Live · New York, NY
Your own grid starts 93 million miles away.
Follow one beam of sunlight from the sun to your kitchen outlet.
This model runs on today’s sun path in New York (41.7° N). The trees follow the season. Power figures are a clear-sky estimate for a 20-panel, 8.8 kW array with a 13.5 kWh battery.
01 · Sunrise
8 minutes, 20 seconds
That’s how long sunlight takes to reach your roof. At midday on a clear day, about 1,000 watts of it lands on every square meter. Panels are rated under exactly that much light, which is why a 440-watt panel rarely makes a full 440 watts.
- 1,000 W/m²
- Standard test light
- ≈ 4 h
- Full-sun hours a day, Hudson Valley, year-round average
02 · Morning
Light in, DC out
Each cell is a thin slice of silicon. Light knocks electrons loose and the cell pushes them out as direct current. A 440-watt panel works at about 41 volts, and it actually makes more power on a cold, bright day than on a hot one.
- ~22%
- Of the light becomes electricity
- 8.8 kW
- This array: 20 panels on the south roof
03 · Morning
Strings, and a red button
Panels are wired in series, called strings, so their voltages add up. Ten of them make about 400 volts of DC. That’s why the code requires rapid shutdown: one switch near the meter drops the wiring leaving the roof below 30 volts within 30 seconds, so firefighters can work safely.
- Red / black
- DC positive and negative
- NEC 690.12
- Rapid shutdown
04 · Late morning
DC becomes the power your house uses
The inverter turns DC into 120/240-volt AC at 60 hertz, the split-phase power every American outlet expects. It also hunts all day for the voltage where the panels give the most power. That’s called maximum power point tracking.
- ~97%
- Of the DC comes out as AC
- Built in the US
- Enphase, Tesla, MidNite Solar
05 · Late morning
The house gets first dibs
Solar power goes to whatever is running right now: the fridge, the well pump, the heat pump out back. The average American home uses about 900 kWh a month. That’s a little over a kilowatt around the clock, with spikes at breakfast and dinner.
- 900 kWh
- A typical month (U.S. average)
- Live
- See Home in the readout
06 · Midday
The extra fills the battery
Whatever the house isn’t using charges the battery. Nearly all new home batteries use lithium iron phosphate (LFP). It’s heavier than the lithium in your phone, much harder to set on fire, and good for thousands of cycles.
- 13.5 kWh
- Covers a typical evening
- 32 °F
- Most LFP batteries won’t charge below freezing without a heater
07 · Afternoon
Battery full? You sell the rest.
Once the battery is full, the extra flows out through your meter to the street and the utility credits you for it. Most New York utilities use net metering. The transformer on the pole steps your 240 volts up to the neighborhood line.
- Both ways
- Your meter counts what you buy and what you sell
- Live
- See Grid in the readout
08 · Evening
After sunset, the battery takes over
When the panels stop, the battery runs dinner, laundry and the evening news. On a time-of-use rate, those are the hours power costs the most, so this is where a battery earns its keep.
- 4–9 PM
- Peak hours on many time-of-use rates
- 0 kWh
- Bought from the utility while the battery lasts
09 · Night
The storm takes out the line. Your lights stay on.
Most people don’t know this: an ordinary grid-tied solar system shuts off in an outage, so it can’t shock a line worker fixing the wires. A battery with a backup switch disconnects your house from the grid first, then keeps running on its own. That’s called islanding.
- Neighbors
- Dark until the line is fixed
- UL 1741
- The standard that makes inverters shut off safely
10 · Your turn
Now look around.
Drag the model to turn it. Change the hour, switch seasons or pull the grid. The numbered markers explain each part.
