Do you want to go solar, but are worried about the price? You don’t have to be! We’ve been living, traveling, exploring, and thriving all over the continent for the past nine years with just 100 watts of portable solar. Let me repeat that...100 watts of solar for the past nine years for our 72 square feet of living space. Our small system cost us about $1,000 and allows us to live, work, and play from almost anywhere.
One mistake people make while converting buses, doing van builds, or RV remodeling is that they try to duplicate everything from a traditional home into a mobile one. For sure, the copper bathtub in your bus looks amazing on your Instagram page but how much energy and water are required to fill it? And how often will you actually use it?
Instant Pots are all the rage right now, but they also have a very high energy demand. Just because you have the space for ten solar panels on your roof, do you really need that many? Some smarter choices that fit your lifestyle goals, will make your mobile lifestyle more sustainable in the long run.
As seasoned tent campers, we thought about our rolling home more like a super comfy, hard-sided tent, than a rolling apartment. This focused on powering what we really needed: lights, exhaust fan, charging laptops, personal electronics, etc. Keeping our needs small, keeping our system small, and we’ve found it enough to sustain our lifestyle. After all, the goal of our downsize was to simplify our life, not overpower it!
Over the years we’ve learned how to squeeze every drop of energy from our system. If you are just starting your build, putting these strategies into your plan can help you make the most of a system that will meet your needs.
#1 Charge Batteries While Driving
We began our solar-powered adventures with a portable panel stored in a secured, custom-made rack so that it could charge our house battery while we went down the road. This offered the great benefit of easily removing the panel so that we could park our vehicle in the shade and still keep the panel out in the sunshine.
Installed this way, we enjoyed the benefit of both portable as well as permanently installed rooftop panels and we didn’t have to use our precious, stored, solar energy to cool our living space down with a fan -- the shade of the forest did the hard work for us. Now, nine years later, with so many new charging products and methods available, any new bus conversion should take a multi-source charging approach to keep the house batteries full.
With the engine running, and the alternator charging the starting battery, it’s a shame to not send an adequate charging current back to the house batteries while simultaneously collecting solar energy. This is a great alternative, especially for those times when the weather may compromise solar gain.
With our Lithium Iron Phosphate batteries, we make the most of a Dual Input DC to DC charger available in 30A and 50A models which plays the role of battery isolator and solar charge controller. These chargers will accept both a charging current from the starting battery as well as a solar array. (Just a note, it’s never a good idea to connect any secondary battery directly to the engine’s alternator).
Many come standard with MPPT (Maximum Power Point Tracking) charging technology which increases the charging efficiency from 10-40% over a standard charge controller with PWM (Pulse Width Modulation). These units have the added benefit of keeping the starting battery charged once the house batteries are full so that you won’t end up stuck out in boondocks with a dead starting battery.
Just this past fall we installed a single input DC to DC charger available in 30A and 50A models. In my parent’s 2017 Toyota Highlander which pulls their 20-foot RV. It has made all the difference in their ability to charge while driving. The charger acts as a pump, boosting the charging current coming from the starting battery and feeding their house/service battery bank. What previously couldn’t be accomplished in a full day’s drive now only takes 2 to 3 hours!
To determine which style of DC to DC charger is best for your needs, and the appropriate size for your system, check out this article.
#2 Use 12 Volt/DC Appliances, USB Charging, & LED Whenever Possible
When living with solar, you have to think of it as a bank account, you can only consume what you can produce through your various charging methods. So, a penny saved is a penny earned, so to speak.
Simply put, if you can use the DC power coming directly from your battery without having to power up an inverter, you will maximize your energy savings. Big solar systems with large battery banks certainly can power anything you want through a 3000-watt (or larger) inverter, but it requires power to do that which eats into your daily solar savings account.
Our DC appliances include: 12V LED strip lights, LED light bulbs, a 12V Fantastic Vent/Fan, and a USB charging station for all of our small electronics, which also keeps them organized.
When we first started out on this life journey, we didn’t fully comprehend the impact that using DC power over AC or LED lighting over incandescent would have on our house battery. During our remodel, our budget ran low, so rather than purchase new lighting, we pulled a string of incandescent lights which we’d had on our house deck to use inside our tiny living space, but this 60W AC appliance simply ran our battery down very quickly.
We had compact fluorescent lightbulbs in our sconce lighting, which drew less power than incandescent but still too much at 15W. But, when we switched over to LED lightbulbs, we took our energy use down to 6W per hour per bulb. Spending the extra time researching any 12V/DC appliance options will pay off later, especially anything that will run for a few hours a day, like refrigerators, lights, and fans.
Sticking with the bank account analogy, knowing how or when to spend your hard-earned solar savings will help you allocate where and when you most need them. At the end of the day, you’ll want to run lights, and other appliances, but do you have enough energy stored? If you’ve sized your system appropriately, you shouldn’t have to trade off on running what you want. (Learn how to size your system in our “Solar 101” video.)
Here’s where you have to experiment with your own system. While running the load you desire, pay attention to the battery’s charge status, (either through Bluetooth Monitor or Battery Monitor). As you observe the battery’s charge status go down over a given time, do the math and see if you have enough.
If you don’t, then it’s time to prioritize what you really need to run and for how long. For example, during the summer, our vent fan needs to run all night long. Even with such a low wattage appliance, we make sure we don’t spend all our daily savings on a high wattage appliance that might leave us sweating in the middle of the night. Investing in your own choices and these simple savings strategies will pay dividends over the long haul.
#3 Limit Your Need for Electricity
This mantra of the solar-powered movement can initially turn people off because it requires a bit of creative thinking. But is that really any more creative than transforming a bus into a home or place of business?
In our traditional on-grid homes, 120V electricity powers many cooking appliances, but that’s not the only way to make great food. Sure, we could run a toaster, coffee pot, instant pot, kettle, microwave, waffle iron, or electric skillet with solar. But we choose other methods to limit our need for extra solar panels and batteries...not to mention the storage space for all those appliances.
We use a flat top griddle on our 2-burner propane stove to make everything from toast and pan-cakes to paninis and veggie burgers. We reheat food in about five minutes, sauté veggies, as well as bake scratch-made recipes in our Banks Fry-Bake. The stovetop kettle and French press make our daily coffee, and an Amish (non-elec-tric) waffle iron makes the best Sunday brunch you’ve ever had!
We are serious camping foodies who never shy away from making awesome meals, even as we limit our need for electricity. We use our vintage 2-burner propane stove inside, our portable camp stove outside, and we never miss a chance to cook over a campfire. The only electric kitchen appliance we even have is an immersion blender to occasionally make smoothies, sauces, pesto, blended cocktails, whip cream, egg white meringue, and more.
The nay-sayers exclaim, “You must spend a ton of money on propane!” Nope, we only spend about $100 per year for propane for both cooking and heating our small space. In our previous traditional home life, it was 15 times that amount!
Another way to limit your electricity is by questioning what it is that you really need. Do you need to power a conventional refrigerator and freezer, or can you live with a 12V fridge/freezer which consumes much less wattage? How much joy does that big-screen TV actually bring that you couldn’t get from your tablet, laptop, or smartphone?
Or even better, engage in activities and entertainment that require no electricity at all – walking, swimming, yoga, hiking, kayaking, cycling, and more. One of the main reasons we wanted to live this lifestyle was to be healthier and live outside more than inside, which has probably added ten years to our lives at this point.
#4 Use an Extension Cord to Maximize Solar Exposure
One question we get all the time is, “Can you run an air conditioning unit with solar?” It depends on the size of your system (number of panels and batteries) as well as the size of your A/C unit.
With a small system like ours, we cannot run A/C, but with our strategies, we simply don’t need to! In the summertime, we typically travel north to cooler and less humid climates. We try to park our vehicle in the shade while keeping our 100W Folding Solar Suitcase out in the sun with a Solar Panel Extension Cord.
Tip: Make sure your extension cord is no more than 20-feet long, or you will start to lose some efficiency via the transmission loss in the wire.
This allows us to keep our living space comfortable through the passive cooling of the forest canopy. We don’t need to waste battery power by running the exhaust fan all day. It’s surprising how cool it can be with just the bedroom window open and the fan pulling air across us at night.
These two tips can have a huge impact on your success when living with off-grid solar. By adjusting your expectations, getting creative, and parking strategically, a small system can be all that you need.
We’ve also learned some tricks to get the most from it. Here are our last two strategies, as well as some backup plans when the weather simply isn’t cooperating.
#5 Pay Attention to the Sun’s Angle
This may seem very basic, but there’s some science and pre-planning that will make a huge difference in maximizing your charging potential. If you use a portable solar suitcase (exclusively or in addition to permanently mounted panels), you can move it into the best sunlight without having to move your vehicle.
These portable panels can be combined with rooftop panels if you find you need more wattage. We’ve seen vehicles of all shapes and sizes use this method...from bus conversions and RVs to vans and vintage campers.
Solar panels produce the highest current when placed at a perpendicular angle to the sun. As the seasons change so does the sun’s angle to our location. That’s why you’ll see solar farms with rows of panels facing the south, with either a fixed angle to average out those seasonal changes or with motorized gimbals to adjust the angle and tilt of the solar array to maximize collection.
We’re always thinking about the position of our portable panel and its angle to the sun. Before we go to bed at night, we’ll shift our panel to face the rising sun in the morning. Especially during the summer, the sun often rises earlier than we do, so taking advantage of that early light can make a big difference.
Likewise, throughout the day, we’ll pay attention to where the panel is in relation to the sun’s path across the sky. If we leave for a hike, we’ll place the panel in the optimal spot for the middle of the day, which provides the best light to charge our batteries.
If you have roof-mounted solar panels, another option is to install them with tilting brackets for those times when you’re set up in a more long-term location and want to take advantage of that extra optimization. Just make sure to return them to their flat position before you get back on the road -- your solar panels, roof, not to mention the underpasses will thank you.
These simple adjustments can make a huge difference in the charge on your battery! While it takes some time to begin thinking this way, you can maximize your watt-hours with some easy pre-planning.
#6 Go Lithium, then Make Use of Excess Power
Before we talk about excess power, let’s talk about batteries for a minute. Many people don’t understand that not all deep-cycle solar batteries are created equal.
There are four different types and they simply couldn’t be more different. While each battery type has its benefits, the cost per watt-hour of a Lithium-Iron Phosphate (LFP) battery is the absolute lowest.
LFPs may have a higher price tag upfront, but it’s going to save you a ton of money (and store twice as much usable energy) in the long run. Check out this article for a side-by-side comparison of typical solar batteries.
Now that we have shown you how to get the most out of a battery purchase, let’s talk about usage.
Once your battery is full, any additional power collected by the panel will go to waste – unless you use it. Before we head out for a day of fun, we check our battery’s status via our BT Module using our smartphone.
If the battery is full or close to full, and the panel will be illuminated for much of the time we will be gone, we use the excess power to charge some of our devices (e.g., laptops, portable speakers, camera batteries, AA/AAA batteries, phone, etc.)
When we return, both our house battery and devices are full and ready to use. This is also a great time for using high wattage appliances (like an instant pot) as you can keep your battery full and just use the excess wattage coming in from the panel. It’s simple pre-planning, but extremely effective and doesn’t require the purchase of an additional battery.
What Can We Run with Our Small System?
We can power our LED light strips and sconce lights, our Fantastic fan, charge up our laptops, smartphones, and other personal electronics, as well as run just a couple of small household appliances like an immersion blender and electric blanket. We keep our needs simple, so our power draw is small.
The Cost of Our Small System:
Total = $1000* ($900 with our 10% discount using promo code “canlife”)
*As Renogy Ambassadors and Affiliates, we’ll help you think through what you need and get you 10% off Renogy products by using this link and discount code (canlife). For under $1000 you can set up a small bus with solar power!
What’s your backup plan? What to do when the lights go off…
Every cynical critic of solar power will ask, “What happens when it’s cloudy?” While annoying, they have a point; there will be times when you cannot charge adequately because of weather and location. Though we’ve rarely experienced a several-day stretch where we can’t get any solar charge, it’s a great idea to have a backup plan.
DC to DC Chargers - As we mentioned in strategy #1, charging while driving is a great option for any bus, van, or RV. These chargers will boost the charging current coming from the starting battery in the engine compartment to appropriately charge the house batteries. So, just driving from place to place will get everything recharged, regardless of the weather.
Inverter Chargers - Also known as “Through Inverters,” these can charge your battery bank while your rig is connected to shore power. Spend a night in a state park campsite with an electrical hook up and make the most of it, or visit that friend in Portland, and plug into their house for a night. Be sure to cook them dinner in return.
AC to DC Chargers (for LFP batteries only) or standard Trickle Chargers (for lead-acid) - These chargers convert AC shore power into an appropriate DC charge for your battery bank. On those rare occasions when we’ve splashed out on an electrical hook-up campsite, we just connect this device and have our Lithium Iron Phosphate charged back up in about an hour. Note: Standard trickle chargers can take 12-24 hours to get a lead-acid battery back up to full charge.
Portable Power Stations - In addition to these great backup strategies, we also carry a portable power bank for some extra “insurance.” This can be charged via a solar panel, vehicle 12V outlet (cigarette outlet), or a traditional wall outlet.
We hope you found these six simple strategies for maximizing a solar-powered system helpful as you build out your bus. To size, a system that meets your needs, download our comprehensive Solar System Sizing Worksheet from our website.
If you have further questions, feel free to reach out to us at email@example.com. We love to help!