Short answer: a typical food truck uses 30 to 50 gallons of fresh water per service day, generates a similar amount of grey water, and consumes 6 to 14 kWh of electricity per service hour. Sizing the tanks and the generator correctly at the build stage is what determines whether you can run a full service day without a commissary visit.
Water consumption: where it actually goes
Three uses on a food truck:
1. Hand washing. Health code typically requires hand washing with hot water for 20 seconds before food handling, after handling raw protein, and at regular intervals. A working cook line averages 6 to 12 hand washes per hour during service. That is 1 to 3 gallons per hour of hand wash water on a 2-person crew.
2. Three-compartment sink and dish washing. Wash, rinse, sanitize. A typical service runs 2 to 5 gallons per hour during cleanup. End-of-day deep clean adds another 8 to 15 gallons.
3. Food prep. Cooking water (pasta, rice), vegetable washing, blanching, deglazing. 2 to 6 gallons per hour depending on menu.
Total: 8 to 20 gallons per service hour. A 6-hour service day uses 48 to 120 gallons. Most operations land at 30 to 50 gallons per day with a typical menu.
Tank sizing
Health code in nearly every jurisdiction requires the grey water tank to be at least 15 percent larger than the fresh water tank, so the truck cannot end up dumping grey water back through the fresh fill.
Common configurations:
| Truck size and use | Fresh tank | Grey tank |
|---|---|---|
| 14ft, low-volume | 25 gal | 30 gal |
| 16ft, standard | 30 gal | 40 gal |
| 22ft, full service | 50 gal | 65 gal |
| Catering, 8-10 hr days | 60 gal | 80 gal |
The truck has to return to commissary at end of day to refill fresh and dump grey. If you need longer operating range (full-day catering, multi-day events), spec the larger tanks at the build stage. Adding tank capacity later is expensive and sometimes impossible without restructuring the floor.
Hot water
An on-demand tankless water heater is the standard on most builds. 6 gallons per minute output, gas-fired, runs off the same propane manifold as the cook line. Capacity is unlimited as long as fresh water and propane are available. A storage water heater (10 to 20 gallon) is an alternative that uses less propane but can run dry on busy services. We recommend tankless for any cook-line truck and storage for low-volume coffee/dessert operations.
Electricity consumption
The numbers are the watts you actually pull during service, multiplied by service hours. Real-world averages:
| Operation type | Avg load | 6-hr service kWh |
|---|---|---|
| Coffee/dessert van | 3-5 kW | 18-30 kWh |
| Standard food truck | 5-7 kW | 30-42 kWh |
| Full multi-cuisine truck | 8-12 kW | 48-72 kWh |
Generator fuel consumption tracks load, roughly 0.6 to 1.0 gallons per hour of gasoline at typical load. Total fuel cost for a 6-hour service: $25 to $45 on a standard truck.
Shore power vs generator
If the operating site has 30A or 50A shore power available (food truck parks, breweries with infrastructure, some event venues), plug in and shut off the generator. Saves fuel, reduces noise, extends generator life.
50A 240V shore (what most commercial sites supply) provides 12 kW continuous, which covers nearly any food truck load. 30A 120V shore provides about 3.6 kW, which is fine for a coffee or dessert truck but inadequate for a full cook line.
Refrigeration is the largest continuous load
The cook line cycles. Refrigeration runs 24/7. Even when the truck is parked at the commissary overnight, the fridges and freezers are pulling 1.5 to 2 kWh per hour. If the truck is not plugged into shore power, that comes from the generator. Operators sometimes underestimate the overnight load and end up running the generator for 8 hours when the truck is “off.”
Fix: a shore power plug at the commissary that the truck plugs into when parked. Most commissaries offer this for an extra $30-$50 a month.
What about all-electric food trucks?
Induction cooking, electric griddles, no propane. Total electrical load on a full-electric truck can hit 20-25 kW at peak, which is well beyond what a typical generator can supply continuously. All-electric trucks usually run on:
- Battery packs sized to handle a service day (200-400 kWh)
- Recharge from shore power overnight
- Some hybrid setups with a small generator for backup
All-electric is the future and we have built a few. The cost premium is currently 30-50 percent over a comparable propane truck. The math works for high-end operations, urban environments where noise/emissions matter, and operators with reliable overnight shore access.
Solar
Solar on a food truck roof can offset 1-3 kWh per day of electricity in good sun conditions. That covers maybe 10-20 minutes of generator runtime. Solar is not a substitute for a generator on a working food truck. It can offset some load and reduce fuel costs marginally, but the payback is long. Most operators we work with skip solar.
Quick reference for your build planning
Tell us your menu and your typical service hours. We will calculate:
- Water consumption per service day → fresh and grey tank sizing
- Electrical load profile → generator sizing
- Propane consumption → tank count and size
Get all three right at the design stage and the truck operates without surprises. Get one wrong and you are dumping mid-shift, tripping breakers, or running out of fuel. Get a free quote or call 719-722-2537.
Related: complete guide to starting a food truck business.
Ready to build your truck?
We design and build custom food trucks and trailers compliant with the regulations on this page. From a single phone call to keys-in-hand in 6 to 8 weeks for most builds.
Built in Woodland Park, Colorado. Delivered to operators in CO, AZ, NE, MT, and WY.