In this article we cover:
- How much do PV panels cost
- What are the different types of PV panels
- Inverter types
- Fixings and cablings
- Battery storage systems
- Monitoring systems
- How solar panels are rated
- How to compare solar panels
PV systems convert sunlight into electricity using semiconductor materials. For a typical residential installation in Ireland, where sunlight levels are moderate but now viable for solar energy, costs will vary depending on system size, supplier and set-up.
Your quote will include all of the elements you need for a PV installation, including panels, inverter, wiring/cabling and monitoring system.
Judging by online quotes in ROI, a 4.4 kWp system (about 10 panels) costs around €5,500-€7,300 after the grant depending on technology option progressed, supplier warranty etc. One quoted €7,500 for a 10-panel system, €5,700 after the grant.
An installer in ROI says you can budget around €6,500 €8,200 after the grant for a complete array on a 6kWp system depending on the technology, supplier warranty, etc.
In NI prices are similar, ranging between £5,200 to £6,700 for 10 to 12 panels; overall a set up can cost between £3,500 and £9,000. There are no grants in NI for solar panels. Also note that in NI, without investing in a battery, the amount of solar panels you can install without a battery will be limited. This is to help NIE Networks balance the grid; a 3.68kW system is the limit without a battery.
Currently there is a tax break in ROI for exporting to the grid, and there is a generous export credit available of 18.5c to 20.5c which makes exporting attractive. However, this isn’t a contracted amount and could fall significantly in the coming years.
This means PV panels are often combined with other tech. They work well with heat pumps, for example, which convert one unit of electricity into four units of heat, and are often fitted with a hot water diverter, whereby excess electricity generated is dumped in the hot water tank.
The set-up may include an EV charger outlet to charge your electric car; batteries are also popular to store the excess electricity the panels produce until it’s needed.
PV Panels
PV panels are the most visible part of the system. They contain cells made primarily from crystalline silicon, which generate direct current (DC) electricity when exposed to sunlight.
Panels are typically mounted on pitched roofs at angles between 30° and 40° to maximise energy capture. Modern panels are monocrystalline; N-type monocrystalline is preferred over P-type.
Panels are framed with weather-resistant aluminium and covered by tempered glass designed to withstand wind, rain, and occasional storms.
In terms of certification the panels must have IEC 61215 and IEC 61730; good to have are IEC 1853 (real-world performance rating), IEC 61701 (for coastal areas) and IEC 62716 (for farms).
You may have heard of manufacturers being Tier 1 on the BloombergNEF list and modules being in PVEL’s “Top Performer” list.
Metrics such as these are meant to be an indication of f inancial stability, but many Tier 1 manufacturers have made losses so above all, do check how many years your installer has been installing the technology, their experience, the warranties and manufacturer quality.
Inverter
This is the most important piece of kit; it converts the solar panel’s DC electricity into alternating current (AC) to use in the house. There are three main types: string inverters, hybrid inverters, and battery inverters. Hybrid inverters allow you to install a battery down the line even if you don’t choose to do so at the start.
In Ireland, string inverters are common due to cost but microinverters are becoming increasingly popular where roofs have shading from chimneys or tall trees. Inverters also maximise output by tracking the optimal operating point of the panels.
Microinverters can be good, but aren’t compatible with batteries and, if there is a fault, require roof access to address. If shading is an issue, optimisers can be added, but all modern panels have bypass diodes which help with shading and modern inverters have algorithms to calculate maximum power point in shade conditions, so they are only necessary in specific instances.
A reputable installer will ensure compliance with all of the requirements, such as the inverter being CE-marked (ROI) or UKCA marked (NI) and compliant with EU/UK safety requirements, certified to EN 50549-1 (grid connection standard for micro-generation) and approved by ESB Networks / NIE Networks for grid connection. In ROI the inverter should appear on the ESB Networks approved equipment list.
As with all electrical installations, in ROI the installation must be carried out by a Safe Electric (RECI) registered electrician and meet ET101 wiring regulations; in NI the installer must be a registered, competent electrician following BS 7671 wiring regulations.
In ROI for grant eligibility, the system must be installed by an SEAI-registered installer using compliant equipment. In NI for quality assurance, systems are typically installed using Microgeneration Certification Scheme (MCS) certified equipment.
Your supplier will give you the certificates of conformity, commissioning certificate and proof of grid notification or approval.
Again, do check how long the inverter company has been in business, how long the installer has been installing this technology and their experience with performance and warranties.
There are shiny inverters on the market every year offering very long warranties. Do check this. Sometimes the company is only in business two or three years yet offers a 10-year warranty.
Fixings and Cabling
Mounting hardware secures the panels to the roof, ensuring stability in wind and rain. On pitched roofs, installers use rail-based systems that attach to rafters through weather-sealed brackets.
Ireland’s building regulations require robust mounting due to high wind zones, particularly along the west coast. Ground mounted systems are also an option for rural properties with ample land. Materials are typically corrosion-resistant, crucial for Ireland’s humid climate.
Specialised cabling links panels to the inverter (DC cabling) and the inverter to the home’s electrical system (AC cabling). Outdoor DC wiring must be UV-resistant and rated for high temperatures.
All cables are routed securely to prevent damage from weather or wildlife. Electrical protections such as isolators and surge protectors are required under Irish standards to ensure safety and facilitate maintenance.
Battery Storage
Cost: €/£1,700-€/£4,000 for lithium-ion batteries depending on capacity, technology option, performance, warranties etc.
You can add a battery to supply electricity to the house when the panels aren’t producing any, e.g. for evening use. In Ireland, the most common solar-battery choice is the lithium-ion battery, especially lithium iron phosphate (LiFePO₄). Older lead-acid batteries exist but are now rare due to bulk, short life and lower usable capacity.
Before buying, check battery capacity (kWh) against daily usage, depth of discharge, warranty cycles, and compatibility with the inverter.
Consider whether the system is expandable, includes smart monitoring, and meets Irish grid standards.
Some batteries will only discharge to 20 per cent; that’s the equivalent of buying a 5kWh battery that in practice is a 4kWh battery.
As with the PV panels, reliable installers and after-sales support are essential for long term performance.
Monitoring System Many modern inverters include built-in monitoring systems that allow homeowners to view energy production and consumption through mobile apps. This data helps homeowners adjust energy usage, like running appliances when solar output is highest, to reduce grid dependence. Smart monitoring systems, which optimise energy use, may come at an extra cost.
