BUILD · EXPERIMENT · DISCOVER
Small town.
Big energy ideas.
Build your own renewable energy city. Can you keep the island’s lights on after sunset?
Make it.
Store it.
Make it work.
What happens to solar power after sunset?
Six solar arrays are ready at 08:00, after sunrise. The town needs electricity after dark too. Predict what will happen, then test it.
Pick a prediction, then select “Run to results” or watch the day unfold.
Progress stays on this device when local saving is available.
Your clean-energy community
YOUR EXPERIMENT
What happened?
See the energy ledger
Generated energy + initial stored energy = delivered AC energy + unused energy + conversion/storage losses + final stored energy.
FOLLOW THE ENERGY
A day tells the whole story.
kW is power right now.
kWh is energy over time.
Run an experiment to see generation, demand, and battery energy.
Timeline data table
| Interval end | Made kW | Needed kW | Served kW | Battery kWh | Unmet kW |
|---|
Your next discovery
Keep your experiment
Designs and badges stay on this device. No account or tracking.
Model assumptions
First Lights starts with empty batteries; other missions start 50% full. This is a toy off-grid community, not a municipal grid or equipment sizing tool. Solar uses a fixed 06:00–18:00 sine curve. Wind uses cut-in/rated/cut-out limits. A shared DC bus supplies a 95%-efficient, 4 kW AC converter. Battery charge/discharge are each 95% efficient.
Houses and school are divisible aggregate demands. The midday pump needs its full 0.4 kW for a five-minute interval. There are no wiring, motor-surge, temperature, aging, or location-dependent shading models. Plot positions do not change output.
The tutorial begins at 08:00; other missions begin at 06:00. Mission success: ≥99% total energy, ≥99.9% critical energy, zero significant critical-shortage intervals, within budget. Sandbox has no win condition.
Power your town in three steps
- Build. Select a numbered plot and add solar, wind, or batteries. Four homes and a school are already here.
- Experiment. Run a day. Watch storage fill, the sun set, and buildings show their service status. Use “Run to results” for a quick experiment.
- Investigate. Read the timeline, change one thing, and run again. Your previous completed run stays available for comparison.
Sunny missions: solar factor 100%; wind 6 m/s in First Lights, 3 m/s in Through the Night. Cloudy mission: solar 35% then 20%; wind 8 m/s by day, 3 m/s 18:00–22:00, 10 m/s overnight. All times are a fixed scenario clock, independent of your device time zone.
Investigate related power and battery mysteries in Energy Detective →
How this simulation works — equations, units, limitations and privacy