Your Complete Guide to
Home Energy System Sizing

These are your home's "heavy hitters" – the equipment that draws the most power. Think of 240V appliances as the workhorses of your home, requiring double the voltage of standard outlets.

How to Find This Information

• Check the nameplate: Look for a metal sticker on each appliance showing voltage, amperage, or wattage
• Look at your circuit breaker panel: 240V circuits use double-width breakers (usually 20-60 amps)
• Use the formula: Watts = Volts × Amps (240V × Amps = Watts)
• Review old utility bills: Many show usage patterns that spike with heavy appliance use

This is your home's "background" energy consumption – all the lights, electronics, small appliances, and phantom loads that run throughout the day.

This multiplier (0.012) represents the average energy density for typical residential construction with modern appliances, but without counting those big 240V appliances we identified in Step 1.

What This Baseline Includes

• Refrigerator and freezer (running 24/7)
• Lighting throughout the home
• TVs, computers, and entertainment systems
• Phone chargers and small electronics
• Microwave, coffee maker, toaster
• Washer (the motor, not heating elements)
• Garage door openers
• Security systems and Wi-Fi routers
• Phantom loads (devices on standby)

What It Does NOT Include

• Those 240V heavy appliances from Step 1
• Extreme weather conditions (very hot or cold days)
• Unusual usage patterns (like running a home business)

If you have solar panels or are considering them, understanding your solar production is crucial for sizing your battery backup system.

Production Depends On:

• Geographic location – More sun in Arizona than Seattle
• Roof orientation – South-facing is ideal in Northern Hemisphere
• Roof pitch/angle – 30-40 degrees is typically optimal
• Shading – Trees, chimneys, neighboring buildings
• Season – Summer produces more than winter
• Weather patterns – Cloudy days reduce production
• Panel efficiency and age – Newer panels perform better

*Ranges depend on location and conditions

Battery Sizing Strategy

One of the biggest misconceptions in solar energy is that certain roof orientations are "bad" for solar. The truth is: with battery storage, every orientation has strategic advantages. Let's debunk the myths and show you how to maximize your energy independence.

Debunking the East Roof Myth

Why West is Best for Time-of-Use (TOU) Rates

When utility rates are structured around time-of-use pricing, west-facing solar becomes your secret weapon:

• TOU Peak Hours: 4pm - 9pm (when electricity costs the most)
• Your Evening Routine: Get home and start cooking 3pm - 6pm
• West Roof Production: Still generating until 6pm (summer) or 5pm (winter)

Alternative Mounting Solutions

When roof mounting isn't ideal, you have options:

• Reverse Tilt Mounting: On north-facing roofs, panels can be tilted to face south using specialized racking
• Freestanding Patio Structures: Build a solar canopy over your patio, driveway, or entertainment area—dual purpose shade and power generation
• Ground-Mounted Systems: Install arrays in your yard with optimal tilt and orientation, independent of roof constraints
• Solar Carports: Protect your vehicles while generating electricity—perfect for homes with limited roof space

Let's break down what you're getting with this powerhouse battery system and what it means in real-world terms.

What Can 18 kW of Power Actually Run?

What About That 48 kWh of Storage?

This is your energy reserve – how long things can run:

*During normal weather conditions with adequate daily solar production

Your Complete Energy Picture: Step-by-Step Assessment

• Start with the big stuff – Your 240V appliances are what really drive your energy needs
• Square footage gives baseline – But actual usage varies based on lifestyle and climate
• Solar is location-dependent – Use conservative estimates for sizing your system
• Guardian E2.0 is powerful – 18 kW handles whole-home backup for most residences
• 48 kWh is substantial – Enough for 2+ days for typical homes, unlimited with solar
• Smart sizing saves money – Don't overbuild or underbuild; match your actual needs
• Monitor and adjust – Your first year's data helps you optimize the system