranties on parts and labour of up to 20 years.
The Cons of Thermal Solar Panels
- Must be installed on a South-facing roof.
- Much like with Thermodynamic panels you need space for the solar hot water cylinder.
- Thermal solar panels provide much more hot water in summer than in winter.
- Normally cannot meet 100% of a household’s hot water needs.
There is plenty of help available if you’re looking to hop on the solar bandwagon. Grants are available towards PV panels and storage batteries, to the tune of €700 per 1KW panel, capped at €3800. Batteries can also benefit from a grant of €1000 per unit. You can also offset some (around 13.5%) of the 23% VAT on your solar panels through your taxes over two years through the Home Renovation Incentive Scheme.
For more information on grants that you may be eligible to receive for installing solar panels, check out our section on SEAI solar grants.
As we can see there are various advantages and disadvantages to each type of solar panel. It is also plain to see that Ireland needs to take steps to move towards more sustainable and renewable methods of energy generation. The prices of electricity and gas in Ireland continuously trend upwards year after year, decade after decade. Ask yourself, is this a trend you want to continue being a part of? Or would you rather opt out altogether?
This is what harnessing solar energy can represent to your household. In addition, installation of solar panels of any type is minimally invasive and can even be finished within a 24-hour period. Conservative estimates of savings for PV panels show €250 a year in energy savings, which means for a basic system (keeping in mind that basic systems may not net you a €250 annual saving) it would take 14 years to pay for itself.
We recommend switching energy providers every 12 months as this can easily save you a few hundred Euro a year. Then with the addition of solar panels, and increasing your household’s energy efficiency, you could more than halve your present energy spend.
To get the most bang for your buck, when opting for solar panels it seems quite clear that Solar PV panels are the way to go, as not only can they greatly contribute towards fulfilling a household’s energy needs, with a diverter hot water bills can also be greatly reduced.
After Solar PV we have thermodynamic panels, which in theory appear much more efficient than solar thermal panels. However some studies have shown issues with Thermodynamic panels so if investing in them, make sure to invest in high-quality well-reviewed, and tested models.
The main issue with thermodynamic panels and solar thermal panels is that they are a very expensive solution for just heating water. If your house is energy efficient enough a hot water heat pump (which costs around €3500 to install) may be a better solution.
Solar Panels for Sale in Ireland
Below you can find a round up of the main solar panel suppliers in Ireland. Interestingly, Ikea have also started selling solar panels in the UK, but as of yet haven’t planned a roll out for the Irish market.