If you’re considering a solar panel, you’ve probably already figured out the the Renogy Monocrystalline Solar Panel is one of the best options you can get for your money. They work exceptionally well, are well-built/designed and are reasonable to setup even if you’re newer to using solar panels.
So I wanted to address a couple things that do come up when you’re trying to figure out exactly what all you need or how many panels you need, etc. when setting everything up.
Update: Renogy has an newer model solar panel available now.
You can click here to compare pricing for the previous model.
HOW MANY SOLAR PANELS DO YOU NEED?
To figure this out, I’ll use a popular and useful scenario as an example. You have a battery which will power your inverter, and then your inverter will power your devices (ie. computer, anything else you need/want to plug in).
So your solar panel will be used to recharge your battery, and your battery is what will keep your inverter going (in order to make power available to the devices you plug into it).
Using this strategy, I’ll provide an example so you can not only see how everything breaks down, but punch in your own numbers depending on your situation to figure out exactly how many solar panels you may want to get.
The first step in each scenario is determining approximately how much power you’ll need.
SCENARIO 1: Powering an LED TV for 10 hours/day
LED TV’s use different amount of power depending on size, manufacturer, energy efficiency, etc. but roughly they can use 50-70 watts per hour. So for this example let’s say our TV uses 60 watts of power an hour.
So to start, you’ll need to multiply 60 watts by the number of hours you’ll be using this per day and you get 600 watts of power needed per day (60w x 10 hrs).
Since we’re working with a battery, we’ll need to convert our total number of watts needed to amps. To do this, we take our total number of watts needed (600w) and divide that by the voltage of our battery (we’ll use a 12v battery for this example) which gives us 50 amps (600w / 12v = 50 Ah).
If you don’t already have a battery you want to use for this, I would recommend going with a good quality deep cycle battery designed to be used with solar panels.
Keep in mind that you ideally don’ t want to use more than 50% of the total charge capacity of a deep cycle battery or you can really start to shorten the life span of your battery. And if you’re using a car battery, you want to keep your battery life at 80% or higher. Otherwise you risk damaging or shortening the lifespan of your car battery as well.
So using the deep cycle battery as our example, since we don’t want it to go below 50%, we actually want a 100 amp battery (because 50% of 100 Ah = 50 Ah). If we were using a car battery, then we’d want a 250 amp car battery (because 20% of 250 Ah = 50 Ah). In the car battery example, we’d only want to use 20% of the batteries total amp capacity to as to not damage the battery.
Something else to note is that you will lose a little power from the inverter as those are not 100% efficient. So to be safe, you’d want to get a little stronger battery such as going with a 125 amp deep cycle battery.
The next step is to use how many sun hours you have in a day. If you don’t know that figure already, you can use this site (just enter your city): globalsolaratlas.info
Let’s say the average amount of sun hours per day where you’ll be is 5. Take that number and multiply it by the number of watts provided by the solar panel you’re considering.
So the Renogy 100 watt, 12 volt Solar Panel would give you 500 watts (5 sun hours per day x 100 watt Solar Panel). Using our example of needing 600 watts to power our TV for 10 hours a day, you’d actually need to get 2 solar panels, or reduce the amount of time you’d be using the TV each day to 500 watts or less.
IS THERE ANYTHING ELSE YOU NEED TO GET THIS SOLAR PANEL WORKING?
There are some additional items you may need to purchase if you’re setting this up for the first time. You’ll also need to get a solar charge controller and the proper cables in order to use your solar panel.
The solar charge controller is what manages the power coming from a solar panel to be used to charge a battery.
If you think you may need a backup power source to charge your battery when the sun isn’t out then you’d want to use an inverter/charger for that.
Renogy has a solar panel kit you can purchase which does include everything you need to get this solar panel up and running.
Update: Renogy now includes their new 30A PWM NegativeGround Charge Controller as part of their kit. So you’re now getting a quality controller with this kit, whereas previously people were having problems with the charge controller they had included before.
FINAL THOUGHTS
Overall, this is one of the best solar panels you can get. It’s affordable, setup is do-able and the quality is good. Just be sure to get the correct amount of solar panels based on what your power needs might be.
If you have any other questions, please don’t hesitate to post those in the comments below!