Most business owners who contact Munster Solar about a commercial solar installation already know about the SEAI grant support available. What surprises many of them is that there is a second, entirely separate financial incentive available through the tax system, which can, in many cases, deliver a bigger immediate financial benefit than the grant itself.
It is called the Accelerated Capital Allowance, and the fact that so few business owners have heard of it is largely because it sits in the world of accountancy rather than energy. This guide shows you how it works in practice with a concrete example, and explains exactly why it matters when you are weighing up a commercial solar investment. Read on to find out how this scheme works and whether your business qualifies.
The Accelerated Capital Allowance, or ACA, is a tax relief scheme administered in Ireland by Revenue and overseen by the SEAI. It is designed to encourage Irish businesses to invest in energy-efficient equipment by allowing them to write off the full cost of qualifying equipment against their taxable profits in the year of purchase, rather than over the standard eight-year period.
To understand why this matters, you first need to understand how standard capital allowances work. When a business buys a piece of equipment, such as a machine, a vehicle or a solar installation, it cannot simply deduct the full cost from its taxable profits in the year of purchase. Instead, the cost is written off gradually over eight years at a rate of 12.5 % per year. This is the standard “wear and tear” allowance under the Taxes Consolidation Act 1997.
The ACA overrides this. Under the scheme, a business that purchases qualifying energy-efficient equipment can deduct 100% of the cost from its taxable profits in the first year. The cash flow impact of this accelerated relief, particularly in the year following a significant capital investment, can be substantial.
Solar PV systems installed on commercial or agricultural properties are qualifying equipment under the ACA, provided the system appears on the SEAI’s Triple E Product Register at the time of purchase. The SEAI maintains this register specifically for ACA purposes, and the equipment categories covered include photovoltaic solar systems, solar thermal collectors and inverters.
This means that when a business in Tipperary, Limerick, Cork or anywhere else in Ireland purchases and installs a qualifying commercial solar system, it can deduct the full capital cost of that system against its taxable profits in year one, rather than spreading that relief over the following eight years.
The ACA scheme, following Budget 2026 and the Finance Act 2025, has been extended to run until 31 December 2030, giving businesses across Ireland a clear multi-year window in which to invest and claim this relief with certainty.
This is the point at which the ACA becomes genuinely compelling for many business owners. The following example illustrates how the relief works in practice.
Suppose a business purchases a 50 kWp commercial solar installation at a total cost of €45,000, before any SEAI grant support. Under standard capital allowances, the business would write off 12.5% of this cost, or €5,625, against taxable profits each year for eight years. The tax saving in year one, at the standard 12.5% corporation tax rate, would be €703. Over the full eight years, the total tax relief would be €5,625 at 12.5% corporation tax, but spread across the decade with limited immediate impact.
Under the ACA, the business instead deducts the full €45,000 from its taxable profits in year one. At 12.5% corporation tax, the tax saving generated in that single year is €5,625. In practice, this means the net cost of the solar system to the business, after combining the SEAI commercial grant and the first-year ACA tax saving, is significantly lower than the headline price. For businesses paying a higher effective tax rate, the saving is proportionally greater.
For a sole trader or farmer paying income tax rather than corporation tax, the tax saving on the same investment at a higher marginal tax rate would be considerably more substantial still. A sole trader in the 40% income tax band would save €18,000 in tax on a €45,000 investment under the ACA, reducing the effective net cost before any SEAI grant to €27,000.
It is important to note that the ACA is not a cash payment from Revenue. It is a tax deduction that reduces your taxable profits and therefore your tax bill. The cash benefit is realised through your annual tax return, rather than as a direct grant. Your accountant will handle this as part of your annual filing.
The ACA is available to any business in Ireland that pays corporation tax or income tax on trading or professional income. This covers companies, sole traders, partnerships and farmers. It is not restricted to large businesses, and small and medium enterprises across all sectors are eligible, provided the conditions are met.
The conditions for the solar ACA are straightforward. The equipment must be new and unused when purchased. It must be listed on the SEAI’s Triple E Product Register at the time of purchase. It must be used wholly and exclusively for the purposes of the business’s trade in Ireland. The minimum qualifying expenditure is €1,000. The equipment must also be owned by the business, because leased or hired equipment does not qualify.
This last point is worth noting carefully. Finance lease and operating lease arrangements are popular ways to acquire solar without upfront capital, but they do not qualify for the ACA because the business does not own the asset. If maximising the ACA benefit is a priority, outright purchase is the approach that delivers it.
There is no separate application process for the ACA. It is claimed through your annual corporation tax return (CT1 for companies) or your income tax return (Form 11 for sole traders). Your accountant handles the claim as part of your standard annual filing, making the process considerably simpler than applying for a grant.
The ACA and the SEAI commercial solar grant are entirely separate incentives and can be claimed in combination on the same installation. This is where the financial case for commercial solar in Ireland really opens up.
The SEAI offers grant support for commercial solar PV installations through the Non-Domestic Microgen Grant, with support rates and ceilings varying depending on the system type and size. When SEAI grant support is received, the ACA is calculated on the net cost to the business after the grant has been deducted, rather than on the full gross installation cost. Even after this adjustment, the combination of the two incentives significantly reduces the effective net cost of the investment.
At Munster Solar, we work through the combined financial picture with every commercial client, making sure the numbers are clearly understood before any decision is made. We will tell you what the system will cost, what the SEAI grant reduces that to, and what the ACA saves you on top of that. The full picture, rather than the headline price, is what allows you to make a confident business decision.
Munster Solar installs commercial solar systems across Tipperary, Limerick, Cork, Kerry, Waterford, Clare and nationwide, and we can confirm the ACA eligibility of our systems as part of the quotation process.
Following Budget 2026, the ACA for energy-efficient equipment has been extended to 31 December 2030. This gives businesses in Ireland a clear multi-year window in which to invest in qualifying equipment and claim the full first-year tax relief.
The combination of the SEAI commercial solar grant, the Accelerated Capital Allowance and ongoing electricity bill savings from solar generation makes a compelling financial case for commercial solar investment in Ireland in 2026. If you would like to see the numbers worked out specifically for your business, including installation cost, grant support, ACA savings, and projected energy cost reduction, the Munster Solar team is ready to help.
Contact Munster Solar on (+353) 87 388 1872 or at info@munstersolar.ie for a free commercial site assessment and quotation.
This article provides general information about the Accelerated Capital Allowance scheme and does not constitute tax or financial advice. The ACA rules are subject to change. Always consult your accountant or tax adviser for guidance specific to your business and circumstances.
