Sunday, May 9, 2010
If you've followed this blog over the last year, then you know it is focused on a group of marine turtles from the Eastern Pacific green turtle (Chelonia mydas) population that aggregate near the South Bay Power Plant in the south San Diego Bay. My work for my Master's at SIO, was just a small part of the research NOAA scientists have conducted for over 20 years at this site. And the aspect of work I've looked at has to do with the fact that these endangered turtles spend much of their time in and near the warm-water discharge channel of the South Bay Power Plant (SBPP), a 50-year old energy plant which uses technology called once-through-cooling (OTC).
The SBPP has been generating less energy in recent years, and this means the amount of warmed water discharged by the OTC plant has been decreasing. You can explore the rest of the blog to learn more about this impact; but given that the population of turtles is remaining steady (about 60 in the San Diego Bay), and that they are in good health, researchers believe the turtles will be just fine once the plant closes completely. We anticipate that the turtles will adjust their location throughout the bay to remain in habitats that are favorable (i.e. the right water temperature range, eelgrass and other food to eat). In fact, early signs of these shifts in distribution were observed in the research I've done as exhibited in the decreased catchability within the discharge channel; and additional research by NOAA scientists and students at SDSU has begun this year to further study these changes.
OTC energy generating facilities are located near a body of water, there are 19 along California's coast. Plants using this type of technology pull in water from the nearby ocean or bay which is then used to cool the steam created by the energy generation process and that water, now warmed, is discharged back into the ocean or bay. Marine life and ecosystems can be affected by organisms being pulled into the OTC plant (entrainment and impingement), as well as changes to the ecosystem caused by the artificially warmer water being discharged. New technology such as dry-cooling (uses air vs. water) and closed loop cooling (reuses water vs. pull in and then discharge) is now common place among newer energy plants and do not have the same impacts on marine habitats.
For sometime now, policymakers in California and other parts of the US have considered legislation that would eventually eliminate the use of such OTC technology. The primary reason for requiring this change in technology is to comply with "best available" standards that guide much environmental regulation - this is often referred to as "best technology available, or BTA". What this means is that new, wide spread technology now exists which is more efficient that older technology and has a less negative impact on the environment and natural resources.
Logically, then, power plants that use OTC should either be upgraded to use the newer and less damaging technology, or they should be shut down completely, and newer, cleaner energy generation facilities should be built and brought on-line.
And this is what California's State Water Resources Control Board ruled on last week.
"The intent of this Policy is to ensure that the beneficial uses of the State’s coastal
and estuarine waters are protected while also ensuring that the electrical power
needs essential for the welfare of the citizens of the State are met. The State
Water Board recognizes it is necessary to develop replacement infrastructure to
maintain electric reliability in order to implement this Policy and in developing this
policy considered costs, including costs of compliance, consistent with state and
federal law." (May 4, 2010, OTC Policy)
The one other key factor that will have to be considered prior to the SBPP and other OTC plants being shut down is that the energy these operating plants generate, is used by us, the citizens of California. And if you recall the "energy crisis" of 2001, you know that reliable energy supply is essential to our lives and economy. Before these plants are shut down completely, a new source of energy (e.g. a new/different power plant), must be online and capable of providing the energy demand currently being met by the OTC plant. In the case of the SBPP, energy regulators have said that the creation of the Sunrise powerlink or a similar transmission line could bring power generated at inland solar/wind power plants to the coastal San Diego community. Alternatively, other power plant(s) may be constructed in south San Diego to fulfill the energy demand that currently exists.
Regardless, closing the power plant prior to having an energy source online and identified would be extremely disruptive to our lives in San Diego.
This OTC technology, created in the 1950s, is clearly no longer the "best available" and so energy decision makers must address this fact and update their plants accordingly, which may mean in some cases that plants are shut down.
The new policy now mandates these changes take place and forces energy companies to make changes that are overdue. These changes will cost money, which is the largest complaint of the energy companies (and these costs, of course, will be passed on to us, the consumers); however the newer technology is also more efficient, which means in the long run, it is a smart business move for the energy companies too, and it will also begin addressing much needed changes in reducing carbon emissions to curb climate change.
Regional Water Quality Control Board May 4, 2010 Ruling
California Rules Restrict Power Plants' Marine Water Use
California okays coastal power plant modifications