Today was a really good test of what the solar system can achieve as we have had no sunshine and heavy cloud cover with heavy rain all day. Last night before switching back to the mains I took the batteries down to 60%. As you can see from the figures the batteries have been recharging whilst the system has been supplying the household with direct power from the little light that is available.
I am more confident than ever that if we add another 10kwh of batteries then we will be able to go through the entire night and in theory be off the grid. The electricity consumption is low today so this may be a little misleading with only 19.6 kwh of consumption and normally on average we would use around 30kwh for the day time.
The roughly 30kwh a day we are saving by using the solar instead of the power grid equates to around R100 daily or $6. In order to generate the returns I need to run the system for far longer and once the 4th battery has been replaced or fixed I cannot do a full run and why I turn off at around 8pm each day which is roughly a 14 hour stint.
The system cost me in the region of R250K which is around $14K which against current prices is worth around 83 300 kwh. If I could run for 60kwh every day then this system would pay for itself within 1388 days which is less than 4 years. Doing a half and half is still great and would still be paid off in less than 7 years.
Mind you this does not include future increases which we know are coming so this does prove how much can be saved. The investment that still needs happen is minimal and would guess less than R40k or around $2K when converting. Adding the extra storage along with the extra solar panels that have already been ordered the monthly electricity bill should be less than $60 and possibly much lower.
What today with the weather being like a European winters day with intense cloud cover and mist is that if you have enough panels your system will still run fine offering enough power to remain off the grid during day light hours. The added expense of having sufficient storage is the key and once paid for there is no extra expenses. When I eventually move back to Europe wherever that might be thee is no question I will install solar immediately as the cost vs savings is a no brainer plus I now have sufficient knowledge of what size system I require and how much that would cost and could import my own if the local prices were steep.
Another household who I know rely on solar did not run their appliances today so no stove and no hot water plus most other items. The overcast weather has totally disrupted their lifestyle. They have a much smaller solar unit which is actually 4 x smaller even though their unit cost more than what I paid. I have told them they need to at least double up to even consider living a normal life because they did not do their homework before purchasing. They have another 4 years left paying their system off and the reality is what they have is not suited to a family of 6.