Small Spaces, Big Solar Power: DIY Systems for Tiny Homes

Powering My Tiny House with the Sun for Over a Decade

It’s hard to imagine that I’ve been powering my tiny house off solar panels for over 7 years now. Not having a power bill for almost a decade has been incredible. With that in mind, I wanted to share my real-world experience with you to give you the full picture of what it’s really like to power your tiny house with solar – how many panels you need, how much it costs, and more.

As one of the few people who are completely off-grid in their tiny house, I’ve had to figure out a lot of things, like how to run my air conditioning off solar, how to cook with solar in a solar oven, and how I use solar generators as backup power in a pinch. Tiny houses are a great candidate for solar power because the smaller space means lower power needs. While the traditional American home uses around 30 kWh per day, my tiny house only uses around 3 kWh per day.

Every decision I made during my tiny house build, from choosing LED lights to a super-efficient mini-split system and an on-demand hot water heater, was chosen to reduce my power consumption. Since I built my own house, these decisions were pretty straightforward, and in the end, didn’t cost me much more. Any additional costs for things like a high-SEER HVAC system quickly paid for themselves by allowing me to have a smaller solar panel array and battery setup.

Determining Your Tiny House Power Needs

Before we dive into the nitty-gritty of setting up your DIY solar system, it’s essential to understand your tiny house’s power usage. A typical tiny house will use around 4 kWh per day. Approximately 80% of that power is usually for heating and cooling, assuming you cook and heat water with propane or natural gas.

Here’s a breakdown of my power usage:

As you can see, the majority of my power goes towards heating and cooling, which is typical for a tiny house. By choosing a highly efficient mini-split system and carefully selecting other low-power appliances and devices, I’ve been able to keep my overall power needs quite manageable.

Sizing Your Solar Panel Array

Now that you have an idea of your tiny house’s power usage, it’s time to figure out how many solar panels you’ll need. The general rule of thumb is to have a solar panel array that can produce around 125% of your daily power needs to account for less-than-ideal sun exposure and other factors.

For my tiny house, which uses around 4 kWh per day, I’ve installed a 1.2 kW solar panel array. This consists of four 300-watt solar panels, which can generate up to 4.8 kWh per day in ideal conditions.

According to The Tiny Life, the number of solar panels you’ll need will depend on factors like your location, roof size, and shading. But a good starting point is to assume you’ll need around 100 watts of solar panels for every 1 kWh of daily power usage.

Fitting Solar Panels on a Tiny House

One of the great things about tiny houses is that they have smaller roof areas, which makes it easier to fit solar panels. However, you still need to carefully consider the placement and orientation of your panels to maximize their efficiency.

I chose to mount my solar panels on the south-facing roof of my tiny house, as this orientation allows them to capture the most sunlight throughout the day. According to Pad Tiny Houses, you’ll want to aim for a tilt angle that’s roughly equal to your latitude, which in my case is around 45 degrees.

Another important factor is shading. Even a small amount of shading on your solar panels can significantly reduce their power output, so it’s crucial to avoid obstacles like trees or nearby buildings. I was lucky enough to have a clear, unobstructed roof for my panels, but you may need to get creative with your placement or consider using a solar tracker to follow the sun’s movement throughout the day.

Building a Tiny House Solar Setup

Once you’ve figured out the size and placement of your solar panels, it’s time to start building your DIY solar system. This can seem like a daunting task, but with a little research and some basic electrical knowledge, it’s a very doable project.

The first step is to choose the right solar panels for your needs. I went with high-efficiency monocrystalline panels, as they offer the best power-to-size ratio and can withstand the elements better than their polycrystalline counterparts. You’ll also need an inverter to convert the DC power from your solar panels into the AC power used by your tiny house’s appliances and devices.

According to the DIY Solar Forum, it’s a good idea to choose a pure sine wave inverter, as they provide cleaner, more reliable power than modified sine wave inverters. You’ll also need to factor in the cost of mounting hardware, cables, and other necessary components.

Once you have all the hardware, the actual installation process is relatively straightforward. I started by securing the solar panels to the roof using heavy-duty mounts, then ran the cables down to my electrical system. From there, it was just a matter of wiring everything up and ensuring everything was properly grounded.

Storing Energy with Solar Batteries

Of course, no solar setup is complete without a way to store the energy your panels generate. For my tiny house, I’ve opted for a bank of deep-cycle batteries, which allow me to store excess power during the day and use it at night or on cloudy days.

The size of your battery bank will depend on your power needs and the size of your solar array. As a general rule, you’ll want to have enough battery capacity to power your tiny house for at least a couple of days without any sun. For my 1.2 kW system, I’ve installed four 6-volt, 390 amp-hour batteries, giving me a total of around 9.4 kWh of storage capacity.

It’s important to note that battery maintenance is crucial for the longevity of your system. I make sure to regularly check the battery levels, equalize them when necessary, and replace them every 5-7 years as they start to degrade.

Connecting Your Tiny House to Solar Power

The final step in setting up your DIY solar system is integrating it with your tiny house’s electrical system. This can be a bit more complex, as you’ll need to ensure everything is wired correctly and up to code.

I started by installing a main electrical panel, which houses the inverter, charge controller, and all the necessary circuit breakers. From there, I ran dedicated circuits to power my various appliances and devices, making sure to label everything clearly.

One important consideration is the type of outlets you use. I opted for a mix of 120V AC outlets for my household items and 12V DC outlets for things like my cell phone and laptop. This allows me to maximize the efficiency of my solar system and avoid the power losses associated with inverting DC to AC and back again.

Embracing the Off-Grid Lifestyle

Powering my tiny house with solar has been an incredibly rewarding experience. Not only have I eliminated my monthly power bill, but I’ve also gained a deep appreciation for the sun’s energy and the importance of sustainable living.

Sure, there have been a few challenges along the way – like figuring out how to keep my mini-split running during extended cloudy periods or learning to adjust my energy usage habits. But the benefits far outweigh the drawbacks, and I wouldn’t trade my off-grid lifestyle for anything.

If you’re considering building a tiny house and want to take advantage of the sun’s abundant power, I encourage you to dive in and start planning your DIY solar system. With a little bit of research and elbow grease, you can harness the power of the sun and enjoy the freedom of living off the grid. Who knows, you might just end up like me, powering your tiny oasis with nothing but the rays of the sun.

And if you’re ever in the market for a high-quality solar energy solution, be sure to check out Solar-A-Systems Inc. They’ve got the expertise and products to help you take your tiny house off-grid in style.