Monitoring Electricity Usage

Table of Contents

• Background
• Monitoring
• Approach
• Project Materials
• Results
• References
• Disclaimer

Background

There are different methods to capture this information. One approach is to put current measurement coils on the main leads to your breaker panel. One of the most well known products is the TED The Energy Detective. The advantage is that you have more resolution than the utility meter reports. The downside is that the computed kilowatt hours may be different from what the Power company's meter says. Another approach is to read the 1 watt IR pulses on the meter. This has nice resolution, but if the system misses any pulses, you loose track of your total usage. The other downside is that you have to mount something on the meter outside in the elements. Sometimes alignment can be a problem. A commercial example would be the Blue line Energy Monitor

Monitoring

There are several other sites that have picked up the slack:

• plotwatt
• myEragy
• wattvision
• peoplepower
• bidgely energy management platform
• pachube -- The internet of things real-time

Approach

I didn't want to keep a desktop or laptop computer tied up reading the utility meter. The ethernet connected open-hardware Arduino seemed like a good fit.

Sparkfun has a USB Host Shield available, but it needs to be modified:

• Cut the USB Host Shield PCB trace going to IO pin 10
• Wire the PCB trace thru small hole to pin 6
• Jumper RST pin to Pin 7
• Connect 9VDC power supply to the arduino. The USB power is not sufficient enough!

typedef MAX3421e<P6, P9>		MAX3421E;

UMSCM,39064629,4,51667*6B
UMSCM,39064629,4,51667*6B
UMSCM,39064629,4,51667*6B
UMSCM,39064629,4,51667*6B

Materials

• Arduino Uno Ethernet $65
• 9VDC Arduino power adapter $6.95
• Sparkfun USB Host Shield $24.95
• USB Host Shield 2.0 for Arduino is an alternative. $25
• Grid Insight AMRUSB-1 Utility Meter Data Receiver $50

Results

Pachube ("patch-bay") connects people to devices, applications, and the Internet of Things. As a web-based service built to manage the world's real-time data, Pachube gives people the power to share, collaborate, and make use of information generated from the world around them.

This is a perfect repository for our House Electricity Usage data. It provides a simple HTTP interface to post data and applications which generate charts that can be included on your web pages:

References

• Simple DIY Arduino Whole House Kilowatt Meter
• Arduino based wireless power meter
• Using an Arduino to Track My Electricity Consumption Cost in Real-Time
• Electricity Usage Monitor

Disclaimer