150-panel solar PV system may suit a large farm, warehouse, factory or commercial property with daytime electricity demand. Its annual output depends on module wattage, site conditions and design. Estimating generation helps a business judge how much power it may use and whether the roof and budget suit the project.
With 400W modules, 150 solar panels make a 60 kilowatt-peak (kWp) system. Applying SEAI’s broad Irish yield benchmark gives an indicative output of about 52,000 kilowatt-hours (kWh) per year. It is a planning estimate, not a promise of production or savings.
System Capacity: 400W, 450W and 500W Panels
A panel’s wattage is its rated capacity. System capacity in kWp is the sum of the module ratings; kWh measure electricity generated over time.
•150 × 400W panels: 60kWp.
•150 × 450W panels: 67.5kWp.
•150 × 500W panels: 75kWp.
The array will not continuously produce its rated capacity. Generation changes with daylight, weather, shade and equipment. SEAI recommends matching system size to building demand, ideally using meter data.
Expected Annual Electricity Generation in Ireland
SEAI estimates that a well-located 3kW system in Ireland generates around 2,600kWh per year, or approximately 867kWh per kWp. Scaling this benchmark gives the following illustrative annual solar panel output:
•60kWp from 400W modules: about 52,000kWh.
•67.5kWp from 450W modules: about 58,500kWh.
•75kWp from 500W modules: about 65,000kWh.
These scaled figures are not site forecasts. About 75% of Irish PV output is generated between May and September. Location, orientation, tilt, shading, weather, module efficiency and system losses affect output. East- or west-facing modules may shift generation towards morning or evening use. Ask for location-specific modelling, such as European Commission PVGIS.
150 Solar Panels Cost in Ireland
Irish commercial solar cost guides vary. LVP lists €850–€2,000 per kWp; a 2026 guide gives €900–€1,500 per kWp and €40,000–€55,000 for a standard 50kWp roof system. At an indicative €850–€1,700 per kWp, a 60–75kWp project is roughly €51,000–€127,500 before grants. This is not a quotation, and difficult roofs or electrical work can increase costs.
The final 150 solar panels cost depends on panel and inverter choice, mounting, labour, scaffolding, roof condition and electrical work. Reinforcement, switchboard upgrades, cable runs or grid changes may add cost; batteries are separate. Ask for an itemised quote covering capacity, yield, equipment, VAT and grant assumptions. See LVP’s commercial PV service.
Roof Space and Building Suitability
A commercial guide estimates 4.5m² of usable roof per kWp, or 270–338m² for 60–75kWp. Walkways, rooflights, vents and maintenance access need room; panel dimensions vary, so the installer should model the layout.
Agricultural sheds, warehouses, factories and retail buildings may have suitable roofs. A survey should check structure, condition, remaining life, wind loading and access; repairs or reinforcement may be needed.
Electricity Savings and Export Payments
Solar power used directly avoids grid purchases. Farms may run refrigeration, pumps, ventilation, milking and workshops in daylight; businesses may use it for machinery, cold storage, lighting or production. Savings depend on operating hours.
For a 60kWp example producing 52,000kWh per year, assume an import price of €0.30/kWh and an export payment of €0.15/kWh. At 50% self-consumption, the site uses 26,000kWh on site, avoiding €7,800 of purchases, and exports 26,000kWh worth €3,900. At 70% self-consumption, it uses 36,400kWh, saving €10,920, and exports 15,600kWh worth €2,340. The example’s total value is €11,700 or €13,260 per year respectively.
These are assumptions, not tariff quotes. Actual value depends on demand, generation and supplier terms. CRU says export payments are based on metered units and the supplier’s rate; separate export income from avoided costs.
Commercial Battery Storage
A battery shifts surplus solar electricity to later use. Match capacity to the site’s load schedule and available surplus. Storage adds cost and charging losses, so compare later grid purchases avoided with export payments forgone. NDMG excludes batteries and supplementary equipment.
SEAI Commercial Solar Grants
The SEAI Non-Domestic Microgen Grant (NDMG) supports eligible non-domestic PV up to 1,000kWp. New applications from 6 October 2026 to 6 July 2027 receive the lower of the capacity-band grant or 45% of eligible invoiced costs. Existing offers are not increased.
Example grant values are €29,200 for 60kWp, €32,200 for 67.5kWp and €35,200 for 75kWp, subject to the cap and approval. Premises must have been built and occupied by 31 December 2024. Apply before buying materials or starting; use a registered company and finish within eight months. The system must serve on-site demand; support is once per MPRN. Eligibility is not automatic.
Farmers may compare TAMS 3’s Solar Capital Investment Scheme: 60% of eligible investment up to €90,000 per holding, subject to reference-cost and selection rules. Do not assume it can be combined with NDMG for the same investment; check current terms.
Payback Period and Return
For illustration, assume the 60kWp system costs €80,000 and receives the €29,200 NDMG example grant. Net cost is €50,800. Using the 70% self-consumption case above, simple payback is approximately 3.8 years (€50,800 divided by €13,260). Grant eligibility and the invoice cap apply.
This excludes finance, maintenance, inverter replacement, degradation and price changes. Lower generation, self-use or grant support can lengthen the commercial solar payback period. Treat it as a scenario, not a promise.
Comparing 100, 125, 150 and 200 Panels
For a consistent comparison, assume 400W modules, an annual yield of 867kWh per kWp and €850–€1,700 per kWp for indicative installation costs:
•100 panels: 40kWp, about 34,700kWh a year, 180m² of usable roof and €34,000–€68,000 before grants.
•125 panels: 50kWp, about 43,300kWh, 225m² and €42,500–€85,000.
•150 panels: 60kWp, about 52,000kWh, 270m² and €51,000–€102,000.
•200 panels: 80kWp, about 69,300kWh, 360m² and €68,000–€136,000.
Assumptions are consistent across sizes; roof access, complexity and economies of scale change quotations. Choose capacity to fit daytime demand and roof area.
Installation and Long-Term Performance
A commercial solar installation starts with bills or half-hourly data and a site survey. The installer checks the roof, shading, system design and grid requirements, confirms grants, then installs, commissions and sets up monitoring. Monitoring can flag shading, faults or underperformance.
Monitor generation, inverter and meter operation inspect periodically. Clean panels only if soiling affects output and follow safe advice. Check warranties and allow for possible inverter replacement during the system’s life.
FAQs
How much electricity can 150 solar panels generate annually in Ireland?
With 400W modules, a 60kWp system may generate about 52,000kWh a year under SEAI’s broad yield benchmark. Actual output depends on site conditions.
How much does a 150-panel solar system cost in Ireland?
A 60–75kWp commercial system has an indicative range of €51,000–€127,500 before grants using published per-kWp prices. A site survey is needed for a firm quote.
How much roof space is needed for 150 solar panels?
Allow approximately 270–338m² of usable roof for a 60–75kWp layout. Access, obstructions and module size affect the final design.
How long does it take for a 150-panel solar PV system to pay for itself?
There is no fixed period. The example gives about 3.8 years after an assumed grant, but real payback depends on price, generation, self-use, export income and grant eligibility.
Conclusion
With 400W modules, 150 solar panels make a 60kWp system that may generate about 52,000kWh annually in Ireland. Higher-wattage panels increase capacity and estimated output, but the site roof, energy demand and installation design matter. Treat the 150 solar panels cost, savings and payback estimates as planning figures, check grant rules before work begins and obtain a site-specific proposal.
For a personalised commercial solar assessment and installation quotation, visit LVP Renewables or contact the LVP team.
