The electricity that powers offices and industry usually travels through a small step-down distribution transformer, however, most of the people in these buildings are completely unaware of what that box in the corner does. In brief, these ubiquitous small transformers present a great efficiency opportunity, an opportunity that was originally explored in 1998 as part of way to build demand for more efficient transformers. In 1996, the distribution transformer industry developed voluntary efficiency standards for transformers that were formalized as NEMA TP-1. Both CEE and ENERGY STAR have supported the market for these high-efficiency products since 1998. Over the years, a growing number of states have adopted NEMA TP-1 into their building codes and state standards. Federal minimum efficiency standards were adopted in both the United States and Canada in 2005.

The CEE Distribution Transformers Committee met in St. Louis to discuss whether any characteristics of transformers and their use present an opportunity for a new, voluntary specification. Achieving efficiencies beyond the federal standard is not a simple matter of improved technology. Instead, several matters have to be taken into consideration before encouraging replacement of distribution transformers.

Challenges Discussed
One consideration is the efficiency calculation itself. There was discussion as to the importance of correctly sizing the transformer for the load it is to carry. If the average load is below 35 percent, some participants believe that optimum efficiency levels will not be achieved. A study sponsored by a group of electric utilities in New England indicated that distribution transformers in the region commonly loaded well below this level. Thermal environment also affects transformer performance as well as the temperature of surrounding space. It was noted that more efficient transformers do not generate as much heat and can help reduce air conditioning loads if they are in or near air-conditioned space.

A second consideration pointed out by one industry partner is that transformers run more efficiently when built out of M6 steel, a metal in short supply due to high global demand. Transformers built before 1980 actually used this metal, and may be more efficient than transformers built since. The way the metal is internally joined together also increases or decreases efficiency, however, it’s more expensive for manufacturers to change construction techniques than it is to change materials used.

A final challenge is that demand for efficient transformers has not increased significantly through past voluntary programs; it was only when state and federal regulations came into force that changes to demand occurred. CEE proposes that it investigate market dynamics for transformers along with market mechanisms, for example, a bulk procurement program, which might aid in adoption of more efficient models.

CEE will also examine ways programs might influence transformer purchasing decisions, perhaps through emphasizing the “second price tag” of operating expense. CEE has industry partners who make high efficiency transformers and who may have advice, along with members who may have thoughts on why their previous incentive programs did not succeed as hoped. Finally, establishing a new voluntary specification also requires working with manufacturers to establish a time frame to enable them to recoup their investment in the new design. The committee plans to take these issues into consideration as they develop a recommendation for moving forward. For more information, contact Ted Jones.

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