How to Use the Simulator
Use this Generator & Battery Comparison Simulator to model your site on a single 24-hour load profile, then compare two configurations side by side—for example your current / initial site versus an alternative with a BESS (battery), different generator size, or solar. It estimates fuel use, cost, CO₂, and recommended generator prime kW (rounded to the nearest 5 kW) for off-grid setups, or grid savings when on-grid.
Before you start
Open the simulator from the button below. Expand How to use this calculator at the top of the tool for a short checklist. Work through the sections in order: load profile, current site, comparison site, then fuel/grid and location. When ready, click Compare site configurations.
Step 1: Site load profile (24 hours)
Low / High load (kW) – Set typical minimum and maximum site demand (whole numbers).
Profile buttons – Choose a preset to fill all 24 hours: Flat profile, Site (Day Shift), Domestic (Evening Peak), Just 24/7 Site, or Construction (day shift). Orange = selected.
Hourly kW (00:00–23:00) – Enter average load in kW for each hour. You can edit any hour manually after applying a profile. The same profile is used for both site configurations.
Step 2: Current / initial site set up
Off grid / On grid – Select application type (orange button). Off grid: generator and optional battery/solar; results in litres of fuel and cost. On grid: grid supply and optional battery/solar; generator is not used; results in grid kWh and cost.
Equipment on site – Turn Generator, Battery, and Solar on or off (orange = included). On-grid shows Grid supply instead of generator. Only enabled equipment shows sizing fields below.
In Current / Initial Equipment on Site, enter generator prime kW, solar kW, and/or battery kW, kWh, and catalog size where applicable. With generator and battery, set hybrid control (strategy, charge limits, SOC, start/stop load). Input current limit (A) defaults from generator size; Max charge rate (kW) updates from battery kW (Victron tiers).
Step 3: Comparison site set up
Repeat the same choices for the comparison scenario—for example generator + battery on a site that today is generator-only. Use Comparison Site Set Up and Comparison Equipment on Site with the same button style as Step 2. This is the “what if” configuration you want to evaluate against your current site.
Step 4: Fuel, grid price & location
Fuel & Emissions (off-grid) – Diesel cost ($/L), CO₂ per litre (default diesel), and optional fuel consumption at 75% PRP (L/h) to refine fuel estimates.
Grid price (on-grid) – Energy rate in c/kWh; updates with selected city where applicable.
Location & season – City (Perth, Sydney, Melbourne, etc.) and season for solar yield on both sites. Applies to any solar size you enter.
Step 5: Compare and read results
Click Compare site configurations. The page scrolls to Site configuration comparison with two columns: Current / initial site and Comparison site—daily / weekly / monthly / yearly usage and cost (L/day off-grid or kWh on-grid). A green banner may show estimated annual CO₂ saving when fuel drops.
If the comparison setup does not match recommended sizing, Recommended equipment (comparison site) suggests Generator (prime) kW and BESS kW / kWh. Use Apply recommendations & recalculate to copy those values into the comparison fields and run again.
Request a Quote opens your email client with a summary for info@ozwidepower.com.au (recommended sizes and comparison figures).
Detailed Results (when shown) include recommended generator prime kW with and without battery, fuel or grid savings with battery, best battery for the load profile, solar sensitivity, and an hourly chart. Use Print results to save or print via your browser.
Important notes
Load is entered in kW per hour; fuel results are in litres per day (scaled to week/month/year). Generator recommendations are prime kW rounded up to the nearest 5 kW, sized for peak demand and generator + battery output—not a specific stock model. Off-grid: generator kW plus battery output kW must cover peak net load (load minus solar). This tool provides estimates for comparison and planning; confirm final equipment with supplier data and detailed design before purchase.
How to use this calculator
- Load profile — Enter kW for each hour (or set low/high and choose a profile to fill all 24 hours).
- Current / initial site — Set off-grid or on-grid, tick equipment on site, and enter sizes (generator, solar, battery, grid as needed).
- Comparison site — Configure the alternative setup you want to compare (e.g. add a battery or change generator size).
- Fuel, grid & location — Add diesel cost and emissions if off-grid; set city and season for solar yield.
- Compare site configurations — Runs both setups on the same load profile and shows usage, cost, CO₂, and recommended prime kW (nearest 5 kW) where applicable.
- Recommendations — If your comparison setup differs from suggested generator or BESS sizes, apply them and recalculate, or use Request a Quote to email your results.
Current / Initial Site Set Up
Choose application type, then select equipment on site. Relevant fields appear below. Turn options on to see "if fitted" savings.
Current / Initial Equipment on Site
Comparison Site Set Up
Choose application type, then select equipment on the comparison site.
Comparison Equipment on Site
Generator Control (BESS)
Variable load calculation; generator start/stop based on BESS state of charge and load.
Start:
Stop:
Fuel & Emissions
Default CO₂ is 2.68 kg/L (typical diesel). If you know your generator's fuel at 75% PRP (L/h), enter it above to override the default 0.28 L/kWh at 75% load.