SunFusion Energy Systems - Solar & Battery Calculator

Design Your Solar + Battery System

Get instant sizing recommendations and pricing for your home's perfect energy independence solution.

🔥 30% Manufacturer's Rebate — Limited Time Offer
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Your Energy Profile

Tell us about your current energy usage

Highest month from your utility bills
Auto-calculated from monthly ÷ 30
Affects solar production estimates
Select based on your monthly usage vs baseline
Blended rate from your utility bill
4-9 PM on-peak rate (Summer Tier 2 = $0.93)
Super off-peak rate (midnight-6am)

💡 Uncheck "Include Solar PV" for battery + inverter only pricing (existing solar or add solar later)

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Build Your Own System

Or let us recommend based on your usage above

Custom System Total
$28,275
49 kWh Storage
18 kW Continuous Power
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Your Goals

What do you want to achieve?

24 hrs
How long to run on battery without grid or sun?
100%
% of usage to offset (>100% for surplus)

Your Custom System Recommendation

Based on your energy profile and goals

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Solar Array
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Battery Storage
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Inverter
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Annual Production
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Estimated yearly
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First Year Savings
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Bill reduction
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Payback Period
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Based on energy savings
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25-Year Savings
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Net benefit
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System Investment
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Installed price
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Recommended System Packages

Pre-engineered solutions for your needs

ℹ️ Important Sizing Notes
  • Solar calculations assume optimal roof orientation (south-facing) and minimal shading
  • Battery sizing includes 20% reserve for system efficiency and degradation
  • Backup duration based on reduced "critical loads" (~60% of normal usage)
  • Actual performance varies based on weather, usage patterns, and system configuration
  • Final pricing subject to site survey and engineering review

📋 Get Your Personalized Quote

Enter your details to save and print your estimate

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Advanced Load Analysis

For precise system engineering

Maximum simultaneous power draw
Essential loads during outage
For solar panel installation
⚠️ Professional Site Survey Recommended
For precise system sizing, we recommend a professional site survey. Factors like roof pitch, azimuth, shading analysis, electrical panel capacity, and local code requirements all impact the final design. This calculator provides estimates for planning purposes.
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Advanced Analysis Results

Detailed system specifications

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What-If Scenarios

Explore how different situations affect your system needs

🚗 Adding an Electric Vehicle

Impact: +20-40 kWh/day depending on driving

Recommendation: Add 6-8 kW of solar capacity and 15-20 kWh of battery storage. Schedule charging during super off-peak rates (11PM-6AM at ~$0.15/kWh).

Pro Tip: Size your system now for future EV - it's 30-40% cheaper than upgrading later.

🔥 PSPS / Wildfire Events

Challenge: Multi-day planned power shutoffs in fire-prone areas like Ramona and Fallbrook.

Recommendation: Size battery for 48-72 hours autonomy (65-98 kWh). Guardian Shell's 1125° fire rating provides critical protection.

SDG&E averages 3-5 PSPS events annually in backcountry areas.

TOU Rate Arbitrage

Opportunity: Buy low, use high with battery storage.

Strategy: Charge at $0.15/kWh (11PM-6AM), discharge at $0.93/kWh (4-9PM). That's $0.78/kWh profit per cycle.

A 49 kWh battery cycling daily saves $2,500+/year on arbitrage alone!

🏊 Adding a Pool

Impact: Pool pump adds 10-15 kWh/day, heating can double that.

Recommendation: Add 3-4 kW solar. Use variable speed pumps during peak solar hours. Consider solar thermal for pool heating instead of electric.

🌡️ Extreme Heat Events

Challenge: A/C running 24/7 during heat waves can use 60-80 kWh/day.

Recommendation: Sol-Ark 18K handles high surge loads. Size battery for overnight A/C operation (25-30 kWh minimum).

Mini-split heat pumps are 30-40% more efficient than central A/C.

🏥 Medical Equipment

Priority: Absolute reliability required for CPAP, oxygen, dialysis, etc.

Recommendation: Oversize battery by 50-100%. Sol-Ark's 5ms transfer time is medical-grade UPS quality. Add generator backup for extended outages.

Guardian Shell's fire protection is critical for home medical safety.

📈 Rising Electricity Rates

Reality: SDG&E rates have increased 7-10% annually for the past decade.

Value: A system breaking even in 6 years at today's rates may break even in 4 years with continued increases. Solar + storage = energy cost insurance.

Lock in your energy costs for 25+ years.

🏠 NEM 3.0 Impact

Challenge: Export rates dropped from ~$0.30/kWh to ~$0.05-0.08/kWh.

Strategy: Battery storage is now ESSENTIAL. Store excess solar for evening use rather than exporting to grid at low rates.

Self-consumption is 3-5x more valuable than grid export under NEM 3.0.

💼 Work From Home

Impact: +15-25% daily usage, but more during solar production hours.

Silver Lining: Better solar utilization since you're home during peak production. May need less battery since daytime loads absorb solar directly.

Reliable power becomes mission-critical for video calls!

Frequently Asked Questions

Common questions about solar + storage systems

Are lithium batteries safe in my home?
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Yes, when designed properly.

Our ECHO battery modules use LiFePO4 (Lithium Iron Phosphate) chemistry - fundamentally different from the lithium-ion batteries in phones/laptops that make headlines:

  • LiFePO4 Chemistry: Most stable lithium chemistry. No thermal runaway below 518°F - standard lithium-ion starts at 302°F
  • Guardian Shell Housing: 1125° fire-rated enclosure provides multiple hours of protection
  • Multi-Level BMS: Monitors every cell, preventing overcharge, over-discharge, and temperature excursions
  • UL Certifications: UL9540, UL9540A (fire propagation), and UL1973 certified

Your system is safer than the gas tank in your car or the natural gas line to your home.

How long will the batteries actually last?
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ECHO 3.0: 6,000+ cycles at 80% DOD = 25+ year calendar life

  • Cycle Life: 6,000+ full cycles. At 1 cycle/day, that's 16+ years of cycles available
  • Calendar Life: 25+ years before capacity drops below 80%
  • Real Usage: Most homes partial-cycle (20-60% DOD), extending life significantly
  • Round-Trip Efficiency: ≥96% — more of your stored energy is available

Warranty: 25-year warranty — the best in the industry.

What is the 30% Manufacturer's Rebate?
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SunFusion is currently offering a 30% Manufacturer's Rebate on all Guardian systems and Sol-Ark kits.

This limited-time rebate significantly reduces your system cost:

  • Guardian E2.0 48 kWh: $39,104 → $27,373 (save $11,731)
  • Guardian Tower: $46,014 → $32,210 (save $13,804)
  • Sol-Ark 15K + ECHO: $16,500 → $11,550 (save $4,950)
  • ECHO 3.0 Bulk (3+): $4,575 → $3,175 per module

Why the rebate? SunFusion wants to make energy independence accessible to more families. This rebate won't last forever, so contact us to lock in your savings.

Note: The federal ITC for residential solar has expired, but this manufacturer rebate provides comparable savings.

What happens during a multi-day outage with no sun?
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Battery capacity + load management = days of autonomy

Example: Guardian E2.0 (49 kWh) during 3-day storm:

  • Day 1: Critical loads only (5 kW avg) = 41 kWh remaining
  • Day 2: Partial solar (20%) + critical loads = 29 kWh remaining
  • Day 3: Minimal solar + reduced loads = 12 kWh remaining
  • Day 4: Storm clears, solar recharges battery ☀️

Strategies: Sol-Ark auto-starts generator at 20% battery. Even cloudy days produce 10-30% rated capacity.

Pro tip: Guardian Tower (65-98 kWh) provides 4-7 days autonomy with zero solar.

Can I run my whole house including A/C and dryer?
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Yes, with smart load management.

Sol-Ark inverter capabilities:

  • Sol-Ark 15K: 15kW continuous, 24kW surge (10 sec)
  • Sol-Ark 18K: 18kW continuous, 36kW surge (10 sec)

Common loads: Central A/C (3-5 kW running, 8-10 kW startup), Electric Dryer (3-5 kW), EV Charger (7.2 kW), Water Heater (4-5 kW).

Sol-Ark's smart load management sequences high-power loads to avoid simultaneous startup. You may need to avoid running ALL high-power items at once during an outage.

Should I wait for better/cheaper battery technology?
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No. Buy when you need it, not when it's "perfect."

  • Waiting game: Costs dropped 85% since 2010. Future drops will be incremental (2-5%/year)
  • Rising rates: You're paying 7-10% more annually while waiting - that adds up fast
  • Current tech: LiFePO4 is proven, safe, and lasts 25+ years
  • Financing: Monthly loan payments can be less than your current electric bill

Math check: System saving $5,000/year. Wait 2 years for 10% price drop ($5,000 savings), but lose $10,000 in utility bills. Net loss: $5,000. Plus rates keep rising.

How much maintenance is required?
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Very little - these are "set and forget" systems.

  • Solar panels: Rain naturally cleans. Optional manual cleaning 1-2x/year in dusty areas. 25-year warranty.
  • Batteries: Zero maintenance - solid-state, no moving parts. BMS handles balancing automatically. Remote monitoring.
  • Inverter: Filter cleaning 1x/year (5 min). Fan replacement every 10-15 years (~$200). 10-year warranty (extendable to 25).

Total annual effort: ~1 hour of your time, $0 in most years.

What if my roof needs replacement soon?
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Replace your roof BEFORE installing solar.

  • Don't: Install on old roof - removal/reinstall costs $5,000-8,000 later
  • Do: Fresh roof + solar = no worries for 25+ years
  • Asphalt shingles: Don't install solar if >15 years old
  • Tile/metal: Can install even on older roofs (50+ year life)

Some installers partner with roofers for combined quotes. You can finance both together.

How long does installation take?
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Typical timeline: 8-12 weeks from contract to power-on

  • Week 1-2: Design, engineering, permit applications
  • Week 3-8: Permit review (varies wildly by jurisdiction - this is the bottleneck)
  • Week 9-10: Physical installation (3-5 days actual work)
  • Week 11-12: City inspection, utility meter swap, PTO granted

Pro tip: Schedule your installation before summer to avoid peak season delays and be ready for wildfire/PSPS season.