Help & Support

🚀 Getting Started

1. 1Dashboard — Start here for a summary of average electricity rates and estimated solar savings across all providers.
2. 2Providers — Browse and sort the full pricing table. Filter by plan type (Standard, EV, Time-of-Use) to narrow down your options.
3. 3Calculator — Select a provider and enter your monthly electricity usage and desired solar system size to see personalised savings estimates.
4. 4Upload — Keep the data fresh by uploading a CSV with the latest provider rates, or reset back to the built-in defaults at any time.

❓ Frequently Asked Questions

🔬 How the Solar Model Works

Frontier Solar offers two simulation modes. Both estimate the same quantities — generation, self-consumption, export, import, and bill impact — but trade off speed against fidelity differently.

1. Monthly model (default)

The default calculator works in twelve monthly buckets. For each month it computes:

• Generation= system size × the month's kWh-per-installed-kW figure (from NIWA-style irradiance data for the selected location) × a user-tunable PV-derate factor (soiling, shading, ageing).
• Consumption = your stated annual mean × a renormalised seasonal multiplier (higher in winter, lower in summer; the array sums to 1.0 so your annual total is preserved).
• Self-consumption fraction (SCF)— the share of generation used on-site rather than exported — is read from a piecewise-linear curve calibrated to Luthander et al. (2015), keyed on the monthly generation-to-consumption ratio. SCF is high when generation is small relative to load (everything you make is used immediately) and low when generation greatly exceeds load (most of the surplus must be exported).
• Battery contributionstores daytime surplus and discharges it into the evening load. The captured energy is bounded by three things at once: (a) the available daily surplus, (b) the battery's usable kWh (one cycle per day), and (c) the evening load remaining after direct solar use. Round-trip efficiency (default 90 %) means storing S kWh of surplus delivers only S × 0.9 kWh back to the load.
• Imports and exports are then derived: anything consumed not covered by direct solar or battery is imported; anything generated not consumed and not stored is exported (subject to the inverter export limit and any export-curtailment factor).
• Bill = imports × weighted import rate − exports × weighted export rate + daily charges. Weighted rates use a 15 % peak / 60 % off-peak / 25 % night consumption split, and a 70 / 25 / 5 split for export.

2. Hourly model (advanced)

The advanced calculator pulls a full year of historical hourly tilted-irradiance data from Open-Meteo for your location, and steps through all 8,760 hours. Each hour it computes generation, applies a typical NZ residential weekday/weekend load profile, dispatches the battery (charge from surplus, discharge to deficit), classifies the hour as peak/off-peak/night for billing, and accumulates monthly totals. This captures real day-to-day weather variability and time-of-use price effects that the monthly model can only approximate.

What the monthly model does not capture

Working in monthly averages hides several effects that we approximate with three correction terms in the SCF function:

• Round-trip battery losses— applied as a 0.9 multiplier to energy delivered from the battery, so a 10 kWh stored surplus offsets only ~9 kWh of evening import.
• Daily-variance penalty— a monthly mean ratio near 1.0 (typical of April/September shoulder months) hides large day-to-day generation swings. On overcast days the battery never fills (forces import); on sunny days it overflows (forces export). Both are invisible to a monthly mean, so we apply a Gaussian penalty (peak ~25 % around ratio = 1, fading away in deep summer or deep winter) to the battery's effective contribution.
• Instantaneous-mismatch floor — even with a generously sized battery, sub-hourly load spikes (oven, kettle, EV ramp), inverter / BMS standby draw, and battery power-rating limits mean a few percent of consumption (default 5 %) always comes from the grid. The model caps daily self-consumption at 95 % of daily load.

Other simplifications still present in both models include: a constant inverter performance ratio (no low-light penalty), no battery max-power (kW) rating, no parasitic standby loads modelled explicitly, and — in the hourly model — the use of one historical weather year applied to all years of the payback projection. Always treat the figures as indicative.

Cost & payback

System cost defaults to NZ$2/W installed (configurable). Battery cost is added on top when a battery is included. Payback = system cost ÷ annual savings, with no discount rate, no degradation, and no future tariff escalation applied — these would all change the long-run picture but are deliberately excluded to keep the headline figure transparent.

📄 CSV Upload Guide

To update provider pricing, upload a CSV file with the following columns (header row required):

Download the template CSV from the Upload page to get started quickly.

⚠️ Disclaimer

All estimates are indicative only and should not be taken as financial or energy advice. Always verify current rates directly with your electricity provider before making any decisions.