Posts Tagged Power

Shedding Light on Solar Generators: Are Portable Solar Generators Worth the Investment?

Shedding Light on Solar Generators: Are Portable Solar Generators Worth the Investment?

Shedding Light On Solar Generators

I get asked a lot about solar generators when people find out I’ve been off the grid full time since 2013. People want to know if a portable solar generator will work for their needs, how to find the best solar powered generator, and how to determine the wattage and size needed. There is a lot of confusing information out there and the fast pace of solar innovation makes it hard to keep up with.

Jakery solar generatorUsually, the people drawn to portable solar generators are beginners in the solar world. It’s often the guy who lives in a typical house, but who would like to start dabbling in solar power. He might have a goal to live in a tiny house someday, or even to purchase a full solar panel system to power his regular-sized home.

It’s important to note the term “solar generator” is a bit of a misnomer. Usually, what people are referring to is a power pack with solar panels. It’s either a setup you can piece together yourself or purchase off the shelf. These are low-power units. They can also get expensive since they’re a turnkey solution, but they’re an excellent way to dip a toe in the world of solar.

solar panel arraySwitching to solar panels completely, without experience, is quite a daunting task (especially if you’re trying to power a typical-sized home). It’s also a significant investment, which I’m all too aware of after writing a $19,000 check for my solar panel system for my tiny house. But after getting over the initial pain of paying so much money for my system, it’s definitely worth it. In fact, it’s hard to describe how awesome it is–I literally haven’t paid a power bill for years! Not to mention that 55% of my system was eligible for a tax credit.

That’s why solar powered generators are a nice way to explore the world of solar without a huge commitment or undertaking. Most of the people asking about solar generators possess a DIY outlook. They’re often wondering if solar is something they can set up on their own. If they purchase a Harbor Freight kit, can they build a small solar power system themselves?

So, are solar generators really worth the investment? Here’s what you need to know before you spend the money on a portable solar generator.

Managing Expectations About Solar Generators

managing expectations on solar generators

My biggest piece of advice to anyone exploring solar generators or solar power, in general, is to keep your expectations realistic. Now, I’ve been on solar power for years, and I really like my system. That said, it was a lot of work and a big investment to set up. There are also limitations.

With a solar panel system, there will be adjustments to your lifestyle that is required when you go off the grid:

  • Bad Weather – if it’s cloudy for a week straight, you might be reaching for a blanket as your battery wanes.
  • Snow – Are you ready to get out and clean snow off your panels in a blizzard?
  • Something breaks – there is no power company to call, if your power goes out, it’s up to you.
  • Maintenance – Batteries to fill, terminals to clean, fuses to change, and panels to clean.

Before you go fully solar, a portable solar generator is an excellent gateway option. It allows you to explore the fundamentals of solar power generation and to understand how the larger systems work. It also lets you get an idea of the capacity (on a small scale) so you can scale up later. This is really useful because you begin to really grasp what you need to do different things.

How to run a tiny house on solar

Now, I’ll be honest, the smallest solar powered generators aren’t super useful. The smallest ones can’t charge more than a cell phone or a small laptop. Don’t expect that a small investment or even a small DIY solar generator kit is going to get you enough power to live off the grid or run your household appliances.

Most small solar generators are under 500 Watts (typically around 2-300 Watts). You’ll invest $500+ or so for the battery and power pack, and you’ll need one or two panels at $3-400 each. These solar generators won’t work for running your stove or your air conditioner (for those larger items, you’ll need a full solar panel system).

Figure where a traditional larger scale system with lead acid batteries you can get it for $1 per watt, in a solar generator you should expect to spent $2-$3 per watt because it’s turn key and often uses lithium ion batteries which are higher performing.

What Are Portable Solar Generators Good For?

What are solar generators good for?

Where portable solar generators really perform is when you’re camping, or if there’s an emergency. If you’re stuck in a hurricane or there’s a big power outage in your city, then a small solar powered generator is great to own. People often purchase them for emergency preparedness kits and shelters. You may not power your whole house on it, but at least you’ll get light and the ability to power your small electronics, which is lifesaving in certain scenarios.

These little solar generators are also handy for tailgating and camping. If you own an RV or a teardrop-trailer, you can use the portable solar generator to power your needs for a weekend trip. They’re excellent for keeping your phone charged or running a small amount of power to an item (like a light). If you tailgate often, a solar generator will easily keep your radio going without draining your car battery during the game.

What can you power with a solar generator?

Possible

  • Small Fans
  • LED Lights
  • Laptop charger

Maybe Possible

  • Television
  • Mini Fridge
  • Microwave

Not Possible

  • Refrigerator
  • AC Unit
  • Furnace

Solar generators work great for small fans, LED lights, charging your small portable electronics, and other small, low-power tasks. Some high-efficiency televisions work well with solar powered generators. You can charge a laptop or tablet with a solar generator, too.

I’ve also known many construction workers and builders who love these portable solar generators for keeping their tools charged on the job. It’s great to use a solar generator at a building site as a continuous source of power for battery driven drills, saws, power tools, and small pieces of equipment. Solar powered generators are perfect if your build-site is away from a power source and you’re working for a few days. If you’re building a cabin or a tiny house in a rural spot, then a solar generator will help keep your tools going.

There are also many jobs where a solar generator won’t cut it. These items require too much power to run efficiently (or even at all) on a portable solar generator.

Things that won’t run well on a portable solar generator include:

  • Anything with a heating element: Coffee pots, hairdryers/straighteners, hot plates, toaster ovens.
  • Small appliances: Microwaves, slow cookers, blenders.
  • Large electronics: Desktop computers, game consoles, and some projectors.
  • Heating and air conditioning: Any size AC unit (window or otherwise), heaters of any size.
  • Refrigeration: A small modern fridge will only run a few hours on a large solar generator.

Like most jobs, it’s all about having the right tool. This is advice I preach in any scenario: if you want to do a good job, you need to invest in the right tools. If you pick the wrong tool for the job, it won’t perform up to your expectations.

How a Solar Generator Works

How do solar generators work?

solar generator parts list

The battery is a power bank. Depending on the voltage of your battery, it holds power until you’re ready to plug-in and run your device. These batteries are also used to charge phone, computer, and power tool battery packs as well. Solar batteries are often finicky and delicate. While many of these solar generators use higher quality lithium ion batteries, it’s still best to use caution so you don’t damage them.

When people think of solar, they forget about the battery component, but it’s essential. If your power source is the sun, then what do you do on a cloudy day? What happens at night? Solar isn’t consistent. The battery stores the power, so it’s available whenever you need it. If the sun is making enough power, then it’s shunting the energy into the item you’re powering. If you overuse your solar source, then your generator goes into the battery.

The other component of a solar generator is the inverter. The inverter converts DC (direct current) power into AC power, which is used by most tools and appliances. AC typically runs at 110-240 volts in the USA, so the inverter ramps up the voltage from the battery to 100-240 volts.

running air conditioning with solar panels

Some people prefer the DIY approach to solar generators. They buy the base pieces of a DIY system and put it together themselves. This is certainly possible, but it’s often a challenging project for a beginner. What I’ve seen happen time and time again is people start down the DIY path but get frustrated and go out and buy an off-the-shelf solar generator instead.

How to Decide Which Solar Generator You Want and Need

what is the best solar generator to get?

If you’ve weighed out the pros and cons of solar generators and feel like you have a realistic idea of what you need (and what the solar generator can do), it’s time to decide which solar powered generator is best for you.

My biggest recommendation for anyone looking to switch to solar power is to figure out precisely what you want to charge first. Determine your power requirements (what’s sometimes called your power profile). What is the breakdown of exactly what you need to charge and plan to use when you use your solar generator?

To figure this out, I’ve created a workbook to help you determine your exact power consumption. Exploring your needs first is such a critical step, even if you’re starting with a portable solar generator because these are big purchases. Even a small solar generator with panels and a power bank will cost you a significant amount. You’ll want to get exactly what you need upfront before you invest a few thousand dollars on something that can’t do more than recharge your phone or run an LED light.

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Once you’ve decided what you want to charge and exactly what size solar generator you need, it’s time to determine your approach Are you more of a DIY type? Do you feel comfortable buying the pieces and building a solar generator yourself, or would you feel more comfortable with an off-the-shelf generator system?

If you buy off the shelf, it’s important to ask the following questions:

  • Can you plug it into the wall with a power manager for back up?
  • Does it do what you need it to do?
  • Is it compatible with other connectors and components or does it only use proprietary components?
  • Is it portable enough for your needs?
  • Can it be charged by a wall socket, car outlets, and solar panels?
  • Does it come with a wide range of power hookups?
  • Can you daisy-chain panels to get more power?

Buying off-the-shelf is a great option, but it’s important to note that different brands use different proprietary connectors (so you must buy their brand’s solar panels and components). Always check before you start investing in a product that won’t work with components you already own.

Solar Generators To Compare

Comparing solar generators

When it comes to solar generators, there are three leading brands out there: Jackery, Goal Zero, and Inergy. Here’s what I’ve learned about each brand to help you compare.

Jackery Explorer

Jackery has three sizes of portable power stations (100 Watt, 240 Watt, and 500 Watt). I had the opportunity to check out the Jackery Explorer 500 Watt Portable Power Station as well as the Jackery Solarsaga 100 Watt Solar Panel. The Power Station looks a bit like a fancy lunchbox with a battery and a bunch of power hookups. This worked well.

The one feature that made this solar generator my preferred choice was that all the connectors were standardized. Other companies used proprietary connectors which was an instant deal breaker for me, making Jackery an easy choice.

Jackery Solar generator
Some aspects I really liked about the Jackery Solar Generator:

  • Doesn’t use proprietary connectors.
  • Well-built, with a robust solar panel (this one impressed me with it’s sturdiness).
  • Compact and easy to use.
  • Lightweight (the Power Station is 13.32 pounds).
  • LCD screen with charge/discharge data and battery life status.
  • Quiet operation.
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Goal Zero Yeti

Goal Zero offers an array of Yeti power stations. These power stations mainly feature lithium batteries and are available in a range of prices and capacity. They’re built to pair with the Goal Zero solar panels, but with some configuring, they can also pair with other panels.

Goal Zero solar generator kits
Some pros and cons of the Goal Zero Yeti systems:

  • Portable and most include Wi-Fi capabilities, as well.
  • Overall positive reviews on the Goal Zero products.
  • Not recommended for radio communications.
  • Concerns about the AC inverter not holding up and shorter battery life.
  • Configuration is necessary to pair with other brand solar panels.
  • Widely available on Amazon, REI, and other retailers.
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Inergy Apex

The Inergy Apex Portable Power Station (previously Kodiak) also has positive reviews. The Apex offers a peak 1,500 Watt pure sine wave inverter and 1,100 Watt-hours of peak battery capacity. It’s also lightweight and compact.

Inergy solar generators
Some pros and cons of the Inergy APEX Portable Power Station:

  • Portable and lightweight.
  • Optional battery expansion option, which is helpful for upgrades and kits.
  • Doesn’t support the Neutrik adapter for third party panels.
  • 500 Watt max output.
  • Reliable and durable according to reviews.
  • The LCD screen is easy to read.
  • Quiet operation.
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When it comes to solar generators, my biggest word of advice is to manage your expectations. You aren’t going to be able to run your refrigerator, blender, microwave, and television on a solar generator. It’s not going to happen. You can, however, use a solar generator to learn how solar works. It can help you get used to the quirks of relying on solar power before you scale up to a full system.

Solar generators are great for camping, charging tools, and for hobbyists. If solar energy is something that interests you and you don’t know where to start, solar powered generators are a cool option to explore.

Your Turn!

  • Have you ever used a portable solar generator?
  • What would you like to power with a solar generator?

How to Run Air Conditioning On Solar Power

How to Run Air Conditioning On Solar Power

Today I wanted to share information about running air conditioning on solar power.

When I was first planning to move into my tiny house, considering the possibility of running a solar powered air conditioner and cooling system weighed heavily on my mind. After all, living in a humid state, I’ll tell you, I’m one who can’t tolerate the heat. This is especially true, coming from New Hampshire—I’m a cold weather guy and here in North Carolina, it gets hot! An AC unit is critical, even if you’re running on solar power.

How to Run Air Conditioning On Solar Power

Well, Charlotte’s heat really came full force this week.  I know for many their climate doesn’t get as humid as it does here, so there are other options besides running a house air conditioner. Unfortunately, here, it’s necessary.  Without AC I can’t really sleep, even using a fan to passively cool the house.

Right now, the humidity is still tolerable, but it’s HOT and the humidity is coming soon.  It has been in the high 80’s and low 90’s outside, which made my house in the mid 90’s inside.

So, what are the tiny house air conditioner solutions? How do you cool off your tiny house (even off the grid) and beat the heat?

Deciding to Buy a Solar Powered Air Conditioner

I thought I’d do a post today because I’ve been able to run a few real-world experiments with my tiny house and solar powered AC.  I haven’t seen any experienced reporting on the topic of running air conditioning on solar power, so I figured it would be helpful for you all to hear what I did.

When it comes to cooling a tiny house, there are three areas to look at: isolation, such as shade, seals and insulation; ventilation, such as fans and setting open windows for cross-winds; and artificial cooling. Many tiny homes, by their portable nature, don’t have basements, where you can retreat if you need to cool off. Since heat rises and your entire home is above the ground, you need alternative methods to cool down.

Desert-dwellers may be able to rely on swamp coolers and evaporation-based cooling systems Here in the humid part of the world, these setups never work because our air is already humid. It’s impossible to cool humidity with MORE humidity.

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Isolation, using shade and insulation to your advantage, is important if you live in off the grid. You can keep your house fairly cool by simply, closing off your space, especially in the heat of the day. This is why I decided to park my tiny house under the trees for shade and run my solar panels in the wide-open field.  While these methods help and should be employed, of course, chances are you’ll still need to rely on a solar powered air conditioner system to get through the hottest days.

After doing my research on what unit would work best with my solar panel set up and power levels. I ordered my unit before I found an installer. I have yet to hook up my mini split air conditioning system (see the update below where I talk about life on solar with my mini split) because it has taken me a long time to find a HVAC installer who would install my mini split AC. As I discovered after buying my mini split unit, most installers insist they need to sell you the air conditioning equipment if they are going to install it. Obviously, this was an unknown factor to me when I ordered my house air conditioning unit…but these are the bumps in the road you experience when you live The Tiny Life.

Fujitsu air conditioning system.

Fujitsu Air Conditioning System

How Much Power Does an Air Conditioner Use?

For heating and cooling, I opted for the Fujitsu 9RLS2 which is a 9,000 BTU Ductless Mini Split Air Conditioner Heat Pump System with a SEER (Seasonal Energy Efficiency Ratio) rating of 27.  To give you an idea, older, less efficient mini split air conditioning systems have a SEER rating of around 8 to 10. Modern air conditioning systems, labeled highly efficient may have a rating of 15 or so, but most today are around 12-13.

The SEER rating was very important because my tiny house solar panel system simply couldn’t handle the less efficient cooling systems.  The SEER rating is determined by BTUs (British Thermal Units) to Watts.  The higher the number, the better.

The other big reason I choose this particular mini split air conditioning unit versus a standard window air conditioner was aesthetics.  My air handler is wall mounted, out of the way and above eye level.  This has a few advantages. First, it keeps my limited square footage clear of clutter. Secondly, it keeps my windows looking nice because there’s no window unit blighting a good design. Lastly, keeping it above eye level also helps you forget about it because as humans we don’t often look up.

Tiny House Friendly Air Conditioning

While I’m working on getting an HVAC installer lined up to put in my Fujitsu Air Conditioning System, I’m using a portable air conditioner, which has worked pretty well.  The downside to using a portable AC unit is it takes up a lot of space and it’s not as efficient. The portable AC unit I’m using has a SEER rating of 12, which means my new mini split system will be 225% more efficient once it’s installed.

UPDATE:  It’s been several years now since I first wrote this post and I’ve been living full time totally off the grid and it’s wonderful.  I was able to find an installer to pull the vacuum in my system and this thing cools like a dream.

During the summer the AC pulls between 450 watts and 700 watts, on “powerful” mode it draws about 1,000 watts.  As a side note for heat, it pulls about 700 watts to 1,000 watts, 1,100 on “powerful”.

If I had to do things all over again I’d go with a Mitsubishi brand mini split over the Fujitsu, because they seem to be a bit more well-designed. The Mitsubishi has also the critical feature of auto dry, which dries the coil of moisture before shutting down.  I’ve had to clean my coils several times in the 5 years and a drying feature would almost eliminate this.

Stress Testing My Portable AC Unit and Solar Panel Power System

I decided to “stress test” my solar panel system by turning the portable AC unit on high and setting the thermostat to 60 degrees. I wanted to see how long it would take for my solar panel system batteries to bottom out (50% discharge).  The charge controller on my solar panel system automatically turns off the power to my house if the batteries power discharges down to 50%. This automatic shut off on the solar panel system prevents damage to the batteries by discharging too deep.

Solar panel batteries and a chart of number of cycles and depth of discharge to determine battery life.

As you see by the chart above, keeping battery discharge at 50% or above gives me a little shy of 2,000 cycles or 5.4 years for the life of my batteries.  I plan to add another set of four batteries to the solar panel system pretty soon, which will give me improved capacity and keep my discharge rate much higher than 50% (though I don’t often get that low).  In about 5 more years we should start seeing really interesting battery technologies hit the market. This should coincide with the life of my current batteries, so I plan to hop on these new technologies as soon as my batteries begin to fade.

UPDATE:  It’s been several years now since I posted this. Last year I bit the bullet and added 6 more solar panels and 4 more batteries.  This was mainly to avoid needing a generator in the winter months because they’re a royal pain.  Cooling my house in the summer is still pretty simple since my house is so small.  I usually turn my air conditioner on when I get home and shut it off when I leave.  This allows the batteries to fully recharge and doesn’t really impact cooling.

My solar panel battery stress test was an interesting experiment. I ran the less efficient, portable air conditioner for three days solid, starting with a very warm house.  At the end of the three days, I was very close to hitting 50% on my battery reserve, but it didn’t ever dip below that threshold.  I decided, after three days, the test had gone on long enough to get an accurate reading and I stopped the test.  I typically turn off the AC whenever I’m gone.

Following the test, the past few days were a bit trickier because since my solar panel battery system was so low, I needed it to build back up. Unfortunately, we had a series of cloudy days, making it tough to get more energy.  While I’ve had plenty of power to run the AC overnight, the battery reserve is lower than I’d like.  To give you an idea: on a normal sunny day my solar panel power system makes about 8,000 Watts, but on a cloudy day (when the clouds are very thick with no gaps) I get between 2,000 and 4,000 Watts.

The Advantage of Solar Powered Air Conditioning

When it’s hottest and the sun is shining the brightest, I can make lots of power!  This allows me to run the AC full blast to keep my house nice and cool. Even with the air conditioner on high my solar panel system still makes enough power to add 2,000 Watts into the batteries. Compare this to heating, where you often need the heat the most at night when the sun isn’t out. This results in a major drain on your batteries.  Compounding the issue of running heating off solar panel energy, heaters are more energy intensive than cooling and air conditioning units.

The other night I decided to conduct another experiment.  I got my house very cold by running the AC unit. Then, I turned off the cool air at midnight (when I usually go to bed).  Outside it was about 65 degrees and about 45% humidity–so not bad.  I left all the windows closed to see how much my body heat would warm up the house. In the summer, opening the windows doesn’t often doesn’t help anyway, even if it is cooler outside because the humidity increases the “feels like” temperature.

As it turns out in just three hours my body heat warmed up the loft of my tiny house to the point I woke up from being so uncomfortable from the heat!  Around 3:30 am I woke up and it was very hot in my loft.  I checked the time and was surprised how little time it took.  I should note when I fall asleep, I usually stay asleep all night, even if I get warm. The fact I woke up from the heat, shows how uncomfortable it was in my loft because it takes a lot!

Fortunately, I had prepared for this and all I did was crank open my skylight (the highest point in my house) and the loft end window. I switched on a fan to draw in cool air.  Within 5 minutes the whole place dropped about 5 degrees and I was back asleep.

So that has been my real-world experiences with the tiny house, AC units and solar panel power systems.  I know I had always been frustrated by not enough stories and real-life examples of AC and cooling issues, so hopefully my story will help others.

Key resources for those wanting more technical stuff:


My Setup For Solar Power

  • Details of my tiny house solar panel system
  • Calculating solar power system requirements
  • Building racks to hold solar panels
  • Adding a solar panel gear cabinet
  • Understanding solar panel electric systems
  • Choosing a backup generator

Common Off Grid Living Misconceptions

It’s been a full year since I moved out of my apartment and into my tiny house, with that came the shift to living off grid.  Many of you have read my tiny house solar posts which talks about all the nitty gritty details of my solar panel system, if not, check it out because I’ve gotten a lot of good feedback on it.  Now that I’ve done this for a while it’s become very clear what I got wrong and what others non-off-griders (grid muggles?) about off grid living.  I can now spot a grid muggle a mile away when they start talking about living off the grid.  Here are some of the misconceptions you learn about when you go off grid.

Harbor Freight solar kits is all I need!

I hear this all the time from folks, “I’m going to get one of those Harbor Freight solar kits to power my house”.  These kits are great, if you only need 45 watts, which really is only good for changing a laptop (30 watts) and cell phone (5 watts), maybe some power drill batteries; all of these things are insanely lower power consumption.  If you need to run much more, these system will leave you very disappointed, cold, hungry, and in the dark.

Clothes washing is easy… right?

Time and time again people geek out over various contraptions for washing your clothes.  I’ve seen them all, the plunger looking things, fancy peddle powered spinning ball gyros, and  hand crank counter top tumblers.  The truth is hand washing clothes isn’t terribly difficult; sure a normal washer is easier, but barring that, I’ve found a tub or large sink really works great.  You can always spot the people who’ve never actually done it because they talk about washing clothes while true off gridders talk about drying clothes.

Drying clothes in an off grid setting in a tiny house is a royal pain.  It’s fine if the weather is nice out, but if it’s really humid, or freezing cold, or worse, raining, you can forget about having dry clothes.  What it really means is for about half the year you get dry clothes, the rest of the year you’ll have mostly dry clothes that you’ll give up and put on because everything is still damp and you need to leave the house.

Drying racks are great if you have just a few things to dry because you can rig something in your shower.  But when you’re talking about a full load, it means you have to setup your drying rack inside your tiny house, which takes up most of your living space, then you need to let it dry in a day or two.  This typically translates into perpetually having your drying rack out, which makes the tiny house much less livable.

The ideal option would be to have a small outbuilding where you could setup a clothes line and have a wood stove in the corner.  You could also do what I do, head to a laundry mat or pay a laundry service.  After doing laundry by hand for 3 months while living in Croatia, I’ve since transitioned to doing my laundry in a normal washer and dryer.  Here in Charlotte I can have my laundry washed, dried and folded for $2.50 a lb, which as someone who loathes folding clothes, is so worth it.

Roof top mounted solar panels

The weird thing about solar is mounting on the panels on the roof is one the worst places you could put them.  By their nature roofs are hot, which heat decreases the efficiency of solar panels.  They are high up, so they are hard to get to in order to maintain, brush off snow and clean grime that builds up over time. Finally, on a tiny house the space you have to deal with is very small, because tiny houses have tiny roofs.

If you’re going to be traveling a lot with your tiny house, roof top is very practical, but you’re going to be hard pressed to do any sort of heating or cooling with that few panels.  The best option is ground mount if you can swing it.  You can access it easily to clean off snow and grime, you can easily inspect it and fix things for maintenance.

Not having backups… for everything

When you are your own power source, there is no power company to call when things go wrong.  In most cases that’s a good thing because you often find yourself at their mercy and if you’re in a remote location, at the bottom of the priority list.

It also means that if something goes wrong, say the morning you have an important meeting to get to, you still need to make breakfast, take a shower, and do what you need to do.  To this end I have backups for each of my main systems:

Thinking you can live off grid with no propane

I hate the fact that I need to use propane, but its an absolute necessity.  Of course if you have $50,000 to spend on your solar system, you wouldn’t need propane, but most folks don’t.  Even my system, which is around $20,000, couldn’t come close to powering a hot water heater or stove/oven.  The one exception to this might be if you have a really good hydro power turbine, then maybe, but that’s dependent on you having flowing water and a large drop, very difficult to find when buying land.

The one thing with all of this is how appreciative and grateful I have become for fossil fuels, they are a true miracle.  They don’t come without their consequences, but the fact that I can pay $2.50 for a liquid, put it into my car and it takes me 50 miles in less than an hour… have you ever had to walk 50 miles?  I have gone on multi night backpacking trips over 50 miles, fossil fuels are a true small miracle.

You could potentially get away with no propane if you did wood heat and had a water heater exchange on it, but honestly the idea of waking up 2 hours before I need to leave every day to make a fire, heat water to shower and cook on, isn’t in the cards.  Even if I had the time to do that, I wouldn’t, I don’t want to spend me entire life chopping wood and stoking a fire, life is way too short.

A wood stove is the dream

This is something that many off gridders have in their cabins, but I personally can’t get into.  When I grew up, I had a wood stove, everyone did when I lived in NH in the 80’s.  I distinctly remember going over to my friend Jimmy’s house and his mother telling us we needed to go chop some wood so we had enough for the night.  Chopping wood, stacking wood, moving wood, building up the fire in the morning: it was just a part of life.

The part that no one talks about how much work it all is. Here’s what every day would be like:

You wake up to a pretty cold house every morning in the winter, dash out of bed to rekindle the fire and put a few logs on the fire.  About an hour later, you can finally take a shower without freezing.  But oh wait, you forgot to fully close the stove and some smoke came back into the house, your work clothes smell like a camp fire.  You head off to work and then come home to a cool home, time to add more wood, but wait you’re out of wood inside.  So you get dressed again to go into the snow, you head to your wood pile and start stacking wood into a wheel barrel.  While you’re loading up, you pull a log to find a snake making it’s move to bite your hand.  You take care of the snake and keep stacking.  Wheel the wood to the door and start carrying it in.  You finally get wood stacked and fire roaring, to turn around and see a trail of destruction where you tracked in mud and dirt from the wood.  You spend the next 15 minutes cleaning the floors.  

Compare that to me:  I walk it, press one button and in three minutes my house is super comfy.  I kick off my shoes, grab a drink and start reading a good book.

Solar tracking is really important

This is another one that I can spot a solar newbie a mile away.  They talk about a pole mounted tracking system, which allows your panels to follow the sun.  But here’s the dirty little secret:  You add one more panel to your system and you’ll make more power and save a lot of money!

Typically solar trackers improve solar gain by about 15-20%, so if your system were to generate 1 KW fixed, it now might do 1.2 KW.  But here’s where it all falls apart.  A solar tracker usually is at least $1000 extra dollars in equipment and you need to pour a large concrete footing for a couple hundred bucks.  Let’s call it $1500 for the whole thing if you do it all yourself.  But if we were to just use a fixed system and buy one or two more panels ($250 a pop) we could increase our system to 1.5 KW in a day.  So for 33% less money I can get around 30% more power AND have no moving parts to break.

DC appliances and propane fridges are worth the money

It is absolutely true that DC is much more efficient and inverting DC to AC takes up some power, but it’s not the only thing to consider.  There is a major myth that is perpetuated from information that was once true, but is now no longer.  The problem is that there are a lot of websites out there with old information.  With recent advances in inverter technology and lower costs for panels, the gap has dramatically decreased.  While it is inefficient to change from DC to AC, you can make up the difference completely by the addition of one or two solar panels.

When you weigh the cost of specialty made DC appliances, for example a Sun Danzer Fridge for $1100, against going regular AC fridge, mine was $130, plus an extra panel, mine are $290 each, the math is simple.  I can add one more panel and save hundreds.

The other part of the story is that a lot of electricians are hesitant to work on DC systems, many won’t.  In addition to that, the market for DC appliances is small; this means less options for a higher price tag.  Going AC give you lots of options, easily sourced electricians and all at a lower price.

My recommendation is to go full AC power and then just add a panel or two to your array.

 

Those are my thoughts on common misconceptions about going off grid

Your Turn!

  • What things have you thought about when going off grid?
  • What surprised you about this list?

My Tiny House Solar Power Setup & How To

I know many of you have been wanting this post for a while, but it’s finally here: my solar panel system for my tiny house.  I wanted to get the feel for what it is like to live off the grid so I could share more details with you all about what it’s really like.

Tiny House solar panels

So first, the high level details of my system:

  • 3,975 (3.9 Kw) of panels – fifteen, 265 watt panels – Canadian Solar
  • Batteries 1,110 amp/hr total – Twelve, 370 amp/hr 6 volt Trojan L16 flooded lead acid (series parallel)
  • Cost for parts about $20,000
  • Off grid, battery bank, plus 5,550 watt backup generator
  • 24 volt system

Specific Parts:

  • (15) Canadian Solar CS-6p 265 Watt Poly Black Frame  (Spec Sheet)
  • (1) Schneider SW 4024 (Spec Sheet)
  • (2) Schneider MPPT 60 Charge Controller (Spec Sheet)
  • (12) Trojan L-16 6v 370 AH Flooded Lead Acid Batteries (Spec Sheet)
  • (1) Schneider System Control Panel (Spec Sheet)
  • (1) Schneider Interconnect Panel (no spec sheet)
  • (1) Midnight Solar MNPV 80AMP Dinrail Breaker (Spec Sheet)
  • (2) Midnight Solar Surge Protection Device AC/DC (no spec sheet)
  • 50 Amp RV power Inlet (Spec Sheet)

Before anything I needed to determine the best placement for the solar panels to make sure it had good solar exposure and didn’t fall into shadows too much.  To do this I used a tool called a “solar path finder” which is a semi reflective dome that you position at the location, then snap a photo.  The photo is then loaded into a program and spits out a whole bunch of calculations.

Solar Path Finder

Solar Path Finder

So once you upload the image into the software and then trace the treeline outline, you enter in your location, date and time.  It then can calculate how much power you’ll produce based on 30 years of weather patterns for your exact location and tree coverage.

My reading with the pathfinder

My reading with the pathfinder

Then it spit out all the calculations:

Solar Power Energy Readings

With that in mind I knew what I could expect out of the system I had designed.  It also was a way to verify my assumptions.

Once I verified that the system was going to be well suited to my needs I had to build my panel support racking.  I did this out of pressure treated 4×4’s that were each 10′ long.  These things about about 300 lbs each so I don’t have to worry about wind picking up the panels.  I opted to build them because it was cheaper than some of the turn-key option out there and most of the for purchase ones required me to cement in the ground; I rent my land, so I wanted a mobile solution.  The racking is technically mobile, but not easily so.  If I remember correctly it was about $500 in materials to build this part.

Installing Solar Panels on a ground stand

Next we installed the panels.  This part was pretty quick and the stands worked out perfectly.  The panels are 250 watt Canadian solar panels.  They are wired in groups of three, then paralleled into the system.  To give you a sense of scale, these panels are 3.3 wide and about 4 feet tall.

Installing Solar Panels

Now I know many people want to know why I didn’t mount these on my roof or could they mount them.  You technically can mount on your roof, but honestly the number of panels that you need to practically power your house is too many for the roof.

There is some other major bonuses of being on the ground:

  • Much cooler, roofs are very hot places in the summer and solar panels drop in efficiency when hot
  • I can put my house under deciduous trees, this means in summer I’m in the shade, in winter I get the solar gain
  • Way easier to clean and monitor

Cleaning your panels is pretty important because you loose efficiency as residue (bird poop) builds up.  Also as I learned just a few days ago, when it snows, you need to clear your panels.  Cleaning becomes super simple and a lot safer when you don’t have to climb onto a roof via a ladder.

Maintaing Solar Panels

Just this week we got a decent snow, 3 inches, which is quite a lot for Charlotte.  The first thing I had to do when I woke up was clear off the panels because with the snow, they made no power.  This was compounded because since it was cold, I needed more heat.  I can’t imagine having to drag the ladder out and try climbing on a icy roof… No Thanks.

Housing your Gear

Next I built a cabinet to house all the gear.  I wanted a stand alone space because the batteries are so heavy.  At 118 pound each, plus cabling and other equipment the whole unit is over 1,100 lbs.   The top and bottom sections are divided so that the gasses from the batteries don’t go up into the electrical section and explode.  More on that later.

Solar Battery Power

The batteries are wired in series parallel.  The batteries are 6 volt each, in series of 4 the create a 24 volt unit, then I have two of these 24 volt units in parallel.  The reason I choose to go 24 volt over a 48 volt (which is more efficient) was because the equipment was a little cheaper, but also it allowed me to select components that I could add more panels and batteries very easily without doing equipment upgrades (just a factor of the abilities of the units I choose).  This way I can add up to 15 panels and a lot more batteries without upgrading the electronics; I can also stack these inverters so if I ever go to a normal sized house, I just add another unit and it just plugs into my current one.

Solar Power Gear

In this photo going left to right: Din Breaker Panel, Charge Controller, Interconnect w/ control panel, inverter.  In general the power flows in the same manner (but not exactly).

  • Breaker Panel: manages power from solar panels
  • Charge Controller: manages power to batteries etc.
  • Interconnect: a main junction box and breaker, holds control panel interface
  • Inverter: takes power in many forms then outputs to they type of power you need

Once the power goes through the system it outputs to a huge cable that you can see sticking out of the bottom of inverter then goes right.  From there it runs to this:

Solar Power Plug

This is a 50 amp RV style plug.  The reason I did this was two fold.  City inspectors are less picky when it comes to non-hard wired things.  This setup also lets me roll into any RV campground and hook up seamlessly.

Solar Power Plug to a tiny house on wheels

The plug goes into a 50 amp RV female receptacle.  This is important that you don’t have two male ends to your cord.  This is dubbed by electricians as a “suicide cord” because if you plug in to a power source, you have exposed conductors that are live; accidentally touch them, you complete the circuit and zap!

suicide cable, use a male to female cord

You want a female end to your cord so that you reduce the chance of being shocked.  I also turn off my main breaker at the power source when I make this connection, then turn it back on.

Shockingly Simple Electrical by Ryan Mitchell

If all these mentions of watts, volts, amps, amp hours etc are making your head spin a little, you may need to go back to the basics.  I have an ebook called Shockingly Simple Electrical For Tiny Houses which guide your through all the basics.  As of now, it doesn’t go too deep into the solar aspects, but the basics of electrical, wiring, power systems and determining your power needs are covered in depth and designed for those who are totally new to the topic.

Electrical Housing and wiring for a tiny house

So once the power passes through the power inlet it goes to the panel.  Near the bottom you can see the backside of the power inlet, it has a large black cord coming out of it, into the box and ties to the lugs.  From there it goes out to the house.

Electrical housing

Back outside now, looking at the cabinet, on the sides of it, you can see the vents.  When you use lead acid (LA) batteries you have some off gassing as the batteries discharge and recharge.  These gasses are volatile and can ignite, possible leading to an explosion.  So to take care of this I installed two vents like this which provide adequate venting.  As mentioned before my battery section is isolated from the electronics section where a spark could occur.

This off gassing is a concern with Lead Acid Batteries, but other battery technologies don’t have this issue.  I choose LA batteries over AGM (absorbent glass mat) because LA’s have more cycles and cost a bit less.  Lithium Ion at this point is cost prohibitive.  My batteries should get about 4000-5000 cycles (11-14 years) before I need to replace them.  I figure in about 5 years battery technology will have progressed so much I’ll change early.  New batteries will cost me about $4,000 of the LA variety.  Grounding wire

Here is my grounding wire for my system.  This is actually one of two, another is located at the panels them selves.  My house is also grounded to this through the cable hook up and to the trailer itself.  A really important note: ground depends on a lot of things, one of which is if you house electrical panels is bonded or not, if you don’t know what that means, read up on it, its very important.

The other component of this system is the generators.  In the winter months I may need to top off my batteries every now and then, basically when its been really cold and very cloudy for a week or more.  I had a Honda EB2000i already which I really like.  It’s very quite and small.  The one downside to the Honda is that it only does 1600 watts and only 120V and I needed more power and 240V.  So I picked up another generator, a 5500 watt 240 volt Generac for $650.

generac generator for off grid tiny house

Here is a video that compares the two generators in terms of size, noise, output and price.

So that’s the surface level details of the system, I’m going to be doing something in the future which will be a how to size, choose parts, hook up and all the other details of doing solar for your tiny house, but that is a longer term project, most likely will take about 6 months to pull together in the way I’d like to do it.

learn how to run ac on solar power

My First Winter In A Tiny House

After getting back from Croatia I’ve been learning a good bit about living in my tiny house in the winter. This December in Charlotte has been breaking records left and right for how cold it has been. Most mornings when I wake up it’s been in the 20’s which is very cold for this time of year.

The real issue for me has been right now I’m running off a generator and propane heater for my heat. Soon my solar panels will be installed and I can shift to my mini split. The generator has been working well, but because of how energy intensive the heater is and how cold it is, a full tank will only last about 3-4 hours. The propane heater works great too, a 1 lb propane tank will last about three hours.

First Winter in a Tiny Home: How to prepare

My strategy has been mainly to heat the house up for about an hour while I get ready for bed and then shut things off. With the propane heater, its a “catalytic” heater that while is technically a flame, it is more efficient and doesn’t use up as much oxygen as a open flame would. I don’t want to leave it running when I sleep because of it being a flame and also the danger of low oxygen. The heater has a low oxygen detector that will shut it off if it comes to that, but I don’t want to chance it regardless. Once I fall asleep, I’m fine until I wake up anyway.

One thing that I’ve learned is that the floor is always cold. Being on a trailer there is obviously an air gap below the trailer. I know a lot of people have used skirts for their house, but I’m not a fan of the look and its not windy in my location, so I’m not sure how effective it would be. It may come to be installing a skirt of a sort, but I think I’d like to start with trying an area rug. I think this might be an easy way because I noticed that when I stepped on a piece of cardboard that I happened to have on the floor, it seemed to do a pretty good job of feeling warm on my bare feet.

So far it’s been a pretty cold winter in my tiny house. That’s about to change.

First Winter in a Tiny Home: Preparations

Very soon a solar panel system is going in that will change my heating situation drastically. I will have a huge battery bank that will let me run my mini split and keep my space heated and on a timer, without the danger of an open flame or running the generator. The timer will be really helpful because I can drop the temperature when I’m asleep nestled under my covers, but then ramp back up right before I wake up and have to get out of bed. I’ll also be able to set it to maintain a minimum temperature, which will be nice because I can keep it a reasonable temperature, but not draw a ton of power.

The other thing I’ve noticed is since its been so cold outside, I’ve been inside my house more and wanting to go outside. Nothing really bad, but I’ve been so used to be going for long walks and just enjoying the weather since its so much warmer in Croatia, right now it’s a little too cold to just spend time outside. I have been spending some time at the gym, at cafes and I also went out and bought an outdoor fire place to have a fire pit at my tiny house. All of these have been great for handling this need to get up and do something. I think this will subside when I get power set up because I can then get Internet hooked up and set up my desk. That will help a lot.