DayNightElectricity

Day Night Electricity

• Gauging the benefit and ideal size of a battery is complex.
• One measure is the number of days when the day time export exceeds the night time consumption, so that the tomorrow morning charge in the battery exceeds this morning.
• To gauge this, I downloaded the data for the church from United Energy. In this file B1 is export and E1 is import. We do not have any other monitoring of our panels. In particular, we have no measure of total daytime consumption, the sum of import and self consumption.
• The kWh in each 5min interval were summed for 6am to 6pm (Day) and 6pm to 6am (Night). As expected the nigh time export was zero except for small numbers during early morning in mid summer. Night time import therefore equals night time consumption.
• Daytime export in green. Nighttime import / consumption in red, against the day in the year measured, ie March 2023 to March 2024

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• Daytime export versus night time consumption. On days above the 45 degree line, the exports diverted to a battery would cover the night time consumption
• A battery of 30kWh capacity would cover most of those nights.

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• The minimum overnight consumption of 20kWh surprised me, but it is consistent with the United Endergy data for lasst January, which shows an average daily import of 36kWh, sum of day and night, when most of the day time load would be met by solar.