written 17 November 2019
published 24 November 2019
Two weeks ago, I described the cost of the recent power down, the likelihood these would continue for a decade no matter what happens to PG&E, and the inadequacies of using backup generators. For economic survival, Ukiah must become more power down resilient to "Keep The Lights On", and the idea of a single whole city array and storage battery was considered. Last week I discussed providing emergency power for the residential portion of the community through small scale distributed storage for each household. This week I will consider distributed power collection within the commercial part of our community.
The lost business income during a power outage is one of the major drivers to "Keep The Lights On" in Ukiah. Solar arrays have a guaranteed return on the investment, providing inflation proof electricity. Businesses have already budgeted for the cost of power. Shifting these expenditures from the current system to renewable arrays is like shifting from renting to owning with a fixed rate mortgage. Not only is the cost fixed, but eventually the system is paid off and subsequent power is free. The stumbling block is funding the initial investment. The City or utility could borrow money to make energy loans to subsidize array installations. Keeping the businesses of the city operational improves everyone's lives, not to mention avoiding business bankruptcies.
Roof top and parking lot canopy arrays, in joint partnership on existing commercial real estate, would eliminate the cost of land for an array, but would incur larger array mounting costs. Because these arrays would be within the boundaries of the Ukiah electric district, connecting to the local distribution system would be easy. Parking lot canopy arrays are becoming more common, and the installation costs are dropping. Canopies also help cool the land under the array, reducing the heat island effect that can worsen urban summers.
An investigation using Google Maps gives a rough estimate for at least 59 possible locations for midsize arrays within Ukiah city limits. There are 24 roof locations that do not yet have solar. Assuming collectors cover 50% of the roof area, these arrays would range from 43KW to 1MW, for a total capacity of over 12.8MW. Covering 50% of 32 parking lots with canopy arrays ranging from 250KW to 1.25MW, would give another 18.8MW. The area along the east edge of the airport could support an 11MW array. Building all these would create a capacity of 42.6MW, about 40% of the 100MW target to power the entire city during the winter. In addition to these estimates, there are many locations for small arrays.
As a society, we have gotten used to having all the power we want whenever we want it. In an emergency, we can modify our normal patterns for the duration, like conserving water in a drought. Businesses could shorten their hours of operation to fit the available power. For example, all gas stations have a canopy over their pumps, which could support an array. Combined with some onsite storage, the array could power the station while the sun shines. If every station was in operation part of the day the gas shortages and long lines we saw during the recent power down could be avoided.
Most restaurants in town use natural gas for cooking, but have to close during a power outage because the hood fans don't work, let alone the lights and credit card systems. Roof top arrays would have to be supplemented with some on site battery storage to keep coolers and freezers alive.
Grocery stores have large energy loads because of all the coolers and freezers, and represent the largest commercial challenge for power resilience. Many of the grocery stores in town have already installed generators, although they are vulnerable to failure, risking large losses.
If you would like to "Keep The Lights On" in Ukiah during a power outage, share these ideas with friends, and email your support to the City Council members below.
dcrane@cityofukiah.com
sscalmanini@cityofukiah.com
There is no single way to accomplish this, and we need a series of workshops to pull together ideas from every part of the community. If we show there is popular support for the basic concept, the Council will make it happen.
