Plug-in Solar Buying Checklist: 10 Questions Before You Buy

Before You Click Buy: Check These 10 Things

Buying a plug-in solar system is a $1,500–2,000 decision. Don't rush it. Run through this checklist first.

1. Is It UL-Listed or UL 3700 Certified?

UL listing means the inverter (and ideally the full system) has passed independent safety testing.

UL 3700 is the new standard for grid-interactive plug-in solar. As of April 2026, no products are fully UL 3700 certified yet, but that's changing by late 2026.

What to do now:

• Ask the seller: "Is this UL 3700 certified or expected to be?"
• If not certified, ask for timeline (most say "late 2026").
• If you're buying now before certification, get confirmation from a tax pro that federal ITC eligibility won't be affected.

Red flag: If a seller doesn't mention UL status or can't explain it, that's suspicious. Pass.

2. Anti-Islanding: Does It Shut Down During Grid Outages?

Anti-islanding is a safety feature. If the grid fails, your system automatically stops feeding power into the lines. This protects utility workers.

All reputable systems have anti-islanding. It's non-negotiable.

What to do:

• Check the spec sheet or manual
• Look for "grid-interactive" or "grid-tie" language
• Call the company if unclear

Red flag: Any system claiming to power your house during a grid outage is likely not anti-islanding certified and is a safety liability.

3. Monitoring: Is There an App? How Good?

You'll want to track what your system generates.

Check:

• Is there an app? (iOS, Android, or both?)
• Does it update in real-time, or once a day?
• Does it show historical data?
• Does it have alerts if the system stops producing?
• Is there a web dashboard if you don't want to use a phone app?

You want: Real-time updates, historical tracking, and alerts. Nice-to-have: forecasts and consumption tracking.

Red flag: No monitoring capability, or an app that requires creating an account with unclear privacy terms.

4. Warranty: How Long, and What's Covered?

Check:

• Panel warranty: 25–30 years is standard (performance degradation, not full replacement).
• Inverter warranty: 5–10 years typical. This is the most likely part to fail.
• Labor warranty: Who installs? If you DIY, is labor covered if something breaks?

Red flag: Warranty shorter than 5 years. That's weak. 10+ years is excellent.

Real talk: Warranty is only valuable if the company is still around to honor it. Craftstrom (5-year history) is safer than a brand new startup.

5. Panel Efficiency: Is It Competitive?

Modern residential panels are 21–23% efficient. Anything under 20% is dated; anything over 23% is premium.

Bifacial panels (like Craftstrom) add 8–12% output in the right conditions, which can matter.

What to do:

• Check spec sheet for "efficiency" percentage
• Compare bifacial vs. monofacial benefits in your mounting scenario
• Don't obsess—the difference between 21% and 22% efficiency is marginal

Red flag: Panels less than 19% efficient. That's old technology.

6. Inverter Brand: Is It Well-Known?

Inverter manufacturers matter. Some are battle-tested; others are new and risky.

Reputable brands:

• APsystems (used by Craftstrom) — solid track record
• Enphase (premium, very reliable)
• SMA (German, excellent)
• Growatt (popular in Asia, expanding in US, reliable)

Less-known brands:

• If the inverter is a no-name brand, be cautious. It might work, but support and replacement parts are risky.

What to do:

• Check the spec sheet for inverter brand
• Google the brand + "reviews" to see if there are common complaints
• Avoid "private label" inverters from small companies

Red flag: Inverter brand you've never heard of with minimal online reviews. That's risky.

7. Cable Quality: Is It Outdoor-Rated?

Your system's cables are exposed to sun, rain, temperature swings.

Check:

• Are cables UV-rated?
• Are they rated for outdoor use?
• What gauge (thickness) are they? Thicker is better.
• What's the temperature range they're rated for?

Red flag: Indoor-rated cables used outdoors. They'll degrade within 2–3 years. Bad move.

Most name-brand systems use proper outdoor cables. But budget DIY combos from Amazon sometimes skimp. Check.

8. GFCI Compatibility: Will It Play Nice With Your Outlet?

GFCI (Ground Fault Circuit Interrupter) outlets detect electrical imbalances and shut off power. They're a safety feature.

Your plug-in solar system needs to work with GFCI outlets (or you need one installed).

Check:

• Does the inverter spec sheet mention GFCI compatibility?
• Are there known issues with the inverter tripping GFCI breakers?

What to do:

• If your outlet isn't GFCI-protected, budget $15–30 for a GFCI outlet or $100–200 for an electrician to install one

Red flag: Inverter that's known to trip GFCI outlets repeatedly. That's a headache.

9. Price per Watt: Is It Competitive?

Current market rates for plug-in solar:

• Budget (Craftstrom): $1.50–1.70/watt
• Mid-range (Bright Saver): $1.75–2.00/watt
• Premium (EcoFlow): $1.58/watt panels + batteries

Anything significantly above $2.00/watt is overpriced unless you're buying aesthetics (Bright Saver design) or battery integration (EcoFlow).

Anything below $1.00/watt might be lower-quality DIY combos.

What to do:

• Calculate cost ÷ system wattage
• Compare against the three major brands
• If it's higher, why? (Better warranty? Better support? Better design?)

Red flag: $2.50+/watt without obvious premium features. Overpriced.

10. Customer Support: Can You Actually Reach Someone?

After you buy, something will eventually need clarification or troubleshooting.

Check:

• Is there email support? Phone?
• What's the typical response time?
• Are there user forums or a community?
• Does the company have technicians you can talk to, or is it all FAQ?

Red flag: No support channel besides a generic contact form. That's risky.

Quality support:

• Craftstrom: Community forums (24–72 hour response)
• Bright Saver: Email and phone (24–48 hours)
• EcoFlow: Professional support, phone and email (same-day typical)

The Real Checklist (TL;DR)

Before buying, confirm:

1. ✓ UL-listed (ideally UL 3700 path to certification)
2. ✓ Anti-islanding certified
3. ✓ App or monitoring capability
4. ✓ 5+ year warranty (10+ ideal)
5. ✓ Panel efficiency 21%+
6. ✓ Inverter from known brand (APsystems, Enphase, Growatt)
7. ✓ Outdoor-rated cables, UV-resistant
8. ✓ GFCI-compatible
9. ✓ Competitive pricing (~$1.60/watt)
10. ✓ Reachable customer support

If a product fails three or more of these, keep looking.

If it passes all ten, you're good to buy.

Next Steps

Ready to evaluate products? Check out our product reviews for details on leading systems, or learn how to size your system.