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| California Electricity Production March 23, 2019 |
Saturday, March 23, 2019, was a windy, sunny day in
California. It was so windy and sunny that at 3pm renewables supplied 68% of
the electrical load. As you can see in the chart above, not only did the California
ISO, the entity responsible for managing California’s energy grid, throttle
back electricity imported from other states, it pulled way back on the
electricity it took from natural gas (thermal) power plants. Ramping down California’s
lone nuclear power plant wasn’t an option—nuclear power plants are pretty much
on or off and take a long time to change from either state. Hydroelectricity
can usually be throttled back somewhat, but after a wet, snowy winter in
California the reservoirs behind the dams are full.
This is not the first time California has had
such a bounty of renewable power. In April and May of last year, renewables at
times made up over 70% of the electrical load. For the last three months, December
2018 -- February 2019, renewables contributed more than 60% of California’s electricity
at some point in each month. So far, the all time high for renewables contribution
to the California grid for any five minute period is 74%.
California has four basic challenges to resolve on its
journey to using solely renewables + large hydro to power its electric grid.
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| Part of the baseload |
1)
The state needs baseload power that can supply
around 20,000 MW delivered around the clock and around the year.
Hydroelectricity, on non-drought years, can provide about 4,000 MW. Nuclear provides another 2,000 MW; however, California’s
aging lone nuclear plant is scheduled to shut down in 2025. Other renewables,
such as biogas, small hydro, geothermal and biomass are together reliably
supplying 2,000 MW around the clock. This leaves a gap of 12,000 MW that is
currently being met by burning natural gas or importing electricity from other
states.
2) California’s second challenge is that summer
demand, higher than any other season, generally peaks around 6pm when solar
panels have lost most productivity. This demand needs to be reduced, shifted to
other times of day, or both.
3)
Challenge three is that in order to meet winter
demand, the state needs to figure out ways to produce electricity on cloudy,
low wind days in December and January, when both solar panels and on-shore wind
turbines may produce only a third of the electricity that they do in other
seasons. Sometimes this low sun/wind combination might last for days at a time,
so shifting demand to other times of day won’t help.
4) The last challenge is what to do with the excess
electricity that will inevitably be produced on windy, sunny days after solar
and wind are built out enough to deal with challenges one through three. With
just the amount of wind and solar being added to California 2019, it is likely
that renewables + large hydro + nuclear will surpass 100% of demand often on
sunny, windy days in 2020. It is likely that renewables alone will surpass 100%
of demand on sunny, windy days after 2022. But this is a good problem to have! Read
on!
How to Provide
Renewable Baseload Power
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| Leaky, leaky |
First let’s discuss why burning natural gas and importing
electricity from other states is not a climate-friendly answer for meeting
baseload or peak power requirements. Though we’ve been led to believe that
natural gas is a “clean” fuel, because the national natural gas distribution
system is so leaky, it turns out that burning natural gas to produce
electricity, while better for our lungs, is almost as bad for the climate as burning coal. We need to transition natural gas out of our homes and out of our
electricity supply in relatively short order.
But why not just buy electricity from other Western states
that have excess to sell? There are a few problems with this. 1.) These states
have peak summer demand right around the time California does, which means
they’re least likely to have excess electricity when we need it most,
especially any produced from hydro, solar or wind. 2) Right now all these
states burn coal. Some of them burn a lot. In fact, most would have no
electricity to sell at all if they didn’t burn coal. The coal burners even
include Washington State, despite its prodigious amount of hydroelectricity.
Even if “officially” California is buying electricity produced by hydro, wind
turbines or solar panels, if these states weren’t shipping electricity to
California, they would burn less coal or none at all. Eventually these states
will build out renewables enough to meet their own internal demand. Until then
they have no business shipping electricity to anyone else.
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| Wyoming is the state furthest west with the most purple. |
3) Even if all these
states installed renewables like crazy, few have much in the way of potential
wind resources. Many have great solar potential but their solar would produce
daytime peaks very close to California’s solar generation peaks, when
California needs to import electricity the least. The exception, as you can see
in the wind map adjacent, is Wyoming. Wyoming has both amazing wind and a small
population. It could easily build out enough wind farms to sell electricity
24/7 all summer to California. Too bad the state is completely in servitude to
coal and perversely unwilling to take advantage of the great renewable,
non-destructive source of energy it is so richly endowed with. Since California
cannot force Wyoming to become sensible, the Golden State will have to make use
of its own great untapped resource to produce baseload energy: off shore wind.
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| Off shore wind beats on shore with a stick. |
On shore wind in California comes and goes. Some days are
blustery; some days are still. In contrast, the wind off the coast of
California is strong and steady all day, all night, and all four seasons. Perfect
for baseload. The wind off the north part of the state is better than the wind south, but even the wind off LA isn't bad.Though the US has been slow to adopt off-shore wind technology,
Europeans have not. Europe now has 18,499 MW of off shore wind turbines
installed, with 4,543 grid-connected turbines. Of turbines installed last year,
the average size was 6.8 MW. Because of deep waters in windy areas, California
will likely need to install floating turbines, although there are some locations
with shallow water where conventional turbines could be used. But Europeans are
ahead of us there, too. There is already a 30 MW floating wind turbine farm off
the coast of Scotland, and a €31 million euro floating wind project
approved off the west coast of Ireland. Since off shore wind farms take several
years to build and install, California should get started now. Building out a
reliable baseload power supply is purely a matter of money and political will.
How to Meet Peak
Summer Demand
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| Up, up, up |
Renewables contribution as a percent of peak load in
California falls in summer months, not because renewable generation falls, but
because demand goes way up with the state’s summer air conditioning load.
It is then that California turns to burning natural gas and importing
electricity in spades.
The main problem is that utility-scale renewables production
is strongest from 9am to 6pm, while summer demand peaks from 3 pm to 9 pm. This
mismatch is partly due to residential solar dampening daytime demand, but also
because heat builds during the day, peaking between 3:30 and 5pm, depending on
how far one is from the coast. (The demand curve during other seasons looks
quite a bit different but it never exactly matches renewable production.) To
meet summer demand without burning fossil fuels or causing other states to burn
them, California would have to build out renewables to the point there would
often be large oversupplies of electricity fall through spring as well as many
summer days until 3pm. Or the state would have to figure out a way to reduce
summer peak demand. Or it would have to do a combination of both.
So what are the options? Waste electricity? Have blackouts
every summer afternoon? Neither! Excess electricity can be used in productive
ways, excess electricity can be stored to be used other times, and peak demand
can be shifted or reduced, all with technology that currently exists. Let’s
explore.
Store Peak Supply Electricity for Peak Demand Hours
1)
Pumped hydro storage. During sunny/windy hours, the
state can use electricity to pump water up behind a dam, creating a giant
battery of potential energy. Let the water fall to provide baseload grid
capacity in late afternoon/evenings. The site can be closed-loop, with
reservoirs that don’t impact existing river systems. California currently has
3,000 MW of pumped hydro storage. Doubling its pumped hydro storage capacity would
go a long ways towards ensuring grid reliability during peak demand hours.
2) Ice batteries. This is a twofer—ice batteries
essentially both store electricity and reduce peak demand. They can be
programmed to charge themselves by making ice when renewable supply exceeds
demand, say 10 am – 2pm, then use the ice to coast through the hottest six
hours with cooling that requires very little electricity. This can be done on
an industrial, commercial, institutional and residential level. The technology
is relatively low tech and already exists. For homeowners, the cost of an ice
battery is equivalent to a conventional AC system.
3) Encourage home batteries via time-of-use charges.
Charge low rates during peak supply hours and very high rates during peak
demand hours. This will both make use of excess electricity and shift demand.
It would also encourage households to install solar on west-facing roofs, which
will provide more electricity late afternoon when it’s most needed.
4)
Utility Scale battery storage—lithium ion, redox
flow, zinc hybrid, etc. Charge during peak generation, use during peak demand.
Reduce or shift demand away from peak hours 3pm – 9pm
1)
Ice batteries (discussed above.)
2) Implement steep cost for electricity during peak
demand for residential and commercial users (discussed above.)
3) Reduce amount of sewage treatment, water pumping
and water treatment during peak demand hours. Some obviously needs to happen
continually, but some can be delayed to off peak times.
4)
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| Go no lawn |
5)
Stop water-crazy agriculture in California that
requires crazy water pumping electrical use. Cotton, rice, and alfalfa are
water-intensive crops that can all be grown in places where water falls from
the sky all summer. Beef fed with irrigated forage, and cheese from cows that
are fed alfalfa require huge amounts of water. These animals can also be raised
in places where water doesn’t have to be pumped hundreds of miles. (Wisconsin!
Iowa!) Almonds can’t be grown in many other parts of the US, but if the
crop is largely being exported to China, then California is just foolishly
exporting cheap water to China. Raising prices to, say, a 1/5th to a
1/4th of residential costs instead of the present 1/100th
to 1/50th would send rice,
cotton, alfalfa and cheese production off to the states they belong in and
would encourage dry farming, drip irrigation, mulching, compost use, and bio-intensive
farming, all of which regenerate the soil and draw down carbon from the atmosphere.
Yes, the cost of food will rise. If we want a planet habitable for the human
race this is inevitable. Better to directly subsidize healthy fruits and
vegetables for low-income households than to waste water and energy as
extravagantly as we do.
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| Singing Frogs Farm--no-till, low water, high biodiversity |
6)
Implement a steep time-of-use rate structure to
move industrial demand off peak demand hours. Demand response programs already
exist but they could be much stronger, on the order of triple for
kilowatt-hours used summer months between 3pm and 9pm. Industrial customers
will either put their own west-facing solar panels on their rooftops, install their
own batteries, or run their operations when electricity is cheaper.
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| In LA, trees=cool |
7) Reduce need for cooling throughout California.
Plant trees, trees and more trees, especially to the west of buildings. Add green roofs, add living walls. Water
them all with greywater. Add awnings to all west-facing windows. Make all roofs
that are not green into white roofs that reflect heat. Reduce urban heat island
effect by ripping up asphalt and concrete and turning it into low-water (but
lovely) green spaces or replace with cool pavements, including vegetated
permeable pavers irrigated with grey water. Add solar canopies to shade
walkways and parking lots. (Better yet, get rid of parking lots.) Increase the
albedo of asphalt by adding light color aggregates or seal existing asphalt
with reflective coating. Discourage housing in high summer heat areas. Create
gentle density and walkable communities in areas with reliable cooling ocean breezes
(within 5 miles of coast) by replacing parking lots with townhouses, duplexes
and apartments. (See Ten Minute Neighborhoods.)
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| Monster Demand Day--July 24th, 2018 |
Peak electricity demand for all of 2018 in California was 46,284 MW, which occurred at 5:35pm on
Tuesday, July 24th. Wind plus solar provided roughly 11,000 MW of that. Total
daytime demand that hot day was a behemoth 876,174 MW-hours. If California had
developed a renewable base load of 20,000 MW, it would’ve been able to cover
480,000 MW-hours of that 24-hour demand. To produce the other necessary 400,000
MW-hours with solar and on-shore wind, solar and on-shore wind production would’ve
roughly needed to have been 2.5 times what it is now. (This is assuming a fair
amount of demand shifting and battery storage to better match time of
generation.) This much wind and solar would mean a significant amount of excess
electricity would be produced fall through spring. Let's look at the winter situation, which is slightly worse.
How to Produce Enough
Renewable Electricity on Cloudy Windless Days
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| Cloudy, windless day, Jan 14, 2019 |
While the sun shines reliably in California in the summer, it
doesn’t in the winter, nor does on-shore wind blow reliably. While demand is
lower in the winter, on some days renewable production is much lower than in
summer. On Tuesday, January 15th, 2019, for example, total system
demand was 600,000 MW-hours. A baseload of 20,000 MW would have covered 480,000 MW-hours
of that, leaving only 120,000 MW-hours for solar and wind to cover. Unfortunately,
on January 15th solar plus on-shore wind only produced 42,000 MW-hours. To meet
demand on this particular day, solar plus on-shore wind would have had to be
built out at nearly three times the level it is now. Since these cloudy, low
wind days can occur for days at a time, shifting demand five or six hours
wouldn’t fix the problem. The good news is the cost of both solar and wind has
dropped and is dropping further! More good news is that there are more than
enough rooftops in California where solar could be installed to meet this
demand without sacrificing agricultural or natural areas. Tripling the number of solar panels in California is
doable. Tripling the number of wind turbines may be less so due to the lack of good wind sites. Maybe quadrupling solar will be a better bet, or maybe adding more floating off-shore wind turbines. It all depends on how expensive floating
wind farms turn out to be.
Either way, building out enough renewables to meet
December/January cloudy, windless days will result in substantial over-generation
of electricity in the spring and fall, summer mid-days, and very often in the
winter. Won’t it all go to waste?
No! Or at least, not necessarily. Now we’re getting to the
good problem to have.
How to Use Excess Electricity
in Productive Ways
1) Schedule sewage treatment, water pumping and
water treatment when excess electricity is available. Some obviously will have
to happen continuously, but there is some ability to ramp and slow down based
on electrical supply.
2) Use excess electricity for electrolysis.
Electrolysis is used in the production of aluminum, lithium, sodium, potassium,
magnesium, calcium, chlorine, sodium hydroxide, sodium chlorate, potassium
chlorate, electrolytic copper, oxygen, and electroplating. Offer plants nearly
free electricity in spring and fall but expect them not to run summer months
from 3pm to 9 pm, or on cloudy winter days. Same can be done for hydrogen and ammonia
production. (See below.)
3) Produce ammonia for fertilizer. Permaculture is
the future of farming, but there will probably still be a place for chemical
fertilizer. Producing it from a simple combination of water, air and
electricity is the way to go. Use electrolysis to crack water molecules
into hydrogen and oxygen. Ramp up ammonia production fall – spring; expect
plants not to operate summers from 3 pm to 9 pm or on cloudy winter days.
4) Same for hydrogen. Though there are high levels
of losses using hydrogen as a fuel, hydrogen may very well come in handy soon
for long-distance shipping. Taking advantage of excess electricity to produce
hydrogen may soon make economic sense even in the Midwest on windy nights.
Oh my gosh, how can these plants possibly make a profit if
they don’t operate on cloudy days or summer late afternoons and evenings? Well,
if one of your primary inputs is electricity, running when electricity is dirt
cheap will make the economics pan out nicely. To extend their operations to, say,
5 pm in the summer, these plants could install arrays of west-facing solar panels so they don’t have to draw from the grid during peak demand
hours.
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| Floating wind--California's future? |
