Electric Mashups (+ Quiz!) | A New Shade of Green | Sherry Listgarten | PleasantonWeekly.com |

Local Blogs

A New Shade of Green

By Sherry Listgarten

E-mail Sherry Listgarten

About this blog: Climate change, despite its outsized impact on the planet, is still an abstract concept to many of us. That needs to change. My hope is that readers of this blog will develop a better understanding of how our climate is evolving a...  (More)

View all posts from Sherry Listgarten

Electric Mashups (+ Quiz!)

Uploaded: Apr 7, 2019
Utilities across the state have been told to lower emissions and use more renewable power sources. How are they doing? It’s surprisingly fun to look at the Power Content Labels of utilities across the state to understand the story they are telling.

Let’s start by taking a look at the whole state. Here is where California got its electricity in 2017. (All charts are from 2017 unless otherwise noted.)

You can read this chart like a clock, starting at the top. Going clockwise, the first five “pieces” (green, brown, light blue, yellow, and gray) show renewable sources. For example, the yellow slice indicates that 10% of the state’s electricity came from solar power. California’s goal is for this renewables section to be 60% by 2030. (1)

Then come two non-renewable but still carbon-free power sources: large hydro in blue and nuclear in pink. (2) Finally, wrapping the rest of the way around the “clock”, we see carbon-intensive natural gas (a big tan section) and coal (black), plus unknown sources (purple). (3)

What do we learn from this? For one thing, California’s electricity is 53% carbon-free. (4) Yay! We still use a lot of natural gas, which we’ve learned is not much better than coal. And we don’t have enough renewables. But it’s a great start.

In our area, we are even luckier. Our electricity content is incredible, 100% carbon-free or nearly so. (PCE has a carbon-free option that many households and cities take advantage of (5)).

CPAU: City of Palo Alto Utilities, PCE: Peninsula Clean Energy for San Mateo County, SVCE: Silicon Valley Clean Energy for much of Santa Clara County

Palo Alto currently has considerably more solar capability than the other two local utilities, but PCE and SVCE both have large solar farms coming on board.

Our local experience makes it hard to imagine who is using all that natural gas in California. Smaller, local utilities like ours have been able to move quickly to adopt renewables and large hydro. The large, often privately-owned utilities have moved more slowly. Let’s consider the four largest of these:
- Pacific Gas & Electric (PG&E): serves much of northern and central California
- Southern California Edison (SCE): serves much of southern California
- Los Angeles Department of Water & Power (LADWP): serves much of the LA area
- San Diego Gas & Electric (SDG&E): serves the south-western corner of California

Can you guess which mix belongs to which utility? (In the case where a utility offers more than one option, such as SCE and SDG&E, the default is shown.)

To help you out, take a look at this easy-to-read map of California's power plants. Where is the nuclear facility? Where do we have more hydro power? Which utilities will find it cheaper to use these? The utility in the lower-left has an impressive 78% carbon-free portfolio. Which one is it? (And what do you think will happen when the Diablo Canyon nuclear plant shuts down in 2025?) The utility in the upper right has an impressive 44% renewables. Which is it? (The answers are in footnote 6.)

How have our electricity mixes changed over time? Are they emitting less carbon each year? Take a look at the chart below.

There is some gradual improvement, but we took a pretty big hit around 2012. What happened in 2012 and, at least for Palo Alto, 2013-2015 to hurt our carbon-free efforts? How did we bounce back? (The answer is in footnote 7.)

Here is Palo Alto in a wet year just before the drought (2011), in a dry year in the middle of the drought (2014), and in a wet year just after the drought (2017). How did the city adjust its portfolio? Will it do better in the next dry year? What can still be improved?

Let’s see how the whole state’s electricity evolved during that same time period:

You can see the improvement in carbon-free electricity from 43% to 53% despite the loss of half of our nuclear power, as solar and wind came aboard. These state-wide changes have led to much lower emissions from the electricity sector. Our electricity emissions decreased by about 25% during this period, and are now just 62% of what they were in 1990. Importantly, this greener electric power gives us more options for moving away from natural gas in other areas like transportation.

To wrap up this blog, I’ll end with one last mix-and-match. See if you can match the power content charts below to the following cities: Healdsburg (in Sonoma County), Modesto, Sacramento, Weaverville (near the Trinity Alps), and Yreka (way up north). Use what you know about where the cities are and what facilities may be nearby. How do you feel about our state capital’s electricity mix? (The answer is in footnote 8.)

Green electricity is critical to our effort to lower emissions, and utilities like our own local options are showing the state and our country how to do it. The next few blog posts will talk about how they are so successful, and what challenges and opportunities they see in this fast-changing market.

P.S. If you would like to be notified when new posts come out on this blog, visit the New Shade of Green page and find the “Follow this blog” link near the top.

Notes and References

1. Technically, the “60% renewables” goal is measured based on electricity recorded by utilities as “retail sales” to homes, industry, etc, while the power content for California shown here is based on all electricity generated at the point of production. The metrics can differ by more than 8%. Some electricity is lost in distribution and transmission. And there are a few uses that don’t count as “retail sales”, like power station service, pumped hydro storage, etc. Thank you to Michael Nyberg of the California Energy Commission for his very lucid explanation about this difference, and his careful reading of this blog post! The individual utility charts shown later reflect only retail sales, so more closely reflect the metrics for renewables.

2. California doesn’t consider large hydro to be “renewable” because of its impacts on fisheries and downstream water flow. Nuclear power has similar environmental issues with the waste that it generates.

3. “Unknown” energy is the amount of energy not specifically claimed by a utility under the Power Source Disclosure Program. This includes spot market purchases, wholesale energy purchases, and purchases from pools of electricity where the original source of fuel can no longer be determined. It can also include "null energy," energy from a certified renewable facility that has been separated from its renewable attributes (Renewable Energy Credits, or RECs) and sold separately.

4. The term "carbon-free" is a simplification, because developing and maintaining these plants results in emissions, and some of the auxiliary infrastructure needed (e.g., power storage) can as well. Starting in 2020, utilities will be reporting emissions, which will help to quantify this. Thank you to commenter Max Hauser for this footnote.

5. PCE provides two options to all customers. The one shown in this graphic is ECOPlus, which is generally the default. Their 100% renewable ECO100 electricity is available to all residents for just a few dollars more per month for most homes. ECO100 is used by nearly all city governments in San Mateo County, and thousands of homes have opted into using it. The city of Portola Valley chose it as the default for its residents.

6. The upper row has Los Angeles Department of Water and Power on the left and San Diego Gas and Electric on the right. The lower row has Pacific Gas and Electric on the left, and Southern California Edison on the right. PG&E has an impressive 78% carbon-free mix, but it will be interesting to see how they manage the closure of our one remaining nuclear reactor. Will they switch to natural gas or to renewables?

7. Two things happened in 2012 to hurt our carbon-free efforts. The first was that the San Onofre Nuclear Generating Station was permanently closed due to concerns over leaking steam generator tubes. This impacted utilities across the state, particularly in southern California (see SCE and SDG&E). In addition, California began an extended drought during this period, which hurt hydropower production. Palo Alto had a very large dependency on hydro, and was forced to purchase carbon-intensive electricity off the grid to make up for the deficit over the next 3-4 years. As a result of the loss of nuclear and hydroelectric power, the state’s natural gas usage increased by 33% from 2011-2012. The utilities recovered by diversifying their electricity sources, over time using cleaner sources.

8. In the top-left is Healdsburg, which has the world’s largest geothermal area, The Geysers. In the top-right is Sacramento, which is woefully dependent on natural-gas. In the center is Weaverville, a small community with large amounts of hydropower from the nearby Trinity Alps. The bottom left is Modesto. And the bottom right is Yreka, supplied by a utility called PacifiCorp. (I am not entirely sure what they mean by their slogan “A cleaner energy future starts now”. They are free to start any time…)

9. The California Energy Commission provides a good summary of our state’s electric power generation for each year.

Comment Guidelines

I hope that your contributions will be an important part of this blog. To keep the discussion productive, please adhere to these guidelines, or your comment may be moderated:
- Avoid disrespectful, disparaging, snide, angry, or ad hominem comments.
- Stay fact-based, and provide references (esp links) as helpful.
- Stay on topic.
- In general, maintain this as a welcoming space for all readers.

Local Journalism.
What is it worth to you?


Posted by Max Hauser, a resident of Mountain View,
on Apr 7, 2019 at 1:59 pm

Max Hauser is a registered user.

Sherry I understand the point you're trying to bring out, but am dismayed at your uncritically repeating the misleading marketing euphemism "100% carbon free." While different in degree and subtlety, this resembles in kind the mind-set of some electric-vehicle owners who think their cars lack carbon footprint, because the carbon burden is out of sight and mind. Renewable energy sources can certainly be cleanER than classic fossil-fuel plants (though with some exceptions even there), but that isn't the same as genuinely carbon-free.

To seriously call wind, hydro, or solar power generation systems "carbon-free" requires examining them in isolated operation, as if the equipment (a) came into existence by magic and lasts forever, and (b) is not actually sourcing power into a wholesale grid. You then deliberately neglect the carbon-emission costs of, respectively, (a) manufacture, maintenance, and decommissioning ("life cycle"), and (b) indirect consequences of use as wholesale power sources.

Wind and solar sources have their own issues. (1) wind generation is unpredictable ("chaotic"), so to provide the stability required for wholesale use, it's customarily backed-up by associated fossil load-following plants of the same capacity; those plants' fast-start features render them less clean than conventional counterparts. (This inherent problem is sometimes, lately, obscured by accounting games.) Solar generation is increasingly problematic, as California's large volume of it increasingly swamps demand, collapsing wholesale market prices (there is nowhere to sell the excess). Even hydroelectic power entails lifetime and maintenance-related carbon footprints.

Again: These sources can be genuinely cleaner, but it is not nearly as simple as clean vs. unclean, or "100% carbon-free."

Posted by Sherry Listgarten, a PleasantonWeekly.com blogger,
on Apr 7, 2019 at 2:46 pm

Sherry Listgarten is a registered user.

@Max -- Great point, and I agree! These sources are not carbon free, either in their production or in their lifecycle. Storage, as you point out, is becoming critical, and can be carbon-intensive, though options are developing. For example, excess renewable power can be used to create hydrogen fuel (for storage) or push water uphill for hydropower at a later time (sounds nuts, but they are doing that today at pumped hydro facilities, four of which are in California). And building and maintaining these renewable (or non-renewable) plants causes emissions. One promising thing on that front is that, starting in 2020, retail power suppliers will report their emissions.

I do plan to cover the issue of storage soon, and the issue of implicit costs (e.g., plant development) some time later. But until then, I will add a footnote to this blog post.

Posted by eileen , a resident of another community,
on Apr 8, 2019 at 11:00 am

Embarrassed to report my results on the quiz--none right on the first, half right on the issue of 2012 ( I got the drought) and half right on the third--got Weaverville and Healdsburg. But I learned something from this as well as from Max Hauser's comment.

Posted by We're all in this together., a resident of Duveneck/St. Francis,
on Apr 9, 2019 at 1:48 pm

We're all in this together. is a registered user.

We can all help by consuming less power. Turn off the lights when you leave the room. Unplug appliances that have LEDs and clocks (why?) that run constantly. These are energy vampires. If you are not using it, turn it completely off.

More importantly, if you want to reduce carbon emissions, drive less. The biggest source of Bay Area carbon emissions is transportation. Bike and walk more for shorter trips. Ride transit when you can. (You have to know local bus, train and shuttle schedules to this, but that's not so hard.)

Posted by Curmudgeon, a resident of Downtown North,
on Apr 10, 2019 at 3:22 pm

Max Hauser and We're all in this together nailed it. Other than the small contribution from in-city solar during daylight, all our electric power comes from the same grid as our neighbors tap into. Turning on a light in Palo Alto causes the same incremental increase in carbon emissions as turning on an identical light in Menlo Park, Mountain View, etc. Not turning on that light in any of those cities avoids that CO2 emission spike.

That's plain physics. Accounting gimmicks like RECs have no effect on actual emissions. We gotta quit fooling ourselves with comforting mirages and get with realizing a true carbon-free state grid. Well-regulated modern nuclear is our best option.

And many thanks for providing this forum.

Posted by Sherry Listgarten, a PleasantonWeekly.com blogger,
on Apr 10, 2019 at 9:31 pm

Sherry Listgarten is a registered user.

@Curmudgeon -- So glad that you are enjoying the forum, and thank you for contributing!

You say that "all our electric power comes from the same grid as our neighbors tap into". Do you want to add a level of detail to that, and/or a reference? The utilities around here do share some of the same transmission lines. But the (contractual) sources for the power are generally different, and they are all very explicit about these. (Managing their power portfolio is what they spend much of their time on, partly because there is a thicket of regulations around it, and partly because it is the heart of their business.) I view contracts as pretty meaningful, and many of them are long-term, which also entails a good amount of risk and investment. It's also the case that PCE, SVCE, and Palo Alto all own some of their own power facilities, but imo that is not necessary to have meaningful ownership for the energy they are contractually purchasing.

Unbundled RECs are indeed controversial, but those are not lately an issue, at least in our area. Max is likely talking about something more subtle, which can happen even when no unbundled RECs are involved, related to how we account for emissions throughout the day and year. The next blog post will be about PCE (Peninsula Clean Energy) -- the CEO there, Jan Pepper, has some very audacious goals in this regard, having worked in/around the utility industry for 30 years. The trick is to be clean in a way that doesn't require anything else to be dirty.

Nuclear is also controversial, and imo a very interesting topic. I can't figure out if I should cover it before or after population growth :)

BTW I think a very weird thing that Palo Alto does is claim carbon-neutral gas. The electricity claim is a very real one. But the gas is just weird, and arguably besmirches the (real) electricity story by association.

Posted by musical, a resident of Palo Verde,
on Apr 10, 2019 at 11:30 pm

Purchasing indulgences always seemed weird to me too. Guess I'm a denier.

Posted by Sherry Listgarten, a PleasantonWeekly.com blogger,
on Apr 11, 2019 at 12:01 am

Sherry Listgarten is a registered user.

Here is a very helpful reference for the topic that @Curmudgeon is alluding to, namely whether any electricity not purchased on-site ("behind the meter") can be considered green. IMO of course it can. You can see how in this case they use the concept of additionality to think about whether their "clean" purchases just result in someone else's "dirty" purchases. In general, the point is that you want (aggregated) marginal clean purchases to increase supply. Supply is increasing like crazy. Would that happen without the power market?

Posted by Curmudgeon, a resident of Downtown North,
on Apr 11, 2019 at 1:26 pm

"You say that "all our electric power comes from the same grid as our neighbors tap into". Do you want to add a level of detail to that, and/or a reference?"

CPAU can confirm that to you. It is also shown on the maps available at Web Link specifically Web Link Our power comes in at the Colorado gateway via a PG&E line from the Cooley Landing PG&E substation, which is in turn fed from their big Ravenswood facility by the Dumbarton Bridge, etc., etc.

"The utilities around here do share some of the same transmission lines. But the (contractual) sources for the power are generally different, and they are all very explicit about these."

True. But the whole point is that the entities they write their checks, to and the entities that put the energy they consume onto the grid that feeds them, are not congruent. The Venn circles overlap but don't coincide. As your Google reference points out, "... we know from physics that on a pooled electricity grid we can't tell if energy came from a “green" or “brown" source, ..." Like, if you pour a glass of Chardonnay into a swimming pool, and someone else fills their glass from that pool, what have they got? (PA consumption is about 0.3% of the grid content Web Link

To the point: Paying suppliers to put green energy on the grid is a very good thing. It displaces the black kind. But we must not fool ourselves that the energy actually lighting our light bulbs is all green. It is whatever gray mix is in the grid pool at the moment.

In particular, we must resist the impulse to 100% electrify our city because "it's totally green." As with anything in the physical realm, decisions to replace gas with electric must be based on objective analysis, not solely on (otherwise laudable) eco enthusiasm.

Posted by Sherry Listgarten, a PleasantonWeekly.com blogger,
on Apr 11, 2019 at 7:29 pm

Sherry Listgarten is a registered user.

@Curm -- It seems to me that if you are looking at the electricity mix statewide (53% carbon-free), then you should also be looking at EV adoption statewide (5% or so). That would argue that we are way behind on EV adoption, no? It's not like we want to wait for the state to be 100% carbon-free, and then suddenly all rush out and get EVs.

Posted by Curmudgeon, a resident of Downtown North,
on Apr 11, 2019 at 10:51 pm

"That would argue that we are way behind on EV adoption, no?"

Way behind what?

EVs are excellent things. They're smooth running, lively driving, very low maintenance, and zero stinking. The big hangup is getting energy into them.

It takes 5 minutes or so to fill up a gas burner, perhaps on top of a similar wait if someone else already has the pump. Not too bad.

EV charging times are tens of minutes, depending on the charger and the car, perhaps on top of a similar wait if someone else already has the charger. That really bites into the day, especially on intercity trips. Running dry means calling a tow truck.

The answer is to replace roadside chargers with battery quick-swap stations. But that requires a high degree of battery and chassis standardization among manufacturers, plus a significant infrastructure startup capitalization. We'll see what happens.

EVs are still the coming thing. Meantime, I favor plug-in hybrids.

Posted by JLN, a resident of Charleston Meadows,
on Apr 15, 2019 at 1:42 pm

JLN is a registered user.

Charging times are changing.

An earlier report about Tesla's upcoming fast-chargers: Web Link
and in today's Mercury News, an article about even faster chargers from Australia for other EVs.

Let's keep an open mind.

Posted by doniya, a resident of Barron Park,
on May 16, 2019 at 12:00 am

great post

Follow this blogger.
Sign up to be notified of new posts by this blogger.



Post a comment

Sorry, but further commenting on this topic has been closed.

Stay informed.

Get the day's top headlines from PleasantonWeekly.com sent to your inbox in the Express newsletter.

Burning just one "old style" light bulb can cost $150 or more per year
By Sherry Listgarten | 5 comments | 1,742 views

Reflecting on lives this Thanksgiving Day
By Tim Hunt | 0 comments | 996 views


Support local families in need

Your contribution to the Pleasanton Weekly Holiday Fund will go directly to nonprofits supporting local families and children in need. Last year, Pleasanton Weekly readers contributed over $83,000 to support eight safety-net nonprofits right here in the Tri-Valley.