If you’re looking to power an off-grid cabin, reduce your power bill, or even just make your home a little more eco-friendly, solar power is one of the most cost effective power solutions on the market. Solar energy is becoming extremely common. In many states, you’ll get a tax deduction for installing solar. If you want to save money on batteries, you can use a grid-tied inverter to feed excess power right back into the grid. No matter what your situation, there are plenty of ways that solar can be used to solve your problems.
Designing a solar system can be tricky. You’ve got to find the right way to store your power, select the correct cables, and find an appropriate solar charge controller. But the most important component of the entire system is your solar panel, and there are many different options to choose from.
No matter what your needs are, a 100 watt monocrystalline panel is often the best choice. We recommend 100 watt panels because they are easy to scale. Whether you’re using a single panel on your RV, or a whole pallet of panels on your home, 100W panels share a common size. This makes it easy to add more if you want to, and you’ll be able to install them on common brackets.
Why You Should Choose Monocrystalline
Panels come in two different forms: monocrystalline and polycrystalline. The individual solar cells are made from a silicone. Monocrystalline cells are cut from a single solid piece of silicone. Silicone is made up of crystals. On mono panels, each cell is made from a single solid crystal. On polycrystalline panels, several silicone crystals are bonded together.
Monocrystalline panels are significantly more power efficient. They produce up to 30% more power, and can handle a wider range of light angle. This means that you’ll be generating power earlier in the day, and later into the night.
Poly panels are cheaper to buy. Several years ago when panels were much more expensive, the savings from poly was worth considering. Today, solar panels are very affordable. You only pay a small premium for monocrystalline, and the benefits are well worth it – especially in large systems.
What Voltage Do I Need?
The large majority of panels on the market are 12V. If you’re buying larger panels (200 Watts and up) you’ll often see 24 volts, or even 36 in some cases. There are good arguments for using a higher voltage system. If you’re using an MPPT controller, 24 volt and higher systems improve panel performance in low light conditions. If you’ve got long cable runs or large amounts of current going in or out of your batteries, higher voltages can reduce line loss. But a common misconception is that you need higher voltage panels in higher voltage systems.
By buying 12V panels, you’ve got enough flexibility to set your system up any way you want. If you wire them all in parallel, they’ll stay 12 volts. If you wire sets of two in series and parallel each set together, you’ve got a 24V system. Three is 36 volts, four is 48 volts. The important thing to takeaway from this is that even if you plan to run higher voltages, the 12V panels will work perfectly. For that reason, this is the size we always recommend.
Will any 12V 100W Panel Do?
Although we recommend this specific type of panel over any other, there are still many differences between them. From mounting arrangement to construction to price, there are many factors to consider. In this roundup, we selected our top three favorite panels. We’ll go through each panel one by one to help you understand the differences between them. After, we’ll help you decide which option is right for you.
Renogy 100 Watt 12 Volts Monocrystalline Solar Panel
One of the most well-respected solar system manufacturers on the market is Renogy, and for good reason. Although their panels aren’t much more expensive than competing brands, they’ve proven to last a long time. Since a full size household solar system can often take 10 years or more to pay off, you really want your panels to last 20. And there is no brand we’d trust more than Renogy for this.
Design & Build
At 47 x 21 inches, these are your standard size panels. The cells are protected with a thick piece of shatter resistant glass, and the frame is made from aluminum. This keeps them fairly lightweight at 16.5 pounds. If you’re installing a couple panes on a van, this weight helps reduce strain on your aluminum or fiberglass roof. If you’re installing a large system on a home, the light weight design helps keep costs low by allowing the use of lightweight mounts.
The aluminum frames come pre-drilled with many mounting holes, and Renogy also sells Z-brackets and bolt kits. This means that, even if you’re inexperienced, getting them mounted is easy. They also use the modern MC4 connectors – a standard and plug and play connectivity system. This makes it easy to tie these panels in with your existing system, or to find the cables locally on online.
The 100 watt designation is more of a general guideline than a true power rating. To find out how much power these panels will actually produce, you’ve got to look at the specifications closely.
These panels have an optimum operating voltage of 18.9 volts and an optimum operating current of 5.29 volts. Wattage is simply volts multiplied by current, so you’ll get 99.9 watts in ideal conditions with a high end MPPT controller. If you’re using a PWM controller (the most affordable and common types) the voltage will be stepped down to 12 volts while charging your batteries. With these cheaper controllers, you’ll get about 63 watts.
These are ideal conditions. Occasionally you’ll get higher amounts of current, but this is what you can expect in direct sunlight during an average day.
You can tell from the moment you pick them up that these panels are built to last. The construction is extremely heavy duty, so you don’t have to worry about them being damaged.
Renogy has all wiring mounted inside an IP65 junction box which is totally weatherproof. The panels themselves are capable of withstanding 5400 pascal snow loads, making them suitable for use even in the chilly states! This is enough weight that they can support an entire winters worth of snowfall, although you’ll probably want to clear them off if you want them to work! If you’re mounting them on a camper van or RV, the 2400 Pa wind resistance means that you can even drive with them on the highway.
In the even that some kind of damage does occur, Renogy provides a 5-year warranty for any physical defects. Additionally, there is a 25-year warranty guaranteeing their power output. If the panels start to degrade and their performance drops, you can get a free replacement.
Alternate Option: ECO-WORTHY 100 Watts 12 Volts Monocrystalline Solar Panel
If you look at the specifications, you’ll notice that this panel is nearly identical to the Renogy model. The frame looks the same, and the cells have identical specifications. You can save a few bucks buying this model, so it seems like it’s a much better option.
There are a few key reasons why you might want the ECO-WORTHY panels. With the Renogy, you’re paying more for the warranty and durability. This model doesn’t support as much snowfall, and it can’t support as much wind. But if you’re living in a warm climate and don’t plan to mount it to an RV, this is a great alternative. If you’re installing 10 or more panels, the discount you get can really add up. So in some cases, we’d recommend this option instead.
HQST 100 Watt 12V Monocrystalline Solar Panel
If size is important to you, the large aluminum frame used on most modern panels can be a problem. Not only do you need to purchase brackets to mount the panels to, but you’ll be adding a ton of weight to an existing system. These flexible panels are the smallest and lightest option you can buy. It’s easy to install them on curved rooves, and installation is a simple process of laying down some spray adhesive.
Design & Build
On the HQST solar panels, the silicone cells themselves are actually made from a flexible material. On most panels, they’re protected with glass and aluminum. But by mounting the panels to a vinyl backing and covering them with a silicone matte, you get something that is only a fraction of an inch thick.
These flexible panels can be bent up to 30 degrees. If you have an RV or camper van with a curved roof, these panels allow you to mount them flat against the roofline. This can improve your fuel economy by reducing wind drag.
The thickest part of the panel is the top-mounted MC4 connector and junction box. The cables come out each side, so series connections are simple. You won’t need any extension cables, just plug one panel into the other.
If you’re not interested in permanent installation, metal grommets in the corner let you affix them with rope, straps, or even Velcro. You do need to mount them against a solid surface, but no other design offers you this much flexibility.
With an optimum voltage and current of 17.7 volts and 5.70 amps, these panels can put out a staggering 100.89 volts under ideal conditions. When was the last time you saw a manufacturer under rate their equipment? It doesn’t happen often. Even if you’re using a cheaper PWM charge controller, you’re still getting close to 70 watts.
There are many flexible solar panels on the market, but many of them have significant electrical disadvantages to hard-top panels. This model performs just as well as the best 100W panels on the market, so there is no disadvantage to choosing this option.
Flexible panels have a lot less material to protect them then full size panels. But unlike earlier models, these ones can hold their own. You can reasonably get 5 years out of them in challenging conditions. By challenging, we mean situations where they are exposed to large amounts of force. Mounted no a roof in a high wind area, or on the top of your RV while driving are examples of tough areas.
If they’re in a stable place, you’ll get close to 10 years out of them. You can improve this life by using silicone around the edges to prevent weak points, and by mounting them to a flat surface with no uneven parts.
Which 100W Panels are Right for Me?
There isn’t a ton of difference between one panel and the other. The model you choose depends primarily on the size of your system, your budget, and where it’s going to be mounted.
We’d recommend using the HQST 100 Watt Flexible Panel if you want something temporary, or if weight is a consideration. These are a popular choice for RV owners, as well as people who want to bring some panels out to their summer cabin, but use their system at home during the winter.
If you’re installing a system with 5 to 10 panels, the Renogy 100 Watt Solar Panel is a good choice. This panel has the best warranty on the market, and tends to last the longest. With smaller systems, every panel counts. So you want something that’s not going to degrade over time, so you can get the most from your investment.
For very large systems, the Eco-Worthy 100 Watt 12 Volt Solar Panel is a great alternative to the Renogy. You save a few dollars, which can really add up while building a large system.
No matter which option you choose, it’s important to remember that choosing the right solar charge controller is just as important as your panel! We recently write a guide to help you select one, so make sure you check it out before you buy your whole kit.