Thermal energy storage and release
for carbon neutrality

With storage, heat exchange, and system integration, we build equipment that stores heat and delivers it when needed.

Our technology Get in touch
PIOST system: solar power to a sand storage module to heating, hot water and process heat
Power · Sand storage module · Heat supply

About PIOST

PIOST is a technology company that develops thermal energy storage systems. We design and analyse storage media, heaters, heat-exchange circuits, and modular systems, then build and instrument them ourselves. Stored heat goes to heating, hot water, and industrial process heat.

Established
2025.12.08
Location
Incheon, South Korea
Co-CEOs
Junbeom Song · Ilwoong Park
Research infrastructure
Dedicated R&D unit · Korean testbed

How it works

Electricity stored as heat

Renewable and grid electricity heat the storage medium. Surplus and off-peak electricity separate the time power is used from the time heat is delivered.

Heat delivered at the required temperature and flow

Stored heat reaches the user through heat-exchange circuits. We choose air or water as the medium and design the temperature, flow, and pressure conditions.

  • Storage capacity and heat loss

    We assess media, heater layouts, and insulation to evaluate temperature distribution and heat loss.

  • Release temperature and delivery conditions

    Heat-exchange methods and fluid circuits are designed around required temperatures and flow rates.

  • Repeated operation and integration

    Measurement and analysis support system validation under repeated heating, storage, and release.

Inside a sand storage module
Section view: heaters and heat-exchange pipes inside an insulated bed of sand Power input Insulation Heater · resistance heating Storage medium · sand Heat-exchange pipe Water inlet Heat output
Heaters inside the sand charge the bed. Heat-exchange pipes draw the heat out.

Applications

Distributed heating

Heat for homes, matched to local conditions.

Initial users
Individual ger homes and resorts in Mongolia
Development focus
Heating and hot water through solar power and thermal storage
Current stage
Prototype development and field trial preparation with a local partner

Industrial thermal storage

Storage material and heat delivery developed as one system.

Partners
Materials specialists and industrial heat users
Development focus
Integrated heating, heat extraction, and instrumentation for byproduct storage materials
Current stage
Proposed staged testing and system development collaboration

Entering the Mongolian heating market

Solar array in front of snow-covered hills
Demonstration site in Mongolia, PV-connected testbed

  • Individual sites first

    Our first users are individual gers and resorts. We visit the sites, consult the users, and confirm power and water conditions. Then we prepare the heating and hot-water module demonstration.

  • Building local delivery capability

    We signed an MOU with the local company YNE TULGA LLC. Procurement, distribution, and maintenance follow together. Prototype quotation requests define the demand.

  • From individual to shared heat supply

    Individual systems come first, then shared heating for ger communities and housing complexes. HaaS, a monthly heat service, is still a business model at the design stage.

Technology and products

Application-specific systems

PHM · Homes and resorts

PHM (PIOST Heating Module) supplies heating and hot water to a single home. It connects solar power with a thermal storage module and is configured to the power and water conditions at the site.

Prototype · Pilot preparation

M-TES · Communities and housing

M-TES is a shared heating model that connects several users to one heat source. TES stands for Thermal Energy Storage. The delivery configuration follows piping and water access. HaaS, a monthly heat service including operation and maintenance, is also under review.

Business model development

Industrial TES · Process heat and steam

Heating and heat extraction systems for industrial users. Collaboration with material specialists supports validation from specimens to integrated modules.

Development proposal

Technology areas

Thermal energy storage

Storage design considers the medium, heating elements, and insulation.

  • Electric resistance heating

    Multi-point thermocouples measure the temperature distribution inside the storage medium on the experimental rig.

    Measurement

  • Storage media and heater layout

    We review storage-medium composition and particle size with material specialists, and design heater placement and insulation. Direct, induction, and resistance heating are compared on the same specimen.

    Design and analysis

Thermal energy release

We design the heat-extraction circuits that draw stored heat out and deliver it to the user.

  • Heat extraction and output conditions

    A comparison rig takes an interchangeable air loop and water loop. Temperature change and heat output are measured per method to validate delivery conditions.

    Test design

  • Direct-contact heat exchange and condensation

    We develop direct-contact heat exchange and condensation-based extraction. Patent applications and circuit designs support evaluation of application conditions.

    Development and patent applications

System integration

Heating, storage, and release circuits are combined in one module and validated by measurement and operation.

  • Prototype construction and operation

    The sand-TES hot-water rig is in operation while field demonstration is prepared.

    Built and commissioned

  • Instrumentation and operating data

    Instrumentation records temperature, flow, and operating history. Charging, heat delivery, and uptime are linked to field fuel use to confirm performance and emission reductions.

    System integration

Two ways to extract heat
Concept: an air loop and a water loop swapped on the same storage bodyAirfan · air channels · hot-air supplyWaterpump · water loop · hot water and heating
Only the loop changes on the same storage body, so the two methods are compared under one condition.
Individual supply · PHM
Solar power to a thermal storage module to heating and hot water in a home Solar · grid PHM module Heating · hot water
The heating and hot-water module as installed at a home or resort.
Sand storage prototype for hot water
Prototype with a stainless storage tank and acrylic hood
Built and commissioned · August 2026 · Korean testbed

Development status and next steps

Workstream Work to date Stage Next validation
High-temperature heating Resistance-heating rig tests and multi-point temperature measurement Measured Thermal cycling, temperature distribution, durability
Heating and hot water Sand storage experimental rig built and commissioned Prototype Domestic testbed and field operation in Mongolia
By-product storage system Proposed staged tests from material samples to integrated systems Proposed Material performance, insulation, heat extraction
Heat extraction and release Air and water circuit designs; direct-contact heat-exchange patent applications Design and development Comparative extraction tests and output-condition validation

Based on October 2026 technical materials.

Our engineering foundation

  • R&D framework

    Work runs in a dedicated R&D unit and a Korean demonstration testbed. Specialist institutions handle storage and insulation materials. PIOST handles heating, heat delivery, and system integration.

  • Power and controls

    With power-operation and software partners we develop systems that link solar, electrical storage, and thermal storage. Remote operation and control are developed as well.

  • Manufacturing

    With manufacturing partners we review TES module fabrication, production methods, and productivity. The manufacturing framework takes us from test specimens to deliverable modules.

  • Related intellectual property

    The related portfolio totals 17 patents: one grant and two applications in PIOST's name, and fourteen applications in the name of Inha University's industry cooperation foundation.

Development plan and history

  1. 2026Current stage

    Prototype validation and pilot preparation

    • Korean testbed secured; overseas pilots in preparation
    • Industrial heat-extraction trials and integrated system proposal
  2. 2027Planned

    Initial supply and operating validation

    • Target: initial heating prototype deliveries
    • Field operating data and product improvements
    • Early demand from households and businesses in Mongolia
  3. 2028Planned

    Community and industrial applications

    • Shared supply for communities and public sites
    • Industrial heat and steam system development
    • Review of the monthly heat service (HaaS)
  4. 2029+Planned

    Further market development

    • Partner development in Central Asia
    • Adaptation to local heating and electricity conditions
    • Evaluation of industrial and district heating opportunities

Industrial TES development process

The development procedure in the October 2026 industrial collaboration proposal. Each stage's test results set the basis for the next design.

StageScopeDeliverable
Comparative testingCompare heating and extraction methods on the same specimen and collect repeated-operation data.Method comparison results
Heat-extraction designAnalyze heat-exchange pipe and heater placement, then refine the design for the required delivery conditions.Extraction circuit and design specifications
Scale-up and modularizationScale up the specimen, review flow paths, layout, and insulation, and carry the results into the module design.Module design and standard specifications
Integrated demonstrationOperate heating, storage, and delivery together, then validate heat loss and repeated-operation performance.Demonstration and performance-validation report

History

Based on October 2026 materials · includes the startup preparation stage.

Research and development

  • 2024
    PCM thermal storage experiment

    Pre-incorporation work covered a sand-battery invention proposal and prior-art research, then PCM-TES rig construction, experiments, and TES power-market analysis. Before incorporation

  • 2026.04
    Molten-salt storage project started

    Thermal storage circuit development with an industrial partner

  • 2026.08
    Sand storage rig for hot water

    Full-scale experimental rig built and commissioned

  • 2026
    R&D infrastructure secured

    Established a dedicated R&D unit and secured a demonstration testbed.

  • 2026
    High-temperature heating

    Resistance heating tests and multi-point thermocouple temperature distribution measurement Tests performed

  • 2026
    By-product storage system

    We submitted a process concept and staged demonstration plan for TES using industrial by-product storage media. The proposed collaboration runs from material tests to heat-extraction comparison, modularization, and integrated operation. Proposal

Selected support programs

  • 2025
    Laboratory startup program

    COMPA · business model development and experimental equipment Startup preparation

  • 2026
    Youth Startup Academy

    KOSME · Prototype development and patent applications.

  • 2026
    Youth startup incubation

    Incheon Technopark · Patent applications and prototype development support.

  • 2026
    Environmental youth startup program

    Korea Productivity Center · Commercialization consulting and mentoring.

  • 2026
    TRYOUT Investment Round

    Incheon Technopark · Pitch consulting and investor networking.

  • 2026
    KEPCO E&C startup support

    Korean Standards Association · Technology transfer and patent application support.

Commercialization and overseas partnerships

  • 2025.11
    Local partnership in Mongolia

    MOU with YNE TULGA LLC · local procurement, distribution, and maintenance

  • 2025.12
    PIOST incorporation

    8 December 2025 · thermal storage system development and commercialization

  • 2026
    Initial demand for the heating module

    PHM-A prototype quotation request received; demonstration prepared for local power and water conditions

Leadership

CEO

Junbeom Song

Drawing on doctoral research in mechanical engineering, he leads experimental planning and project operations. His responsibilities span business strategy, schedules, budgets, and deliverables.

CTO

Il Woong Park

He leads technology development, drawing on thermal engineering research and experience leading an industrial TES research project. His responsibilities include heat balances, system design, analysis, and equipment sizing.

Contact

Areas of cooperation: heat storage and delivery demonstrations, materials and manufacturing, controls, and local supply and operation. Share your site and heat delivery requirements and we will explore the scope together.

piostinc@gmail.com