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By Sherry Listgarten

The Grid Next Door

Uploaded: Jun 5, 2019

A post or two ago I wondered what you are doing about power outages. Some of you mentioned having backups such as a gas generator (including one with a large propane tank) or your own solar+battery system. Another predicted cars stuck in garages, especially with the new parking lifts. Some of you thought outages are not a big deal (“Impaired access to Safeway is more in the category of nuisance”) while others think they represent significant harm to businesses, schools, and more.

Where do our local public services stand, especially given that outages may be getting more common even as we electrify more of our lives? In this final power-related post for a while, I want to talk a bit about what our utilities are doing to help protect us against outages.

It’s pretty easy to build a reliable power system if money and land are no object. You build two of everything -- power plants, transmission lines, distribution networks. Or better yet, three. You add in some variety -- different types of plants, in different places, with wires preferably underground -- and you will be in pretty good shape. In that vein, ever since Palo Alto’s ten hour city-wide power outage in 2010 (and even before then), the city has explored adding more redundancy to our network. But it is expensive.

Money and land are not freely available. Our utilities have goals around both reliability and cost. That is what makes the evolution of “distributed energy resources” so interesting. These are essentially mini power plants that can go in homes or businesses or community spaces -- think rooftop solar and/or batteries -- to supplement the grid and shore it up when it has problems. These not only add spare capacity, they can make our power infrastructure more resilient (1) and lower the overall cost.

Back in the days of mainframe computers, if you wanted a system to be up 24x7 and you didn’t have funds for a spare computer, you were pretty much out of luck. You would just do your best to take good care of the machine and maintain it during off-hours. “Put all your eggs in one basket, and watch that basket,” as the saying goes. Then smaller systems came along, and networked systems, and suddenly we had scalable, cheaper, more resilient systems (if they were engineered well). The unit of failure was smaller and cheaper to replace. It wasn’t a total win -- there was added complexity, and the network had to be robust. But it allowed us to build fast, reliable computing power at a scale we had never seen. As one example, Google famously built its data centers full of less than reliable machines to keep costs down while building bigger and bigger search indexes.

We have started doing this to some degree with our power infrastructure. As we have decentralized and expanded our power market, moving away from monopoly utilities, we have networked our power plants. With more sharing of spare capacity and more power plants to choose from, if one plant or line goes down, another somewhere on the grid can pick up the slack. Now the state and utilities are asking if we can take this a step further, using local resources like rooftop solar and storage. Can these distributed energy resources hook into the grid and further increase reliability and decrease costs by kicking in when power is scarce or expensive or the network is congested?

In a recent opinion piece in Utility Dive, representatives of some large power consumers argue strongly in favor of this, railing against how conservative the state has been with its resource requirements. “Essentially, we build the grid like shopping mall parking lots — with enough capacity for Black Friday shoppers, but a sea of empty spaces the rest of the year. As electricity customers, we all pay the price.” They call for “a culture shift within regulatory agencies and grid operators away from reliability-at-all-costs and toward reliability-at-the-right-cost”. Those who need it most can build what they need, they suggest. “Customers that place the highest value on reliability — such as hospitals and military facilities — have never had more options to ensure that grid disturbances do not cause them harm.” But what about residents? As a commenter wrote on the preceding post on outages, this is too problematic to be left to homeowners. “I think this acceptance of power supply outages becoming the norm is a backwards philosophy and should be stopped.”

Indeed, cities and utilities are taking action. The city of Calistoga got an early taste of PG&E’s Public Safety Power Shut-Offs last year, and with more outages expected this year, they are working with Menlo Park-based Clean Coalition to see if a networked combination of batteries and local power sources (a “microgrid”) would allow their town to be more independent from the failure-prone grid. Across the country, in New Hampshire, an outage prone town with just a single incoming power line compared the cost and benefit of duplicating that line versus adding a large amount of battery storage and related incentives, and opted to move forward with the latter. The battery not only improves resilience during outages, it also helps them avoid peak pricing during normal operation. In fact, they calculate the local storage approach will both save money and reduce emissions. This idea of “resilience for free” is intriguing.

Closer to home, both Peninsula Clean Energy (PCE) of San Mateo County and the City of Palo Alto are evaluating microgrids to support emergency service hubs. PCE is funding a project with Interfaith Power and Light to identify three to five faith institutions in San Mateo County that could serve as community emergency hubs. The buildings would be equipped with solar and battery so they could serve as emergency shelters for local residents when the grid is impaired. In addition, PCE has a joint project with East Bay Community Energy in Alameda County to evaluate microgrids at critical facilities (e.g., fire and police stations) in both Alameda and San Mateo counties. Palo Alto is working with VMware to explore a microgrid at VMware headquarters in Palo Alto. This pilot project would help both city and company explore the value of these solar-plus-storage setups, while also serving as a communications hub and place to charge emergency response vehicles during a major outage. Catherine Evert, communications director for Palo Alto Utilities, says “This is still a proof of concept, but could lead to something larger in the future. We are very excited about this idea.”

Palo Alto looked at establishing their own energy storage program as recently as 2017, but the costs did not pencil out. More recent evaluations of energy backups at two city facilities -- the new public safety building and Cubberley -- led to determinations to use diesel generators. The city has, however, identified a battery storage site at the public safety facility should costs come down and space constraints improve. Palo Alto is very happy to support residential customers who are implementing solar and/or storage systems. There is a good amount of work to be done just to ensure that the local distribution lines can accommodate the increased levels of residential solar and EVs, as outlined in this 2018 report. Palo Alto sees their advisory role for customers growing, including developing this site that evaluates the costs of solar, storage, and various efficiency improvements for homes.

Jan Pepper, CEO of Peninsula Clean Energy, agrees that providing emergency shelters and backup power for critical government institutions is just a start. “Some future projects include looking at how we can help residents who need reliable power to keep medical devices operating obtain and site battery storage, or solar plus battery storage, so that they remain safe. We will also be looking at siting battery storage for homeowners in general, or in concert with their new or existing solar system, for backup power. We are interested in working with them to store the solar power produced during the day, and use it during the evening peak hours, to allow us to more closely match the county's electric demand to the electric supply.” PCE is also partnering with Clean Coalition, Stanford, and many others in an expansive “Advanced Energy Community” in southern San Mateo County, which probably deserves a blog post all its own as it develops. Its goals are not only to provide low-cost renewable backup power, but also to create local jobs and investigate potential revenue streams from the renewable power infrastructure.

The evolution of small-scale solar and batteries is leading to an interesting dynamic, in which the electric utilities become more like brokers among smaller players, much as the state’s “independent system operator” (CAISO) has become a broker among many small utilities. Thinking even more micro, consider the fact that this area has among the highest EV adoption rates in the whole country. EV batteries in aggregate are a substantial and growing power resource, and could also become an important part of the grid for supply, not just for demand. How would that look, even if the batteries were just used for resilience to outages? Home energy storage is very expensive, but an inverter for a car battery costs just a few hundred dollars. Is it worth looking into?

What do you think about this dilution of power generation and storage across ever smaller and more local players? Is it going to work out, with generally cheaper and more reliable power? Or is this mesh of participants at multiple levels going to prove too complicated to operate cleanly and reliably? The state of California is paying close attention and hasn’t entirely made up its mind yet. What are your thoughts?

Notes and References

1. This brief article distinguishes between reliability and resilience. I don’t know if it’s a generally accepted distinction, but it is an interesting one to think about. In a nutshell, a “reliable” system has few outages, while a “resilient” system can recover quickly from outages. I think of the efforts around distributed energy resources as targeting resiliency more than reliability. We are not eliminating or even reducing the sources of outage -- you could even say we are adding to them. But we are improving our response to outages by deploying many local backup systems. But it may be splitting hairs because either way the overall system becomes more reliable.

2. This writeup by the director of a microgrid for the North Bay, an area hard hit by recent fires, explains their rationale for pursuing more autonomous power.

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