Solar battery banks might be one of the best home improvement options for keeping your home ready for off-grid situations. Emergency power via gas or diesel generators may not be an optimal choice because of the fumes generated by burning fuel. A solar battery bank can last for 10 years and be used optimally to reduce your power bill over the lifetime of the battery bank. With Tesla now making their own battery tech open source, it opens up the arena for making battery banks for solar more affordable for everyone.