Need advice / technical information about DIY solar powered outdoor evaporative cooler (swamp cooler)

[Pauline]

I have no experience with electrical, electronics, or solar. I am new to this website (https://diysolarforum.com) and am seeking advice / help about my DIY solar project: I want to make a 12 volt, outdoor, solar powered evaporative cooler (outdoor portable swamp cooler on wheels). I purchased four Thuderbolt brand, 12 volt, 100 watt, 7 amp portable briefcase solar panels from Harbor Freight Tools store. I purchased two 12 volt, 120 watt, 12 amp automotive radiator fans, two 12 volt, 20 amp motor speed controllers (one motor speed controller for each fan), a 12 volt, 30 watt, submersible water pump, and swamp cooler water pads from Amazon.com. I would prefer to buy and use four buck step-down voltage regulators that will stabilize the voltage & wattage output of my four Thunderbolt brand, 12 volt, 100 watt, 7 amp portable briefcase solar panels by preventing voltage & wattage output fluctuation during use of the panels. I was hoping I could use four buck step-down voltage regulators wired to my four solar panels, instead of purchasing and implementing a solar-charge controller and batteries. The rated output of each of my 12 volt, 100 watt, 7 amp briefcase portable solar panels is: 14 - 22 volts which will slowly, eventually damage my two 12 volt, 120 watt, 12 amp automotive radiator fan motors and my 12 volt water pump if I do not implement a voltage regulator or if I do not implement a charge controller and battery to stabilize the voltage at 12 volts. According to Thunderbolt Solar, the 'Open Circuit Voltage' (VoC) of each of the 12 volt, 100 watt, 7 amp portable briefcase solar panels, is: 21.5 volts, and the 'Typical Maximum Power Point Voltage' (MPPT) is: 17.5 volts, and the 'Typical MPPT Current' is: 6.2 Amps DC. Various sellers on Amazon.com sell Adjustable Buck Voltage Regulators which stops fluctuation of voltage output of solar panels, stabilizing the voltage to 12 volts or whatever voltage I adjust the Buck voltage regulators to allow as the output voltage of each solar panel. Will I need to buy and implement one or more batteries to stabilize the wattage output to 100 watts? If so, I am presuming I should buy a solar charge controller instead of using Buck voltage regulators because I would need to buy one or more batteries anyway. I also need diysolarforum.com members to advise me on choosing the correct type and size fuses for protecting all the devices / components of my 12 volt, solar powered, portable outdoor evaporative cooler (outdoor portable swamp cooler).

 

[Risky Rob]

I need a way to keep my inverter cool, and I am thinking about retrofitting an old 115V swamp cooler with a 24V fan and water pump. I could run it from the load terminal of my charge controller. For me, it would be easier to retrofit an existing unit. There are complete swamp cooler builds on YouTube.