(As we mentioned in Chapter 2 of “Building Our Tiny Cabin,” the mere thought of figuring out our energy needs was (and is!) flat mind boggling. It’s not that it’s so difficult … quite the opposite truthfully … it’s just that with all of the other construction “stuff” that needs to be done, it seems to take a bit of a backseat. By the time we come “down off th’ mountain,” we’re too mind-weary to think about, well … anything. With 20/20 hindsight, we should have designed the power system back when we were figuring out floor plans for the cabin … something we definitely recommend for those of y’all who are in the planning stage. Since we’ve lived “off-grid” before, we kinda took a “yeah, yeah, we know” attitude to the whole sub-project. Thankfully, we discovered Tiny House Systems who has taken much of that particular burden from our (sunburned) shoulders.
We’ve been avid followers of the Tin Hat Ranch for some time now … from which we’ve lifted this wonderful article explaining all the ins, outs, where-fors and why-fors of DIY off-grid solar power. Enjoy …)
The Ultimate Guide To DIY Off Grid Solar Power.
Humanity has survived since the dawn of time without electricity, yet today’s society would collapse in an instant should the grid go down for any length of time. Most of us do not need electricity to live, but even in a grid down scenario, electricity gives us a few advantages; it can save us time by automating tasks, allow us to extend work ours through artificial lighting, and even provide for moments of levity and entertainment.
The goal of this series is simple. Solar power is truly DIY. An average person, with average skills, and common tools can put a system together. The general problem is solar power is a somewhat complexsystem. Understand how it works and choosing the right parts and pieces is key in putting together a system that fulfills your needs, works properly, and is safe. This series is designed to teach you the things you will need to know when sizing, installing, and using your system.
The system is not designed to replace all of your current electrical needs. The system is to provide power for necessities should the grid go down for good as well as provide you with emergency power in a shorter term outage. It also just so happens to be a great system for an off the grid cabin or homestead.
To help put the system together we teamed up withRenogy. The reasons are simple, we were looking for a reputable company that specialized in off the grid systems, good pricing, and the ability to support all the friends of the Tin Hat Ranch that might follow along. Our base system consists of a Renogy 400W Premium Kitand Renogy 1000 Watt Pure Sine Wave Inverter. We also chose to use batteries from Batteries Plus, again, nationwide, good pricing, and the right product. These are the major components, all of the bits and pieces can be found in the our system schematic, but before we get too far, well, lets just start with the videos.
This first part of the series will get you going on understanding solar power and sizing your system.
In this video we mention a tool to help you assess your power consumption and needs, the Kill-A-Watt meter. It’s inexpensive and at the very least, can help you make significant cuts in your electric bill. It is a must for anyone considering solar. Check out the Kill-A-Watt meter here. We also talked about a solar assessment worksheet, that can be found here.
Once you have the power generation all squared away, you are going to need to store that energy. We currently tend to lean towards lead acid batteries (although the Tesla Power Wall is coming!). There are lots of things you need to know when sizing, understanding, and using your batteries. Hopefully we answer all those questions in video 2, How to Understand, Size, and Choose Batteries:
In the battery video, we talk specifically about the Duracell SLIGC125 from Batteries Plus, a good option that is available nationwide.
Once you have considered sizing the major components, there are some crucial things you need to understand on locating and mounting your solar panels. Your decisions here can make or break how the systems function, even if you get the best components money can by. You don’t want to miss this one:
To properly point your panels, you will need to consult a Solar Angle Calculator like this one. While we used Unistrut (available at most home improvement stores) to mount our panels, you can purchasepre-made brackets or make your own. We found this gate strap hinge to be the perfect pivot point for our panel mount. Again, links to lots of the bits and pieces can be found in our downloadable schematic.
The heart of some of your key decisions will be in wiring your solar panels. Our Renogy 400W premium kit gave us a bunch of options. If you are unfamiliar with electrical principles, this is the video for you. In this video, we show you how you can wire your panels in a way that works best for you. This video will clear up some of the mysteries you may have, or may have never thought of, in putting together your system. Find out how by wiring your (4) solar panels in different ways can have dramatically different results in performance:
Once you’ve selected the number of panels you need, chosen a spot to wire them, and decided how you will wire them, your next choice is which charge controller you are going to use to wire your batteries. We have two basic choices in charge controllers, the PWM (Pulse Width Modulation) type controller and the MPPT (Maximum Power Point Tracking). Both charge charge batteries, one is ten times the cost of the other, but which one is right for you? Make your decision after watching this video:
So, you’ve got the power to the batteries, but where did you put your batteries? Even a single flooded lead acid battery contains an enormous amount of energy, they need to be enclosed to avoid accidents. Speaking of accidents, please don’t overlook solar safety. The home you live in, whether you know it or not, contains a century worth of advancements in electrical safety. Solar power, being relatively new, is just beginning to gain popularity and hence installations. It can be dangerous, but the answers to making both the battery box and the system safe are in this video:
In the video we mentioned a battery charge state chart. You can refer to this chart to estimate the percentage of battery power remaining in your bank (remember, the batteries must neither be charging or discharging to get a good reading). Click on the picture to the left, right click on the picture and “save as”. You can then print it out and laminate it. Links to the safety items mentioned in this video are available in the, you guessed it, downloadable schematic.
OK, so you have the system installed, now what? I guess we just sit around an wait for the grid to go down. Actually, my advice would be to practice. Disconnect the mains once and a while and live off your back up. In part 7 we take a look at some of the nuances to using solar power should the grid go down for good, as well as some tools that might make your time a bit easier:
In this video we hinted at some of the things we will show you how to do in future videos. There are a couple of tools that you can employ that will make your power decisions quite a bit easier. The first is the Acu-Rite weather station, this station is very low power (<3 Watts) so it won’t be a major drain on your system. It also “learns” your environment and provides a pretty accurate 12-24 hour forecast. More on this in a future article or video (haven’t decided).
Second, is a REALLY cool tool. The NooElec SDR Dongle. We’ve mentioned it before, it does a ton of different things, but in this case we are using it to forecast the weather by downloading information directly from weather satellites.
On the comms side of things, the really awesome Multi-Cam radio was the Icom IC-7200 (also the subject of a future video). The 7200 is one of the best deals in HF transceivers. For those of you who don’t want to get licensed or want a lower cost approach to listening to the world, the NooElec HAM It Up Converter is an inexpensive way to get the listening side of HF Radio. It works in conjunction with the aforementioned SDR Dongle and an antenna, with it you can listen to the world.
The Ultimate Guide to DIY Off Grid Solar Power is a work in progress. We have one episode left in production. If you are new to the Tin Hat Ranch and would like to get updates on this series or other prepping and survival information, you can follow us two ways. Click here to go to our YouTube channel and hit the subscribe button, or follow us on Facebook and hit the like button.
Thanks for watching!