OwlWatt vs Sense — which one do you actually need?
Short answer
OwlWatt and Sense both sit in the "home energy monitoring" category, but they don't compete on the same problem. Sense identifies which devices in your home are consuming power. OwlWatt measures whether your solar panels are producing as much as your warranty requires. If you have solar and suspect your system is underperforming, you need OwlWatt. If you want to know why your electricity bill spiked and which appliances are the culprits, Sense is the right tool.
What Sense does well
Sense installs a current-transformer sensor at your electrical panel and uses machine learning to disaggregate your home's load into individual devices. It genuinely does this better than most alternatives at its price point.
- Device-level detection — Sense identifies individual loads (refrigerator, dryer, EV charger, HVAC) based on their electrical signature. It doesn't require you to label anything manually; it learns from your panel's waveform over time.
- Real-time home usage — the app shows a live view of what's running right now, updated every second. That's genuinely useful for understanding standby draw and phantom loads.
- Device alerts — you can set notifications when specific devices turn on or off, or when usage crosses a threshold.
- Solar flow visibility — if you have solar, Sense shows how much is going to the grid versus the home load in real time. It gives you a net view of your energy balance.
Sense is not trying to do what OwlWatt does. It has no pvlib model, no installer-facing documentation, and no comparison to what your panels should be producing on a given day.
What OwlWatt does that Sense doesn't
OwlWatt reads directly from your inverter (Enphase or SolarEdge) and compares your actual production to what the NREL PVWatts model predicts given your panel specs, location, tilt, azimuth, and observed weather. That comparison is the core product.
- Expected vs actual production — every day, OwlWatt computes what your system should have produced using pvlib's PVWatts implementation. The gap between expected and actual is your shortfall.
- Warranty claim documentation — OwlWatt generates a dated PDF with your shortfall calculation, the model parameters, and a reference to the relevant warranty clause. The report is formatted for a direct conversation with your installer.
- Per-microinverter data — on Enphase systems, OwlWatt tracks each microinverter individually. If a single panel is consistently underperforming, the report isolates it.
- Installer-auditable math — the report documents the exact pvlib version, parameter set, and weather adjustment used. An installer who disputes the finding has to show their own model, not just assert the system is fine.
Side-by-side comparison
| Feature | OwlWatt | Sense |
|---|---|---|
| Solar production tracking | Yes — from inverter directly | Partial — net flow at panel, not per-inverter |
| Expected vs actual modeling (pvlib / PVWatts) | Yes | No |
| Warranty claim letter generation | Yes | No |
| Per-panel / per-microinverter data | Yes (Enphase); aggregate on SolarEdge | No |
| Device-level disaggregation | No | Yes — core feature |
| Real-time home consumption view | No | Yes — live, updated every second |
| Device alerts & notifications | No | Yes |
| Hardware required | Optional Pi collector (or inverter cloud API) | CT sensor at electrical panel (included) |
| Price | See pricing | ~$299 device + optional subscription |
| Free trial | Yes — start free | No |
When you need both
They're genuinely complementary. Sense answers "where is my electricity going?" OwlWatt answers "is my solar system generating what it promised?" A home with solar panels and a varied appliance load gets real value from both running at the same time.
A practical combined workflow: OwlWatt flags a week where production ran 18% below model. Sense shows that home consumption was normal that week, ruling out a shading or load-interference cause. The combination narrows the failure to the inverter or a specific panel string, which sharpens the warranty conversation with the installer.
When OwlWatt is the right choice
- Your solar system is under a production guarantee and you want documentation if it underdelivers.
- Your installer told you production looks normal, but your bills haven't dropped the way you expected.
- You have Enphase or SolarEdge and want to know if individual microinverters or strings are degrading faster than expected.
- You're approaching the end of a workmanship or production warranty window and want a clean record before it expires.
When Sense is the right choice
- You don't have solar (or don't care about verifying production against a warranty).
- You want to understand which devices are driving your electricity bill up.
- You want real-time alerts when specific appliances turn on — useful for EV charging management, HVAC monitoring, or detecting a fridge that's running too often.
- You want a single device at the panel that gives you a live picture of your whole home's energy balance without needing inverter API access.
Frequently asked questions
Can Sense track whether my solar panels are underperforming?
Sense can show how much power your solar system exports to the grid and how much it contributes to your home load. It does not model what your system should be producing given your panel specs, location, tilt, and weather — so it cannot tell you whether your system is underperforming relative to its warranty baseline.
Does OwlWatt identify which appliances are using power?
No. OwlWatt focuses on total solar production versus the pvlib model baseline. It does not perform device-level disaggregation. If you want to know that your dryer ran for 45 minutes this afternoon, Sense is the right tool.
Can I use both OwlWatt and Sense at the same time?
Yes. They monitor different things and don't interfere with each other. Sense installs at the electrical panel and tracks consumption plus solar flow. OwlWatt reads from your inverter (Enphase or SolarEdge) and tracks production accuracy over time. Running both gives you a complete picture.
Does Sense generate warranty claim documentation?
No. Sense does not produce installer-ready reports comparing actual production to modeled expectations. OwlWatt generates a dated PDF with your shortfall calculation, the pvlib model parameters used, and the relevant warranty clause — structured for a direct conversation with your installer.
My installer says my panels are fine. Can OwlWatt help me push back?
That is exactly what OwlWatt is for. The report includes the full pvlib parameter set — your panel specs, tilt, azimuth, location coordinates, and weather adjustment — so the installer cannot dispute the model without showing their own math. Many OwlWatt customers use the report as the starting point for a warranty conversation their installer takes seriously.