Do i need a grant to install an eco3 system? You do not need to apply for a grant with any energy company in particular, since they are all obligated to achieve certain reduction targets by the Government, the ECO3 installer can attempt to obtain funding for your measures from any of the medium to large energy companies.What is the eco3 scheme and how does it work? The energy company obligation (ECO3) scheme is one of the mechanisms the Government has established to help achieve the goal of being carbon neutral. One of the things that the ECO3 scheme does is provide grants to fund energy efficiency upgrades to homes that reduce emissions, electricity and energy bills.How do i log in to e3? E3 login page. E3 Logon. Enter your username and password below to access E3. Once you have logged on to E3 you can log off again using the 'Logout' link, which can be seen by holding your mouse over the 'Home' link in the navigation bar near the top left of the screen, or within the navigation bar at the left of most screens.