StarNest Solar Autonomy Calculator

Solar, storage, recovery, and load-priority planning for remote observatories

STARNEST LABS · CONCEPT MODEL

BETAPlanning estimate only. Compare configurations and explore uncertainty, but validate the final battery, solar, MPPT, wiring, protection and thermal design with measured equipment and site data before procurement or installation.

Locked battery capacity

— Ah

— kWh nominal · — kWh usable · assumes —% poor-day solar

Adjust battery sizing

Locked solar capacity

— W

— W energy-neutral minimum · — kWh/day expected after system losses

Full reserve-to-full recovery in — days: — W

Adjust solar sizing

Design basis

Manual location—

4.50 PSH/dayselected month

— Wh/daynormal operation

— dayspoor-solar autonomy

1 · Location and monthly solar resource

City or postal code

Matching locations

Latitude

Longitude

Sizing basis

Scenario month

Solar irradiation / peak-sun-hourskWh/m²/day

Lock manual solar value

Default planning value. Select a location and load monthly climatology.

2 · Operating loads

StarNest core averageW

Telescope averageW

Imaging session/nighth

Dew shields / accessoriesW

Dew duty during imaging%

Thermal system when activeW

Day thermal duty%

Night thermal duty%

Thermal load represents one active heating, cooling, or dehumidification load—not simultaneous heating and cooling.

Connectivity

Online averageW

Cold-boot power assumptionW

Cold-boot/acquisition timemin

Low-SOC connection windowmin

Low-SOC connection intervalhours

Self-protect loadW

Close/secure energy reserveWh

Load conversion efficiency%

3 · Storage and solar design

Battery nominal voltageV

Required poor-weather autonomydays

Poor-day solar generation% avg.

Protected reserve SOC%

Battery discharge efficiency%

Battery age/temp margin%

PV/MPPT/wiring yield%

Solar design margin%

MPPT maximum output currentA

Battery maximum charge rateC

Lowest expected battery temperature°F

Heated battery or verified low-temperature charge protection

Solar sizing target

Full-recovery targetdays

Battery is the sizing driver. Move either slider; the other capacity will update automatically.

Starting battery SOC%

Repeating weekly solar pattern

4 · Load-shedding policy

Begin Starlink scheduled cycling% SOC

Suspend thermal management% SOC

Resume thermal management% SOC

End session and safe-close% SOC

Battery self-protect% SOC

Permit next imaging session% SOC

At 25%, the model stops imaging and closes. Continuing an image session after physical closure is not modeled. Thresholds use hysteresis to avoid rapid cycling.

30-day battery state of charge

Left axis: SOC · right axis: remaining battery capacity in Ah · hourly energy model with 720 calculations

Installed systemRecommended system

Installed minimum SOC—

Recommended minimum SOC—

Completed imaging nights—

Installed period balance—

Installed average solar harvest—

Suggested MPPT output—

Installed ending SOC—

Long-term behavior—

Monte Carlo reliability simulation

1,000 randomized trials · correlated weather averaging two poor-solar days per week · planning model

P10–P90 rangeP50 median

Number of trials

Monthly solar uncertainty% σ

General load uncertainty% σ

Thermal-duty uncertainty% σ

Usable-battery uncertainty% σ

Starlink boot uncertainty% σ

Reproducible sample seed

The simulation will update automatically after calculator inputs change.

Run the simulation to calculate probabilistic reliability.

How to read this: each percentage is the share of randomized simulation periods with that outcome—not the percentage of nights completed. “Low / typical / high” shows the P10 / P50 / P90 range.

Chance of a perfect period—

Chance of meeting the 80% target—

Average nights completed—

Chance of at least one safe-close—

Chance battery reaches self-protect—

Chance full charge is maintained or regained—

Ending SOC · low / typical / high—

Lowest SOC · low / typical / high—

Completed nights · low / typical / high—

Typical full-recovery time—

Monte Carlo assumptions and metric definitions

Chance of a perfect period is the share of trials that complete every scheduled imaging night; one interrupted night makes that trial imperfect. Chance of meeting the 80% target is the share of trials that complete at least 80% of scheduled nights and is usually the more useful availability measure. Safe-close and self-protect percentages show whether the event occurred at least once anywhere in the selected period, so a trial may have a safe-close and still meet the 80% target. Poor weather occurs at a long-run average of two days per week and is clustered so multi-day cloudy periods can occur. The model still schedules imaging every night, including poor-weather nights, so this is conservative compared with an observatory that skips unusable cloudy nights. Each trial varies monthly solar resource, daily weather, general electrical loads, thermal duty, usable battery capacity and Starlink boot energy. The NASA monthly value remains the expected monthly mean; weather variability is centered around that mean to avoid double-counting cloudy-day losses. Percentages marked σ are one-standard-deviation planning uncertainties. Results are planning estimates until calibrated with site and prototype measurements.

Year-round sizing comparison

Orange: solar required for the selected battery · red: battery required for the selected solar array

Load NASA monthly data to compare all 12 months.

Month	Solar resource	Solar needed	Battery needed
Monthly data not loaded.

Engineering checks

30-day energy summary

Period	Solar factor	Solar generated	Load consumed	End SOC	Lowest SOC	Operating result

Power-management sequence

Battery trigger	Connectivity	Thermal management	Telescope / enclosure

Thermal management uses separate suspend and resume thresholds to prevent rapid cycling. Field testing must determine when temperature or humidity protection should override energy-priority shedding.

Variables requiring field validation

Measure Starlink cold-boot energy and reconnection time; telescope and DRACO operating draw; thermal duty as a function of enclosure insulation, sun, ambient temperature and humidity; dehumidifier condensate behavior; dew-heater duty; enclosure close energy and retry allowance; MPPT, conversion and cable losses; solar shading, panel temperature and soiling; LiFePO₄ temperature/aging derating; parasitic standby loads; and the required cloudy-weather autonomy.

Calculation basis and limitations

Battery sizing covers the net energy deficit during the selected number of poor-weather days, using the adjustable poor-day solar fraction rather than assuming zero generation. It also includes closure reserve, protected SOC, discharge efficiency and age/temperature margin. The primary solar recommendation replaces one normal day of energy during the selected month and then applies the solar design margin. It does not force immediate recovery of the entire autonomy battery; recovery may occur over several better-solar days. The optional fast-recovery value is reported separately. Full-year mode applies all 12 NASA monthly solar values across a 365-day non-leap-year calendar. NASA POWER monthly all-sky surface shortwave irradiance is treated as equivalent peak-sun-hours before PV-system yield and design margin. Solar charging is routed through a separate MPPT/charger path and is not part of the StarNest 300 W load-side PDU. MPPT current, battery charge acceptance, low-temperature charging, wiring, fusing, panel orientation, snow and shading require final hardware and site verification. This is a planning model, not a final electrical design.

Reference sources

NASA POWER Climatology API · Open-Meteo Geocoding API · Starlink power specifications. Starlink cold-boot power and acquisition time remain editable engineering assumptions pending direct measurement.