In a previous blog entry, Saving Energy with Wire Mesh Networks, we mentioned the need for systems that can monitor your energy use—and savings if you’re using a photovoltaic solar system, for example.

Some expensive systems are out there, but do you need to spend five figures just to be able to better monitor your electricity consumption?

Tom Pirelli and Ron Mocogni of Solaris Home Systems don’t think so. I wrote about Pirelli’s house, Lucia, which won our Home of the Year Silver award for Green Homes. Lucia uses HomeSeer software and Solaris’ customized programming to monitor the family’s energy use and conservation. (The house has a 4-kilowatt array of solar panels.) With all the pieces and parts, Mocogni figures a comparable system would come out to $3,000 to $4,000.

“For the power monitoring we used two separate systems. First we used the RS232 interface on the Sunny Boy 3800U inverter to read the power being generated by the PV panels. Then we used a product from Brultech Research called the ECM-1220 to read the power that is being consumed by the house (the ECM-1220 has a USB interface). Brultech modified its firmware for us so that we could tell which way the current is flowing. We use the current flow direction to determine whether we are buying or selling power. After we have all this info, our software does some calculations and displays the whole house power usage, PV panel power production, and how much power we are buying or selling to the power company,” Mocogni says.

“The calculations for all the power and temperature sensors are done through our own customized software program. We then feed that info back into HomeSeer. HomeSeer can do calculations, but it’s much faster if we handle it in our program.”

Mocogni says that Solaris is currently putting together a small system that will consist of an 8-inch touch screen, very small PC with flash drive, HomeSeer software, touchscreen interface, Solaris’ custom software, and a whole-house power meter with either a hardware or wireless ZigBee interface. 

“The system will integrate with all of the devices that HomeSeer supports in addition to the devices that we communicate to (whole house power meter, Sunny Boy PV inverter, Elk M1 alarm panel, etc.),” Mocogni says.

Watch for more companies marketing energy monitoring systems like this. There’s a lot of this in development now. Stay tuned.

Steven Castle - Contributing Writer

Steven Castle is Electronic House's managing editor. he has been writing about consumer electronics, homes and energy efficiency topics for two decades. He is also the co-founder of GreenTech Advocates.