Love how you framed the benefits of investing in clean energy! About ten years ago we used a HELOC to borrow money to pay for solar PV, then refinanced everything into a 30-year mortgage when the rates were so low. Little by little we're paying for the solar power we've been enjoying (spread into 360 payments), and the savings keep getting more valuable as the price of electricity has increased. Our new mortgage payment is much less than our old mortgage plus electricity bills, so we've been able to put the savings into a retirement account every month.