A 500kW solar system can turn a large commercial roof or suitable site into a substantial source of on-site electricity. For Irish factories, warehouses, farms and distribution centres, the opportunity is not just about installing as many panels as possible. The system has to match the business’s daytime demand, roof structure, available grid capacity and export arrangements.
This guide explains what a 500kW commercial solar PV system involves, how to estimate its panel count and footprint, and what Irish businesses should check before investing. Figures below are planning estimates, not a site-specific design or quotation.
What does a 500kW commercial solar PV system mean?
Solar array size is commonly described in kilowatt-peak (kWp). It is the panels’ combined rated DC capacity under standard test conditions. A 500kWp array is made up of modules whose ratings add to about 500kWp; it will not produce 500kW continuously. Output changes with sunlight, temperature, orientation, shading and system design.
The inverter converts the panels’ DC electricity into AC electricity for the building and grid. Its rating is stated in kilowatts (kW) and may differ from the array’s kWp rating. The approved maximum export capacity is another separate figure set through the connection process. A battery is measured in kilowatt-hours (kWh), which describes stored energy, not instantaneous power.
In daylight, solar electricity is used by equipment on site first, subject to the electrical design. Any surplus may be exported if the connection and commercial arrangements allow it. When generation is below demand, the business continues to import electricity. A battery can shift some solar energy to later hours, but adds capital cost and should be assessed against the site’s load profile.
500kW solar panel count by module size
Divide 500,000 watts by the rating of one panel to estimate the module count. Since modules are whole units, some choices land just above or below 500kWp.
For a 500kWp target, the panel count depends on the wattage of each module:
•400W panels: 500,000 ÷ 400 = 1,250 panels, giving an array of 500.00kWp.
•450W panels: 500,000 ÷ 450 = 1,111.11, so use 1,112 panels to reach or exceed the target. This gives 500.40kWp.
•500W panels: 500,000 ÷ 500 = 1,000 panels, giving an array of 500.00kWp.
•550W panels: 500,000 ÷ 550 = 909.09, so use 910 panels to reach or exceed the target. This gives 500.50kWp.
For 450W panels, 1,111 modules total 499.95kWp; 1,112 modules total 500.40kWp. For 550W modules, 909 total 499.95kWp, while 910 total 500.50kWp. Final design may use a slightly different DC capacity to fit the roof, electrical design and inverter configuration. The table gives the 500kW solar panel count arithmetic, not a final string layout.
500kW solar roof space and land requirements
Panel count alone does not tell you whether a roof can host the array. Module dimensions vary by product. As one reference, SEAI illustrates a 30kWp system using 75 panels over about 125m². Scaling that example to 500kWp gives roughly 2,083m² of panel surface at the same module density.
That figure is not the usable-roof requirement. Designers must allow for walkways, roof edges, fire and maintenance access, drains, roof lights, plant equipment, fall-protection arrangements and spacing needed by the mounting design. As a first desktop screen, a business might test whether it has roughly 2,600–3,500m² of clear, usable roof, but this is a rough allowance—not a regulation or structural approval. An engineer must assess roof condition, load capacity, wind forces and the proposed mounting system before installation.
For a ground-mounted array, the panel footprint is only part of the land take. Row spacing, access, inverters, electrical infrastructure, drainage, boundary setbacks and planning constraints all affect the site layout. Around 0.5–1 hectare can be used as a very preliminary area to investigate for a project of this scale; it is not a guaranteed requirement. A measured site plan and concept layout are needed to establish the actual land requirement.
How much electricity can a 500kW solar system generate in Ireland?
A useful starting point is the European Commission Joint Research Centre’s PVGIS tool, which models solar radiation and photovoltaic performance by location and system configuration. Illustrative PVGIS 5.3 fixed-system runs for Dublin, Cork and Galway, using a 1kWp south-facing array at 35° tilt and 14% system losses, give approximately 982, 994 and 926kWh per kWp per year, respectively. Scaled to 500kWp, that is about 463–497MWh annually at those three representative locations. This is an indicative model, not a production guarantee; a low-tilt east–west roof, shading, a different loss assumption or a different site will change the result.
Production is seasonal. Long summer days generally bring stronger generation, while short winter days reduce it. Irish cloud and rain affect irradiance, but PV panels generate from daylight rather than requiring hot weather. Orientation and tilt influence how much sunlight reaches the array. Nearby buildings, trees, roof structures and equipment can cause shading, and inverter conversion, wiring, soiling and downtime create further losses.
A project forecast should use the site’s Eircode or coordinates, actual roof planes, module and inverter specifications, shading analysis and a justified loss factor. The business should also compare the hourly generation profile with its electricity use. Annual generation alone does not tell you how much imported electricity the system will displace.
Price of a 500kW solar panel installation in Ireland
The 500kW solar system cost Ireland figure cannot be responsibly reduced to a single national price. LVP Renewables’ commercial PV page publishes a broad installed-cost range of €850–€2,000 per kWp, while describing its systems as typically ranging from 2kW to 400kW. That public range is useful background, but it is not a 500kW quotation and should not simply be multiplied by 500 to promise a project price.
A project-specific price depends on the panels and inverter architecture; mounting equipment; cabling, switchgear, protection and monitoring; labour and lifting equipment; roof repairs or structural reinforcement; engineering and surveys; grid studies and connection works; and commissioning. Roof material, working-at-height constraints, asbestos or other site hazards, cable routes, export limits, civil works and battery storage can materially alter the total. Grid upgrades or a constrained connection point may add costs or affect timing. Ask for an itemised proposal that states whether VAT, grid works, monitoring, maintenance and battery equipment are included.
Grants and support for commercial solar in Ireland
SEAI’s Non-Domestic Microgen Grant (NDMG) is open to eligible businesses and other listed non-domestic applicants, including agricultural, public-sector, school, community and non-profit applicants. The scheme page says systems up to 1,000kWp can be supported. As displayed on 14 October 2026, SEAI states that new applications made from 6 October 2026 through 6 July 2027 may receive an enhanced effective 45% rate. For the 201–1,000kWp band, the listed grant calculation is €300 per kWp. A 500kWp system therefore calculates to €150,000 before the invoice limit, subject to the scheme’s conditions. SEAI says the payment is the lower of the amount on the application summary or 45% of the invoiced cost.
This is not automatic funding. Applicants should check the current scheme terms and eligibility, appoint a registered SEAI Non-Domestic Microgen company, agree the formal contract and submit the grant application before starting works. SEAI says to wait for the grant offer before works begin. The installer must also apply for the electricity-network connection before installation. Existing grant applications do not qualify for the October 2026 increase, and the enhanced window has an end date. Confirm the live terms directly with SEAI before relying on a grant in a business case. Other supports may apply in particular circumstances, but eligibility and tax treatment need separate confirmation; do not assume that grants or capital allowances can be combined in a particular way without professional advice.
Savings, export revenue and payback
The most important savings variable is how much solar power the business uses while it is being generated. A factory with steady daytime demand may consume a greater share on site than a premises that is quiet during sunny hours. Electricity avoided on site is generally valued at the business’s avoidable import rate. Exported electricity earns whatever payment is available under the business’s supplier or export contract; do not assume a domestic microgeneration tariff applies to a 500kWp installation.
A simple estimate is:
Annual net benefit = (on-site solar use × avoidable import price) + (exported solar × export rate) − annual operating and maintenance costs.
For illustration only, assume 500kWp generates 480MWh a year, the business uses 75% on site, the avoidable electricity price is €0.20/kWh, the export rate is €0.08/kWh, and annual maintenance is budgeted at €6,500. Those are modelling assumptions—not current market quotes or guaranteed tariffs. On-site use is 360MWh, worth €72,000; 120MWh exported is worth €9,600; and the illustrative net annual benefit is €75,100 after maintenance.
If a separately quoted project cost were €650,000 and the business received the full illustrative €150,000 NDMG award, the net investment would be €500,000 and simple payback would be about 6.7 years (€500,000 ÷ €75,100). The €650,000 cost is only a scenario input, not a verified 500kW market price. This simple payback excludes financing, tax, degradation, inverter replacement, downtime, changes to energy prices and the timing of grant payments. A proper investment case should test lower and higher generation, self-consumption, import and export prices, project costs and grant outcomes.
Main components and suitable sites
A large-scale commercial solar system normally includes PV modules, mounting structures, DC cabling and isolators, inverters, AC switchgear and protection, metering and monitoring, safety labels and shutdown arrangements, and the grid connection equipment required by the approved design. A battery is optional. Its capacity in kWh and power rating in kW should be selected to solve a defined operational or commercial need, not added by default.
Potential sites include factories, warehouses, farms, distribution centres, food processors, schools and large business premises with a suitable roof or ground area and meaningful daytime electricity demand. A high annual bill is not enough on its own: load timing, roof life, structural capacity and the export limit matter too.
Installation, planning and grid connection
A typical project begins with electricity-bill and interval-data review, a site survey, roof and structural checks, shading and layout work, and a technical and financial proposal. The design then defines array kWp, inverter kW, expected production, export arrangements and any battery. Planning requirements depend on the site, the building and the applicable exemptions; confirm them with the local planning authority or project advisers rather than assuming every commercial roof has the same exemption.
The installer must establish the appropriate ESB Networks application route and obtain the required connection approval before commissioning. ESB Networks’ large-scale generation guidance says applications below 40MW are initially submitted to ESB Networks for distribution-level connection; it also provides generator application steps, technical information and network-capacity tools. That threshold does not itself confirm that a particular 500kW site can connect or export its full output. The approved maximum export capacity, local network capacity, protection settings and any required connection works must be established for the project. Electrical design and installation should meet applicable Irish wiring rules, network requirements and safety procedures, followed by testing, commissioning, metering and handover. Timelines depend on surveys, approvals, equipment lead times and grid works, so a fixed duration should only be stated after the connection route is known.
Warranties, maintenance and performance
Panel product and performance warranties, inverter warranties and mounting-system warranties are separate; check each supplier’s terms and exclusions. Ask how performance will be monitored, who responds to faults and how warranty claims are handled. Ongoing care commonly includes reviewing monitoring alerts, inspecting electrical and mounting equipment, keeping drains and access routes clear, and cleaning only when site conditions and the manufacturer’s advice justify it. A monitored system makes it easier to identify underperformance and compare actual generation with the forecast. Output will change over time, so a financial model should include reasonable degradation and future equipment replacement assumptions.
LVP Renewables’ published commercial page describes commercial PV work, roof and ground-mounted systems and installations on several roof types, and states a typical system range of 2–400kW. A 500kW project is above that stated typical range, so businesses should confirm directly whether the company can assess and deliver the required scale and connection design. LVP can be contacted through its commercial solar page to discuss electricity consumption, roof space and project requirements and request a tailored assessment and quotation.
FAQs
How much does a 500kW solar panel installation cost in Ireland?
There is no verified single price for every 500kW project. Cost depends on the roof, equipment, grid connection and site works. LVP Renewables publishes a broad €850–€2,000/kWp range for commercial PV, but its page describes typical systems up to 400kW; ask for a site-specific 500kW quotation rather than treating that range as a price promise.
How many solar panels are needed for a 500kW solar system?
It takes 1,250 panels rated at 400W, 1,112 at 450W (500.4kWp), 1,000 at 500W, or 910 at 550W (500.5kWp). Final design may adjust the total slightly.
How much roof space is required for a 500kW solar installation?
SEAI’s example implies about 2,083m² of module surface when scaled to 500kWp at the same panel density. Allow additional usable roof area for access, safety clearances, roof features and mounting layout. A rough early screen is 2,600–3,500m², subject to a structural survey and detailed design.
How much electricity can a 500kW solar system generate annually in Ireland?
Illustrative PVGIS results for Dublin, Cork and Galway indicate around 463–497MWh per year for a 500kWp south-facing fixed array at 35° tilt, with 14% system losses. Actual output depends on the location, roof orientation and tilt, shading and installed system losses.
