Do smart plugs consume electricity?

Yes, smart plugs require power to maintain their Wi-Fi connection and internal circuitry. While consumption varies by model, they typically draw between 0.5W and 1.5W constantly, which must be factored into any energy-saving calculation.

Is it worth it to use smart plugs for phone chargers?

Generally no. Modern phone chargers have very low standby power draw. The cost of the smart plug, combined with the plug's own standby energy consumption, would result in a net financial loss over the life of the device.

Can I use a smart plug with a power strip?

Yes, using a smart plug to control a power strip is a common method to manage multiple devices simultaneously. This can make the investment more cost-effective if multiple high-draw devices are grouped together, provided the total load does not exceed the smart plug's rated capacity.

Smart Plug ROI Analysis for Vampire Power Mitigation

Question: Should a household use 'Smart Plugs' (e.g., Kasa) to eliminate 'vampire' power loads, considering the standby power consumption of devices vs. the cost of the plugs?

Prepared by the ChoiceScore Research Desk · Editor-approved for the curated library · Reviewed July 22, 2026

It depends Choice Score: 45/100

Direct answer

For most households, smart plugs are a net financial loss if purchased solely to eliminate vampire power, as the cost of the plug often exceeds the annual energy savings. While they provide significant non-monetary value through convenience, scheduling, and automation, they are rarely cost-effective as a standalone energy-saving tool for low-draw devices.

Summary

Smart plugs, such as those in the Kasa Smart ecosystem, are designed primarily for remote control, scheduling, and home automation. When evaluating these devices for the purpose of mitigating 'vampire' (standby) power loads, users must weigh the cost of the hardware against the actual energy savings achieved. Because smart plugs themselves require a constant, albeit small, amount of electricity to maintain Wi-Fi connectivity and internal circuitry, the net energy savings are often lower than the gross standby consumption of the target device. Unless the target device has a high, consistent standby draw, the financial payback period often exceeds the expected operational lifespan of the smart plug. This analysis explores the trade-offs between automation benefits and financial ROI.

Choice Score breakdown

Overall 45/100 — Synthesized from choice_score.

Best for / Not best for

Best for

Automating lighting schedules
Managing high-draw devices with known standby issues
Remote power cycling of frozen hardware

Not best for

Small electronics with negligible standby draw (e.g., phone chargers)
Devices that require constant power for updates, background tasks, or memory retention

Scenarios

High-Draw Device (e.g., Legacy Electronics) (70% likely)
Using a smart plug to kill power to a device drawing 15W in standby. (Illustrative scenario, user-adjustable probability). This probability is an illustrative, user-adjustable scenario weight, not an empirical forecast.
Low-Draw Device (e.g., Modern Charger) (90% likely)
Using a smart plug to kill power to a device drawing 0.5W in standby. (Illustrative scenario, user-adjustable probability). This probability is an illustrative, user-adjustable scenario weight, not an empirical forecast.
Convenience-First Automation (80% likely)
Valuing the ability to control lights or appliances via voice or schedule, ignoring energy savings. (Illustrative scenario, user-adjustable probability). This probability is an illustrative, user-adjustable scenario weight, not an empirical forecast.

Calculations

Metric	Result	Formula
Annual Energy Savings (Illustrative)	13.14 USD/year	(standby_watts × 24 hours × 365 days / 1000) × electricity_rate
Break-even Time (Illustrative)	1.14 years	plug_cost / annual_savings
Net 3-Year Impact (Illustrative)	24.42 USD profit	(annual_savings × 3) - plug_cost

Pros & cons

Pros

Enables remote power control and scheduling for non-smart devices.
Integrates into broader smart home automation routines via mobile applications.
Provides a physical disconnect for devices that lack a dedicated 'off' switch or that require periodic power cycling.

Cons

Smart plugs themselves consume electricity to maintain connectivity, which must be subtracted from total savings.
High upfront hardware cost relative to the marginal energy savings of most modern, low-draw electronics.
Potential for connectivity issues or firmware updates to temporarily interrupt power to the connected device.

Assumptions

Electricity Rate: 0.15 USD/kWh — Illustrative average residential rate used for calculation consistency.
Smart Plug Cost: 15 USD — Illustrative median price for a standard Wi-Fi smart plug.
Plug Standby Consumption: 0.5W — Typical illustrative consumption of the smart plug itself while idle.
Illustrative scenario probability — High-Draw Device (e.g., Legacy Electronics): 70% — A user-adjustable modeling weight used to compare scenarios; it is not a measured probability or forecast.
Illustrative scenario probability — Low-Draw Device (e.g., Modern Charger): 90% — A user-adjustable modeling weight used to compare scenarios; it is not a measured probability or forecast.
Illustrative scenario probability — Convenience-First Automation: 80% — A user-adjustable modeling weight used to compare scenarios; it is not a measured probability or forecast.

Practical next steps

Audit your home for devices with high standby consumption using a plug-in power meter.
Calculate the annual energy cost of those specific devices using your local utility rate.
Compare the annual energy cost against the purchase price of a smart plug.
Prioritize automation and convenience features over energy savings when deciding where to install smart plugs.
Use power strips for groups of devices to maximize the impact of a single smart plug if energy reduction is the goal.

Methodology

The analysis utilizes a standard Return on Investment (ROI) framework. We compare the annual cost of standby energy consumption against the retail cost of a smart plug. All calculations are based on illustrative, user-adjustable assumptions for electricity rates and device power draws. The analysis acknowledges that while energy savings are often negligible, the qualitative benefits of automation represent the primary value proposition of smart plug technology.

Sources

Sources support specific claims; they do not replace our analysis. Read the research and source standards.

FAQ

Do smart plugs consume electricity?: Yes, smart plugs require power to maintain their Wi-Fi connection and internal circuitry. While consumption varies by model, they typically draw between 0.5W and 1.5W constantly, which must be factored into any energy-saving calculation.
Is it worth it to use smart plugs for phone chargers?: Generally no. Modern phone chargers have very low standby power draw. The cost of the smart plug, combined with the plug's own standby energy consumption, would result in a net financial loss over the life of the device.
Can I use a smart plug with a power strip?: Yes, using a smart plug to control a power strip is a common method to manage multiple devices simultaneously. This can make the investment more cost-effective if multiple high-draw devices are grouped together, provided the total load does not exceed the smart plug's rated capacity.

Related decisions

Disclaimers

Financial calculations are illustrative estimates based on user-adjustable energy costs and may vary significantly based on local utility rates and specific device usage.

Smart plugs should not be used with high-wattage appliances like space heaters or air conditioners unless the plug is specifically rated for those loads.

Scenario probabilities are modeling weights and are not empirical data.