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Chun-Lin Lai

01, Profile

Chun-Lin Lai, Software Engineer & Energy Market Analyst

Building the software layer between battery assets and Japan's power markets.

00:0012:0024:00

One trading day · 48 × 30-minute intervals, Tokyo, Japan

02, Focus

Three areas of focus

  1. 01

    Japan Power Markets

    Analysis of spot and intraday prices on the Japan Electric Power Exchange (JEPX) and of products in the EPRX balancing market (需給調整市場). That analysis feeds forecasting, bidding, and decision-support workflows, so market rules are applied the same way every day instead of being re-read case by case.

    JEPX spot/intraday · EPRX products · Forecasting · Bidding workflows · Decision support

  2. 02

    Battery Storage & Energy Systems

    Dispatch logic for battery energy storage systems (BESS), and integration with the energy management system (EMS), power conditioning system (PCS), and battery management system (BMS) on site. The work also covers telemetry, operational constraints, and the site workflows that keep schedules realistic.

    Battery dispatch · EMS/PCS/BMS integration · Telemetry · Operational constraints · Site workflows

  3. 03

    Software Engineering

    Backend services and data pipelines in Python, Django, and FastAPI on PostgreSQL, Docker, and AWS. APIs and analytical systems are built so that other engineers can maintain and extend them.

    Python/Django/FastAPI · PostgreSQL · Docker/AWS · Data pipelines · API design

03, Selected Work

Three systems between the market and the battery

Case studies from recent work on battery storage in Japan's power markets: a market operations platform, a balancing-market price analysis tool, and a revenue monitoring and photovoltaic (PV) forecasting platform. Each describes the problem, the approach, and my part in it; company names and periods are intentionally omitted.

Case 01

Japan BESS Market Operations Platform

An Aggregation Coordinator (AC) platform that connects JEPX and EPRX market processes with battery sites through EMS integration, from bid suggestion to performance reporting.

Role
Backend development and analytical logic design
Technologies
  • Python
  • · Django
  • · PostgreSQL
  • · REST APIs
  • · Docker
  • · AWS
  • · EMS/PCS/BMS integration and telemetry
  1. JEPX/EPRX markets
  2. AC platform
  3. Site EMS
  4. PCS/BMS
Information flow from the markets, through the AC platform and the site EMS, down to the PCS and BMS.

Context

Battery energy storage in Japan earns revenue across several markets at once: spot and intraday trading on JEPX, and balancing products in the EPRX market. The Aggregation Coordinator that operates the batteries has to hold market rules, bid deadlines, settlement intervals, and on-site constraints in one place, and act on them every day. This platform was built to be that place for the operations and market teams.

Approach

I developed the backend and the analytical logic behind bid suggestion, bid-result review, charge/discharge scheduling, and performance reporting for JEPX and EPRX. A large part of the work was translating market rules and operational constraints — state of charge, power limits, availability — into explicit system logic that the team could inspect and challenge. The platform connects to battery sites through the EMS and, below it, the PCS and BMS, so telemetry and schedules travel through the same system as the market data. The user interface is bilingual (JA/EN), so Japanese- and English-speaking staff work from the same screens.

Scope

  • Operations dashboard for market and site status
  • Bid suggestion and decision support for JEPX and EPRX
  • Bid-result review for JEPX and EPRX
  • Charge/discharge schedule pages
  • Performance reports
  • Bilingual (JA/EN) user interface

Outcome

Bids, results, schedules, and performance are visible in one system for the JEPX and EPRX markets. Because market rules and site constraints are encoded in system logic rather than held by individuals, the daily cycle from bid to schedule to review can be repeated consistently from one day to the next.

Case 02

EPRX Market Price Analysis Tool

A data pipeline and analysis tool for balancing-market prices by product and time block, built to support bidding decisions and give the team a reproducible view of how each product has been priced.

Role
Data pipeline and analysis logic design and development
Technologies
  • Python
  • · pandas
  • · SQL
  • · PostgreSQL
  • · Time-series analysis
  • · Reporting
0003060912151821
The market day in forty-eight 30-minute intervals; the tool aggregates published prices per product across these intervals and the blocks they form.48 × 30-min intervals3-hour blocksHighlighted block

Context

Prices in the EPRX balancing market differ from one product to the next and across the time blocks of the day, and bidding decisions need them at a finer grain than is practical to read from each publication by hand. Teams preparing bids need a consistent, repeatable view of that price behavior, produced the same way each time.

Approach

I designed and developed the data pipeline that collects and normalizes published price data and the analysis layer that aggregates prices by product and time block; the reporting views for the people who prepare bids are built on that layer. The pipeline keeps source data and transformations separate so results can be re-run and checked.

Scope

  • Data pipeline for published balancing-market price data
  • Aggregation by product and time block
  • Analysis views to support bidding decisions
  • Reporting for market understanding and review

Outcome

Bidding discussions can start from a shared picture of recent price behavior. The resulting dataset also serves as a reference for revisiting assumptions when products or market rules change.

Case 03

BESS Revenue Monitoring and PV Forecasting Platform

Revenue monitoring across battery sites, combined with PV generation forecasting and JEPX price forecasting for dispatch and decision support.

Role
Backend and forecasting workflow development
Technologies
  • Python
  • · FastAPI
  • · PostgreSQL
  • · pandas
  • · Time-series forecasting
  • · Docker
  • · AWS
00:0012:0024:00
Illustrative daily curves: PV generation and the JEPX price shape the charge and discharge windows across the day.JEPX pricePV generationChargeDischarge

Context

Battery revenue depends on dispatch decisions made against prices that are not yet known, and PV generation is one of the main drivers of the daytime price shape on JEPX. The platform brings together realized revenue by site and the forecasts — PV generation and JEPX prices — that feed the next day's dispatch.

Approach

I developed the backend that ingests and stores revenue, price, and generation data per site, together with the forecasting workflows for PV generation and JEPX prices. I also set up routine comparison of forecasts against actuals so that accuracy can be tracked over time. Forecast outputs are served from the same backend rather than kept in notebooks, so dispatch planning and reporting work from the same figures.

Scope

  • Revenue monitoring across battery sites
  • PV generation forecasting workflow
  • JEPX price forecasting workflow
  • Forecast evaluation against actuals
  • Forecast inputs to daily dispatch planning

Outcome

Revenue by site sits alongside the current forecasts, and forecast accuracy is checked against actual outcomes as part of normal operations. That checking, more than any single model, is what makes the forecasts usable for dispatch decisions.

04, Experience

Roles to date

  1. Nov 2025 – Present

    Lehman Holdings

    Software Engineer & Energy Market Analyst

    Software engineering and market analysis for battery storage operations in Japan's power markets.

    • Develop backend systems and data pipelines for battery storage operations.
    • Analyze JEPX and EPRX market data to support bidding and dispatch decisions.
    • Work with operations and market teams on requirements, in Japanese and English.
  2. Feb 2025 – Sep 2025

    Recharge Power

    Senior Backend Engineer

    Backend design and development across services and data pipelines.

    • Designed and developed backend services and REST APIs in Python (Django, FastAPI) on PostgreSQL.
    • Built and maintained data pipelines and analytical features, and supported deployment on Docker and AWS.
    • Reviewed code and coordinated technical work with other engineers.
  3. Sep 2023 – Jan 2025

    Recharge Power

    Backend Engineer

    Backend engineering on services and data pipelines.

    • Developed backend features and REST APIs in Python on PostgreSQL.
    • Implemented data pipelines and reporting features.
    • Set up Docker-based development environments and a CI-friendly project structure.
  4. Feb 2023 – Sep 2023

    The News Lens

    Data Analyst Intern

    Data analysis internship supporting internal teams.

    • Wrote SQL and Python analyses for internal teams.
    • Prepared recurring reports and kept the underlying analysis reproducible.

Additional

  • Earlier library internship, before moving into software and data work.

05, Capabilities

Tools and domains, grouped by use

  • Python
  • Django
  • FastAPI
  • PostgreSQL
  • REST APIs
  • Docker and AWS
  • CI-friendly project structure
  • Data pipelines
  • Time-series analysis
  • Forecasting workflows
  • Reporting
  • Analysis in pandas and SQL
  • JEPX spot and intraday markets
  • EPRX balancing-market products
  • 30-minute settlement intervals
  • Bidding workflows
  • Market rule interpretation
  • Battery dispatch scheduling
  • EMS/PCS/BMS integration
  • Telemetry ingestion
  • Operational constraints (state of charge, power limits, availability)
  • Working with operations and market teams
  • Turning requirements into system logic
  • Bilingual (JA/EN) documentation and communication
  • Taiwan–Japan cross-border collaboration

06, Background

Education and languages

Education

National Taiwan University

BA, Library and Information Science

Languages

Japanese
JLPT N2 — professional written communication and everyday workplace conversation
English
Professional working proficiency
Mandarin Chinese
Native (Taiwan)

Work experience in both Taiwan and Japan, including bilingual (JA/EN) documentation and cross-border collaboration.

07, Contact

Get in touch

For roles, projects, or conversations about software for Japan's power markets and battery storage, the easiest way to reach me is LinkedIn. Messages in English, Japanese, or Mandarin are welcome.

Tokyo, Japan