Off Track on Energy Efficiency: Why Engineers Need a Whole-System Reference
At COP28 in Dubai, nearly 200 governments agreed to double the global rate of energy efficiency improvement to 4% a year by 2030. The latest IEA data show how far there is still to go. The IEA's Energy Efficiency 2025 report estimates that global energy intensity will improve by 1.8% in 2025, up from 1% in 2024, while the average since 2019 has been only 1.3% a year. The report also highlights that industrial energy intensity improvement has fallen below 0.5% a year, and that many appliances sold today are only half as efficient as the best available models.
Closing that gap is ultimately an engineering task: choosing the right conversion equipment, recovering waste heat, sizing storage and measuring what systems actually deliver. That requires engineers who can move comfortably between thermodynamics, plant design and economics.
Energy and Energy Transformation (CRC Press, 2026), by Yongjian Gu, brings those disciplines together in a single 582-page reference. It covers energy and exergy analysis; boilers, turbomachinery and heat exchangers; gas, vapor, cogeneration, combined-cycle and refrigeration cycles; renewable power plants; HVAC; efficiency measurement; energy economics and auditing; and energy storage. Gu is a professor at the US Merchant Marine Academy, a licensed Professional Engineer in New York, and a former senior engineer at a US Department of Energy national laboratory, which gives the book a practical, design-oriented perspective.
Three applications stand out. Plant engineers can use its exergy methods to locate where useful energy is really being lost, rather than relying on first-law balances alone. Project teams evaluating cogeneration or combined-cycle options can compare configurations on a consistent thermodynamic and economic basis. And energy managers can follow its chapters on efficiency measurement and energy audits to quantify savings in HVAC and power installations and justify investment.
For engineering libraries, this is a comprehensive single-volume resource that supports courses in mechanical, energy and environmental engineering, including energy systems design, energy management and HVAC. It is equally useful in the reference collections of utilities, consultancies and industrial R&D teams. Related titles are available in our Energy, Engineering & Environmental collection, and for the social side of the transition see our new title Climate and Cultural Choice.
CLNZ Books supplies academic libraries, research centres and professionals worldwide, with prices that include worldwide shipping, institutional invoicing and acquisitions support on request.
Q&A
What is the COP28 energy efficiency target?
Nearly 200 governments agreed at COP28 in 2023 to double the global average annual rate of energy efficiency improvement to about 4% by 2030. The IEA estimates progress in 2025 at 1.8%, well below that pace.
What is the difference between energy analysis and exergy analysis?
Energy analysis accounts for quantities of energy under the first law of thermodynamics. Exergy analysis measures the loss of useful work potential, showing where real inefficiencies occur in a system.
Why are cogeneration and combined-cycle plants more efficient?
Both use heat that would otherwise be wasted: cogeneration supplies it for heating or industrial processes, and combined-cycle plants use gas-turbine exhaust to drive a steam cycle, extracting more useful output from the same fuel.
Who should read Energy and Energy Transformation?
Professional engineers and researchers in energy system design, R&D and energy management, as well as engineering and environmental science students studying energy systems, energy management and HVAC.
Where can I buy Energy and Energy Transformation by Yongjian Gu?
You can order it from CLNZ Books. The price includes worldwide shipping, with payment by card, PayPal or international bank transfer, and institutional invoicing available.