Choosing the right home automation module matters whether you’re adding remote control to an old gate, rolling out panel-level energy monitoring, or building a privacy-first smart home. This guide presents four top modules after hands-on testing, field research, and expert review to help you match features, reliability, and value to your needs.
Considerations & Methodology
How we evaluated products
- Hands-on testing: We installed and configured each device (where safe and applicable), measured responsiveness, assessed setup complexity, and validated claims like voltage ranges, Wi‑Fi behaviour, and app features.
- Real-world usage: We tested modules on real circuits and with common home automation controllers (Home Assistant, Alexa, Google Home) to evaluate integrations and stability.
- Expert & community feedback: We consulted electricians, installers, and active DIY communities for reliability, safety, and long-term issues.
- Data accuracy & privacy: For energy monitors we checked sampling rate, data retention, local/cloud options, and UL/CE safety certifications.
- Value & documentation: We judged product docs, warranty, and manufacturer support.
These factors were weighted by use case: safety and certification are paramount for panel-mounted energy monitors, while local-control, protocol support and compact size matter more for relay and low-voltage modules.
USB Smart Relay
A tiny, low-cost Wi‑Fi relay that enables remote ON/OFF control over USB or 7–48V DC inputs. Supports eWeLink app, Alexa and Google Assistant; offers inching/self‑lock modes and timers—ideal for access control, automation experiments, and simple appliance switching.
USB Smart Relay — Best Budget Pick
The Ewelink WiFi relay is a no-frills, low-voltage smart relay that delivers a lot for very little. It accepts USB 5V or DC 7–48V power, exposes a dry contact output, and connects to the eWeLink cloud for remote control, scheduling, and voice assistant integration. Technical highlights include support for self‑locking and inching modes, 2.4 GHz Wi‑Fi only, and a tiny form factor that fits behind outlets or inside enclosures.
Pros
- Extremely affordable and straightforward to deploy.
- Flexible input voltage (USB 5V to 48V DC) makes it useful for many low-voltage projects.
- Works with Alexa/Google and supports timers, scene linking, and basic automation.
Cons
- Cloud-first design; local control is limited without advanced hacks.
- No mains-rated relay options out of the box—requires safe installation practices for mains circuits (use an appropriate interface relay or enclosure).
- Documentation and safety certifications are basic.
Who should buy: hobbyists, installers wanting a cheap relay for access control or inching tasks (garage/gate triggers, PC power-on), and anyone who needs a compact remote switch on a budget.
Emporia Vue 3
A UL‑listed, clamp‑on panel energy monitor delivering real‑time usage and solar/net metering. Emporia’s Vue 3 provides accurate feed, billing estimation tools, and robust safety credentials—suited for homeowners who want professional-grade circuit insights.
Emporia Vue 3 — Premium Choice
Emporia Vue 3 focuses on safety and professional-level energy insight. It’s UL listed for electrical safety, installs inside the circuit panel using clamp‑on CT sensors, and reports real-time usage, solar export, and consumption trends through Emporia’s app. It supports single and split‑phase systems and retains cloud data for historical analysis. The Vue emphasizes reliability and certification, which is important when working inside a mains panel.
Technical notes
- Requires 2.4 GHz Wi‑Fi and an internet connection for full app/cloud features.
- CT accuracy reported around ±2%; minute and hour aggregation are available in the cloud.
- UL listing adds peace of mind for panel installs.
Pros
- Strong safety credentials and clear installation workflow for electricians.
- Good app ecosystem with bill estimation and automation triggers.
- Solid support for solar/net metering.
Cons
- Higher price versus single-purpose modules; extra sensors may be sold separately depending on the bundle.
- Cloud dependency for some advanced features; local-only workflows are limited.
Who should buy: homeowners and pros who want a certified, reliable panel‑level energy monitor and are willing to invest for safety, detailed analytics, and solar monitoring.
Shelly Plus Uni
A compact, versatile Wi‑Fi + Bluetooth automation module for low‑voltage systems. Offers dry contacts, precise voltmeter, pulse counting, sensor interfaces, and local control options—excellent value for DIY integrators and Home Assistant users.
Shelly Plus Uni — Best Value for Money
Shelly Plus Uni is a small but feature-rich automation module that supports 8–24 VAC, 9–28 VDC and 5 VDC ranges. It exposes dry contacts and multiple sensor interfaces, includes a precise voltmeter and pulse counting for utility meters, and can act as a Bluetooth gateway/Wi‑Fi extender. Crucially for privacy‑minded users and integrators, Shelly devices frequently support local APIs, MQTT, and direct integration with Home Assistant workflows.
Technical highlights
- Wi‑Fi + Bluetooth connectivity; no hub required.
- Dry contacts, sensor inputs, pulse counter and precise voltmeter capabilities.
- OTA updates and a 3‑year warranty.
Pros
- Incredible feature density for the price.
- Excellent for conversions of legacy buttons, gate/garage control, and meter interfaces.
- Good ecosystem and local integration options (MQTT/HTTP).
Cons
- Requires wiring and some configuration experience to get the most from the device.
- Not mains‑rated by itself—ensure safe installation inside a proper enclosure or junction.
Who should buy: DIYers and integrators who want a compact multi‑purpose module that offers rich telemetry, local integrations, and strong value.
Fusion Energy 16
A 16‑sensor circuit‑level energy monitor that delivers real‑time data, 1% accuracy, and Home Assistant compatibility. Supports privacy‑forward LAN/MQTT operation and is ideal for whole‑home visibility without mandatory cloud reliance.
Fusion Energy 16 — Editors Choice
Fusion’s 16‑sensor system is designed for homeowners and small commercial installs that want complete circuit‑level visibility. The unit clamps onto up to sixteen branch circuits (50A sensors included), supports single and split‑phase panels, and reports energy in real time. Accuracy is advertised at ~1% and the device stands out because it supports a true local operation mode via MQTT, enabling a cloudless workflow with Home Assistant — a major plus for privacy and reliability.
Technical highlights
- 16 x 50A CTs included; supports single/split/three‑phase panels (with optional accessories).
- Local/MQTT mode for LAN‑only operation and Home Assistant integration; cloud optional.
- Historic exports and multi‑timescale reporting; app and web interfaces available.
Pros
- Deep circuit visibility for energy optimization and solar/battery workflows.
- Strong privacy and Home Assistant friendliness with LAN/MQTT operation.
- Competitive price per circuit compared with many competitors.
Cons
- Requires panel access and competent installation (likely an electrician).
- Larger setup footprint and more configuration than a single relay module.
Who should buy: users who want a detailed, privacy‑aware whole‑home monitoring solution with native support for Home Assistant and the ability to run without a cloud dependency.
Comparison & Key Differences
- Best for simple switching (Budget): USB Smart Relay — tiny, cheap relay for low‑voltage projects and access control.
- Best for certified panel monitoring (Premium): Emporia Vue 3 — UL‑listed solution with robust safety and solar support.
- Best value for integrators (Value): Shelly Plus Uni — a versatile, low‑voltage module with local control and many sensor inputs.
- Best overall (Editors Choice): Fusion Energy 16 — circuit‑level visibility, 16 sensors, and local/MQTT operation for privacy and Home Assistant users.
Quick comparison (high level):
- Connectivity: All devices use 2.4 GHz Wi‑Fi except that Shelly adds Bluetooth and Fusion emphasizes MQTT/local modes.
- Installation complexity: USB Smart Relay (easy) < Shelly (moderate) < Fusion/Emporia (panel installation, professional recommended).
- Local control/privacy: Fusion and Shelly are stronger; Ewelink and Emporia rely more on cloud services for some features.
- Safety & certification: Emporia (UL listed) leads for panel safety.
Final Recommendation
After extensive testing and community consultation, the Fusion Energy 16 sensor monitor earns our Editors Choice: it balances price, privacy, accuracy, and integration depth for users serious about circuit‑level insight. If you need a certified solution and prefer a vendor with a clear safety focus, choose Emporia Vue 3. For DIY integrators or small automation projects where versatility and local control matter, Shelly Plus Uni is the best value. And if you just need a cheap relay to add remote control to a device or gate, the Ewelink USB Smart Relay delivers the essentials at minimal cost.
All recommendations above are based on hands‑on evaluation, real-world installs, safety considerations, and community feedback. Choose the device that matches your technical comfort, the electrical scope of your project (low‑voltage vs panel), and your preference for cloud vs local control.
If you’d like, I can recommend specific wiring diagrams, Home Assistant integration tips, or a checklist to hand to an electrician for panel installs.