RV Photo voltaic methods might be something from a single panel you intention on the solar whilst you’re parked someplace, to a dozen or extra panels mounted to your roof. How a lot photo voltaic is the correct amount? Sizing your RV Photo voltaic system correctly can prevent money and time in addition to ensure that your system performs as anticipated. This text is targeted on determining simply what number of photo voltaic panels you want.
RV Photo voltaic System Sizing
Individuals have informed us their solely large highway block to getting a system, isn’t figuring out how a lot photo voltaic they want. I’ll even admit I didn’t know both, and bought an multi function equipment that works nice, however isn’t fairly as large as I wanted. You may learn my evaluation of that equipment right here.
It doesn’t matter in case you’re residing the Van Life or RV Life or rocking a Faculty Bus Conversion, the best way you choose the dimensions of your system is similar.
Step one is to learn the way a lot energy you’re going to be utilizing. That is essentially the most tedious half, but additionally crucial. You might want to add up the overall electrical energy used from each equipment you could have. The simplest manner to determine the overall energy is to transform your whole calculations into watts. Don’t fear, there may be a simple manner to do that too!
RV Photo voltaic Energy Math
Your entire main home equipment could have a sticker on them someplace that claims what number of Amps its attracts and what number of Volts it runs on. For instance, now we have a residential fridge in our RV and contained in the door I discover the facility ranking sticker under.
Right here you see that our fridge runs on 115 Volts and attracts 3 Amps. To transform this to watts, we use the system AMPS x VOLTS = WATTS. So doing 3 x 115 = 345, we all know that our fridge is utilizing 345 Watts per hour when it’s working. I determine the fridge is simply truly working half of the day, and in standby mode the opposite half, so we take our Hourly Wattage (345) and multiply that by the Run Time (12) per day and get 4,140 Complete Watts Per Day.
Simple proper? Now we simply have to do this identical factor for all of the home equipment in your RV, and write it down, so we will tally up the overall watts per day for all of them. As soon as now we have a complete wattage for all the things we’re going to be working in our RV, then we will transfer on to the following step, which is selecting a kind of battery to retailer our RV Photo voltaic Energy.
Flooded Lead Acid
In terms of RV Batteries there are 3 principal varieties it’s important to select from. The most typical one, and the one that’s most probably in your RV from the manufacturing facility, is a Flooded Lead Acid (FLA) Deep Cycle.
It’s much like the battery in your automotive, however designed to have the ability to drain down earlier than being recharged. The FLA type of battery is able to a 50% discharge with out damaging it earlier than it must be recharged.
A FLA Deep Cycle is sweet for a median of 5 years earlier than they should be changed. Whereas they do have the bottom up entrance prices, they do require some upkeep to maximise their life span. After a median of 200 discharge and recharge cycles, a FLA battery will begin to have a decline within the quantity of vitality they’ll retailer.
FLA batteries additionally should be in an exterior compartment, and that compartment must be vented to the surface air. Through the charging cycle they produce gasoline emissions that might kill you if they’re in an inside space of your RV or Van.
AGM Batteries
The following kind of battery known as an Absorbent Glass Matt (AGM) Battery. An AGM battery is a complicated model of the usual FLA Battery. One main attraction to them is that they’re utterly sealed, so there isn’t any hazard of battery acid being spilled out of them.
AGM Batteries are additionally upkeep free and final on common twice as lengthy than a regular FLA Battery. On the up entrance value they’re going to value 20 to 50 p.c extra per battery relying on the dimensions of the battery.
LiFePO4 Batteries
The final kind of battery is a Lithium Iron Phosphate (LiFePO4). That is thought-about to be the holy grail in RV Photo voltaic methods. A LiFePO4 battery might be discharged 80 p.c with out lack of energy or doing harm to the battery itself. Most LiFePO4 batteries will final by means of 5,000 charging cycles.
At a fee of 1 cost cycle per day with a photo voltaic system, it ought to final you round 12 years in your RV. One other benefit to the LiFePO4 is it may well deal with a lot bigger sustained energy utilization than its lead acid counterparts. If you’re planning on working an AC unit together with your photo voltaic system, that is the best way to go.
The LiFePO4 does have the very best up entrance value, at a median of three instances the worth of a FLA battery, nevertheless they’re additionally just one third the burden. Relying on the dimensions of your RV Photo voltaic system it’s possible you’ll want a number of batteries to retailer the facility, in order that weight can add up quick.
How Many Batteries?
After getting determined which kind of battery is the most effective match to your finances and energy wants, the following step is to determine simply what number of batteries you want. For this we’re going to seek advice from the Complete Watts Per Day from step 1. So shall we say that after you added all of it up, you bought a complete of 10,000 watts per day.
You may convert the Amp Hours of the battery you select into watts utilizing the identical system to maintain all the things straightforward. For this instance lets assume we’re going to use a 200 Amp Hour LiFePO4 battery. So doing our math of 200 Amp Hours X 12 Volts = 2,400 Watts.
With a purpose to run all the things for twenty-four hours with no recharge, you would wish 5 batteries. If you would like to have the ability to run all the things for 48 hours with no recharge, you would wish 10 batteries. You might be solely restricted on the variety of days you go by your personal finances and out there battery house.
Many RV Photo voltaic professionals advocate with the ability to run for 48 hours on battery energy alone in case of foul climate.
How Many RV Photo voltaic Panels Do I Want?
So right here is the place the mathematics will get just a little tough, however not unattainable. You might want to know the way a lot Peak Solar you’re going to get every day to cost your batteries again to 100 P.c. Close to the equator you get extra, close to Canada you get much less. We’re going to use Common US Irradiance of 5.3 to assist determine this one out. Since we’re going to be touring all over, the quantity will change anyway primarily based in your location.
To learn the way a lot Complete Photo voltaic Energy you want, you divide your every day want by the 5.3 common Peak Solar time. Utilizing our 10,000 watt instance from above, we divide 10,000 by 5.3 for a complete of 1,886 Watts Of Photo voltaic Panels Wanted. To offer your self a cushion, and make your math simpler, spherical it as much as 2,000 Watts Of Photo voltaic Panels.
There are a number of mixtures you are able to do to realize the two,000 Watts you want. You are able to do 20 One Hundred Watt Panels. Or you are able to do 10 Two Hundred Watt panels. You are able to do 5 4 Hundred Watt Panels. You see what I’m getting at.
The approximate RV Photo voltaic Panel dimension is 2 Toes by 4 Toes. How a lot out there roof house you could have, will decide how manel panels you may truly match up there, which can let you know what wattage you want. For instance, say you could have sufficient room on the roof of your RV to solely match 4 panels. With a purpose to get the wanted 2,000 watts, you would wish 4 500 Watt panels.
What Dimension Photo voltaic Cost Controller Do I Want?
The reply to this query will rely fully on the Photo voltaic Panel Voltage, Photo voltaic Panel Wattage, and in case you plan to wire your Photo voltaic Panels in Sequence, Parallel, or Sequence-Parallel. Your greatest plan of action is to ask your RV Photo voltaic supplier what gauge wire you’ll need to go from the roof of your RV, which manner the panels ought to be wired collectively, and which of their cost controllers mates with the remainder of the system the most effective.