written 22 Aug 2021
published 29 Aug 2021
In "A Worthwhile Effort, part 2", I estimated that a 50% reduction in carbon emissions within Mendocino County requires increasing renewable production about 450 megawatts (MW) by 2030, averaging 60MW per year. Locating this additional production within the county would avoid expensive grid upgrades to transport the expanded load, and increase local power resiliency. The latest IPCC report suggests decreasing grid reliability as the climate emergency grows. Fires this summer have already caused wide spread Public Safety Power Shutdowns across northern California, although most of Mendocino County has been unaffected so far.
Grid scale arrays take 2-3 acres per megawatt, so we need about 150 acres each year. Experience shows that grazing and many crops thrive in the shade of arrays, so some agricultural land can serve dual purposes. Within urban areas with little open land, arrays have been placed on closed landfills, floated on sewer plant and water reclamation ponds, placed on roof tops, and on canopies over parking areas. The Ukiah Unified School District recently put canopy arrays on parking lots at three of their sites outside the City. Within Ukiah City limits there are more than 75 acres of parking lots and 25 acres of large roof tops. The 37 acres of sewer percolation ponds must be exempted as an important waterfowl flyway resource, but the 25 acres of water reclamation ponds should be considered. Ukiah is in the process of annexing 640 acres of land in the western hills, some of which might have solar potential.
All Ukiah City, and Mendocino County, land and facilities should be inventoried for potential solar installation, supporting not only normal operations, but with an eye toward emergency power preparedness. For example, the Mendocino County complex at Low Gap Road, with about 8 acres of roof top and parking lots, has several critical functions (administration, sheriff, motor pool, jail, and juvenal detention) which would make this a good candidate for an emergency micro-grid.
Increasing distributed storage is also important. Every MW of array should have about 4 megawatt hours (MWhr) of storage, requiring adding 240 MWhr a year for the next 8 years. This requires about 4 acres per year, since a 1MWhr battery fits in a single 40' container. Storage should be located at every array to smooth out the load on the grid. In addition, storage should be installed at every substation within the county, allowing power to be prepositioned, avoiding grid congestion during periods of high demand, increasing grid efficiency and power resiliency for the local distribution systems serviced by that substation. The best design would also have a large array near each substation, further increasing local power resilience.
Since the power in Mendocino county is already mostly carbon free, adding more renewable power production is only a first step toward real emission reductions, because it is the heating and transportation portion of our emissions that requires the most extensive transformation.
In the last few years, the global automotive industry has begun a massive retooling to produce electric vehicles (EVs), with ranges increasing and prices dropping. Many automotive companies have announced an end to internal combustion production in the near future, and financial institutions are divesting from further fossil fuel development projects. However, the charging infrastructure needs rapid expansion for EVs to become a significant portion of our transportation economy.
Even though charging times are getting shorter, long-distance driving is still difficult. But most driver's needs can be met by charging overnight at home, which should be promoted. Locating multiple EV charging stations at City and County motor pool locations would power expanded County and City EV fleets, in addition to offering multiple stations for staff and daily customers. All the school bus fleets should be electric, and charged overnight at their central bus barns.
Given our partisan polarities, this massive transformation may seem foolishly naive. Some believe that it is already too late, or that Earth would be better with no humans. However, I believe humanity is more than we have so far manifested: that we can transcend the Us/Them illusion, and nurture all life on Earth. But we are now at the "do or die" phase for this species: the middle ground is gone. Without immediate massive effort, we have little chance of having a functioning economy by the end of a 30-year mortgage.
