Off-Grid Energy: Solar

Intro

If anything separates comfort from roughing it, it’s the presence of electricity. Whether you’re camping, dealing with an outage, or are in a prolonged disaster, having power can really change the nature of the experience… most of the time for the better. With alternative energy coming to the market and promising great things, many people have turned to Solar to keep their devices charged and some lights on while camping. Some have incorporated Solar energy into their disaster plans.

There are some critical factors that we want to discuss in this article as they relate to solar power and disaster planning. The first thing we need to say is “temper your expectations”. Solar isn’t a miracle energy source, and the panels themselves aren’t as important as other factors – some of which you have no control over.

So let’s take a look at solar power, some of the strengths and weaknesses, and a few products we’ve tested.

Solar Power

Solar power uses crystalline cells to take sunlight and turn it into direct current (DC) electricity. While it seems pretty straightforward (Sunlight in, power out) the reality is that it’s not nearly that simple outside the laboratory. Here are a few things to consider as we take the first steps in separating fact from fiction:

• The basic function of a solar panel is to allow solar radiation to charge particles by freeing electrons.
• Orienting the panel towards direct sunlight produces the best results. The more obliquity (angle away from the sun) that the panel has, the lower the power output will be.
• The hotter the panel gets, the lower the output.
• The size of the panel is less important than the Wattage; A Watt is a unit of measurement of electrical energy.
• Direct Current isn’t all that efficient when it comes to converting to higher or lower voltages.* This means that in order to use the panel, you need to store the DC energy, and free it using an AC sine wave inverter.
• Most solar panels are given an STC and PTC rating: the PTC rating is the only one that takes into account ‘real world’ conditions, so pay close attention to it when you’re looking for panels (especially for a home array). You’re probably not concerned with optimal output in a laboratory setting.
• Batteries have an “amp hour” rating – like solar power, the rating and the reality are often very different. Here’s a great link to help you calculate the usable amp hours of your battery.

How we think about Energy

A friend of mine who is an electrical engineer told me when I asked him about solar:

‘The first thing you need to do is revise your expectations.’

Solar isn’t going to keep you in power like the grid does, at the time of this writing. Another piece of advice we’d give: Have a vision for the specific purpose of your alternative power array. If it is meant for a home, don’t try to buy a base camp setup and “make it work”. It probably won’t, and you’ll be disappointed.

The bottom line is, even panels and setups with high efficiency ratings aren’t nearly as efficient as fossil fuels. This is going to ruffle feathers, but trust us: we’d love solar energy to be the way of the future, too. In it’s current form, it’s just not.

It’s not efficient enough, lacks longevity, and requires specific conditions. At present the battery banks and inverters are insufficient to run a contemporary household.

So why consider it?

Solar Backup

We’ve found that Solar panels do a good job of a few things. They can trickle charge deep cycle batteries for low drain purposes (such as backup lighting). It can be used to keep small devices powered, as well. As to running a fridge or doing laundry, get a generator. Why? Most arrays/battery banks just aren’t up to the task of producing enough startup power to keep these appliances going.

When considering solar power, there’s a cost benefit metric that has to be considered:

The return on investment for a home sized backup kit usually takes 20-30 years, depending on the cost and financing. The lifespan of the panels is about 30 years, so think about the cost versus the benefit.

What does solar do well?

From our experience living in homes with solar panels, using solar basecamp setups, and mobile solar panels, here’s the long and short:

• Offset energy consumption: Solar panels on a home can offset your energy consumption and cut costs. Home systems are usually “grid tied”. The main benefit is the public utilities generally have to pay you for energy you produce. It can also keep lights on in a storm or outage, though these types of arrays can be damaged in such events.
• Keep small devices charged: Phones and portable MP3 players can be charged pretty easily off smaller systems. Even panels that can fit in your backpack can keep your devices up and common batteries charged. Our approach has shown that charging batteries and using them in devices works best… when possible.
• Gives a small measure of independence during grid down issues.
• An excellent way to keep high-efficiency lighting going during blackouts.

What it’s not:

• A path to energy independence (for most people used to the western standard of living – it won’t be).
• A energy source that will maintain your dishwasher, laundry, and refrigerator for extended periods if the power goes out.

Basically, if you’re looking to power small devices, while otherwise living a 1930’s standard of living, yeah! Solar all the way.

If you’re looking to keep modern appliances going, this is not the answer… at least at the time of this writing.

GoalZero Nomad7

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The Nomad7 is a foldable, 7 Watt solar panel suitable for backpacking. Bottom line up front, nothing about this device was impressive. It did fine charging the supplied AA batteries, but beyond that, it was an underwhelming performer. It has a solidly built port, which can accept USB and provides a couple common chargers. The battery pack comes with a little light on it, too. Quaint!

Just kidding. Ridiculous.

In traditional GoalZero style, it’s well advertised and the production value is good, but it stops short of being useful for anything other than a college student looking to charge an iPod. It’s not all bad, so let’s take a look at the Pros and Cons:

Pros:

• Slim, well-designed
• Portable
• Multiple charging options; USB and cables come with the panel, as well as a AA battery pack and 4 AA batteries.
• Versatile and affordable
• Reasonably priced – while it’s an older model, it’s available for $70, which is comparable to other panels.

Cons:

• Slow charging
• Heats up/loses efficiency quickly in direct sun
• Requires continuous efforts to optimize output
• Will not charge all devices, doesn’t do well with tablets/laptops.

Bottom line: A decent choice for cell phones or charging a few extra AA batteries. It’s not something I would carry as a minimalist, because frankly nothing it charges is critical. However, for a group, they could be handy. Especially paired with some hand-held AA battery powered radios. It’s not a bad panel, but for $80, there should be something that can manage a tablet, at least. It did poor job of powering the handheld HAM radio, and wouldn’t touch the Laptops.

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Giaride 40W solar

The Giaride 40W array was an impulse grab. As a ‘deal of the day’ on Amazon, it was listed for some half the asking price (~$60, at that time), and I was hoping it’d fill a niche that the Nomad7 failed with. High marks for Giaride for building a reasonably efficient panel setup, and no lie, I was very impressed with the size of the array. Folded, it’s 8 panels weren’t much larger than the Nomad7’s two. They also did a great job with an innovative adaptor setup, utilizing essentially a modular cord and adaptor that covers most modern electronics. We found the Giaride to be pretty efficient at getting a charge on our devices (Pads, radios, etc), but we also found that the device would read full and then just blow through the charge. It’s hard to say if that’s the array or the device, but keep it in mind any time you’re using sunlight to power your stuff. It isn’t perfect. The Giaride shows signs of cheap material and craftsmanship, and others have had problems with their ports working loose.

Pros:

• Small and well designed.
• Portable.
• Multiple charging options.
• Versatile and affordable.
• Fast charging.
• Capable of charging laptops and larger devices.
• Reasonably price: Found it on sale for $65, retail is around $100.
• It’s not GoalZero.

Cons:

• Material quality seems low.
• Gets hot fast. Others have complained about defects in workmanship, and the heat will certainly speed that up.
• Pouch for adapters is poorly sized, and doesn’t stay shut.
• Requires continuous efforts to optimize output.

Bottom Line: Does what the Nomad 7 does, but puts out 40W for not much more space, and instead of being proprietary, it’s got adaptors for everything. Don’t expect miracles, but it’s a reasonable setup for trickle charging small devices. The Giaride did a good job initially charging both the HAM and the Laptop (as well as FRS radios), but the charge didn’t hold long. Be aware that your device may indicate a false charge level after using these panels.

GoalZero Boulder 30 Base Camp setup

The Boulder 30 base camp array comes with 4, 30 Watt panels, a 350 Watt deep cycle battery, and an inverter.

The great news is that the battery is junk and the cables are all proprietary! Just kidding. That’s the reality.

The bad news is the same though. Within a year, the batteries were totally useless, and unable to be revived by desulfurizing methods. The inverter was pretty strong, but real talk: GoalZero is using literally the exact same battery you buy from Home Depot for lawnmowers. Made at the same plant in Mexico and everything. This may have changed with newer vintage, but what this means to you is: Don’t buy a GoalZero battery.

Not only are you paying way too much for what you get, but all GoalZero has done is made the plugs proprietary so you can’t rapidly adapt it to other charge controllers and panels.

The beauty of Solar is that it can be used to charge most batteries. Being limited to just the factory batteries (which aren’t anything special) hamstrings your ability to scavenge or daisy chain batteries, and use your own charge controller to rig the panels.

If you’re looking for a Clamping setup, look no further. If you’re looking for a way to actually power an expedition, you can build something better on your own with only some very basic electrical knowledge.

Pros:

• The panels are actually good quality, and are very tough.
• The setup is easy to scale up or down.
• The batteries are portable and stackable
• The hardware (ports on the panels) is definitely well made. The Cables too.
• The lighting package is tough, works well, and goes up easily. Great for camping.

Cons:

• The battery link cables are garbage. They break if you look at them wrong.
• The battery is just a cheaply made, generic 35 amp hour battery encased in a pretty shell. You pay $1/Watt (or $350) for a $25 battery. Literally the exact same thing as the little 30 amp lawnmower batteries you get for $35 at Home Depot, made at the same Johnson Battery plant in Mexico. Not at all worth what they ask.
• Poorly suited for anything beyond trickle charging small device.
• Stupid expensive for what you get. This setup was about $2750.
• My biggest pet peeve: Proprietary everything.

Bottom line, just avoid GoalZero. My initial impressions of the GoalZero base camp setup has changed a lot in the 6 years since I initially wrote my impressions of it. Initially, I thought it was both reasonable and well-made. After pulling some components apart, dealing with solar arrays weekly for a couple years, and seeing the deterioration of the products over a short period of time, I wouldn’t be comfortable recommending this product to anyone – especially at the asking price. This array would charge a laptop without a whole lot of trouble. It would charge the HAM radio as well. As set up, it had enough power – when there was sunlight – but the battery longevity was the failing link. Especially aggravating given the cost of the batteries. For a home based energy independence, go ham on insulation, efficient lighting, efficient appliances, and have a backup generator. After that, a solar array can help offset some costs, but the return on investment for most people is about the working life of the panels.

Conclusion

Get into solar knowing this:
It’s for small devices and lighting.

If you do, you probably won’t be disappointed. We opened this article with advice from an electrical engineer that said basically the same thing. Our experience (over 6 years of testing) suggests that this is still true. Our friend at Last Man Projects built a DIY emergency power pack that’s every bit as capable as the Boulder 30 array for $200. Between the lines, GoalZero is providing comfort gear… not hard use, reliable solar generators for any situation. Regardless of how much you want Solar to be the answer, the truth is you’ll be far better served with something simple, like Brandon’s DIY Power pack, and a small gas or diesel generator.

Solar has its place, truly, but keep in mind that unless you’re able to assemble a battery bank of 25 batteries, and top them off with a well designed array, you’re just never going to get much more than trickle charging small devices and lights.

We’ll keep testing some solar arrays, and we’ve got plans for our own DIY generator, but until, if you’re looking for a home backup, just go with a gas or diesel generator and a few gallons of spare fuel. If you do decide to get panels, keep them in perspective; their innate limitations mean you’re probably best off with something small that’s dedicated to managing small device charges, or if you’re in a climate that will sustain it, just go full tilt and put in a grid tie system.

Our experience says that if you’re using them for radios or phones, you’re doing it right.

Hopefully, this will serve as a useful guide for whatever you decide on.

Aaron

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*Electrical energy is either direct or alternating current. Nikola Tesla made a lifelong enemy of Thomas Edison (who was kind of a scumbag) by proving the efficiency of A/C when compared to D/C during the “Current Wars” of the 1890’s.