Index of instruments
§ A · CALCULATORSWorking tools that do the math for you. All client-side, all free, with shareable result links.
§ A-1
Wire-Size
AWG, voltage drop & breaker for any DC run.
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§ A-2
System Sizing
Panels, charge controller & daily yield.
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§ A-3
Battery Bank
Usable Ah, depth-of-discharge & reserve.
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§ A-4
Load Audit
Daily watt-hours by appliance & duty.
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§ A-5
Array Layout
Series/parallel strings & roof fit.
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§ A-6
Panel Capacity
Breaker-panel load & NEC capacity check.
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Worked example · result
6AWG
30 A · 24 V · 20 ft one-way · copper
Voltage drop
2.45%
under the 3% target
Overcurrent
40A
30 A × 1.25 continuous → next std. size
Assumptions: copper conductor, 20 ft one-way run (voltage drop computed on the round trip), ampacity per NEC Table 310.16 (60°C column — 6 AWG = 55 A), and the NEC 125% continuous-load factor applied before rounding up to the next standard breaker size. Building this exact run? That's 6 AWG battery cable and a 40 A surface-mount DC breaker (affiliate links).
Fundamentals
§ B-1 · COMPONENTSThe core components — panels, batteries, controllers, inverters, and safe wiring. Learn what each part does before you buy.
Fundamentals
Solar Panel Types Reference: Mono vs Poly vs Thin-Film
A complete reference on solar panel technologies — efficiency, temperature behavior, cost per watt, and which type fits each off-grid use case.
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Fundamentals
How to Build a DIY Solar Battery Bank
Battery types, sizing calculations, wiring configurations, and BMS basics for a safe, long-lived off-grid storage bank.
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Fundamentals
LiFePO4 Batteries Reference (+ Top Picks for 2026)
How LiFePO4 chemistry works, cycle life and BMS specs that matter, and a decision table comparing the leading solar battery options.
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Fundamentals
Solar Charge Controllers: MPPT vs PWM Reference
When MPPT pays for itself, how to size a controller to your array, plus a quick-pick table for 2026.
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Fundamentals
Solar Inverter Types Explained: String vs Micro vs Hybrid
Pure sine vs modified sine, string vs micro vs hybrid topologies, and which inverter type fits an off-grid build.
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Fundamentals
Solar Inverters Reference (+ Top Picks for 2026)
String, micro, and hybrid/off-grid inverters compared on surge rating, efficiency, and waveform — with current picks.
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Fundamentals · Popular
Solar Wiring Diagrams: Complete Visual Guide
Print-ready diagrams for series, parallel, series-parallel, MPPT/PWM, and 12V/24V/48V systems with charge controllers and inverters.
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Fundamentals
Solar Roof Mounting Guide: Tilt, Flashing & Wind Load
Mounting hardware, optimal tilt angles, watertight flashing, and wind-load considerations for roof and ground arrays.
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Fundamentals
DIY Solar Panel Installation: Step-by-Step
Planning, tools, wiring, permits, and safety for installing your own panels — for beginners and experienced DIYers alike.
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Fundamentals
How to Wire Solar Panels to Your Breaker Panel
NEC code requirements, backfeed breakers, the 120% rule, and safe shutdown for tying solar into a panel.
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Sizing & Design
§ B-2 · METHODTurn your power needs into real numbers — system voltage, panel wattage, and wire gauge. Pair these with the calculators above.
Sizing & Design
How to Size an Off-Grid Solar System (Step by Step)
The complete sizing method: load audit, sun hours, battery autonomy, array wattage, and controller/inverter selection — with worked examples.
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Sizing & Design
12V vs 24V vs 48V Solar Systems
How system voltage affects wire size, cost, and efficiency — and which voltage is right for an RV, cabin, or whole home.
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Sizing & Design
100W vs 200W vs 400W Solar Panels Compared
Real output, physical size, and cost per watt across common panel wattages — and how many you actually need.
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Sizing & Design
Solar Wire Sizing Guide: AWG Charts & Voltage Drop
AWG ampacity charts, voltage-drop math, and a sizing method to get the right gauge for every run in your system.
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Sizing & Design
How Much Solar Do You Need to Run a Refrigerator?
A worked sizing example: fridge watt-hours, panel wattage, and battery capacity to keep food cold off-grid.
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Build Guides
§ B-3 · APPLICATIONSComplete, application-specific builds — cabins, vans, sheds, boats, and RVs. Each one walks the full system end to end.
Build Guide
Off-Grid Cabin Solar System: Design & Build
Energy audits, panel sizing, battery banks, and generator backup for a complete off-grid cabin power system.
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Build Guide
Tiny Home Solar System: Design & Cost
System sizing, panel and battery selection, and wiring for THOW vs. foundation tiny homes.
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Build Guide
DIY Solar for Sheds
Add solar to a shed for lighting, tools, and an off-grid workspace — panel sizing, battery options, and wiring.
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Build Guide
DIY Solar for Your Garage & Workshop
Run power tools, compressors, and welders from solar — sizing for high-draw loads and inverter selection.
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Build Guide
Van Life Solar System: Complete Build
Power audits, panel sizing, LiFePO4 batteries, MPPT controllers, inverters, and wiring for a reliable van build.
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Build Guide
RV Solar Panels Reference (+ Top Picks for 2026)
Rigid vs flexible vs portable RV panels, roof mounting, and a comparison of top-rated kits for 2026.
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Build Guide
Boondocking Solar Setup Guide
A practical solar setup for dry camping and boondocking — sizing, portable panels, and battery strategy for staying off-grid longer.
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Build Guide
Solar Panels for Boats: Marine Solar Guide
Marine solar for sailboats, powerboats, and liveaboards — flexible vs rigid panels, ABYC wiring, and corrosion-safe mounting.
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Build Guide
Portable Solar for Camping & Overlanding
Foldable vs rigid panels, wattage guidance, and charging tips for camping, overlanding, and car camping.
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Build Guide
Off-Grid Solar Kits Reference (+ Top Picks for 2026)
What a complete kit includes, where pre-packaged kits make sense, and a comparison for cabins, RVs, and tiny homes.
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Systems & Appliances
§ B-4 · LOADSPowering the things that make a place livable — water, refrigeration, heating, internet, and backup power — plus keeping it all running.
Systems
Solar Powered Well Pump: Off-Grid Water
Submersible vs surface pumps, DC vs AC, and solar sizing for reliable off-grid water from a well.
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Systems
Off-Grid Refrigeration: Fridges & Freezers
DC vs AC fridges, propane options, and power-consumption comparisons for keeping food cold off-grid.
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Systems
Off-Grid Heating & Cooling Guide
Wood, propane, mini-split, and 12V options for staying warm and cool off-grid — with realistic power budgets.
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Systems
Starlink + Solar: Off-Grid Internet
Starlink power consumption, solar system sizing, and battery backup for reliable connectivity off-grid.
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Systems
Solar Generators Reference (+ Top Picks for 2026)
How solar generators (power station + panel combos) work, when they beat a DIY bank, and current picks.
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Systems
Wind & Hydro Off-Grid Power
When small wind turbines or micro-hydro complement solar — output expectations, siting, and hybrid charging.
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Systems
Off-Grid Maintenance & Troubleshooting
Keep your system healthy: panel cleaning, battery care, common faults, and a diagnostic checklist for when output drops.
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Systems
EcoFlow vs Bluetti vs Jackery: Power Stations
Three leading portable power station brands compared across capacity, output, charging, and value.
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Systems
Renogy vs Rich Solar: Budget Brand Comparison
Panels, batteries, charge controllers, warranties, and pricing compared between two popular budget solar brands.
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Land & Legal
§ B-5 · SITINGWhere you can legally live off-grid, what the laws say, and how to start. The lifestyle side of energy independence.
Start Here · Beginner
Off-Grid Living: The Complete Beginner's Guide
Solar power, water systems, heating, internet, costs, legal issues, and the best states to go off-grid — the full starting picture.
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Land & Legal
Best States for Off-Grid Living: Laws, Land & Solar
States ranked on laws, land prices, solar potential, and water rights for going off-grid.
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Land & Legal
Is Off-Grid Living Legal in Texas?
Texas off-grid laws on solar, septic, water collection, and zoning — what's allowed and where the gray areas are.
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Land & Legal
Is Off-Grid Living Legal in Florida?
Florida's rules on disconnecting from the grid, septic, and rainwater — and the county-level details that matter.
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Land & Legal
Is Off-Grid Living Legal in Arizona?
Arizona off-grid laws on solar, water rights, and building codes — one of the most solar-friendly states.
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Land & Legal
Is Off-Grid Living Legal in Colorado?
Colorado's rules on rainwater collection, septic, and zoning for off-grid homesteads — including recent law changes.
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Why Trust Off Grid Authority?
Spec-Verified
An independent, research-driven reference. Recommendations are based on manufacturer specifications, certification listings, and cross-referenced owner reports — checked against NEC/ABYC code requirements, not first-party lab testing and not marketing copy.
Maintained, Not Abandoned
Every guide carries a "last verified" date and is reviewed when codes, products, or prices change. Find an error? Tell us and we'll fix it.
Free & Open
No hype, no paywall. The calculators run entirely in your browser and the reference is free to read. We may earn affiliate commissions on gear links — clearly disclosed, never the point.
No sponsors.
No paywalls.
Just data.
Built on data.
Checked against code.
Shared freely.
Checked against code.
Shared freely.