36 watts x 2 plus 8 watt gives a total of around 80 watts which is the total required consumption level here.
Total intended consumption is = 80 watts.
The above power may be consumed from 6 am to 6 pm which becomes the maximum period one can estimate, and that's approximately 12 hours.
Multiplying 80 by 12 gives = 960 watt hour.
It implies that the solar panel will need to produce this much watt hour for the desired period of 12 hours during the entire day. However since we don't expect to receive optimum sunlight through the year, we can assume the average period of optimum daylight to be around 8 hours.
Dividing 960 by 8 gives = 120 watts, meaning the required solar panel will need to be at least 120 watt rated.
If the panel voltage is selected to be around 18 V, the current specs would be 120/18 = 6.66 amps or simply 7 amps.
Now let's calculate the battery size which may be employed for the inverter and which may be required to be charged with the above solar panel.
Again since the total watt hour fr the entire day is calculated to be around 960 watts, dividing this with the battery voltage (which is assumed to be 12 V) we get 960/12 = 80, that's around 80 or simply 100 AH, therefore the required battery needs to be rated at 12 V, 100 AH for getting an an optimal performance throughout the day (12 hours period).
We'll also need a solar charge controller for charging the battery, and since the battery would be charged for the period of around 8 hours, the charging rate will need to be around 8% of the rated AH, that amounts to 80 x 8% = 6.4 amps, therefore the charge controller will need to be specified to handle at least 7 amp comfortably for the required safe charging of the battery.
That concludes the entire solar panel, battery, inverter calculations which could be successfully implemented for any similar kind of set up intended for an off the grid living purpose in rural areas or other remote area. For other V, I specs, the figures may be changed in the above explained calculation for achieving the appropriate results.
In case the battery is felt unnecessary and the solar panel could also be directly used for operating inverter.
A simple solar panel voltage regulator circuit may be witnessed in the following diagram, the given switch may be used for selecting a battery charging option or directly driving the inverter through the panel.
In the above case, the regulator needs to produce around 7 to 10amps of current therefore an LM396 or LM196 must be used in the charger stage.
The above solar panel regulator may be configured with the following simple inverter circuit which will be quite adequate for powering the requested lamps through the connected solar panel or the battery.
R3, R4 = 15 ohm 10 watt
T1, T2 = TIP35 on heatsinks
The last line in the request suggests an LED version to be designed for replacing and upgrading the existing CFL fluorescent lamps. The same may be implemented by simply eliminating the battery and the inverter and integrating the LEDs with the solar regulator output, as shown below:
The negative of the adapter must be connected and made common with the negative of the solar panel