The technologies that make energy efficiency possible A recent study by McKinsey states that, over the next 20 years, at least $37 billion will be invested annually in energy efficiency, using the new technologies available. American investors have been investing in the sector for some years now, with very good results, such as Hannon Armstrong, which last year made its debut on the New York stock exchange, with notable success. In Spain, the first funds focused on this sector are already being created.
