Free tool · Solar sizing

PV + vapor-compressionDirect solar adsorption

Solar Cold-Chain & Ice Sizing Calculator

Real formulas · PV-compression + direct solar adsorption. Size the array, battery and machine for a cold room, an ice supply, or both — then see capex and payback against grid/diesel power.

What this page is for

This calculator gives a first-pass estimate of the solar array, battery and refrigeration machine for a cold room, an ice supply, or both — plus rough capex and payback against grid/diesel power or bought ice.

Every input shows its unit and an example under the field.
Results update live from the formulas printed at the bottom of the page.
It is an estimate for planning a quote — not an engineering design or a site survey.

How the estimate works Open the monitor

Numbers are indicative. Confirm equipment sizing, structural loads and electrical design with a qualified supplier before buying.

Site & load

Start from a scenario

Peak sun hours (kWh/m²/day)

Average daily sun hours at the site — it determines how much PV is needed.Example: 5.5

Ambient temp (°C)

Average high ambient temperature the equipment works in — it raises the heat load.Example: 32

Cold room

Cold room volume (m³)

Internal volume of the room; the envelope area is estimated from it.Example: 24

Setpoint (°C)

Target storage temperature the cooling system holds.Example: 2

Product in (kg/day)

Product entering the room each day; pre-cooling it adds to the load.Example: 120

Product entry temp (°C)

Temperature of the product when it arrives, before cooling to setpoint.Example: 18

Grid/diesel power ($/kWh)

What a kWh costs you today (grid tariff or diesel); used for savings and payback.Example: 0.30

Ice alternative cost ($/kg)

What buying ice costs today; it values the ice the machine makes. Use 0 if you do not buy ice.Example: 0.30

Battery autonomy (days)

Days of battery backup for cloudy weather; more autonomy means a bigger bank.Example: 1.5

Machine capex override ($, 0 = estimate)

Leave 0 to use the built-in machine cost, or enter a supplier quote in USD.Example: 0

Sizing result

Solar array needed (PV)

3.35 kWp

PV derate 0.75 · daily electric 14 kWh

Battery bank

17 kWh

storage for cloudy days

Daily electric

14 kWh/day

compressor energy per day

Cold-room heat load

575 W thermal

cooling needed at design conditions

Adsorption collector

0 m²

used when heat-driven

Economics

Est. total capex

$11,352 est.

array + battery + machine, installed

Daily saving vs alternative

$6.21 /day

vs bought ice or grid/diesel power

Payback

5.01 years

capex ÷ (daily saving × 365) · estimates only

Cumulative savings vs capex

Cumulative savings ($2.3k/yr)Capex $11kPayback 5.0 years

What each result means

Solar array (kWp): Peak DC capacity of the PV needed to run the load on an average sun day.
Battery bank (kWh): Usable storage sized from daily electric use × the autonomy days you entered.
Daily electric (kWh/day): Energy the compressor (or ice machine) uses in a typical day at these inputs.
Cold-room heat load (W thermal): Cooling power needed to hold the setpoint: envelope + product + infiltration.
Adsorption collector (m²): Collector area for the heat-driven route; it uses no compressor.
Est. total capex: Array + battery + machine, using built-in estimates unless you overrode the machine cost.
Daily saving: Cost of the alternative today (grid/diesel or bought ice) minus the estimated running cost.
Payback (years): Capex ÷ (daily saving × 365). A rough break-even time, not a financial forecast.

Result colours

Sizing output — array, battery and collector capacity
Cost or load — energy, heat load and capex
Positive saving — daily saving above zero
No saving — the alternative is cheaper at these inputs

See plans

Cold room: 36 m² envelope, transmission 274 W, product 186 W.

Myth buster

The viral “sun heat → ice” device

The viral “sun heat → ice” device: the physics is real (adsorption chillers have made ice from sun heat since 1986 at ~4.5 kg/day per m² of collector, COP 0.1–0.12), but the viral −48 °C copper-coil devices are stage props — an open coil cannot reach that claimed temperature. Real solar ice bottoms out around −10 to −15 °C. Pick “Direct solar adsorption” above to size the real machine.

Independent sizing tool — estimates only, not a substitute for a site survey.

Formulas: Q = U·A·ΔT + m·c·ΔT/86.4, ×1.25 infiltration margin; A≈6·V^⅔; U=0.25 W/m²·K (100 mm PU); COP=1.8 @ high ambient; PV derate 0.75; ice 0.45 kWh/kg (compression); adsorption 4.5 kg ice/day per m² collector (Pons & Guilleminot 1986; ISAAC field units). Estimates only — verify against site survey.

Where to go next