Useful information, with its working shown.

Our guides bring together public information and practical questions to ask before making a decision. Each guide links to its sources and shows the date they were checked. We distinguish examples from local rates and avoid presenting estimated savings as guaranteed results.

This first edition was prepared with AI assistance, including translations. It has not been independently reviewed by a qualified energy professional. Check project-specific details with the linked official service and your installer. Illustrative images do not show an installation we have tested.

Illustrative image generated with AI.