Oct 052012

By Linda Kor
A work session held with the Joseph City School District Governing Board on Tuesday lent credence to the possibility that the district may be able to upgrade its existing systems for energy savings in-house rather than go with an outside firm for a complete overhaul of its systems.
Midstate Energy officials had presented a proposal to the district to provide energy savings totaling $400,000 through the replacement of nine of the district’s older HVAC units, installation of an energy management system district-wide with demand control capability, upgrades to light fixtures and outdoor lighting, and the installation of occupancy sensors for HVAC and light control, as well as the installation of vending machine power management and improvements to existing buildings, such as by replacing weather stripping.
Upon reviewing the proposal, members of the board and several residents of the community decided to explore the possibility that the existing systems could be modified with upgrades that could be done in-house to provide those savings at a fraction of the cost.
Bob Martinueau, who is employed by Arizona Public Service Co. at Cholla Power Plant and also teaches power plant operations for Northland Pioneer College, had explored the possibility in depth and addressed the board regarding the matter.
He informed the board that the district has installed the Allen Bradley Programmable Logic Control System throughout the schools, as well as the district office, and that the system is capable of being programmed for all the tasks proposed by Midstate.
To determine usage and how to manage it, he suggested the installation of a power and energy manage-ment system that would talk directly to the existing system through something called a DeviceNet system for services that have demand meters. “The DeviceNet would monitor the usage on each meter and provide in-formation on how to delay starting of large loads when the demand is high, or how to shed some loads to keep demand down,” explained Martineau. “Obvious things such as chillers and large lighting areas are fairly easy to determine, but all loads need to be examined. As we proceed, we can go one meter at a time.”
He went on to explain that the present system has plenty of memory and expandability to perform all of the controls needed, as well as to monitor functions of the boilers, pool and heat exchangers, and also show how energy is being used in the schools. Martineau further explained that an interface called RSView has capabilities to be the complete control interface for the system, and could be set up in one or multiple locations, and would even call cell phones if a problem is detected.
“We have purchased previously, and are presently on the shelves, enough motor monitors to cover the larger motors in the system, such as the heating, cooling and the boiler pumps. These modules monitor cur-rent and voltage on each phase, and replace the existing motor overload relays that do not have the remote monitoring capabilities. We can extract from these units a live data of how much energy is being used by each motor and convert that information to dollars,” stated Martineau.
As he explained the equipment already available and the equipment that may need to be purchased, Martineau added another cost saving measure. “We have people in the community that work for the power plant as electricians or engineers that have and are willing to volunteer their time for this, and others you can ask or even offer to pay if you need to. This system is not so complicated that it cannot be taught to your people,” stated Martineau.
After the discussion the board asked that administration work with Martineau on creating a proposal to present to the board that would include costs and long-term savings.
“We will need a detailed proposal with complete documentation for liability. We do have the resources available in our community; we just need administration to look at it and see how it will fit into our budget,” explained board member Ralph Bushman.
Superintendent Robert Klein said he would work with Martineau on the proposal, noting that it may take several months to complete.