Shipping Container Project: Solar is up!

When most people ask how my “tiny house” is progressing; they want to see pictures of the interior. Everyone is fascinated by the flooring choice, wall materials, countertops, and bathroom fixtures. However, I get very few questions about the systems that actually run everything. The entire thing is designed to be 95% self sufficient and operate in an off-grid format.

For all my fellow Energy Nerds out there — this one is for you!

Solar System Overview:

  1. Three 330 watt panels on the roof connected to custom tilt + turn mounts (Roughly 1kw of solar input total)
  2. Charge controller for managing the solar power (Renogy Rover 60 AMP)
  3. 24V Battery bank = 4x 180AH 6V deep cycle batteries wired in Series
  4. 3000 watt inverter with 9000 watt surge capability.  (AIMS Pure Sine)

Now the above system overview is probably too simplified for some people and a bunch of gibberish to others. First, I’ll provide a basic description of how this all works, and we can get technical later.

View of the 3 tilt turn panels installed

Whenever the sun is shining it’s releasing Energy that can be captured and used. The three solar panels on our roof are harvesting this energy and sending it (through thick wires) down into the container where it hits the Renogy Charge Controller. The charge controller stabilizes the solar power and inputs it safely into the batteries. It insures the batteries do not receive TOO much solar electricity (which would result in battery failure and be unsafe). It also keeps the solar electricity moving in one direction — you wouldn’t want electricity going BACKWARDS towards the panels. Basically, a charge controller is required in any off-grid solar system.


After the charge controller — the electricity is pumped into our battery bank. This is essentially four large batteries designed to be capable of holding various amounts of electricity at any given time. The amount of electricity contained in the batteries is displayed on the charge controller as a percentage. 0% meaning we have no usable solar electricity stored in the batteries and 100% meaning we are fully charged. Above you can see that I currently have 71% of usable electricity remaining, with 102watts of electricity going into the batteries from the Solar Panels. (the sun was setting at this point, because normally our panels are inputting around 700W on a sunny day) Making sense?

6V batteries wired in series creating 24V battery bank

The next step is getting the sunlight energy from the batteries to the house. This is done with our AIMS 3000W Inverter which converts the battery electricity to usable “household” electricity and sends it to all the outlets, lights, appliances, etc… Whenever the Inverter is turned on, the outlets throughout the shipping container are active. Plug something in and it works! Just like a standard household outlet. The 3000W part of the Inverter is describing how much maximum electricity we have available through this size Inverter. FOR EXAMPLE: 5 lights, radio, the mini fridge, fan, and my laptop use about 265 watts — well within the capacity of this Inverter. As you turn things on, the amount of watts rises, with the maximum available being 3000 watts.

This particular AIMS Inverter also has the option to charge the batteries from a standard “on-grid” source of electricity. If the container was near a structure that has grid power available; you can plug the container into a outlet (insuring proper breaker size for the amp draw) and have this charge the batteries or even bypass our entire system and run the shipping container off standard power.

AIMS Inverter hard at work

We will get into mechanical systems in a separate blog — but I want to note that our Minisplit (which is how we have air conditioning during summer) uses roughly 825 watts and is the biggest electrical user in the shipping container. Recently, during a sunny 90F day — I worked for 6 hours with the Minisplit providing AC the entire time. The batteries had a 100% charge when I arrived and were at 45% when I left.

Using a very inexpensive wall mounted power meter; you can view the total amount of electricity being used at any given time. Below you can see that I am using 463 watts of electricity at this point in time. By looking at this little power meter, and comparing it to the Renogy Charge controller — you can actively see if you are using more energy than the sun is currently inputting. Pretty fun thing to do as you turn things on and the sun moves around 🙂

Solar used monitor
We were using 463 watts of electricity when this picture was taken

Solar System Budget:

  • 330W Solar Panel x3
    • $215 each = $645 total
  • Renogy Rover 60 AMP Charge Controller (12/24V)
    • $215 total
  • AIMS 3000W Inverter/Charger
    • $925 total
  • Solar LCD Power/Energy Display
    • $20 total
  • 400 AMP/Hour 6V Batteries x4
    • $85 each = $340 total

$2,145.00 total cost before wiring, disconnect, switches, etc

I’ll write up a technical article later that outlines how/why we wired everything including wire sizes, connections types, lengths etc.

For now, this is a good overview of where we started at for our Shipping container tiny house renewable energy system. We plan to double the battery bank in 1-2 weeks, but for now this is working great.

Thank You,

Written By:

Luke Langhals

Thermal Camera for DIY Projects

Thermal Camera’s are an essential tool for people trying to discover energy losses and home comfort issues. For many years, these were expensive gadgets that only a professional would consider buying. However, we are now beginning to see some affordable options hit the market!

If you plan to add insulation to your home or want to find where those pesky cold drafts are originating — I would highly recommend you invest $200.00 in the FLIR Thermal Camera (on Amazon).

This nifty little device plugs directly into your Android or Iphone. It is then as simple as point and capture. Your goal will be to see where heat is leaking into and out of your home. Further, you can see how heat is moving around your house and this assists with finding plumbing/ducting behind walls.

Here are a few shots I’ve taken with my FLIR. It becomes pretty obvious where insulation will be most effective.

Hotwaterpipethermal resized
Hot water pipes wasting energy: Click picture to link to the blog
Basement Rim joists wasting energy: Click picture to link to the blog

Overall, anyone worried about Energy Usage needs to better understand where their heating/cooling air is being used. This is the most expensive part of your utility bills and understanding it’s movement will help save you money 🙂

Written By:

Luke Langhals

Luke’s Pennsylvania Housing Presentation: Breathe Easy — March 13th, 2019

Next week I’ll be presenting at the Pennsylvania Housing Research Center’s annual conference. Feel free to come learn about fresh air!

My session is from 1:15 – 2:45 PM. I will be outlining different ventilation requirements, technologies, and how they make our home’s healthier.

This conference will focus on different High Performance building techniques. I’m very excited to share my knowledge about ventilation, but more excited to hear other presenters talk about blower door tests, high performance windows, and Net-Zero energy!

There is a lot to be learned and this is the place to do it. I would highly recommend this event to anyone nearby State College, PA.

Call me an Energy Nerd….I don’t mind 🙂

PHRC Agenda 2019.PNG

Here is a LINK to the conference website:

Written By:

Luke Langhals





Tech Tip: Smart Outlets

Information is king in the world of energy saving. Understanding how much electricity is being used will give you an opportunity to eliminate waste. I picked up a pair of the Etekcity smart plugs for $27.00 on Amazon.

These smart outlets have the ability to turn power on/off from your smartphone. It also gives you a breakdown of Energy usage and allows for scheduled timers. Any plugged in appliance will have some power waste even when turned off. Gaming systems, TVs, cable boxes, and computers are notorious for wasting energy when not in use.

Here is the home screen for one of my outlets. My bedside lamp and cell phone charger have used only 0.82 kWh this month

Owning these outlets allows you to understand how much power things are using over time. Further, the schedule/timer feature provides the ability to turn off energy wasting appliances when they are dormant.

Here is the yearly chart of electricity usage from this same outlet. This tells me that I did more night time reading during the month of May.

Overall, I plan to continue purchasing more of these whenever they are on sale. Understanding and programming my electricity usage is a valuable commodity. I can save money by eliminating energy waste — I can also look cool by turning lights on and off from my cell phone!

Written By:

Luke Langhals

Finally: An Affordable Indoor Air Quality Monitor!

Each month I will try to introduce a new “tool” for creating a healthier, more efficient, or more sustainable home. Today, I will outline my Foobot IAQ Sensor!

Summary: An Indoor Air Quality sensor will help you visualize how healthy your home is. I personally have several different sensors operating at all times. My Foobot is the first “all in one” device and measures a number of different items. I have been happy with its ease of use and highly recommend people with IAQ concerns start here. Information is king!

This nifty little gadget has been making me more aware of the air I am breathing. Although I do not consider the $200 price tag to be cheap, it definitely offers fantastic “bang for the buck.” Most IAQ monitors come with a much higher cost and generally they only monitor one aspect of air quality. Common household sensors include either Humidity, particulate matter, C02, or volatile compounds. With the Footbot, you get all of these conditions in one neat little box.

Here is a quick rundown of the different aspects of IAQ and why they are important:

1. Humidity: The amount water vapor in your interior air. An optimum house will have a continuous relative humidity level between 35% and 55%. When your home begins to get above 55%….mold can grow. When levels drop below 35%….the air becomes uncomfortable.

2. Particulate Matter: For our purposes this is measured as fine particles in your air that can be inhaled into your body. Any small particles from smoke, cooking, pet dander, allergens, cleaning supplies etc. If you have someone with asthma, COPD, or allergy issues….this is an important level to watch. Your goal is to keep your home below 12 (uG/m3) a minimum of 95% of the day.

3. C02: Levels of interior C02 will rise because of a number of conditions. Mainly, I see mine spike when I entertain guests (more people breathing) or while I’m cooking on my gas stove. Your goal is to keep your home below 1300 ppm for the majority of the day. C02 is not considered particularly dangerous at these levels…but it is a good identifier for how much fresh air you have. Also, a Harvard research study found that C02 levels above your desired threshold can lead to lower cognitive function. You are reading that correctly! Having high C02 in your home might be making you stupider!

4. Volatile Compounds: The level of interior VOCs are generally determined by the level of gases or chemicals that might have been brought into your home. A number of items could be effecting your VOC level. Including off-gassing carpet/furniture, paint, cleaning supplies, building materials, etc. If you have ever noticed cans of paint at the hardware store that say LOW VOC….this is exactly what they are talking about. Aim to keep your interior VOC level below 300 ppb. Whenever you choose to do some household painting or cleaning; these levels will likely surpass your desired threshold.

Blue Foobot = healthy air!

My Footbot manages to stay “blue” roughly 90% of the day. However, it always reacts when I am cleaning or cooking in the house. Different household actions will lead to “bad” air. Luckily, I can see these conditions taking place and try to limit the amount of time/frequency.

Orange Foobot = Unhealthy Air
Here is the smartphone AP from Foobot on a normal day with 4 people in the house. My C02 levels are beginning to creep upwards from the occupancy but overall everything looks good. A Winter interior humidity level of 31% is common in old houses and leads to uncomfortably dry air…but we will talk about this later 🙂

Overall, the main benefit of owning a Foobot is that you will have a better understanding for how your actions might be effecting your home. Information is king in the world of sustainability. I’ve now had this little device active for 11 months. I can honestly say that the information is useful and as I make other upgrades to my 100 year old home…I can see how they correlate with my air quality.