Ever since I became aware of the need to be prepared for a disruption of life as we know it, I’ve been drawn to solar power. I’ve been impressed with solar power since the first time I saw a solar powered calculator many, many years ago. A tiny photovoltaic chip generated enough energy from ambient light to run a calculator. How cool is that?
I’ve wanted to dip my foot in the solar pool (so to speak) as part of my preps. What has kept me from it so far is that I wanted to start small. Why? Because solar can be expensive and I’m on a low budget, and because I’m a solar power dummy. Unfortunately, the problem with starting small in solar power is that there just aren’t a lot of small applications that would be of any real value to me. (Beyond the nifty calculator mentioned above, that is…but these days that doesn’t have a lot of value either.) Yes, I could shell out $100 for a solar gadget that would recharge a cell phone or power an LED light, but it just didn’t meet a real need or solve a real problem in my life, so I put solar power on the back burner.
I’ve Finally Got a Problem that Solar Power Solves!
But now I’ve acquired a problem for which solar power is the ideal solution. In my last blog I discussed our decision to purchase a pellet-burning stove (as opposed to a more conventional wood-burning stove) as an alternative heat source for our home. You can read about my contrarian reasoning in that blog. But one of the key factors that impacted my decision to go with pellets was a critical piece of information provided by my stove vendor. He told me that a pellet stove, while it requires electrical power to operate, uses so little electricity that you can get a battery back-up unit to run it when there is a power outage. I asked our stove guy how much a back-up system like he was talking about would cost and he said $500.
I’m no stranger to battery back-up systems. We’ve been using battery-powered back-ups with surge suppressors and voltage regulators on all of our desktop computer systems in our office for over 20 years. The problem with those battery back-up units is that they don’t run very long. The battery just isn’t big enough to provide power for very long. They have to be recharged from a working electrical outlet. That’s not a long-term solution in a grid-down situation. And that’s when I knew that I had found my perfect small-scale application for solar power. I could get a battery back-up that recharges from a solar panel. No need for an electrical outlet. So long as the sun keeps coming up each day, I would be in business.
What Components Do You Need for a Solar Power System?
If you’ve read this blog for very long, you know that I’m a guy who knew nothing about prepping when I started. Dumber than a bag of hammers when it came to gardening, guns, first aid, ham radio, solar power — you name it. But I like doing research. I read a lot. I like to shop online. So I set about to learn what I needed to meet my modest solar power need.
My research soon took me to a line of products offered by Goal Zero, a company that I liked well enough to add as an advertiser to this site. They make a nice line of products that address a wide range of small-to-medium sized solar applications, including three sizes of portable “solar generators.” Sounds like just the thing. And at $460 for the Yeti 400 model, the price was in line with the stove guy’s quote of $500 for a conventional battery back-up for the pellet stove.
Not content to be taken in by Goal Zero’s slick website, I dug further online looking for reviews of their products from people who weren’t selling them. I lurked online in solar power forums and off-grid websites. What I found were two types of people: those who actually used Goal Zero products and liked them, and those who claimed that you could easily assemble components to build your own system for half the price. The second option intrigued me. If I can put my own kit together, be able to upgrade bits and pieces as needed, and save a buck in the process, I’m all for it. (More on Goal Zero vs. DIY below.)
What components do you need to build a solar powered battery back-up system? You’ll be pleased at how simple it is:
- An energy source. Since we’re talking solar here, solar panels are the obvious choice. Just to expand your thinking a little bit, the power source could also be a windmill or a water wheel, but for our purposes, we’re sticking to solar panels for now.
- A charge controller. Solar panels capture energy from the sun, but they don’t store it. You need a battery to store the energy until needed, but you can’t tie your solar panels directly into the battery. You need a charge controller between your panels and your batteries to control the flow of energy into the batteries. As it turns out, batteries are kind of fussy about such things. Too much juice all at once will ruin them, so you need a charge controller.
- One or more batteries. Batteries store the electrical energy until you tap into it. Be advised that there are a lot of types of batteries that can be used with solar systems, and some kinds are better for some applications than others. I’ll do a blog that discusses battery types and features in the future, but this one is about solar power for dummies, so we’re keeping it simple. But I will say this — not all batteries are suitable for indoor use. Some of them emit fumes that require that they be for outdoor use only. Read the small print before you buy.
- An inverter. Solar panels and the batteries used with them have something important in common. They work with direct current (DC) power. Your car battery also uses DC power. Nothing in your house does. All the electrical appliances and gadgets that we use run on alternating current (AC). So how does one get the DC power stored in your batteries into the AC power that your electrical stuff craves? With an inverter. Don’t ask me how it does it. I’ve already told you more than I know. But the bottom line is that you plug your stuff into the outlets on your inverter and it works, just like plugging into your home’s electrical outlets.
Just four pieces. Panels, charge controller, battery, and inverter. Mystery solved.
Is that really all you need? If you’re keeping it small, portable, and simple, the answer is yes. If you’re going to expand your system, which you can do to meet your growing needs, you’ll want to add fuses and input/output meters and who knows what else. But at that point you’ve gone beyond small, portable, and simple, which is what we’re shooting for today.
More on Inverters
I told my stove guy that I was looking into a solar powered solution to my electrical back-up need for the pellet stove. He was dubious. While he was pro-solar in general, he had heard a number of reports from customers who had tried solar powered back-up systems and had poor results. The electrical components of the pellet stoves ran erratically or not at all when running on solar power. He didn’t know why.
Ah, but I do! It all goes back to the inverter, the magic box that coverts the battery’s DC power to usable AC. The electricity coming out of your wall socket comes out in nice, smooth “sine waves.” All of your electrical devices love these pure sine waves, but less expensive inverters don’t generate pure sine waves. They generate “modified” sine waves. In this case, modified means chunky. Depending on how good the modification is, the waves can be almost pure or they can be clunky, chunky stair steps. A modified sine wave is good enough for many electrical devices, but not all of them. You’ll get a lot of “noise” on TVs or audio devices — and apparently, pellet stoves don’t like modified sine waves at all. For my purposes, I would need an inverter that generates pure sine waves. You can buy them, but they’re more expensive than modified sine wave units.
DIY vs Goal Zero
So how does the home brew system match up with the sleek and sexy Goal Zero equipment? I put a lot of time and effort into finding the right components to beat the price of the Goal Zero Yeti 400 solar generator, but I just couldn’t do it. Too many trade-offs. I wanted small, simple, and portable. I wanted something that was safe for indoor use. I wanted a pure sine wave inverter. The expandability of a homemade component system would be nice, but not absolutely necessary for a starter purchase. The Goal Zero Yeti 400 provides all of the features I wanted and more.
If (when) my power goes down, I’ll want more than just my pellet stove to work. The Goal Zero Yeti 400 has two AC outlets and two USB ports. It doesn’t come with solar panels. You have to buy them separately (just as you would with a homebrew system). But here’s a huge plus — you can also charge the battery on the Yeti 400 by just plugging it into a wall outlet. Your home’s electrical system can keep the Yeti fully charged and ready to rock until your power goes off. This is a feature that I really, really like, because recharging the Yeti from solar panels might not always be a better option than from a wall outlet while the grid is up. It also meant that I didn’t need to buy solar panels right away (which my dwindling budget appreciated). A wall outlet recharger would be a fifth piece to a DIY setup, and I only found one vendor that carries anything like that. You can buy them online from Northern Arizona Wind & Sun, but it adds $154 to the price of the component system. This made the Yeti the clear winner for my needs in terms of both features and price. Another added plus is that you can also recharge the Yeti from a car battery. That feature might be the icing on the cake for some users, but it’s not something that I feel a need for right now. But it’s there if I need it. Better to have it and not need it… And the Yeti also has a simple meter built into its control panel that shows you how much charge is currently in the battery and how much power is being drawn by the stuff that you’re running off of it. A meter like this would be another expenditure in a homemade system.
Getting back to the expandability issue that I said would be nice, the Yeti 400 allows you to daisy-chain more batteries to the system, giving you more capacity than what comes in the box. You can’t add on to it infinitely like you could with a homemade system, but it provides a degree of flexibility while staying small and simple. I’ll most almost certainly go to a component-based solar setup at some future date, but that doesn’t negate my preference for a Goal Zero Yeti for my particular current need. Having a solar unit that was designed from the ground up to be grab-and-go portable just makes good sense to me, for bug-out or any number of other uses.
The Bottom Line
I haven’t had my new pellet stove delivered and installed yet because I’ve been gone on vacation, so the solar back-up unit hasn’t been an immediate need, but I knew going into the pellet stove purchase that this would be a vital part of the stove system. I never would have bought the pellet stove without this capability being available to me, but by the time you read this, I may have already placed my order with Goal Zero.
As a closing remark, I said up front that I wanted something small to get into solar power, but it had to be something that met an actual need cost-effectively. I’m guessing that most of you don’t have a burning need for a back-up power system for a pellet stove (yet, but many of you may have a need for an electrical outlet where none exist. It could be while you’re camping or doing something in your yard or elsewhere outdoors. Goal Zero has a lot of products that meet these kinds of needs head on. Simple, portable, rechargeable electric power. I know some folks who use the dreaded CPAP masks for sleeping with apnea. A battery back-up system like one of the Yetis could be wonderful to have for when your power goes off. CPAP users can even go camping with them. There are probably other medical devices that aren’t coming to my mind right now that could be run off a Yeti when the power goes down.
I’m not trying to sell you anything (although, in the interest of full disclosure, we make a little money from the purchases made when you click on the ads on this site). We NEVER want to nudge anyone toward buying something they don’t want or need) — just doing a little brainstorming. At the risk of nullifying what I’ve just said about not trying to sell you anything, allow me to inform you that Goal Zero is having a Buy 2, Get 1 Free sale on their 15-watt solar panels. It’s a $90 value (nothing to sneeze at), and is good through October 31, 2014 when you use the code EXTRASOLAR at checkout. Just thought you’ like to know.