In the first instance, a storage battery can take its charge from renewables. (I.e., from solar panels, or wind or hydro turbines.) So, you can charge your battery using free, green sources. And, because the energy from renewables is intermittent, a storage battery allows you to harness it more efficiently for consistent use.
Short answer: yes. Domestic battery storage without renewables can still benefit you and the grid. This is especially true for those on smart tariffs; charge your battery during cheaper off-peak hours and discharge during more expensive peak hours, cutting your bills and reducing strain on the grid during peak energy use times.
As with capacity, there is no set definition regarding storage duration. According to US Energy Information Administration, storage duration depends on how grid scale batteries are used. It notes the following regarding capacity-weighted average storage duration in megawatt hours (MWh): Why is grid scale battery storage necessary?
China’s CATL, the world’s largest battery producer, says its energy storage batteries can last for 25 years. Will it save the planet? Not on its own — but grid-scale energy storage is part of the combination of clean energy technologies that is needed to reach net zero.
So, you can charge your battery using free, green sources. And, because the energy from renewables is intermittent, a storage battery allows you to harness it more efficiently for consistent use. In the second instance, a storage battery can also take power from the grid. Here, the battery will charge using low-cost, off-peak energy.
The average household uses between 8-10 kWh of electricity per day. Home storage batteries start at around 2.5-5 kWh in capacity for small systems, up to the larger systems which offer around 13-15 kWh of energy storage. We would typically size a system by following a two step approach: