Synergy Battery Feasibility Analyser

Analyse your Synergy (Western Australia) electricity usage data to determine whether a home battery is financially worthwhile.

This project was built with AI assistance — thanks Claude! I had a personal need to review my energy usage and determine whether a home battery made financial sense. The speed at which I could go from idea to a working tool that analyses, visualises, and informs that decision was fantastic. Maybe someone else will find it useful too!

Features

• Synergy API integration — Fetches 12 months of half-hourly interval data directly from Synergy's self-serve portal via email or SMS OTP authentication
• Tariff-aware analysis — Auto-detects your energy plan (EV Add On, Midday Saver, Home Plan A1) or allows fully custom tariff rates and supply charges
• Battery simulation — Models half-hourly charge/discharge cycles, charges from solar export, discharges to offset grid import, with optional grid top-up during the cheapest tariff period
• Feed-in credit accounting — Calculates DEBS feed-in credits (configurable peak/off-peak rates) and tracks lost credits when the battery captures energy that would otherwise be exported
• Offline analysis — Saves raw API responses locally so you can re-run analysis with different parameters without re-authenticating or hitting the Synergy API
• Light/dark theme — Toggleable via header button, honours system preference with flash-free page load
• CSV export — Download the full interval dataset for use in spreadsheets or other tools
• Cross-platform — Standalone binaries for Linux, macOS, and Windows with no dependencies required

Quick start

1. Download the latest release for your platform from the Releases page
2. Run the binary — your default browser will open automatically to the app

No installation or dependencies required.

How it works

1. Enter your premise address (must match your Synergy bill) and verify via email or SMS OTP
2. Select your energy plan or let it auto-detect, and configure battery capacity, date range, and feed-in rates
3. The tool fetches your half-hourly consumption and export data from Synergy (and saves it locally for future use)
4. Each interval is categorised by tariff period and a battery charge/discharge simulation is run
5. Results are presented as summary cards and six interactive charts

Charts

• Daily Usage — Stacked area chart of daily consumption broken down by tariff period (peak, off-peak, super off-peak, overnight) with solar export overlay. Includes a zoom slider for navigating the full date range.
• Cost Breakdown — Daily cost in dollars split by tariff period, showing the financial impact of each rate tier over time.
• Import vs Export — Grid import and grid export as overlaid line charts across the full analysis period, useful for spotting seasonal generation and consumption patterns.
• Battery Simulation — Per-day view with a date picker to jump to any day. Shows battery state of charge (left axis) alongside half-hourly consumption, solar export, and battery discharge bars (right axis).
• ROI — Cumulative savings curve over the analysis period. If a battery cost is provided, shows the breakeven point and estimated payback period.
• Heatmap — Hour-of-day vs date grid showing consumption intensity. Highlights usage patterns across time of day and season.

Development

Requires Python 3.14+ and uv.

# Run the dev server
uv run uvicorn synergy_analyser.main:app --host 127.0.0.1 --port 8000

# Run tests
uv run pytest -v

# Build standalone binary
uv run --group dev pyinstaller synergy-battery-analyser.spec

Data notes

• kwHalfHourlyValues from the Synergy API is in kW (power) — the tool converts to kWh by multiplying by 0.5
• kwhHalfHourlyValuesGeneration is grid export, not total solar generation — already in kWh
• Feed-in rates default to DEBS: 10 c/kWh peak (3pm–9pm), 2 c/kWh off-peak

License

This project is licensed under the Elastic License 2.0.