The cost after the grant depends on the installer’s quote, system size, roof, electrical work and any extras such as a battery or scaffolding. In simple terms, you would subtract the SEAI-approved grant from the eligible part of the installation cost, but not every item on a quote may qualify. Ask a registered solar PV contractor for a written, itemised quote showing the expected grant and your estimated balance to pay. Grant approval and the final amount are decided under SEAI’s current rules, so check the latest guidance on the official SEAI website before committing.