Simulate
Pick a place and a start date. Run plays it as a time-lapse from midnight: the sun crosses the sky over the model and the dashboard shows the batteries filling and draining. It carries the charge over each midnight and keeps going until you press Stop or the batteries run out.
The weather service didn't answer, so this run uses a clear-sky estimate with no clouds.
–kWh solar
–peak solar kW
–battery
–kWh the home used
–lowest charge
–kWh short
Solar power and home load, kW, by hour (local time)
Solar usedOver the PV limitHome load
Battery charge, %, by hour
Every home size on this day
Batteries vs. kWh short, this home and day
Batteries ran outOver the inverter's 6.2 kW
Hour by hour
How it's worked out
- Panels face due south at a 30° tilt, like the rack. Sun on the panels is Open-Meteo's tilted irradiance for that place and hour, from the ERA5 weather reanalysis.
- Hot cells make less power: −0.35% per °C above 25 °C, with cell temperature from air temperature, sun and wind.
- 8% DC losses for dirt, mismatch, wiring and ageing.
- Anything over the inverter's 6 kW PV limit is cut off. That limit is a typical value, not yet checked against the manual.
- The charger puts 95% of the solar power into the batteries, which hold 10.24 kWh and stop at full.
- Each battery's built-in BMS is taken as 100 A continuous, in or out, which is typical for this class of battery (the POERUNI listing doesn't give it). At 51.2 V that is 5.1 kW per battery, so from two batteries up the inverter's 6 kW PV input and 6.2 kW output are always the tighter limits and the battery current never holds anything back.
- Home use comes from the EIA's 2020 Residential Energy Consumption Survey (RECS). It has no figures by bedrooms, so floor area stands in. A 3 bed 2 bath home uses 1,500 to 1,999 sq ft, or 11,009 kWh a year. A 4 bed 3 bath uses 2,500 to 2,999 sq ft, or 13,031 kWh. A 5+ bed uses 3,000 sq ft or more, or 15,489 kWh. The US average is 10,566 kWh (table CE2.1).
- With the state and month box ticked, that use is scaled by how that state's homes used power in that month against the US average (RECS table CE8.5.M). Arizona in July is about twice the average, for example, and California in January is about half.
- The EV adds 3,099 kWh a year, what RECS finds for EV charging in 3,000+ sq ft homes (table CE5.3a). It charges at 7.2 kW from 6 PM until full.
- The hour-by-hour shape is a typical pattern, not measured data: low overnight, a morning bump, an evening peak, and a later afternoon peak in summer when the air conditioning runs. Use is averaged over each hour, so short spikes like a compressor starting aren't shown.
- Solar covers the load first and the batteries cover the rest, with 92% inverter efficiency. The inverter puts out at most 6.2 kW, the rating in the video title (the listing you sent says 10 kW). It drops the load at 10% charge to protect the batteries. Anything over 6.2 kW, or anything after the cutoff, counts as short.
- The day runs midnight to midnight in local time. In the 3D view the sun's position is worked out for that place, date and minute, and clouds dim it by how far the recorded sun fell short of a clear sky.
Weather data: Open-Meteo (CC BY 4.0). City list: GeoNames.