RegularDad

Hello, So looking for some good advice to get this right the first time. I have 2 x 200l 5.5kwh Geysers set up in what looks like series, but im not 100% convinced. I use approx 800 units on prepaid Eskom direct per month. winter this runs to 1100 odd. i guess the geysers are warming up more often. I would like to be able to have lights and some plugs on during the evening load shedding for up to 8 hours. Ideally I would like to use the sun to warm the water through and inverter. however, It seems this could be tricky as i only have funds for what looks like a 5kw system. Is better to go retrofit solar geysers, and a small battery back up with a couple panels or whats the best call here. any Idea on the unit savings form a small 5kwh syetem with 5, 450w panels? is this enough to warm the hot water. Ideally I would like to make 1 right decision now and be sustainable over the next 7 to 10 years