My (pilot) Solar Power Setup

(Note : Ideas and calculations are all mine.  If you will be setting up your own system based on what was written here, I take no responsibility for any failure.  Not to discourage you or anything but mainly for safety since working on this stuff can burn your house or injure a person most likely to be you.)

Solar Panels
A 100W panel generates around 5A peak.  In my setup, this occurs between 11:00AM to 1:00PM and at this time of the year.  I actually have two units so it is 200W total capable of pushing 10A of current.  As early as 7AM, the PVs generates about 1A rising gradually until it peaks around noontime.  It is a downhil afterwards until it is back again to 1A at 4-5PM.  If I have to estimate the number of hours when the panels generate power, it would be around 8 hours but with substantial current flowing in the inner 6 hours of this period.  In my last post, I calculated the theoretical generated power of a 200W panel in a day which is about 600W-hr.  I believe this is a good estimate based on my monitoring data.

The above information by the way is when the weather is good and sunny.  Unfortunately, this is not always the case and it is the nature of weather to be somewhat fickle minded.  I have some observation data but to make things very simple I have a rule of thumb that whenever it is cloudy, the generated power is 50% and 25% of the maximum when it rains.  Therefore if it is cloudy the 600W-hr becomes 300W-hr and drops further to 150W-hr if it is rainy.

Charge Controller
Current measurements are taken from the LCD display of the 30A PWM charge controller.  I am not sure about the absolute accuracy of the readings but I'd be happy if it is better than 10%.  This is a cheap unit but is smart and it seems to do its job quite well.  The seller warned me not to disconnect the battery while the panels are connected.  I've violated this unintentionally a number of times and controller is still alive which makes this unit a sturdy one as well.  Aside from the PV current, it also monitors the A-hr generated that I find handy.

Deep Cycle Battery
I bought a 100Ah battery for this off grid setup.  This means I have around 600Whr of energy to spend while the sun is out.  That is at 50% DOD and provided the battery was able to reach a full charge during the day.  The only possible indication of this event is when the controller displays 14.5V for the battery voltage and the charging current cycles between zero and maximum or some value in between. This could mean that the PWM switching mode takes over to trickle charge the battery.  On weekends when there is no office work, my observation is that at dawn the battery reaches a voltage of 13V+ which then goes down to an average of 12.2V the following morning.  Less final voltage of course when the weather is not so good which is around 12.7V to 12.9V.  There was only one morning when I saw it at 12V but was never less than this value.

Inverter
The inverter which I've been using for a month now is low cost (cheap) 1000W unit.  It can drive our 8.5cuft refrigerator, 50inch LCD TV and even my electric drill.  It complains when it is asked to power a grinder, though.  But for LED bulbs, electric fans and charging gadgets, this is more than fine.  The only gripe is the idle consumption which I estimate to be 10W. This is equivalent to 20Ah lost daily assuming the inverter is connected all the time.  I hope this is not a fixed offset  and drops to close to zero when a load a connected.  I need to buy a wattmeter for confirmation.

Loads
As mentioned previously, my setup has been running for a month now.  At the moment, the refrigerator is still unplugged and we failed to watch Miss Universe 2017.  We are still in test drive mode while closely monitoring our consumption because we are completely off grid.  No rice cooker and no ironing of clothes.  Just bulbs for lighting, occasional electric fan, wifi router, diy stereo and gadgets charging.

... but NO electric bills to worry about.