Tree Solar Shade Calculator | Lost Solar Savings

ShadeHunter – Solar Obstruction & Hour-Loss Calculator

🌤️ ShadeHunter

Solar Obstruction & Hour-Loss Calculator

Tree, chimney, or neighbor’s roof blocking sun? Find out exactly how much energy & money you lose — and if it’s worth trimming.

Units:

Use phone compass: South=180°, East=90°, West=270°

Close: <10ft Medium: 10-30ft Far: >30ft

Visual estimate: hold phone at panel height, angle up to treetop

Pitch affects total sun exposure — steeper roofs catch different sun angles.

Bare branches (winter) Partial leaves Full canopy (summer)

Adjust based on tree type. Full canopy = maximum shade.

Default US avg $0.16/kWh. Adjust to your utility bill.

Typical residential: 5–8 kW. ~400W per panel, so 12 panels = 4.8kW.

Get local arborist quote — used for “Trim or remove?” ROI analysis.

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📘 User Guide

How to Use ShadeHunter & Why It Matters

Turn shade uncertainty into a clear financial decision — in under 60 seconds.

⚡ Why This Calculator Exists

Most homeowners with solar (or shopping for it) have a nagging suspicion: "That tree probably costs me money, but how much?" Installers often dismiss small obstructions because they can't easily quantify the loss. ShadeHunter closes that gap. A single tree blocking sun from 1–3 PM can steal 300–500 kWh/year – that's $50–$80 annually, or $1,200–$2,000 over 25 years. This tool turns a vague annoyance into a clear ROI decision.

🧭 How to Use – 60 Second Guide

1. Point phone compass at roof → enter Azimuth (South = 180°).
2. Measure distance to tree / chimney (feet or meters – use toggle).
3. Estimate height angle (hold phone at panel height, sight treetop).
4. Select roof tilt & seasonal leaf coverage (crucial for trees).
5. Enter electric rate ($/kWh) + system size (kW).
6. Add tree removal cost → get “Trim or remove?” YES/NO verdict.

⬆️ After filling the calculator above, click "Calculate My Solar Shade Loss" — results include lost hours, annual kWh, $ loss, and a sun path diagram.

📐 The Math Behind the Magic

🔹 Lost Hours per Day = (verticalAngle/75) × distanceFactor × azimuthPenalty × 4.5
Example: 30° tree at 20ft, south roof → 0.4 × 0.7 × 1.0 × 4.5 ≈ 1.26 hours lost (before seasonal/type adjustment).

🔹 Annual kWh Loss = (lostHours/6) × annual unobstructed yield (approx 1400 kWh/kW × system size × tilt factor)
Example: 6kW system, 1.5h lost daily → (1.5/6) × 7800 kWh ≈ 1,950 kWh/year stolen by shade.

🔹 25-Year Dollar Loss = annual kWh loss × electric rate × 25 years.
Example: 350 kWh/year × $0.16 × 25 = $1,400 lost over lifetime → if removal costs $900, trimming pays off (+$500).

⚙️ The "Trim or remove?" logic compares 25‑year loss vs. your local arborist quote. Simple, powerful, and installer‑friendly.

❓ Frequently Asked Questions

🤔 How accurate is ShadeHunter?

Within ±25% — precise enough for a "cut or leave" decision, but not an engineering-grade simulation. Use as a financial guide.

🍂 What if my tree loses leaves in winter?

Use the Seasonal Leaf Coverage slider at 20-30% for bare branches. The calculator automatically scales loss based on canopy density.

🏠 Does roof tilt really matter for shade loss?

Yes. A steep roof (35°+) catches ~8% less total annual sun, so absolute shade loss is slightly smaller. ShadeHunter accounts for tilt in the base production estimate.

📏 Can I use this BEFORE installing solar?

Absolutely — that’s the best time. Test different roof faces or decide if tree removal is worth it before panels go up.

🌳 What if my obstruction is a chimney or neighbor’s wall?

Select “Solid obstruction” — the calculator applies a full-block multiplier (no diffuse light passes through).

💡 Why does the sun path diagram show a shaded arc?

That red/black arc represents the portion of the sun’s daily path blocked by your obstruction. The longer the arc, the more peak hours lost.

💡 Real-world example: A homeowner in Texas with a 6 kW system, a 25ft oak tree at 35° above panels (full canopy) lost 1.9 hours/day → 470 kWh/year → $75/year → $1,875 over 25 years. Removal cost: $1,100 → ✅ “Trim or remove? YES” — net gain $775.
ShadeHunter — Solar Obstruction & Hour-Loss Calculator | Estimates for guidance only.

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