A detailed feature breakdown of leading whole-home energy monitoring solutions — from DIY open-source to consumer plug-and-play.
Gelidus Research PM1v2
Emporia Vue 3
Sense Energy Monitor
IoTaWatt
| Feature | Gelidus Research PM1v2ESPHome · DIY · Advanced | Emporia Vue 3Consumer · App · Mainstream | Sense Energy MonitorAI/ML · Hands-Off · Premium | IoTaWattOpen Source · Local · Pro |
|---|---|---|---|---|
| Pricing & Availability | ||||
| Price (USD) | ~$39 board only and kits ~$60–$80+ | $99–$200 (whole-home to 16-sensor bundle) | $299 standard; $349 with solar | ~$300+ ⚠ production ceased Apr 2025 |
| Currently Available | Yes | Yes | Yes | Limited |
| Hardware & Electronics | ||||
| Primary Circuit IC | Microchip ATM90E32 | Proprietary | Proprietary (ML-based) | MCP3208 12-bit ADC |
| Wireless Connectivity | WiFi 6 or Thread | WiFi 2.4 GHzEthernet | WiFi 2.4 GHz | WiFi 2.4 GHz |
| Max Monitored Channels | 3–18 (expandable via riser boards) | 3 mains + up to 16 branch circuits | 2 mains only (whole-home) | Up to 14 CT channels |
| CT Sensor Range | 20–200A per channel | 200A mains; 50A branch | 200A mains (Flex sensors for 400A) | Up to 200A (many CT types supported) |
| ADC Resolution | 16-bit | Not specified | Not specified | 12-bit |
| Measurement Accuracy | 0.5–1% | 2% | ML-based estimation | ~1% |
| Phase Support | Split single-phase, 2-phase, 3-phase Configurable Isolated Voltage Reference Inputs 80-300VAC | Single, split-phase, 3-phase 4-wire Wye (no Delta) | Split-phase (120–240V) only | Single, split, and 3-phase |
| Expandability | High — stackable riser boards; up to 18 ch | Moderate — up to 16 branch CTs; add 2nd unit | None — hardware fixed at 2 mains CTs | Moderate — 14 fixed CT inputs |
| Enclosure | 3D-printed (STL files free to download) | Proprietary plastic housing | Proprietary plastic housing | Proprietary plastic housing |
| DIN Rail Mount | No | Yes (optional) | No | No |
| Data & Measurements | ||||
| Data Measurements | Voltage, Current, Frequency, Active Power, Reactive Power, Apparent Power, Harmonic Power, Power Factor, Phase Angle, Peak Current, IC Temperature | Voltage, Current, Real Power (W), kWh, Solar/Net Metering | Watts, kWh, estimated per-device usage | Volts, Watts, kWh, VA, Power Factor |
| Real-Time Sampling | Yes — continuous sub second capable | Yes — 1-second granularity | Yes — 1 MHz sampling; 1-sec app updates | Yes — 5-second intervals to local storage |
| Device / Appliance Detection | No — direct measurement only | No — direct CT measurement | Yes — AI/ML signature detection | No — direct CT measurement |
| Local Data Storage | Via ESPHome / Home Assistant | No — cloud only | No — cloud only | Yes — SD card (15+ years) |
| Cloud Dependency | None — fully local | Required — mandatory internet | Required — mandatory internet | Optional — can run fully local |
| Software & Ecosystem | ||||
| Software / Firmware | ESPHome (open-source; YAML-configurable) | Proprietary Emporia app (iOS/Android/Web) | Proprietary Sense app (iOS/Android/Web) | Open-source firmware; browser-based config UI |
| Open Source | Yes — ESPHome + hardware docs | No | No | Yes — hardware & firmware |
| Home Assistant Integration | Native — ESPHome first-class | Via third-party community integration | Via third-party integration | Native — direct integration |
| Smart Home Ecosystem | Home Assistant, Matter, Thread, Zigbee | Emporia ecosystem, Alexa, Google Home, Home Connect (Bosch, Siemens…) | Alexa, Google Home, Philips Hue, TP-Link Kasa | Emoncms, InfluxDB, Grafana, PVOutput |
| Solar / Net Metering | Yes — fwd & reverse energy | Yes — built-in | Yes — optional Flex add-on | Yes |
| EV Charger Integration | Via Home Assistant automations | Yes — native Emporia EV ecosystem | Yes — via app automations | Via third-party dashboards |
| Subscription Required | No | No (optional premium) | No | No |
| Installation & Safety | ||||
| Installation | Non-intrusive CT clamps; AC cord powered | Inside panel; CT clamps; requires neutral connection | Inside panel; 2 CT clamps on mains | External to panel; CT clamps; wall outlet for voltage ref |
| DIY / Technical Level | Moderate — YAML, ESPHome knowledge | Beginner-friendly — app-guided | Beginner-friendly — minimal wiring | Intermediate — electrician recommended |
| UL / Safety Certification | Not specified | UL 61010 · UL 2808 · CE | ETL/Intertek Certified | CE (commercial version) |
| Summary | ||||
| Best For | HA power users, 2 or 3-phase setups, maximum data detail, privacy-first | Mainstream homeowners wanting polished app & ecosystem integration | Hands-off appliance detection without wiring each circuit | DIYers wanting open-source, local-first, multi-circuit monitoring |
Key Takeaways
Gelidus Research PM1v2
The most technically capable and affordable board for ESPHome/Home Assistant users. Widest wireless protocol support (WiFi 6, Thread, Zigbee), deepest electrical metrics (harmonic power, phase angle), and full local operation — but requires technical know-how.
Emporia Vue 3
Best mainstream choice: polished app, broad ecosystem integrations including Home Connect appliances, wired Ethernet option, and no subscription fees. Cloud-dependent, but reliable for most households.
Sense Energy Monitor
Ideal for users who want hands-off appliance detection without wiring individual circuits. Trade-off: accuracy depends on AI learning curves, and there’s no guaranteed circuit-level granularity.
IoTaWatt
Was the gold standard for local-first, open-source multi-circuit monitoring. Production has ended (April 2025), making new purchases difficult. Still an excellent reference design.
Data compiled from manufacturer specifications and published documentation · May 2026