The first type of solar street light retrofit system you can install would be a grid intertied system. This is the perfect setup if you want to offset some of the usage of that light, and possibly more, and save money on electricity. Look at what the state of New Jersey didwith its light poles. They. The second type of solar street light retrofit would be to take the systems off the grid completely by installing an off-grid solar-powered street light. This is the right choice when there. Battery backup systems are the best of both worlds. With a battery backup system, you generate the power for the batteries primarily, typically smaller battery assemblies than.