Rusk Newsletter for Energy Engineers
Volume 1, May 23, 2025
Photo credit: Grok, Printing the Rusk Newsletter
From Richard Rusk
I am writing to provide insights to managers in energy engineering and their direct reports. Please pass it along to anyone who might benefit.
When I say “energy engineering” I mean energy project development, commissioning, facility management, and design.
My perspective is with the users of energy, behind the meter and inside the project boundaries. On-site generation is a topic, too--solar photovoltaics, Battery Energy Storage Systems, Virtual Power Plants, and cogeneration.
Feel free to help me spread the word that I’m studying and writing about what I find in trade magazines, social media discussions, email newsletters, and research papers.
I want to see my ideas spread widely. I hope you do, too. I am on X, Substack, and LinkedIn as Richard Rusk, Engineer and the username @richardrusk007. Between the three social media platforms I now have about 1500 followers, subscribers, and contacts. The count is growing every day.
Business model
The business model for my writing and teaching career is to provide both information at no cost and in-depth information with a set price. I am experimenting with formats but right now I think a newsletter format is something known to readers and to me as a writer. I have not established a frequency of publication.
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If so inclined, you can subscribe for a month or more right now but with no extra benefits over a free subscription. The Substack company has a business model where they take a percentage. I pay no up-front fees to Substack so they encourage paid subscriptions every chance they get. Don’t be surprised.
You might want to start your own Substack writer’s account. There is no charge and the community of Substack readers is large and growing.
See this as a professional reading service
We all need to stay current. You can think of my newsletter as an extension of your own professional reading. Feel free to comment in the Chat area on my website at Substack. I take suggestions.
This issue’s contents
1. Battery price predictions and lithium futures, a topic from a discussion I was in on the web
2. ASHRAE Journal, May 2025, my review of nine articles
3. Three upcoming no-cost webinars
4. A vocabulary word from my reading
5. Life advice under the heading Plan Your Work and Work Your Plan
Lithium prices are rising but battery prices are falling.
From a discussion on the web
Summary: In percentage terms, the cost percentage of the lithium metal in a lithium-ion battery is holding steady at about 25% to 30% of the total cost. But the price of lithium is rising. The cost of other components have been falling faster than lithium prices are rising. Lithium is the Cathode Material of the first graph below.
This week a correspondent on X posted a graph showing the expected decline in battery prices. The source is an unsigned article posted on the Goldman Sachs website. The subject is batteries for electric vehicles but I think it should apply to stationary batteries, too.
The graph shows historical prices through 2023 and projections from 2024 to 2030. I marked the division point.
I wondered if lithium prices would explain the drop in total price. It turns out the answer is no. Lithium is the Cathode Material in dark blue on the graph and the price rises from 2025 to 2030.
What are the declining costs “Opex, DD&A” and “Cell-to-pack?”
Opex is Operating Expense. These are expenses that appear on the current year’s tax filing of the manufacturer.
DD&A is Depreciation, Depletion, and Amortization. These are names expense items for the manufacturer that are spread out in tax filings over a period of years.
Cell-to-pack is the name for the strategy to assemble a pack of cells without intermediate modules, the outgoing common assembly practice. Cell-to-pack increases power density for vehicle batteries and reduces complexity for all uses of batteries.
Lithium prices fall, then rise
I found websites where lithium prices are quoted. The product I am following is traded as Lithium Hydroxide. I found past prices and futures contracts for the next two years.
Past prices
The price was in the range of about $20 to $50 per kg in 2023, declining to $8.56 on May 12, 2025. Trading in lithium started in the last few years.
Past price of lithium, dollars per kg
https://www.barchart.com/futures/quotes/LMK25/overview
The futures chart shows lithium prices rising for the next two years.
Future price of lithium, dollars per kg
https://www.cmegroup.com/tools-information/quikstrike/product-expiration-browser-metals.html
Trade Magazine Review, ASHRAE Journal, May 2025
There are nine articles. I reviewed them from the perspective of an energy engineer. There are three categories; Features, Technology Awards, and Columns. Each category has three articles.
For non-members, articles are available for purchase at $8.00 each on the ASHRAE Technology Portal, ASHRAE Technology Portal - ASHRAE Journal Articles.
Article Contents
Feature Articles
Feature 1. Laboratory Research on Airborne Infection Control in Hospital Operating Rooms
Topic
· Post-surgery infections, one operating room explained
Insights
· CFD is a valuable tool
· Future research is anticipated
Costs
Savings
Payback Period
Rules of Thumb
Tables or graphs
· Characteristics of the OR studied
· Particle concentrations
· CFD air flow drawings
Memory Trick
For Reference Library
· HVAC for an OR is likely to be Laminar Airflow (LAF) or Mixing Ventilation (MV)
· Process used in the study
· Fifteen references
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
Feature 2. Two- vs. Four-Pole Motors in Chilled Water Pumps
Topic
· Hypothetical pump selection considering pump speed
Insights
· Designers should compare pumps at different speeds early in pump selection
· Potential benefits are in maintenance cost, installation costs, energy savings
· Inverse relationship, 2-pole is faster than 4-pole
Costs
Savings
· Comparison of costs, two pump speeds
· Payback Period
Rules of Thumb
§ HVAC systems 40% of a building’s energy use
§ Preferred Operating Range, POR, is 70% to 120% of flow at Best Efficiency Point (BEP)
Tables or graphs
· Pump curves, one per speed
· Energy cost comparison
For Reference Library
· In the pump selection process, rpm is a criterion
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
Feature 3. Decarbonization of Large Domestic Hot Water Systems
Topic
· Hypothetical selection of water heating technology
Insights
· Using CO2 as a refrigerant in a heat pump gives rejected heat at a higher temperature, can heat water to 140 °F
· Suggested design strategies using heat recovery chillers for HVAC and DHW
Costs
Savings
Payback Period
Rules of Thumb
· CO2 produced and energy needed to heat water for multiple water heater technologies
· COP of heat pump water heaters in various design strategies
Tables or graphs
· CO2 emissions and energy needed in heating water
For Reference Library
· CO2 production
· Heat pump system design pros and cons
· Five references
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
Technology Awards
Technology Award 1. Emphasizing Energy Efficiency in Hospital Construction
Topic
· Chilled beams and DOAS in a new-construction hospital
Insights
· Water-cooled screw chillers in series-counterflow configuration, 0.38 kW/ton
· Commissioning was performed
Costs
· $6300 per ton for complete system, $5700 per ton for an AHU-based system
Savings
· Energy savings 8% compared to model
· 923 equivalent metric tons of CO2 saved
Payback Period
· Payback period of 24 months
Rules of Thumb
Tables or graphs
· Energy use modeled and actual
For Reference Library
· An example of a successful chilled-beam application Heat pump system design pros and cons
Codes, Standards, Legislation
· ASHRAE Standards 90.1, 62.1, 170, and 55, plus local code in Brazil
Calculation Method, Software
Design Strategy
Technology Award 2. Achieving Japan’s Highest Level of Data Center Cooling Energy Efficiency
Note 1: A slide deck is available at the owner’s website. Slide 9 explains the energy-efficiency strategy. Slide 16 shows the HVAC system. Slide 21 describes equipment.
https://www.iij.ad.jp/en/ir/library/session/pdf/shiroiDC_E.pdf
Image from Slide 16:
Note 2: Swirling Induction Type HVAC System, SWIT,® 2-page explanation available at the link. Takasago Thermal Engineering Co. is the manufacturer.
https://www.jase-w.eccj.or.jp/technologies/pdf/factory/F-87.pdf
Topic
· The Shiroi Data Center Campus, 2019 building
Insights
· Outdoor air used for economizer cooling 55% of the time
· Server rack inlet kept at 75°F to 79°F
· Humidification by evaporation in warm return air
· In electrical and UPS rooms a Swirling Induction Type air system (SWIT) was used to raise COP by 2 times
Costs
Savings
Payback Period
Rules of Thumb
· PUE of 1.2 is the highest level in Japan
Tables or graphs
· Comparison of air transfer efficiency of three buildings
For Reference Library
· For designers, an example of architectural and mechanical design
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
· Architecture of the building which puts energy efficiency first (outdoor air cooling)
· High-efficiency AC equipment
· Controls use AI
· Airflow control
Technology Award 3. Decarbonizing the CARB Southern California Headquarters
Note: Further information available at the designer’s website:
https://aeieng.com/news/aei-ashrae-exemplary-decarbonization-recognition-carb-headquarters
Topic
· Office and lab building, CARB Southern California Headquarters
Insights
· The model showed 56 kBtu/ft2-yr, actual was 108 kBtu/ft2-yr due to increased lab use
· Heat recovery chiller has seen little use since the heat reclaim source has produced little heat, also has control challenges at part load
Costs
· Not stated. The contract type is stipulated sum design-build.
Savings
· The computer model beat the standards, but the actual consumption exceeded prediction due to increased use, equipment issues
Payback Period
· 10 year simple payback period
Rules of Thumb
Tables or graphs
· Monthly modeled energy use vs actual
For Reference Library
Codes, Standards, Legislation
· ASHRAE 90.1-2010
· Title 24 2016
· LEED Platinum v4
· CALGreen Tier 2
· ASHRAE 55-2010
Continued: Technology Award 3. Decarbonizing the CARB Southern California Headquarters
Calculation Method, Software
Design Strategy
· Photovoltaics with BESS
· EV charging capability
· Dual-temperature cooling, 57°F chilled water for sensible cooling
· Fluid cooler
· Adiabatic humidification
· Heat recovery chiller
· Active chilled beams and DOAS
· Daylighting, daylight harvesting
· Laboratory airflow control
· Air quality sensors
Columns
Column 1. HVAC Fundamentals: Understanding Mold and Moisture Problems Inside Housing
Topic
· Instances of mold growth
Insights
· Apartments more susceptible than houses
· Moss on a roof directs moisture in
· List of recommendations
Costs
Savings
Payback Period
Rules of Thumb
· RH over 85% for mold growth
· Families of 4 generate 3 gallons per day moisture
Tables or graphs
For Reference Library
· Photos of common mold locations
· Thirteen references
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
Column 2. Engineer’s Notebook: Understanding Hydronic Cell Dynamics
Topic
· Troubleshooting, heating inadequate after a renovation
Insights
· Examine startup records, no TAB or Cx was done in this case
· Get all TAB results
· Perform Cx steps even if late
· Examine air side and water side
· The problem was in the hot water piping
Costs
Savings
Payback Period
Rules of Thumb
Tables or graphs
For Reference Library
· TAB process description
· Troubleshooting process description
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
Column 3. Refrigeration Applications: Under Pressure
Topic
· A lesson in compressor terms
Insights
· Under certain circumstances isentropic efficiency can be more than 100%
· Likewise, under certain circumstances volumetric efficiency can be more than 100%
Costs
Savings
Payback Period
Rules of Thumb
Tables or graphs
For Reference Library
· Compressor efficiency terms; Isentropic, Volumetric
· Compressor pressure terms; Pressure ratio, pressure difference
Codes, Standards, Legislation
Calculation Method, Software
Design Strategy
Upcoming Webinars
1. Mastering Low RH with Desiccant Dehumidification, sponsored by Condair and Engineered Systems
Thursday, May 29, 1 pm Eastern, Noon Central
Description: “Gain insights into system selection, including sizing considerations, regeneration, and design best practices.”
https://register.gotowebinar.com/register/4620344020081500507?source=Engineered+Systems
2. From Concept to Machine Learning in Practice, sponsored by Energy Twin
Thursday, May 29, Noon Eastern US, 11 am Central US (originating from the Czech Republic)
Description: “Join Energy Twin and the University Centre for Energy Efficient Buildings (UCEEB) of Czech Technical University in Prague as we explore the rising importance of load-side flexibility in today’s dynamic energy systems.”
3. Energy Management 101 – The Building Blocks of an Effective Energy Management Program, sponsored by EnergyCAP and the Energy Management Association
Tuesday, June 3, 2 pm Eastern, 1 pm Central
Description: “This insightful and engaging webinar is designed for energy professionals looking to enhance their energy programs. Attendees will walk away with a practical framework for implementing and optimizing an energy management strategy that delivers measurable results.”
Plan Your Work and Work Your Plan
I think every bit of advice about accomplishing a goal fits somewhere in this well-known maxim. This issue’s quote is:
“If you are willing to do more than you are paid to do, eventually you will be paid to do more than you do.” Anonymous
This quote fits the Work in Work your Plan.
Expand Your Vocabulary
Obsequious
adjective
US pronunciation /əbˈsi·kwi·əs, ɑb-/
too eager to serve or obey someone:
She is embarrassingly obsequious to anyone in authority.
(Definition of obsequious from the Cambridge Academic Content Dictionary © Cambridge University Press)
Thanks for reading.
Richard Rusk