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Doug Bechtel
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Believe it or not I didn't forget that I promised to talk about our Long Range Plan. It is just that there is so much going on with the Bonneville reinvention process that it is hard to get away from that for very long.
Our Long Range Plan identified three problems: The first and most pressing of these problems is our inability to get adequate voltage into our Eastsound substation during extreme cold weather. Even though our voltage is adequate today, I can tell that we are approaching the limit of what we can do with the existing system. All power lines have some voltage drop as-sociated with them. We know this happens and we design for it. Each of our substations has voltage regulators that correct for these voltage variations so that the voltage you see in your home remains fairly consistent regardless of what else happens on our system.
The Long Range Plan confirms our suspicions that we were headed for problems on this transmission line. While the Long Range Plan examines several alternatives, the end result confirmed the 1981 Long Range Plan which called for increasing the voltage on this transmission line from 25,000 to 69,000 volts. Indeed, the overhead portions of this transmission line have already been built to operate at the higher voltage, but much still remains to be done.
The OPALCO substation near the ferry landing on Orcas and the substation on Shaw were designed to operate at 25,000 volts. In addition to rebuilding these substations, we need to build 69kV submarine cable terminals on Orcas and Shaw.
In 1993 we laid a 69kV submarine cable between Lopez and Shaw which is in use today. Another cable was laid between Orcas and Shaw, but hasn't been connected yet. The Long Range Plan pointed out that we don't have enough room at our site near the ferry landing on Orcas to build a new terminal and rebuild the substation. The best solution is to build the substation at another site north of the ferry landing near the transmission line. After we build the substations and cable terminals we are going to need a second 69kV submarine cable in the Lopez to Shaw and Shaw to Orcas crossings for reliability.
When does this need to happen? Several years down the road. This summer, cul-minating with the outages in October, we installed a 69,000/25,000 volt transformer on Lopez. We es-timated that this transformer would improve the voltage situation in Eastsound and buy us time until we needed to accomplish a full conversion to 69kV. It appears this transformer will do even better than we had projected and may defer the need for these improvements for five to ten years.
If you can tell me how fast our electrical load will grow, I can tell you exactly how many years until the work needs to be done. The important thing is that the installation of this transformer on Lopez has bought us several years until we need to make millions of dollars in investments in the OPALCO system.
More next time about other findings of the Long Range Plan.
Doug Bechtel
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