OPALCOGRAM 114
4/28/94

Doug Bechtel
In the last OPALCOGRAM I told you that we had received the final report on the Distributed Utility Study that the Bonneville Power Administration did. The purpose of this study was to help OPALCO defer major investments in submarine cables and substations that would be required over the next several years, to meet the load growth that we are experiencing. We have previously discussed the fact that we have to build our system to withstand the absolute peak load that we may experience. Unfortunately, our revenue is based to a large extent on the average power that we sell. The closer the peak load comes to the average load, the lower our cost to operate would be.

The Distributed Utility Study at-tempted to identify those things that OPALCO could do at a relatively low cost that would help decrease our peak loads. Some of the suggestions included installing generation or operating our existing small generators at our peak load times to reduce these peaks.

The Study recommends that we investigate potential wind generation sites that could provide generation. It appears that we will usually be able to count on the winds blowing during the peak period of our cold snaps. Thus, winds may provide a cost effective alternative. It will be a year or more before we collect enough information to determine this.

The Study also examined photovoltaic generation, using sunlight to make electricity. This was rejected early on (and ultimately left out of the final report) because our peak loads occur in the wintertime when our hours of sunlight are at the minimum.

This Study also looked at more direct ways to reduce our peak loads. For many years utilities all over the country have directly controlled the electric loads of their customers by radio or other means. Many utilities currently install a radio controlled switch that will interrupt power to your electric hot water heater for up to fifteen minutes an hour during the peak load period. We estimate for each water heater controlled, we would save 1,000 Watts, or one kWh, at our peak load time, saving OPALCO $50 per year. Direct control of water heaters would also enable us to restore power much more rapidly after an extended outage. By keeping the water heaters turned off for a few minutes after power comes on, we would reduce the initial cold load pick up which limits how fast we can restore power.

One of the more surprising results of this study was an investigation of a new application of an old technology called Energy Thermal Storage or ETS. ETS uses special bricks which are heated during OPALCO’s off-peak period and then retain enough heat to keep the room or house warm during the peak load period. These units directly replace electric baseboard heaters or, with slightly more involvement, an electric furnace. These units have small fans which help move the air in the room, making the room temperature more even. These units appear to cost about $700 per room, but will save the customer money by enabling them to purchase power from OPALCO at a lower cost during the off-peak period. OPALCO would also save by having a reduced electrical demand during our peak period (6 a.m. until noon). More on this study later.

Doug Bechtel