Building an off-grid solar system for your home or cabin may seem like a daunting prospect, but it is expected that 12% of American households will live this way by 2035. You are capable of designing the right setup, and now is the opportune moment to do it.

The benefits of an off-grid solar system are clear. They include financial savings, energy independence, resilience against grid failures, and support for a cleaner environment. However, particularly in challenging climates like the Midwest, you must also account for seasonal extremes such as snow cover, freezing temperatures, and reduced solar availability.

Here’s how to design your system in six detailed steps—with added insights on critical winter-readiness.

Special Note on Midwest Winters

Before diving into the steps, understand that designing a system for a Midwest off-grid home must factor in 4–6 months of snow cover, snowstorms, cloud cover, and shorter winter days. These elements can reduce solar generation drastically and introduce challenges in requiring larger solar systems that waste energy on the sunny days because you need all fo the extra capacity for the short winter days. You’ll need robust planning, oversized systems, and resilient backup strategies.

How to design an off-grid solar system diagram.

Step #1. Calculate Your Energy Needs

Every system begins with understanding what you’ll need to power—especially in winter when heating loads rise and sunlight drops.

To calculate:

  • List all appliances and devices (lights, fridge, HVAC, etc.)

  • Record their wattage and daily usage in hours

  • Multiply each to get Watt-hours per day, then total them weekly

  • Add a 20–50% buffer for unexpected loads and cloudy days

Midwest Winter Tip: Consider seasonal shifts in usage—winter heating, more indoor lighting, and electric heaters and blankets increase load. Plan for your worst-case month, not your average.

Step #2. Select Your Battery

A critical piece of winter resilience is energy storage—especially when the sun may not shine for days.

Key considerations:

  • Lithium-ion vs. Iron-Phosphate: Lithium performs better in cold, has deeper discharge cycles, and requires less maintenance.
  • Choose a battery with temperature control or heated elements/enclosures to prevent freezing damage.
  • Calculate capacity to store 3–5 days of energy usage in case of prolonged storms.
  • Consider a 48V system for large setups to reduce losses and handle high demand.

Winter Concern: Battery efficiency drops in cold temperatures. A heated battery closet or thermal insulation is essential.

Step #3. Select Your Solar Panels

If you want to convert sunlight into energy efficiently enough to support off-grid living, the right choice and number of solar panels will be key. Selecting a reliable brand is a good starting point, but you should also confirm that the model is appropriate by;

Again, it is possible to install additional solar panels at a later date. However, it makes sense (financially and practically) to get this right at the first attempt. Otherwise, you won’t generate enough solar energy to power your home through the night. 

Winter Concern: Panels buried under snow are useless. Plan for manual snow clearing, use ground-mounted racks for accessibility, or install oversized systems and storage units that can mitigate seasonality and prolonged storms.

Step #4. Choose A Charge Controller

The charge controller is another crucial piece of equipment. It is placed between the solar panel and battery in order to regulate the current and voltage from the panel as well as battery charging. For starters, it must match the voltage and amperage of those items.

Controller types include;

  • A simple On/Off switch.
  • An MPPT that is costly but highly efficient.
  • A PMW, which sits between the two.

An MPPT is usually the best for off-grid solar systems. MPPT controllers boost voltage, which is crucial when panels underperform due to overcast skies.

Step #5. Choose An Inverter

An Inverter essentially turns a DC current into an AC current. In other words, it is the piece of equipment responsible for turning harvested solar energy into usable electricity. For that reason, it’s a key feature that will help you gain energy independence. The three main types are;

  • A square wave, which is the cheapest but least powerful and versatile.
  • Modified sine wave, which won’t suit many of the electromagnetic devices used in the home.
  • Pure sine wave, the most likely solution suitable for home applications.

Again, it’s best to choose what works for you, but the pure sine wave solution is the most likely by far. Just be sure that the power is at least equal to the demands previously calculated.

Winter Concern: Some inverters may shut down in extreme cold. Choose models rated for -20°F or below, or house it in a climate-controlled space.

Step #6. Plan for a Backup Generator

Even with a perfectly designed system, snowstorms, cloud cover, or equipment failure can leave you in the dark.

Recommended Generator Features:

  • Cold-weather kits with block heaters or battery warmers
  • Propane or diesel fuel, which stores better than gasoline
  • Integration with your battery bank via an auto-transfer switch
  • Examples: Cummins 20kW Cold Weather or Generac Whole Home 26kW, or Kohler 14RCA

Winter Concern: Generators must start reliably in subzero temps. Keep fuel dry and accessible, and test monthly.

Step #7. Complete The Installation

Designing an off-grid solar system that uses the right equipment for your requirements is one thing, but completing the installation is another. While it would be possible to take a DIY approach, it is always advised to hire an expert. Wolf River Electric is perfectly placed to install your system (and help with the design if necessary) so that it is ready to deliver years of service.

The installation covers several key steps. After finding the right spot to install the solar panels, such as the roof or ground, it must be mounted securely. All components must then be connected and wired correctly. This can be done with either series or parallel connectors. Finally, all equipment should be tested for quality and safety.

Whether you need help designing a winterized off-grid solar system or installing one for your property, Wolf River Electric is here to help. From calculations to panel placement and generator selection, we’ll ensure your system doesn’t just survive—but thrives—through every snowstorm. Get in touch to learn more now.