How to Calculate Your Solar Power Needs


Welcome back to eat crv! We are really excited today, because this is video number two of our solar series where we’re sharing, how to calculate your RV solar needs that’s right. We’re, going to be helping.

You calculate your actual energy consumption with your appliances, the battery bank, you’re, going to need to support that. How big of an inverter that you’re, going to need to power your appliances off your batteries and how much solar? You might want to keep your batteries topped off, while you’re operating in the woods.

This video is going to be slightly intense because it is a lot to cover, but we want you to be able to take it piece by piece and if you’re. Looking for something specific, like just information about the inverter or just information about the solar panels, go to the description below in the video notes, section will actually have timestamps, so you can go directly to the information that you’re looking for.

But if you are looking to do a full RV, solar kit and you’re, not quite sure how it all works, I suggest watching this video in full and make sure to go to our blog, because we have a very detailed write-up that gives Great graphics, I especially love our battery usage graphic so that you can better understand how this all works together.

Definitely read the blog in conjunction with this video. It’s just going to re-instill everything we talked about here and you can read it at your own pace. We’re, going to go through a lot of information today so be sure and read the blog as well so to get started.

The very first thing you’re going to have to do is determine your actual energy usage. So we suggest writing down absolutely every appliance on your RV that you would like to operate with your entire RV solar system and you’re.

Going to have to find the wattage that’s, how much power the device actually draws in order to operate and the wattage is going to help you determine the actual size battery bank. You need, based on the number of days that you want to be able to dry camp without having to plug into short power, run your generator and possibly, if you do have solar, but it’s cloudy for a few days and you’re not getting enough recharge for your batteries.

The wattage is also going to help. You determine the number of panels that you need and the size inverter you need. You’re, going to look for the wattage in two ways. One of the easiest ways is actually looking at the label that is on each product.

Sometimes it’s on a sticker other times it’s actually written on the item, but most every appliance. You have should have this wattage available and you’re, looking specifically for the output wattage.

Sometimes it only gives you the volts and amps of the output, and you’re, going to have to use a little bit of math to figure out the wattage when that’s, all they give you so you’re. Going to use the formula Watts equals volts amps, and that will help you determine the actual Watts.

If that’s, all that’s, provided sometimes you’re, going to see appliances that only give you milliamp s’now, if they only give you the milliamp, so you’re going to use The formula milliamps divided by 1000, which equals the amperage or amps, then you have to use the formula from before Watts, equals volts times amps to figure out the wattage.

If you hate math like me, I promise it’s not too intimidating, and our blog gives you real live examples of items on our RV. That only gave us milliamps or only gave us the volts and amps for us to calculate the wattage.

The easier way to do all of this is by using a kilowatt easy. This is a relatively cheap item that you can purchase and plug into an outlet. Then you plug your appliance in operate your appliance and you push the up or down button in order to see the actual wattage that the appliance outputs.

Now. This also will show you the amps, but you do not want to use the amps from the kilowatt easy, because most outlets on your rig will run on 120 volt AC. Now we’re, going to be pulling amps from your battery bank, which is in DC power, so unfortunately that conversion is not the same.

So even though you see amps on your kilowatt, ez do not use that number right. Now. All you’re looking for is the wattage. Once you’ve calculated the wattage for every single thing on your RV. You want to run you’re, going to need to figure out your average daily use.

You might be thinking well, if I know my wattage doesn’t that mean my average use, not always. For example, our co2 sensor runs 24 hours a day. So, in order for me to calculate that, I’m, going to times the wattage of our co2 sensor times 24, and that gives me the total wattage that I use in a day for that appliance.

Now you’re, going to do this for every single appliance again. This may seem tedious, but it’s, really not that bad. I make them up with a total number of wattage use in a day. So now we’re, going to take the average number of watts you use in a given day, and we’re, going to use that number to help.

You determine your battery bank size as well as the number of solar panels. You need and your inverter there are a ton of calculators online that you can use. None of them are really that great, but I’m, going to be showing you one today that I think does the best job and it’s from alt e, which is a solar company.

It has lots of information if you’d, like to learn more about how the entire solar system works. But you’re, going to go to the calculator and you are going to enter the total number of watts that you use in a given day.

So realistically, I calculated that I would be using twenty five hundred watts on average per day and that’s. If I use absolutely every single appliance, if I wanted to be safe and look at what we just use on a normal day without using extra appliances like my hairdryer, blender or coffee maker, I could calculate what I know I use, which is much closer to the Two thousand watts per day just to be safe, and for this demonstration I’m, going to use twenty five hundred watts.

The next step is to determine how many days you want to run your system without Sun. Most people like to shoot for two or three days without Sun: it’s, a general rule of thumb to get started. I’m going to enter in two days, but if you want to go longer, feel free to add that here next you want to estimate what the average temperatures your batteries will be exposed to, because you are V it’s unlikely.

You’re, going to be in the same temperature year-round, so you need to take into consideration if you do go into really low temperatures like 30 degrees or if you’re, mainly staying in a warmer climate.

We do move all over. The United States, so I’m, going to put 40 degrees. Sometimes we do get down to 30 degrees, but it is telling me that, based on my consumption, we would need 1246 amp-hours for our battery bank to allow us to run two days without needing to plug in to shore power or recharge.

Next, it’s, going to give you your solar panel information, so you’re, going to choose the state that you are in most often with. I know you guys moving around. Obviously it’s, not going to be a perfect answer, but the United States as a whole actually has relatively good solar exposure and for most places you’re, going to see anywhere from four to five hours of Sun.

Since we’re technically from Tampa Florida, I’m just going to enter that in here, and you can see it. Doesn’t change much from Colorado. Then it tells you the actual watts or kilowatts that you would want for your total solar panels and you get to determine if you want to have 100 watt solar panels.

If you want to do 150 watt solar panels right now, we have a setup with a hundred watt per panel, and it would tell us that we need 800 watts total. So you’d, want eight panels, and the last part of this calculator is actually sizing your solar charge controller.

It tells you based on the number of panels. It suggests you need what size charge. Controller you want. Few consideration is that you need to think about when choosing your battery setup number one. Do you want to do maintenance on your batteries? Because if you went with a flooded battery over a sealed or lithium once-a-month, you’re gonna have to crawl into wherever you have these things stored and refill the distilled water in the cells to keep the batteries healthy.

The second consideration is the actual space. Where you’re, going to be storing these batteries. Do you have enough space to store four or six, or only two batteries? Depending on what Bay you’re, going to be putting them in the third consideration, I would suggest you to think about is your budget.

You can go with a flooded system and it would be the cheapest possible scenario. You can go with the AGM system like what we have, which is sealed maintenance-free. So you don’t have to refill the water.

They’re gonna charge five times faster than a regular flooded lead-acid and they’re. Gon na give you a higher amp power rating than a flooded lead-acid battery, as well with that said, though, they are tad larger and they will require a bit more space to store than the smaller 12-volt led acid flooded batteries, so topping off the budget.

Scale are gonna, be your lithium ion batteries. Those definitely are way more expensive than the other two we mentioned, but the benefits are a lot greater as well. They’re gonna be smaller with higher amp power ratings.

You can discharge them a lot lower down to 20 %, as opposed to 50 % with lead acid or an AGM, and you get more charge cycles out of them, meaning that the life of the battery will be much longer than the previous two we mentioned important Note here before we go, any farther is: do not drain your batteries below 50 % of charge, because that can be very detrimental to the life of the battery itself.

So, in my opinion, it’s, always better to start with a solid foundation and as large of a battery bank as your space and budget allow. That way, when you start adding your solar panels on you & # 39. Ll have enough space to complement the amount of energy that the solar panels are pushing into the batteries themselves.

The next thing you need to determine is your inverter size. You already wrote down all of your appliances, amps and watt usage, and this is really where the watts come into play. You’re, going to look for the highest use, watt appliance for us.

The blow dryer was one of the highest usage. This actually ran us almost 1,100 watts to use our microwave really stole the show, though, at 1500 watts that told us that, for our inverter size, we were going to need at least 1500 watts in order to power.

The appliances on our coach, but we don’t, want to just be at 1500 watts if something pulls 1,500 watts. We want to be safe and give ourselves a buffer, so we went up to a 2000 watt inverter. Now there are two types of inverters modified sine-wave and pure sine-wave.

We suggest getting an inverter that is pure sine-wave and if you go to our blog post, there is more information as to why you would choose a pure sine-wave over a modified sine-wave. But it’s. Just going to allow your appliances to work a little bit smoother first bit, we want to talk about in the solar panel setup is at the actual solar charge controller.

Whenever you’re, looking at solar charge, controllers be sure to go with one that has possibly a higher amperage rating, then you actually need the renergie kit that we got was a 300 watt panel kit that came with a 40 amp charge controller so That means we can actually add an additional panel to the roof later if we want and run it through our solar charge controller, just save yourself some money and go bigger the first time because you don’t want to have to do a reinstall Of the solar charge controller later, the very last piece of puzzle is the actual solar panels themselves.

Now there is no perfect formula to help. You calculate the number of panels you need and that’s, primarily because it depends on the type of panels. You have there’s, a flexible panel there’s, monocrystalline panels, polycrystalline panels.

You can either tilt your panel or keep them flat. So there’s, a lot of variables that first off affect the quality of energy being pulled in from your solar panel to begin with, and then you have to take into account the latitude that you’re at the season.

You’re in if it’s actually a sunny day or not, and that’s also going to affect the amount of amp hours being produced from your panel. So there’s, no perfect answer, but we found on average for our 100 watt panels.

We get anywhere from 4 to 8 amps per hour, and that equates to about 25 to 35 amp hours. In a day. These solar calculators are great, but take them with a grain of salt, because the calculator told us we needed 800 watts of solar panels, plus a thousand amp hours worth of battery bank storage.

We don’t have the budget nor the space to accommodate that kind of system. So we ended up going with what our budget and space limitations allow. We ended up going with a 300 watt solar panel kit, plus a 120 watt portable LAN kit, and only a 225 amp hour battery bank system.

So while those numbers might sound compared to the perfect solar system that the calculator told us to get, we actually find that that works very well for us. As long as we have good Sun hitting the solar panels, we can run at least four or five days without ever having to supplement with the generator.

The Achilles heel, though, is going to be. If it’s, a cliff it’s. Cloudy for a week or rainy for a few days, we will have to supplement with our generator but hey as a give and take for what our space and our budget would allow.

You might be asking yourself. So what do I really need that’s? Gon na be a decision you have to make for yourself definitely take into account the perfect solar setup that the calculator gives you and then decide where to go from there.

As far as your space and your budget allows, that was a lot of information. We hope this made sense for you and we kind of broke it down into a digestible and understandable way. But if you do need more support, even if you don’t need more support.

We do suggest reading the blog post, because it gives lots of beautiful graphics and further detail to help you better, create the perfect RV solar system for your rig and your needs yep. If you have any additional questions for us feel free to leave them in the comments below.

You can also leave comments on the blog page. If you liked this video, give it a thumbs up. While you’re there, if you haven & # 39, t already hit the subscribe button and ring the bell that way, you get alerts for future releases.

Next, we’ll, be talking about our inverter and batteries install it’s more of a DIY than a how-to. But if you’re interested in seeing what we did for our rig, we’ll. Have that in our third video for the Solar Series? Alright stay tuned, we’ll, see you next Monday, bye, [, Music, ], [, Music, ]