System 1: 200W Safe Harbor
What You’ll Build
This afternoon, you’ll generate your first solar watt.
You’re building a 200W standalone solar system — a single panel, a charge controller, a battery, and a few DC loads. No permits required. No electrician needed. No connection to the grid or your house wiring. Just clean, independent power for your shed, garage, or workshop.
Oregon’s Solar Installation Specialty Code exempts standalone systems under 200W from all permits and inspections. That’s the legal foundation, and it’s what makes this the simplest possible entry point into solar.
What this system is: A self-contained DC power station. It charges a battery from sunlight and runs 12V loads — LED lights, USB chargers, a small fan. Think of it as a permanent, weatherproof version of a portable power station, except you built it yourself and it recharges for free every day.
What this system isn’t: It won’t power your house, run your fridge, or replace your utility bill. It’s a starting point — a way to learn how solar works by building something real that you’ll actually use.
What You Can Power
A 200W panel in Oregon generates roughly 0.6 to 1.0 kWh per day depending on the season and weather. That’s not a lot in absolute terms, but it’s more than enough for:
- Phone and laptop charging — a phone takes about 15Wh per charge, a laptop 50-60Wh. You could charge both daily and barely dent your battery.
- LED lighting — a 12V LED strip or puck light draws 5-15W. Run lights for 4-6 hours per evening, no problem.
- Small fan — a 12V DC fan draws 10-30W. Good for a workshop in summer.
- Radio or Bluetooth speaker — negligible draw.
- USB devices — anything that charges over USB.
The key is keeping your loads DC. The moment you add an inverter to convert to AC (household power), you add cost, complexity, and energy loss. This system stays simple by staying 12V DC.
Shopping List
You can build this system for under $300 with a lead-acid battery, or around $500 with LiFePO4. Here’s what you need:
| Item | Specs | Approx. Cost |
|---|---|---|
| Renogy 200W Monocrystalline Panel | 200W, monocrystalline, MC4 connectors | ~$150 |
| Victron SmartSolar MPPT 75/15 | 15A MPPT charge controller, Bluetooth monitoring | ~$100 |
| LiTime 12V 100Ah LiFePO4 | 12V, 100Ah, built-in BMS | ~$240 |
| Renogy 30A ANL Fuse Holder | Inline fuse, between controller and battery | ~$10 |
| BougeRV 10AWG PV Extension Cable | MC4 connectors, UV-rated, 10AWG | ~$25 |
| Renogy Z-bracket Mounts (set of 4) | Universal panel mounting brackets | ~$20 |
| CT CAPETRONIX 12V LED Interior Lights | 12V DC, your first solar-powered load | ~$15 |
| Total (LiFePO4 build) | ~$560 |
Buying advice: Get a name-brand charge controller — Victron, Renogy, or EPEver are solid choices. The MPPT type extracts more power from your panel than PWM, especially in partial shade or low light. For the battery, LiFePO4 is worth the premium over lead-acid: it lasts 5-10x longer, weighs less, and handles deep discharge without damage. Buy new panels — used panels are a gamble on degraded output and damaged connectors.
Wiring Topology
This is an all-DC system. No inverter, no AC, no household wiring. That’s what keeps it simple and safe.
Connection sequence:
Panel → MC4 cables → Charge Controller → Fused connection → Battery → DC Loads
The charge controller sits between the panel and the battery. It regulates voltage and current to charge the battery safely — preventing overcharge, managing float voltage, and optimizing power extraction (if MPPT). Your DC loads connect to the battery or to load terminals on the controller, if it has them.
Wire gauge: Use 10-12 AWG wire for all DC runs. For the exterior run from the panel to the interior, use UV-rated PV wire or USE-2. For interior connections, standard stranded copper wire is fine.
Keep runs short. Voltage drop matters more at 12V than at higher voltages. The same resistance that causes a 1% drop at 120V causes a 10% drop at 12V. Keep your wire runs as short as practical — ideally under 15 feet from panel to controller.
A visual wiring diagram is coming soon.
Step-by-Step Build
Seven steps. One afternoon. Here’s the sequence.
1. Pick your spot
South-facing, minimal shade. The panel needs direct sunlight for the longest possible window each day. A shed roof, a south-facing wall, or even leaning against a fence works for a single panel. Avoid spots with shade from trees, buildings, or other structures during peak sun hours (10 AM to 3 PM).
2. Mount the panel
Z-brackets work well for roof mounting on a shed. If you’re just getting started and want to test before committing, lean the panel against a south-facing wall at a 30-45 degree angle. You can always mount it permanently later. Secure it so wind won’t knock it over.
3. Run wire from the panel to the interior
Use UV-rated PV extension cable (MC4 connectors) from the panel to where you’ll mount the charge controller inside. Route through a wall penetration, under an eave, or through an existing opening. Seal any holes with silicone or a weatherproof grommet.
4. Connect the charge controller (panel side)
Mount the charge controller indoors, on a wall or shelf. Connect the MC4 cables from the panel to the controller’s solar input terminals. Do not connect the battery yet.
5. Install the inline fuse
Wire the inline fuse holder between the charge controller’s battery output terminals and where the battery will connect. This is your protection against short circuits. A 20-30A fuse is appropriate for this system.
6. Connect the battery
Connect the fused output to the battery terminals. Positive to positive, negative to negative. The charge controller should light up and show the battery voltage.
7. Connect your DC loads
Wire your 12V LED lights, USB charger, or other DC loads to the battery or to the charge controller’s load terminals (if available). Turn them on. You’re running on sunlight.
Safety
Five rules. All non-negotiable.
- Fuse the battery. Always. A $5 fuse prevents a fire. There’s no excuse to skip it.
- Use listed/certified components. UL-listed panels and charge controllers cost the same as unlisted ones. They won’t burn your shed down.
- Mount the charge controller indoors. Protected from weather, accessible for monitoring.
- UV-rated wire for exterior runs. Standard household wire degrades in sunlight. PV wire is designed for outdoor use.
- If anything feels wrong, stop and ask. A weird smell, unexpected heat, a spark where there shouldn’t be one — stop, disconnect (panel first), and figure out what happened before proceeding. Get in touch if you need a second opinion.
Upgrade Path
Once your 200W system is running, you’ll have a working mental model of how solar actually works — panels, charge controllers, batteries, and loads. That understanding is the foundation for everything bigger.
What comes next:
- More panels and bigger battery — scale the same standalone concept to generate and store more energy.
- An inverter for AC loads — add a small inverter to run 120V devices from your battery.
- System 2: The Permitted Standalone — a full 3.2kW system with battery storage, a 120V outlet, and a proper permit. That’s the next guide: System 2: Permitted Standalone.
Related learning:
- Learn: Batteries — deep dive on LiFePO4 vs. lead-acid, sizing, and BMS
- Learn: Wiring and Safety — wire sizing, fusing, and connection quality
- Consulting — if you want a second set of eyes on your build plan
DATA SOURCED FROM: Oregon Solar Installation Specialty Code (2010), Section 301.1 Commentary; Oregon Residential Specialty Code (ORSC), Section R105.2; Oregon Revised Statutes, ORS 479.540 (homeowner electrical work exemption). Component specifications from manufacturer datasheets.