Effective Capacity per Battery = 10 kWh x 90% = 9 kWh Number of Batteries Required = Total Energy Needed ÷ Effective Capacity per Battery = 30 kWh ÷ 9 kWh = 3.33 This implies that a UK household would require at least 4 lithium-ion solar batteries to sustain their energy needs for three days without any solar input.
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:
For smaller systems, such as a 3 kW or 5 kW solar array, the required battery capacity decreases. A household consuming around 8.5 to 10 kWh of electricity per day can effectively use most solar batteries in the UK, which have an average capacity of 10 kWh.
Armed with the necessary information, follow these systematic steps to calculate the optimal solar battery storage capacity: Conduct a detailed assessment of your household’s energy consumption, accounting for all electrical appliances and devices. Express energy usage in kWh to facilitate accurate calculations.
Factors like peak demand, battery efficiency, and whether you live on or off - grid affect which solar battery size will work best for you. Smaller homes can do well with a 3 kW system matched with about a 5 kWh battery, while larger spaces might need a 10 kW system paired with a 10-15 kWh battery for optimum performance.
Considering a popular Lithium-ion battery that offers a 10 kWh capacity with a 90% DoD: Effective Capacity per Battery = 10 kWh x 90% = 9 kWh Number of Batteries Required = Total Energy Needed ÷ Effective Capacity per Battery = 30 kWh ÷ 9 kWh = 3.33