Day: February 18, 2023
Will this smooth the renewable highs and lows?: Xcel Energy announces testing of 100-hour batteries in Pueblo by as early as 2025. Will this displace natural gas peaker plants? — @BigPivots
Click the link to read the article on the Big Pivots website (Allen Best):
Holy Cross Energy aims to distribute 100% emission-free electricity to its 55,000 members in the Aspen, Rifle, and Vail areas by 2030. How will it do that?
Tri-State Generation and Transmission, Colorado’s second largest utility, has a different but related problem. It wants to best use infrastructure associated with its coal-burning operations at Craig after the last unit closes before 2030.
One clue may lie in Pueblo. There a pilot program testing a new technology for long-duration energy storage will be deployed by Xcel Energy and Form Energy by the end of 2025. The new iron-air batteries will be able to use chemical processes to store electricity and then discharge it for up to 100 hours.
The new battery technology has been reported to be 10 times less expensive than lithium-ion batteries. Iron is abundant in the United States, and the batteries are non-flammable.
In announcing the pilot projects, Bob Frenzel, the chief executive of Xcel, said the 100-hour batteries at Pueblo and at a coal site in Minnesota “will strengthen the grid against normal day-to-day, week-to-week, and season-to-season weather variability, in addition to extreme weather events, including severe winter storms and polar vortex events.”
Duration of storage matters entirely as electric utilities add low-cost and emissions-free renewables. Short-duration storage, such as the lithium-ion batteries installed in conjunction with a new solar farm near Glenwood Springs in 2022, can help. They provide two to four hours of storage.
With 100 hours of storage, utilities can smooth the highs and the lows of renewables. Consider Uri, the week of cold in 2022 when wind on Colorado’s eastern plains ceased for several days. Utilities cranked up turbines burning natural gas that was suddenly in high demand. Consumers are still paying off those bills. Tri-State even resorted to burning oil.
Summers have brought inverse problems of spiking demand caused by heat. In 2021, it got so hot in Portland that electric lines for trains melted, and some people without air conditioning literally baked to death in apartments. Colorado regulators worry whether the state’s utilities can handle such weather extremes.
Iron-air batteries alone are unlikely to solve the intermittencies of renewable energy or the havoc produced by a warming and more erratic climate. This pilot project does represent a notable effort to explore whether they can be scaled.
“This is an exciting new frontier for energy storage in Colorado,” said Mike Kruger, chief executive of the Colorado Solar and Storage Association, a trade group of 275 members. “This announcement goes to show that when there is clear policy, American companies can innovate to meet the electric power sector’s needs.”
Holy Cross Energy has been diversifying its supplies, both locally and regionally, but still depends largely upon wholesale deliveries from Xcel. The Glenwood Springs-based cooperative in 2022 delivered 50% emissions free electricity but has a goal of 100% just seven years from now.
Sam Whelan, the vice president for finance at Holy Cross, said that increased reliability by Xcel will help Holy Cross reliably deliver electricity to its members.
Holy Cross has been investigating its own options—and has had conversations with Form Energy. It will look at many alternatives, including green hydrogen and pumped-storage hydro, each with problems but also promise.
“You have to start something, and you have to start in small increments as well,” says Whelan.
The solar industry, he also started small. “It was not that long ago that solar costs were significantly higher,” he observed. Now, solar has become competitive. “It will take these incremental storage projects to prove out and hopefully pave the way.”
Tri-State, at a recent meeting with stakeholders, also reported that iron-air storage technology was among several options for Craig being studied once the coal plants there close. Transmission lines already exist, capable of carrying renewable energy to the site to be stored – and then released as needed.
Xcel may have gleanings about how they will act at scale and be used to manage the grid by 2026.
Will these new batteries eliminate need for expensive natural gas plants designed for use to meet peak demands? Such plants are expensive to build, and they do produce emissions. Too soon to tell, says Robert Kenney, the president of Xcel Energy’s Colorado division.
“If we see success with this program, we will explore how we can expand it and scale it up further. But to what extent it will displace ‘peaker’ plants or any other technology, that would be the learning that we would expect to come out of the pilot itself. So stay tuned.”
Big Cities Are Downsizing Their Water Footprints — Sustainable Waters #conservation
Click the link to read the article on the Sustainable Waters website (Brian Richter):
My research group spent three years collecting water data and other information from 28 water utilities that serve a total of 23 million people in the American Southwest. The task wasn’t easy: 39 researchers were involved in collecting data from 45 different utility employees. Each of these utilities we surveyed is dependent on the Colorado River for some portion or all of their water supplies. You can find our full results in this paper from the Journal of Water Resources Management & Planning.*
Overall, cities dependent on the Colorado River have done a fantastic job of managing their total water use under very high rates of growth. They’ve cut their water use by 18% while their populations grew by a whopping 24% during 2000-2020.
Big cities are doing a much better job with water conservation than smaller cities. Cities with more than 1 million residents cut their water use by an impressive 24% but water use in small cities actually grew by 3%. This is due to two factors: smaller cities are growing very fast, yet they don’t have the financial capabilities to invest in water conservation programs.
Key to big water savings is being able to get your customers to substantially reduce their average daily use of water, known as “Gallons Per Capita per Day” (GPCD). On average, big cities (>1 million pop.) were able to lower their Total GPCD by 35%. Medium cities (100,000-1 million pop.) lowered their GPCD by 30%, and smaller cities (less than 100,000 pop) lowered it by 25%.
But even with impressively lower per-capita needs, smaller cities simply grew too fast (median=42% growth) to keep their overall water demands in check.
Some of the primary water conservation strategies being applied in these 28 cities include offering rebates for replacing old water-guzzling toilets and other plumbing fixtures, and paying homeowners and businesses to rip out lush green lawns and replace them with drought-tolerant and often native shrubs, flowers, and grasses. Many cities also used water rate structures to control water use, such as by increasing the cost per gallon as water use rises.
Not Much Help for the Colorado River, though….
Unfortunately, those impressive water conservation efforts didn’t do much for the Colorado River, because total use of the river by the 28 cities we surveyed actually increased slightly during 2000-2020. That means that cities are taking less water from other water sources — such as their local rivers or from groundwater, or from desalination or water reuse — but not reducing their pressure on the Colorado River.
Water Conservation is Still Largely Untapped
Based on the fact that per-capita water use varied greatly among our 28 cities (low of 80 to a high of 286 in Total GPCD), there’s clearly room for the under-performing cities to tighten up their water belts. In larger cities, there is still great potential for reducing outdoor water use, or tapping into ‘alternative’ water supplies, such as reusing water more thoroughly, capturing stormwater, or encouraging homeowners and businesses to harvest rainwater.
The Southern Nevada Water Authority — which supplies water to nearly 1.4 million residents in Las Vegas, Nevada — is a great example of water conservation’s potential. During 2000-2020, the city reduced its total water use by 10% and lowered its Total GPCD by 47%, even while its service population grew by a staggering 69%! Yet the water authority has set an admirable goal of lowering its GPCD by another 23% by 2035.
*Note: If you are unable to access our paper using the link in the first paragraph above, please drop me a note at brian@sustainablewaters.org and I’ll send you a copy.
Deadpool Diaries: The chance of deadpool declines — John Fleck @jfleck #GreenRiver #ColoradoRiver #COriver #aridification
Click the link to read the article on the InkStain website (John Fleck):
First the bad news from the Colorado Basin River Forecast Center’s mid-February forecast – this year’s runoff into Flaming Gorge, which is at record low thanks to Drought Response Operations Agreement releases to prop up Lake Powell, is forecast to be below average this year, at 86 percent of average. At some point we’ve gotta refill this hole.
But the Lake Powell forecast continues to hover well above the “average” line, currently sitting at 117 percent.
Reclamation’s latest 24-month study “most probable” shows Powell bouncing back to above elevation 3,550. In the “olden days” (like, last year?) 3,550 would have been awful, but in the midst of our current crisis management fire drill it looks pretty good.
Mead stays awful in the current “most probable”, ending the water year at elevation1,034, another 10 feet below current levels, which should be enough for photojournalists to find some fresh wrecked pleasure boats, or possibly mob hits.
Under the “min probable”, Powell ends the water year at 3,544 and Mead ends at 1,021.
To help frame the current discussions, here’s the hypothetical Lower Basin cuts under the six-state and California SEIS proposals under elevations in the min probable forecast:
cuts, by state, at Mead elevation 1,020-1,025 6-state proposal California proposal California 1,424,000 750,000 Arizona 1,252,000 1,568,000 Nevada 67,000 82,000 total 2,743,000 2,400,000
Solid start to 2022-23 snow season in Colorado: Water planners optimistic for a strong finish, but cautious — @DenverWater #snowpack
Click the link to read the article on the Denver Water website (Jay Adams):
The winter of 2022-23 is off to a cold and snowy start across most of Colorado, which is good news for the state’s water supply.
So far, water watchers say we’ve had the best start for the statewide snowpack season since 2017.
However, while some parts of the state, like Steamboat Springs, are seeing the highest snowpack levels in over a decade, numbers in some parts of the state are lagging.
Snowpack is a measurement of the amount of water packed into the snow.
“Colorado is a big state and it’s not uncommon to see a wide range of snow totals across various regions,” said Nathan Elder, Denver Water’s manager of water supply.
For example, the snowpack in the northwest corner of Colorado sat at 151% of normal as of Jan. 31, but the southeastern corner was just at 83% of normal.
Sign up for our free, weekly TAP email to stay on top of this season’s snowpack. (Scroll down to put your email in the light blue sign-up bar.)
The amount of snow that falls in the mountains is critical in Colorado because that’s where most of the state’s water comes from each year.
Denver Water provides water to 1.5 million people in Denver and several surrounding suburbs, and 90% of the utility’s water supply comes from snow. The utility collects water from roughly 4,000 square miles of terrain in the mountains and foothills west of Denver in the Upper Colorado and Upper South Platte river basins.
Denver Water collects roughly half of its water from the Colorado River Basin and half from the South Platte.
In the areas where Denver Water collects water, as of Jan. 31, the snowpack in the Upper Colorado River Basin stood at 111% of normal, while the Upper South Platte River Basin stood at 82% of normal.
“The difference in snowpack is why Denver Water has built a large collection system spread across several counties. That way if one area is having a down year, hopefully things are better in another area. And that’s what we’re seeing so far this year,” Elder said.
Elder said this year the snowfall in the mountains has been steady since November 2022, compared with last winter, which will be remembered for having only a couple big storms that hit over the holiday season and ended up providing the bulk of the entire season’s total snowfall.
“As a water planner, it would be nice to have a steady, predictable snowpack season, but weather doesn’t work that way and each year plays out differently,” Elder said. “That’s why we constantly monitor the mountain snowpack and adjust our water planning accordingly.”
See how Denver Water monitors the snowpack from the air, on the ground and by using automated weather stations.
Denver Water’s reservoir storage stood at 82% full heading into February, which is average for this time of year. Elder said he’s cautiously optimistic the reservoirs will fill when the snow melts in the spring due to the snowpack so far.
He’s also encouraged by the fact that soil moisture for the state is the best it’s been in eight years.
“When the soil moisture is in good shape, it means more water will flow into rivers and streams instead of being absorbed by dry ground,” he said.
Denver Water monitors snowpack throughout the winter season, using monthly measurements gathered by crews on the ground and daily reports from automated weather stations. The utility also gets information about the snowpack from planes surveying its collection system using high-tech equipment.
This year, planes will fly over forests in Summit and Grand counties where Denver Water collects water — and for the first time also will fly over the utilities’ South Platte and South Boulder Creek watersheds.
“We’ve got our snowiest months of the season coming up, and we’re hoping the snow will keep falling,” Elder said. “Snowpack typically peaks around the third week of April, so that’s the key snowpack measurement we’ll be watching.”
Elder said that even though water supply looks good now, the winter months are a great time to get your house into water-wise shape indoors by finding and fixing toilet leaks, installing low-flow aerators and replacing old showerheads with WaterSense-labeled fixtures.
The latest El Niño/Southern Oscillation (#ENSO) diagnostic discussion is hot off the presses from the #Climate Prediction Center/NCEP/NWSEL
Click the link to read the discussion on the NOAA website:
ENSO Alert System Status: La Niña Advisory
Synopsis: ENSO-neutral conditions are expected to begin within the next couple of months, and persist through the Northern Hemisphere spring and early summer.
Although a weak La Niña was still apparent during January, below-average sea surface temperatures (SSTs) continued to weaken further across the equatorial Pacific Ocean. The latest weekly Niño index values were mostly near -0.5oC, with the exception of Niño-1+2 which was +0.1oC. Like the surface, negative subsurface temperature anomalies continued to weaken, with above-average subsurface temperatures expanding eastward at depth and near the surface of the eastern Pacific Ocean. Low-level easterly wind anomalies continued, but were confined to the western and central Pacific Ocean. Upper-level westerly wind anomalies were evident over the east-central Pacific. Suppressed convection persisted over the western and central tropical Pacific, while enhanced convection was observed over western Indonesia. Overall, the coupled ocean-atmosphere system continued to reflect La Niña.
The most recent IRI plume predicts a transition from La Niña to ENSO-neutral in the next couple of months. The forecaster consensus is largely in agreement. ENSO-neutral is expected to prevail during the spring and early summer. There are increasing chances of El Niño at longer forecast horizons, though uncertainty remains high because of the spring prediction barrier, which typically is associated with lower forecast accuracy. In summary, ENSO-neutral conditions are expected to begin within the next couple of months, and persist through the Northern Hemisphere spring and early summer.