How to Size Your Solar System in 5 Steps

Published: December 15, 2024 | 8 min read

Sizing your solar system correctly is crucial for maximizing your investment and ensuring your energy needs are met. Follow these 5 essential steps:

Step 1: Calculate Your Daily Energy Consumption

Start by listing all your appliances and their power consumption. Multiply the watts by hours used per day to get watt-hours (Wh). Add everything up for your total daily consumption in kWh.

Example: If you use 10 kWh per day, you'll need enough solar panels to generate that amount (plus 20% for losses).

Step 2: Determine Peak Sun Hours in Your Location

Peak sun hours vary by location. Most areas get 3-6 peak sun hours daily. Use our calculator tool to find your exact location's solar potential.

Step 3: Calculate Required Solar Panel Capacity

Formula: (Daily kWh / Peak Sun Hours) × 1.2 = Required Watts

For 10 kWh with 5 peak sun hours: (10 / 5) × 1.2 = 2,400W or 2.4kW system

Step 4: Size Your Battery Bank

Multiply your daily consumption by the number of days of autonomy you want (typically 2-3 days). Account for battery depth of discharge (DoD).

Step 5: Select the Right Components

Match your MPPT controller to your panel voltage and current. Choose an inverter that can handle your peak loads plus 25% safety margin.

Pro Tip: Use our interactive solar calculator to instantly size all your components!

LiFePO4 vs Lead Acid: The Ultimate Battery Comparison

Published: December 12, 2024 | 12 min read

Cost Comparison

Lead Acid: $100-150 per 100Ah @ 12V = ~$83-125 per kWh

LiFePO4: $400-600 per 100Ah @ 12V = ~$333-500 per kWh

Lifespan

• Lead Acid: 500-800 cycles at 50% DoD = 3-5 years
• LiFePO4: 3,000-5,000 cycles at 80% DoD = 10-15 years

Usable Capacity

Lead acid should only be discharged to 50% to preserve lifespan. LiFePO4 can safely discharge to 80-90%.

Result: A 200Ah lead acid gives you 100Ah usable. A 100Ah LiFePO4 gives you 80Ah usable.

Cost Per Cycle Analysis

Lead Acid: $150 / 500 cycles = $0.30 per cycle

LiFePO4: $500 / 4000 cycles = $0.13 per cycle

Winner: LiFePO4 is actually cheaper long-term!

Our Recommendation

For permanent installations where you plan to stay 5+ years: LiFePO4

For temporary setups or extreme budget constraints: Lead Acid

MPPT vs PWM: Which Solar Controller Should You Buy?

Published: December 10, 2024 | 10 min read

What's the Difference?

PWM (Pulse Width Modulation): Simple, cheap ($30-100). Pulls down panel voltage to match battery voltage. Wastes energy.

MPPT (Maximum Power Point Tracking): Smart, expensive ($100-400). Converts excess voltage to current. 20-30% more efficient.

Real-World Testing Results

We tested both with identical 300W panels:

• PWM: Delivered 210W to battery (70% efficiency)
• MPPT: Delivered 270W to battery (90% efficiency)
• Difference: 60W or 29% more power with MPPT

When PWM Makes Sense

• Small systems (under 400W)
• Panel voltage matches battery (e.g., 12V panel for 12V battery)
• Tight budget

When MPPT is Essential

• Large systems (over 800W)
• Higher voltage panels (e.g., 48V panels for 24V battery)
• Cold climates (MPPT performs better in cold)
• You want maximum efficiency

The Math

MPPT costs $150 more but generates 60W × 5 hours = 300Wh more per day

That's 110 kWh per year × $0.12 = $13/year savings

Payback period: 11.5 years... but your panels last 25+ years!