Intelligent Power Strip
Power Strip: Intelligent vs. Always On
Automation is used to control a power strip that turns off power to unused equipment using control strategies including master switching of related peripherals, sensing equipment in standby mode and occupant sensing.
Devices that draw energy even when they are not being used can account for a substantial portion of the electricity used in homes and commercial buildings. Between 9% and 15% of residential electricity use and 30% of commercial electricity use may be due to these “plug loads,” and these numbers are increasing.
Even though some devices are becoming more efficient, the extra economy of plugging them into a power strip that shuts them off after they have not been in use for a specified period of time is predicted to save 25 to 180 kWh in offices and 25 to over 100 kWh in homes annually.
A strip from Enmetric offers multiple control strategies for each plug and allows scheduled and load-sensing options. Multiple power strips can be controlled from a website and are openADR-compliant for use with demand response. The National Renewable Energy Laboratory studied it and found scheduling devices saved the most energy—22-48% depending on the type of device. Cost is about $100 per strip but payback varies widely—from 1-50 years. Note that this is not an endorsement for Enmetric, but rather an example of a more advanced product that has had studied by a reputable research organization recently.
As the smart grid is further developed, such strips can respond to price signals from utilities and decide when it is most economical to operate, in addition to responding to on-site needs.
Energy Savings: 28%
Energy Savings Rating:
Approved Measure What's this?
|1||Concept not validated||Claims of energy savings may not be credible due to lack of documentation or validation by unbiased experts.|
|2||Concept validated:||An unbiased expert has validated efficiency concepts through technical review and calculations based on engineering principles.|
|3||Limited assessment||An unbiased expert has measured technology characteristics and factors of energy use through one or more tests in typical applications with a clear baseline. |
|4||Extensive assessment||Additional testing in relevant applications and environments has increased knowledge of performance across a broad range of products, applications, and system conditions. |
|5||Comprehensive analysis||Results of lab and field tests have been used to develop methods for reliable prediction of performance across the range of intended applications.|
|6||Approved measure||Protocols for technology application are established and approved.|
Simple Payback is one tool used to estimate the cost-effectiveness of a proposed investment, such as the investment in an energy efficient technology. Simple payback indicates how many years it will take for the initial investment to "pay itself back." The basic formula for calculating a simple payback is:
Simple Payback = Incremental First Cost / Annual Savings
The Incremental Cost is determined by subtracting the Baseline First Cost from the Measure First Cost.
For New Construction, the Baseline First Cost is the cost to purchase the standard practice technology. The Measure First Cost is the cost of the alternative, more energy efficienct technology. Installation costs are not included, as it is assumed that installation costs are approximately the same for the Baseline and the Emerging Technology.
For Retrofit scenarios, the Baseline First Cost is $0, since the baseline scenario is to leave the existing equipment in place. The Emerging Technology First Cost is the Measure First Cost plus Installation Cost (the cost of the replacement technology, plus the labor cost to install it). Retrofit scenarios generally have a higher First Cost and longer Simple Paybacks than New Construction scenarios.
Simple Paybacks are called "simple" because they do not include details such as the time value of money or inflation, and often do not include operations and maintenance (O&M) costs or end-of-life disposal costs. However, they can still provide a powerful tool for a quick assessment of a proposed measure. These paybacks are rough estimates based upon best available data, and should be treated with caution. For major financial decisions, it is suggested that a full Lifecycle Cost Analysis be performed which includes the unique details of your situation.
The energy savings estimates are based upon an electric rate of $.09/kWh, and are calculated by comparing the range of estimated energy savings to the baseline energy use. For most technologies, this results in "Typical," "Fast" and "Slow" payback estimates, corresponding with the "Typical," "High" and "Low" estimates of energy savings, respectively.