On my house I have a photovoltaics solar system. To use more of the generated energy myself (I get a reimburstment of about 11 cents per kWh but have to pay ~33 cents per kWh that I consume from the public grid) I built my own LiFePo4 battery with just beneath 8 kWh of storage. The battery inverter is a nice Multiplus II from Victron. Victron also provides a really nice website that shows the current consumption and some other stats.