How To Power a Tiny Home | A Step-By-Step GuideMay 27, 2019
Powering your tiny home yourself is no easy task.
Many a Tylenol have been bought from the DIY’ers who dare to undertake the project.
But fear not, it is possible, and you CAN DO IT!
Start your project here and get tons of immensely helpful tips and tricks for powering your tiny home yourself.
So let’s get started and uncover tons of valuable resources that will be paramount to your success.
Table Of Contents
- 1 National Electrical Code
- 2 Step One: Calculating your tiny house electrical needs
- 3 Step 2: Bringing the Power – From Pole to Panel
- 4 Step 3: Planning Your Circuitry
- 5 Step 4: Check Your Tiny House Electrical Work
National Electrical Code
Here’s the first thing I’d recommend checking out.
National Electrical Code (NEC) is a set of guides and rules that sets the foundation for electrical safety in residential, commercial, and industrial occupancies.
It’s cut and dry, but if you remember anything, remember this…
Every rule is informed by something gone wrong in the past, so the rules are there for yours and others’ protection. There is a reason that circuits within a certain distance of sinks need to be ground fault protected – to make it’s more difficult to get electrocuted.
We’ve all seen old movies or tv shows where someone drops a toaster into a bathtub, right? What Hollywood doesn’t show you, is that if the electrical wiring had been done correctly, nobody would have gotten electrocuted. The wire would have been simply too short.
So, as much as I sometimes like to buck the rules (like living ‘illegally’ in a tiny house, but that’s for another conversation on another day), I’m going to advise that you follow them in all aspects that concern yours and others’ safety, and powering a tiny house is definitely one of those.
That being said.
Consulting or hiring a professional electrician to work on your tiny house, while more expensive than doing it yourself, can save a load of headaches (and worse) for your future self.
So for all of the DIY’ers out there, read on to learn invaluable tips and tricks that will help you achieve your goal of powering your tiny home yourself.
Step One: Calculating your tiny house electrical needs
Start from the top.
This means deciding how much electricity your tiny house is going to need. A few things to consider with this is whether your tiny house will be stationary or mobile.
Both permanent and THOW’s (tiny house on wheels) are likely to be wired the same once the power is in the house, but getting it from a power line (or alternative energy source) to your tiny house’s service panel will differ based on your anticipated location.
For the purposes of this blog, I’ll stick to focusing on THOWs
There are lots of online calculators that will tell you how much current an appliance uses, but there’s also some simple math that you can do as well.
First off, what is the voltage of the electricity you’ll be using?
If you’ve ever looked at your houses service panel you’ve probably noticed some breakers that appear to be two separate breakers hooked together. These double breakers provide twice the amount of voltage to specific circuits that require it.
These 240-volt circuits are generally used for things like electric clothes dryers and electric ranges.
It’s unlikely that you’ll choose to install either of these in your tiny house, so you probably won’t need 240-volt circuits.
120-volt electricity is what most of the receptacles in your house use, so if all the things you hope to power in your tiny house plug into a normal electrical outlet, then you’ve already made your tiny house electrical system simpler, by eliminating half the work.
Here’s the easier part.
We need to calculate exactly how much electricity your tiny house will require at any one time.
This measure of draw of electricity is measured in Amperes (A), commonly known as Amps. To determine how many Amps of electricity you’ll need available, think of all the electrical devices you might want to use at once.
Maybe you make a big breakfast every Saturday and plan on using your waffle iron, electric kettle, and toaster all at once.
Calculate how much power these appliances will draw.
To do that, we plug in some information into this simple equation:
Watts/Voltage = Amps.
Remember, since we’ve decided that your tiny house doesn’t need any 240v circuits, we’ll constantly be dividing by 120volts.
Each appliance you have should list how many watts of electricity it consumes.
Here’s a quick example:
Mini Waffle iron 350Watts/120V= 2.9 Amps
Electric kettle 1500Watts/120V = 12.5 Amps
Toaster 1050Watts/120V = 8.75 Amps
Total circuit load = 24.15 Amps
This doesn’t mean we can’t have all of these appliances in your tiny house, but if you try to use all of them at once on a 20 Amp circuit, you run the risk of…
Popping a breaker!
If your whole house is set up with a main breaker rated at 20 Amps, you may have to be careful as to what things you’re using at the same time.
So to recap:
Now that we’ve done the math, we have an idea of what our maximum draw for your tiny house will be. If you’ve kept it under:
20 Amps, awesome – you can power your entire tiny house electrical system with a standard extension cord.
30 Amps, still good – you can power your tiny house electrical system with a standard RV extension cord.
- It will be a little more difficult for you to find a receptacle to plug into and your cord will be heavier and cost a bit more, but you’re still doing well.
- There are also adapters that go from a 30Amp type cord to a 20/15 Amp cord type, so that if you don’t actually need more than 20 Amps, you can plug into a regular receptacle.
30+ Amps, your tiny house electrical system could use some slimming down.
- There’s nothing wrong with wanting to live a big life in a tiny house, but considering what you do or don’t actually need in your tiny house makes for a much more enjoyable tiny life.
- RV electrical cords do also come in 50Amp models, but your options for plugging in are going to be less than with either of the previous two options.
- You may be relegated to RV parks or campgrounds and will likely end up with a higher electric bill as well, and that’s sort of a bummer.
Step 2: Bringing the Power – From Pole to Panel
Your next step is to decide how you’re going to get electricity into your tiny house.
Here’s the easy way to do that.
With a THOW, install an electrical inlet port that allows you to hook up an extension cord to the outside of your house. From there you wire the electrical inlet to your electrical system’s service panel (aka. Breaker box, fuse box, electrical panel).
Finding an appropriately sized service panel for a tiny house can be difficult because, unlike a standard house, you don’t need a 200 Amp main breaker and room for 30 different circuits.
Finding a panel often labeled as a sub-panel will save you some room and get you down to a more reasonable size.
Simply enough, if you’re installing a 20Amp system, then you’d install a 20Amp main breaker, not a 30.
The main breaker is basically a switch that allows electricity to enter your service panel and potentially power the other circuits.
Safety tip: Turning off the main breaker is an important safety measure whenever you might be working on a circuit in your tiny house to guard against getting electrocuted.
120volt electricity isn’t generally enough to do real harm to an adult, but getting shocked does certainly leave you feeling a bit tingly. I’d just take my word on that.
A better step to protect yourself while doing any wiring is to make sure your tiny house is either:
- The circuit feeding the plug (at the campground, your friend’s house, etc.) is turned off.
- Both A & B.
Step 3: Planning Your Circuitry
Next up, you’ll want to plan out the different circuits that will weave their way throughout your tiny house electrical system.
Although it might be feasible to fit everything onto a single circuit, depending on how small your tiny house electrical system is, it’s certainly not preferred.
You’ll want to be able to shut off a single circuit to potentially troubleshoot something without having to turn off the electricity to your entire house.
Likewise, if you happen to overload a circuit and throw the breaker, it’s good to not suddenly be completely in the dark and without power.
As a result, it’s a good idea to break things down into circuits based on the type and potentially by placement as well. You might break up your tiny house to have 4 circuits:
2) Kitchen receptacles
3) Other receptacles indoors
4) Outdoor receptacles
Each circuit will have one set of wires running from the service panel out through your tiny house to complete the circuit. You’ll want to make sure that these wires are appropriately sized to meet your electrical needs.
This is what you’ll want to remember.
Wire sizes are measured in different gauges, with the wires getting bigger as the gauge gets smaller (so 10 gauge wire is a larger diameter than 12 gauge wire).
If you’ve ever been to the electrical/wiring section of a big box store, you’ve probably felt overwhelmed at the assortment of sizes, colors, and types of wiring available.
The good news is…
Luckily for you and your journey to a tiny life, living more minimally means you need to spend less time in this part of the store.
The gauge of a wire determines how much current it can carry throughout a circuit.
So, a 10 gauge wire can carry up to 30 Amps, 12 gauge wire 20 Amps, and 14 gauge wire 15 Amps. Those are the only sizes of wire you’ll need to concern yourself with.
And … luckily for you, they’re even color coded.
Likewise, when we’re talking about wire, we’re actually talking about a number of individual wires wrapped together in a strand and covered in a plastic sheath. You’ll see wire labeled things like 10-2 and 12-3.
Pro tip: The first number in this pairing is the gauge of the wire, while the second is the number of carrier wires in the sheath. So, you’d think 10-2 wire is made up of 2 wires wrapped together in a sheath, right?
Not quite. And this can be confusing, but stick with me – it’s actually pretty simple.
A 10-2 wire actually contains 3 wires: 2 carrier wires (black & white), as well as a ground wire (either copper or green).
Wire types ending with a 3 mean there are 3 carrier wires (usually black, red & white), but luckily for you, those are generally used in wiring 3 and 4-way switches – something you’re unlikely to have to worry about in a tiny house.
So now that we know a little about the different types of wiring, we need to decide how many Amps each circuit should be similar to what we did before for the entire tiny house electrical system.
As a general rule of thumb.
Most lighting circuits will be 15 Amps, as will be many circuits containing receptacles. However, you’ll likely want a 20Amp receptacle circuit on your kitchen countertop.
You’ll also want to install a Ground Fault Current Interrupter (GFCI) receptacle at the start of this circuit to protect the circuit because it will be near water.
Next up is planning what each circuit will contain. Your lighting circuit might include kitchen lights, loft lights, a bathroom light, living room lights, and porch light. You’ll do the same thing with each circuit, determining how many receptacles we plan on including and making a rough determination of where they’ll be located.
Those locations will help you plan out what all materials you’ll need for your tiny house electrical system.
Phew, that was a mouth full. But we’ve made it to the home stretch!
Step 4: Check Your Tiny House Electrical Work
Review your plans.
We all make mistakes and assumptions when planning so give yourself some time to check your work (and math). Are you really going to be ok with waiting to make your tea until your waffles are done, or did you undersize your electrical system to a degree that will drive you crazy later?
Likewise, going tiny doesn’t mean giving up all the luxuries you enjoy, it just means getting more out of the ones you enjoy and eliminating the excess.
So, if you feel like you really need air conditioning in your tiny house, plan for it now and save your future self the trouble of trying to determine a second time how to power a tiny house.
Interested in alternative power sources for your tiny home? Check out our awesome article on using solar to power your tiny house here!