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The 800 watt limit, and how much that will help, is the main question. My solar yesterday
so I need the battery to cover from 05:30 to 08:00 and 16:50 until 00:30 next day. So approx 7.5 hours in the evening, so around 6 kWh if drawing 800 watt for the whole of the time, I have some heavy usage for first hour, but that is over the 800 watt, so average more like 500 watt, so need around 4 kWh to see me until off-peak starts if maximum draw is 800 watt. This assumes battery fully charged at 4 pm.
Yesterday produced 24.4 kWh of solar, with 6 kW panels, so adds seem to show around 750 W for balcony solar, so 24.4/6000x750 = 3 kWh so 12 kWh my daily use, minus 3 = 9 kWh of which 4 at 8.5p/kWh and 5 at 32p/kWh so £1.94 and without any battery or solar, 12 x 25p/kWh = £3 so £1.06 reduction lets call it £1 a day saving so saving £365 per year. Allowing for bad days, I would think £250 a year is more realistic. With 750 watt panels we can assume no export, it would have a job recharging the battery never mind export.
Cost of system approx £1500 so around 6 years pay back time, but will we get that output from a near vertical panel? Picture looks good
but 2 panels face different direction to other 4.
But the main problem is, once fitted, will you ever want proper solar array on the roof? As seems likely either or, not both. I suppose I could set a battery bank to charge 00:30 to 05:30 and discharge 14:30 to empty, so adding say 2 kWh to the total battery capacity at a set 200 watt during winter months, and it could also serve as a portable power supply in the summer. But only if used dual-purpose will it really pay, as summer I have loads of solar and battery anyway.
In summer would not want balcony solar panels, they would stop me sun bathing, and in winter would they stand the wind? I envisage seeing whole of the balcony railings on the patio below after high winds. So battery pack, maybe, panels, would not trust my railings would survive high winds with them on it.
so I need the battery to cover from 05:30 to 08:00 and 16:50 until 00:30 next day. So approx 7.5 hours in the evening, so around 6 kWh if drawing 800 watt for the whole of the time, I have some heavy usage for first hour, but that is over the 800 watt, so average more like 500 watt, so need around 4 kWh to see me until off-peak starts if maximum draw is 800 watt. This assumes battery fully charged at 4 pm.Yesterday produced 24.4 kWh of solar, with 6 kW panels, so adds seem to show around 750 W for balcony solar, so 24.4/6000x750 = 3 kWh so 12 kWh my daily use, minus 3 = 9 kWh of which 4 at 8.5p/kWh and 5 at 32p/kWh so £1.94 and without any battery or solar, 12 x 25p/kWh = £3 so £1.06 reduction lets call it £1 a day saving so saving £365 per year. Allowing for bad days, I would think £250 a year is more realistic. With 750 watt panels we can assume no export, it would have a job recharging the battery never mind export.
Cost of system approx £1500 so around 6 years pay back time, but will we get that output from a near vertical panel? Picture looks good
But the main problem is, once fitted, will you ever want proper solar array on the roof? As seems likely either or, not both. I suppose I could set a battery bank to charge 00:30 to 05:30 and discharge 14:30 to empty, so adding say 2 kWh to the total battery capacity at a set 200 watt during winter months, and it could also serve as a portable power supply in the summer. But only if used dual-purpose will it really pay, as summer I have loads of solar and battery anyway.
In summer would not want balcony solar panels, they would stop me sun bathing, and in winter would they stand the wind? I envisage seeing whole of the balcony railings on the patio below after high winds. So battery pack, maybe, panels, would not trust my railings would survive high winds with them on it.
