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The award-winning Phase Change Matters blog tracks the latest news and research on phase change materials and thermal energy storage. E-mail tips and comments to Ben Welter, communications director at Entropy Solutions. Follow the blog on Twitter at @PureTemp. Subscribe to the weekly PCM newsletter. Or join the discussion on LinkedIn.




PCM mats helped lift Virginia Tech to first place in Solar Decathlon

Ben Welter - Monday, February 18, 2019

FutureHAUS, front elevation

The Virginia Tech team that won first place in the 2018 Solar Decathlon Middle East credits a good share of its success to the deft use of phase change material donated by Insolcorp LLC of New London, N.C.

FutureHAUS, the lone U.S. entry, topped 13 other finalists and more than 60 total entrants in the competition organized by the U.S. Department of Energy and the United Arab Emirates’ Dubai Electricity & Water Authority. Australia's University of Wollongong finished second. The finals took place in November in the desert heat of Dubai.

Insolcorp donated 400 square feet of two types of Infinite R PCM mats. Both are salt hydrates, one with a melt point of 21 degrees Celsius, the other a melt point of 22 degrees C. The phase change material acts as a thermal battery, absorbing and releasing thermal energy as it solidifies and melts.

The Virginia Tech team deployed the mats in the plenum of its 900-square-foot solar-powered house. The PCM allowed the team to take advantage of a rule that limited the use of solar energy to 8kw at any one time, with one exception: Unlimited use of solar energy for air conditioning was allowed during daily inspection periods to assure visitor comfort. The PCM mats, solidified during those periods, helped keep the house comfortable at other times. That helped the FutureHAUS achieve the highest score in net energy use, a key metric in the competition.

Joseph Wheeler, AIA"Every team struggled with the 8kw limit," said Joseph Wheeler, right, lead faculty on FutureHAUS and co-director of Virginia Tech's Center for Design Research. "Typically, during peak energy, you would be generating lots and lots of power, which you could easily charge your batteries with, which you could easily run all your tasks, and you could feed the grid, and build up quite a bit of surplus so that you would remain energy positive throughout the two weeks of competition.

"But, since they limited inverter use at any one time to 8kw, it really put a limit to what our energy budget was. We saw phase change as batteries. A massive ton of batteries. ... It's more of a strategy for a competition than it is for a realized situation. But in a realized situation, we know the value of the PCM. Heat energy, cost of power being cheaper at night than during the day where you can charge your systems and load shift. Practically, PCMs make a lot of sense. And we wanted to have the PCMs in this house for practical reasons, not just for competition reasons. ...

"In simple terms, we eased the demand for the HVAC every afternoon. It was the hottest time of the day and it was also the time when we were getting less power from the solar panels because the sun was moving down. It was a critical time because we knew that once the sun went down, we had to survive on battery. And we had a limit. They limited every house to 15kw of battery."

FutureHAUS, kitchenThe FutureHAUS team finished in the top three in eight of the competition's 10 categories: first place in Architecture, House Functioning and Sustainable Transportation; second place in Sustainability and Innovation; and third place in Engineering/Construction, Energy Efficiency and Comfort Conditions.

The FutureHAUS entry was a two-year university-wide effort. More than 100 Virginia Tech students helped design and build the structure, with help from faculty members in architecture, urban studies, science, engineering and other departments.

The house consists of 18 modular  "cartridges" built inside a Virginia Tech research facility. It was first assembled on campus in Blacksburg, Va., last summer. After testing, it was disassembled, shipped to Dubai and then reassembled at the competition site in just two days. It has since been shipped back to Blacksburg, where it will undergo testing to measure its various energy-saving components.

"We now have a system in place where we can collect data and can truly test the performance," Wheeler said. "We know the PCM worked for us during the competition because we did have some temperature sensors in the ceiling. And so we were able to prove that we were reaching the pre-state when those PCMs were being charged. But we really want to collect a lot more data and look at it in real-world situations."

Research roundup: Self-luminous wood composite; palmitic acid/mullite composite; corrosion sensitivity of metal alloys; more

Ben Welter - Tuesday, February 12, 2019

From Energy Storage Materials:

Self-luminous wood composite for both thermal and light energy storage

From International Journal of Refrigeration:

The thermal performances of a refrigerator incorporating a Phase Change Material

From Renewable Energy:

Enhanced thermal conductivity of palmitic acid/mullite phase change composite with graphite powder for thermal energy storage
An experimental study on the corrosion sensitivity of metal alloys for usage in PCM thermal energy storages

From Energy Conversion and Management:

Sorption thermal energy storage: Hybrid coating/granules adsorber design and hybrid TCM/PCM operation
Novel hybrid microencapsulated phase change materials incorporated wallboard for year-long year energy storage in buildings

From Thermochimica Acta:

Experimental Investigation on Thermal Properties of Sodium Acetate Trihydrate based Phase Change Materials for Thermal Energy Storage
The preparation of AgI/Au/foam-Cu as a framework of composite for water-based cool storage phase-change material with low supercooling

From Energy and Buildings:

Nano-encapsulation of phase change materials: from design to thermal performance, simulations and toxicological assessment
Investigation of phase change materials integrated with fin-tube baseboard convector for space heating

From Journal of Energy Storage:

Nano-enhancement of phase change material in a shell and multi-PCM-tube heat exchanger

From Applied Energy:

Numerical investigation of phase change material thermal storage for space cooling

From Journal of Materials Chemistry A:

Vertically aligned carbon fibers as supporting scaffolds for phase change composites with anisotropic thermal-conductivity and good shape-stability

Research roundup: Thermal conductivity; decarbonization potential of compact heat storage; liquid desiccant cooling systems; more

Ben Welter - Wednesday, February 06, 2019

From Energy:

Effects of thermal conductivity and density on phase change materials-based thermal energy storage systems

From Renewable Energy:

Melting process investigation of phase change materials in a shell and tube heat exchanger enhanced with heat pipe

From Applied Thermal Engineering:

Compact latent heat storage decarbonisation potential for domestic hot water and space heating applications in the UK
Numerical and experimental study of phase-change temperature controller containing graded cellular material fabricated by additive manufacturing
A novel composite phase change material with paraffin wax in tailings porous ceramics
Characterisation and evaluation of a new phase change enhanced working solution for liquid desiccant cooling systems
Thermal properties enhancement and application of a novel sodium acetate trihydrate-formamide/expanded graphite shape-stabilized composite phase change material for electric radiant floor heating

From Environmental Research:

Latent heat storage biocomposites of phase change material-biochar as feasible eco-friendly building materials

From Colloids and Surfaces A:

A facile microencapsulation of phase change materials within silicone-based shells by using glass capillary devices

From Microporous and Mesoporous Materials:

Phase change in modified metal organic frameworks MIL-101(Cr): Mechanism on highly improved energy storage performance

From Applied Energy:

Role of porous metal foam on the heat transfer enhancement for a thermal energy storage tube
Energy saving performance assessment and lessons learned from the operation of an active phase change materials system in a multi-storey building in Melbourne

From Building and Environment:

Comparative analysis of the PCM application according to the building type as retrofit system

From Construction and Building Materials:

Evaluation of the potential use of form-stable phase change materials to improve the freeze-thaw resistance of concrete

From Results in Physics:

Application Research of Nano-storage Materials in Cold Chain Logistics of E-commerce Fresh Agricultural Products

From Journal of Energy Storage:

Using PCM as energy storage material in water tanks: Theoretical and experimental investigation

Patent application: Phase change materials from wax-based colloidal dispersions

Ben Welter - Monday, January 28, 2019

U.S. patent application 20190023959 (applicant Henry Co. LLC, El Segundo, Calif.):

"This invention generally relates to phase-change materials (“PCM” or “PCM materials”) made from colloidally-protected wax-based microstructures. This invention also relates to such PCM materials configured in various physical forms. This invention further relates to a process of configuring such PCM materials for a variety of end-use applications in which dampening of temperature fluctuations by absorption and desorption of heat is desired. This invention further relates to preparing colloidally-protected wax-based microstructures in particulate form that function as PCM materials."

PCM briefing: Cash infusion for PCES; call for e-textile conference papers

Ben Welter - Monday, January 28, 2019

Phase Change Energy Solutions Inc. of Asheboro, N.C., last week announced an investment by Pegasus Capital Advisors, Emerald Technology Ventures and Third Prime, an early-stage venture fund and prior investor. Dennis McGill, operations advisor at Pegasus, joined PCES last month as chief executive officer. The company says it will use the proceeds to fund the continued development of its thermal storage products and expand its operations globally. Terms of the investment were not disclosed. 

Mark RichardsMark Richards, right, CEO at Emery Mechanical Engineering in San Diego, is featured in a recent episode of the HVAC 360 podcast. Richards, former applications engineering manager at Phase Change Energy Solutions, talks about "Phase Change Materials in Practice." 

1414 Degrees of Australia reports that the first commercial pilot of its molten silicon energy storage system is one step closer to commissioning. The GAS-TESS will store energy to generate electricity from biogases produced at a wastewater treatment plant. 

• In collaboration with Canada's Université Laval, researchers at the University of the Basque Country in Spain conclude that "fake ISO 9001 quality certificates are very widespread across Chinese companies and that the certification processes of the auditing companies lack credibility." 

• The Association Connecting Electronics Industries has issued a call for technical conference abstracts and educational course proposals for IPC E-TEXTILES 2019 to be held Sept. 11 in Philadelphia, Pa. Topics include reliability, test methods, design, washability and materials innovation. Abstracts and proposals are due by April 10. 

Research roundup: Micro environmental control system; alkali nitrate salts; sodium thiosulfate pentahydrate; more

Ben Welter - Tuesday, January 22, 2019

From Journal of Thermal Science and Engineering :

Phase Change Material Freezing in an Energy Storage Module for a Micro Environmental Control System
Phase Change Material Melting in an Energy Storage Module for a Micro Environmental Control System

From Renewable Energy:

Form-stable oxalic acid dihydrate/glycolic acid-based composite PCMs for thermal energy storage
Molecular simulation of the structure and physical properties of alkali nitrate salts for thermal energy storage

From Applied Energy:

Effect of inclination on the thermal response of composite phase change materials for thermal energy storage

From Solar Energy Materials and Solar Cells:

Characterization and thermal performance of microencapsulated sodium thiosulfate pentahydrate as phase change material for thermal energy storage
Fabrication and applications of dual-responsive microencapsulated phase change material with enhanced solar energy-storage and solar photocatalytic effectiveness

From Energy:

Numerical investigations of optimal phase change material incorporated into ventilated walls

From Polymer Degradation and Stability:

EG-based coatings for flame retardance of shape stabilized phase change materials

From Construction and Building Materials:

Freeze-thaw performance of phase change material (PCM) incorporated pavement subgrade soil


Research roundup: Hydrophobic lauric acid; paraffin in heat exchanger; EnergyPlus vs. IES; more

Ben Welter - Thursday, January 10, 2019

From Journal of Energy Storage:

Preparation of hydrophobic lauric acid/SiO2 shape-stabilized phase change materials for thermal energy storage

From Applied Thermal Engineering:

Development of paraffin wax as phase change material based latent heat storage in heat exchanger

From Renewable Energy:

Characterization and stability study of a form-stable erythritol/expanded graphite composite phase change material for thermal energy storage

From Journal of Building Engineering:

Comparison of EnergyPlus and IES to model a complex university building using three scenarios: Free-floating, ideal air load system, and detailed

From 4th International Conference on Renewable Energies for Developing Countries :

Phase Change Materials in a Domestic Solar Hot Water Storage Tank of the Lebanese Market
Numerical and experimental investigations of a PCM integrated solar chimney
Integrating a High Solar Combi-Plus System using PCM Storage in a Smart Network: KSA Case Study

From International Journal of Advanced Research In Applied Sciences, Engineering and Technology:

Solar Cooker with Heat Storage System: A Review [pdf]

From Energy and Buildings:

From Solar Energy Materials and Solar Cells:

Bio-based poly (lactic acid)/high-density polyethylene blends as shape-stabilized phase change material for thermal energy storage applications

From Construction and Building Materials:

Microstructure-guided numerical simulation to evaluate the influence of phase change materials (PCMs) on the freeze-thaw response of concrete pavements

From Energy Conversion and Management:

Thermal management of Li-ion battery pack with the application of flexible form-stable composite phase change materials
Experimental investigation on cylindrically macro-encapsulated latent heat storage for space heating applications

From International Communications in Heat and Mass Transfer:

Experimental investigation on using a novel phase change material (PCM) in micro structure photovoltaic cooling system
Experimental investigation on a novel composite heat pipe with phase change materials coated on the adiabatic section

From Journal of Cleaner Production:

Research roundup: Solidification/subcooling in spherical capsule; cement-based thermal storage; heat transfer in flexible container; more

Ben Welter - Friday, December 21, 2018

From International Journal of Refrigeration:

Experimental studies on solidification and subcooling characteristics of water-based phase change material (PCM) in a spherical encapsulation for cool thermal energy storage applications

From Construction and Building Materials:

Thermal energy storage characterization of cement-based systems containing microencapsulated-PCMs

From Renewable and Sustainable Energy Reviews:

Seasonal thermal energy storage system for cold climate zones: A review of recent developments

From Heat and Mass Transfer:

Analysis of heat transfer in latent heat thermal energy storage using a flexible PCM container

From Energy Conversion and Management:

Plate type heat exchanger for thermal energy storage and load shifting using phase change material

From Applied Thermal Engineering:

Experimental studies on the charging performance of single-tank single-medium thermal energy storage
Investigation of thermal energy storage properties of a microencapsulated phase change material using response surface experimental design methodology
Financial and energetic evaluation of solar-assisted heat pump underfloor heating systems with phase change materials

From IOP Conference Series: Materials Science and Engineering:

Thermal Performance Through the Use of Radiant Barrier and Phase Change Material in Concrete Flat Roofs

From Solar Energy Materials and Solar Cells:

Synthesis of novel form-stable composite phase change materials with modified graphene aerogel for solar energy conversion and storage

From International Journal of Heat and Mass Transfer:

Development of vacuum impregnation equipment and preparation of mass/uniform shape-stabilized phase change materials

PCM briefing: Virginia Tech takes first place in Solar Decathlon; Pluss is expanding R&D team

Ben Welter - Monday, December 10, 2018

Virginia Tech's FutureHAUS team has won first place in the 2018 Solar Decathlon Middle East, a competition organized by the U.S. Department of Energy and the United Arab Emirates’ Dubai Electricity & Water Authority. The lone American team topped 14 other finalists and more than 60 total entrants. The team said its use of phase change material in the solar-powered home set it apart from the competition. Look for an interview with Joseph Wheeler, an architecture professor who directs Virginia Tech's FutureHAUS research program, in the next issue of Phase Change Matters.

• Via LinkedIn: "Pluss Advanced Technologies Pvt. Ltd. is hashtag#Expanding its hashtag#Research team for hashtag#PCM Business. Chemistry Graduates with 0-2 years of experience preferred. However, others will be considered too. Usual job descriptions apply! Want to understand more about the opportunity? Please write to Ruchika Garg at Hurry! The vacancies are limited."

• U.S. and German researchers who have studied a PCM alloy made from germanium, antimony and tellurium say liquid water and liquid PCMs may have the same underlying physics. "The experiments reveal that the so-called Stokes-Einstein relation, which connects the viscosity of a liquid to the diffusion coefficient of its molecules, appears to break down above the melting point of the material and at very low viscosities – just as in water," Physics World reports. "The result will be important when making phase-change memories from GeSbTe alloys and related PCMs in the future."

CleanTechnica's Tina Casey takes a deep dive into the U.S. Department of Energy's efforts to develop next-generation, long-duration energy storage systems. Her conclusion: "The new R&D program practically guarantees that the hurt will continue for coal miners, their families and their communities long after Trump leaves office."  

kW Engineering of Oakland, Calif., offers tips on how to use a famously complex energy modeling program: "Best Practices for Successful Building Energy Modeling with EnergyPlus." 

Research roundup: Dynamic building envelope; multilayer glazing facades; spherical capsule with pin-fins; more

Ben Welter - Wednesday, December 05, 2018

From Applied Energy:

Form-stable and thermally induced flexible composite phase change material for thermal energy storage and thermal management applications
Influence of the storage period between charge and discharge in a latent heat thermal energy storage system working under partial load operating conditions
Dynamic building envelope with PCM for cooling purposes – Proof of concept

From Air Force Research Laboratory:

High Energy Advanced Thermal Storage (HEATS) [pdf]

From Solar Energy:

Synthesis and characterization of sensible thermal heat storage mixture containing phosphate compound of cobalt and sodium
Thermal performance of non-ventilated multilayer glazing facades filled with phase change material

From Applied Thermal Engineering:

Charging nanoparticle enhanced bio-based PCM in open cell metallic foams: An experimental investigation
Thermal performance analysis and optimization of a spherical PCM capsule with pin-fins for cold storage
A phase change material with enhanced thermal conductivity and secondary heat dissipation capability by introducing a binary thermal conductive skeleton for battery thermal management

From Materials:

Characterization of MgCl2·6H2O-Based Eutectic/Expanded Perlite Composite Phase Change Material with Low Thermal Conductivity

From Solar Energy Materials and Solar Cells:

Size controlled lauric acid/silicon dioxide nanocapsules for thermal energy storage

From Energy Procedia:

Life Cycle Assessment of thermal energy storage materials and components

From MATEC Web of Conferences:

A Numerical Method for Analysing Heat Conduction in Composites Containing Encapsulated Phase Change Materials [pdf]

From Journal of Building Engineering: