Intelligent Immersion

Customer is a retired couple and they have 4kWp of roof mount solar and an I2W solar diverter. Children have left home reducing hot water demand giving rise to large exports from spring to autumn. Customer would like to be as independent of grid electricity as is economically possible.

Investigation

Customers electricity consumption with solar panels is 3500 units per year (5000 units before solar panels). Consumption during the day is higher than average due to retirement.  Garage roof available for more solar but shaded in morning by gable end of house.

Recommendation

Fit an additional 3kWp of solar on garage using microinverters to reduce shading power loss. Fit a 12 kWHr battery storage system based on overnight usage. Prioritise the battery over the hot water diverter.

Results

The customers electricity consumption is now < 1000 units per year and practically zero spring to autumn months. The battery storage also gives an emergency power output for use in power cut. There is a small increase in gas consumption for hot water heating during winter due to battery being given priority.