For existing homes, the return on investment for a light energy efficiency retrofit yields is greater than adding solar panels. A light retrofit of a typical existing home can deliver an 18.5% return annually, nearly twice that of long-term stocks. “Light retrofit” includes sealing air leaks and other low-cost efficiency measures.
The return is much higher than that of residential rooftop solar, though both deliver complementary cuts in carbon emissions. From an environmental standpoint, ideally homeowners would retrofit and add solar, but not everyone can afford to do both. With limited funds, though homeowners will typically get more for their money by prioritizing efficiency.
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