Compare the fryer you have with a replacement, using your own figures where you have them and typical values where you don't. Running costs are priced from official UK business energy prices, and the environmental case is set out alongside the financial one.
Applies to both the existing and replacement fryer.
A busy chip shop fryer may cook 70–110 kg a day; a staff canteen fryer often under 25 kg.
Written from the figures above, ready to paste into a purchase request or sustainability report.
Carbon uses UK Government greenhouse gas conversion factors (2026 set): electricity 0.13096 kg CO₂e/kWh, natural gas 0.18231 kg CO₂e/kWh (gross CV). Household comparisons use DESNZ typical consumption of 11,200 kWh gas and 3,400 kWh electricity a year.
Average prices paid by UK non-domestic consumers, all size bands, including Climate Change Levy, from DESNZ Quarterly Energy Prices (tables 3.4.1–3.4.2). Some early periods were published excluding the levy; for those the main CCL rate has been added and the row says so. Edit any value, or overwrite the latest row with your own tariff.
| Period | Electricity (p/kWh) | Gas (p/kWh) | Basis |
|---|
The organising idea is that every piece of equipment, whatever it is, resolves to the same thing: a yearly quantity of each fuel or consumable it uses. A fryer uses kWh of gas or electricity plus litres of oil; a dishwasher uses kWh plus water and chemicals; a compressor uses kWh. Once everything is expressed that way, a single pricing, carbon and payback engine works for all categories, and a uniform comparison view follows naturally.
What differs between categories is only how that yearly quantity is calculated. So the category-specific parts are kept as data (attribute definitions and a named energy model) rather than as separate tables per product type. Adding a new category means defining its attributes, its usage inputs and its calculation, with no change to the schema.
erDiagram
CATEGORY ||--o{ ATTRIBUTE_DEF : "defines"
CATEGORY ||--o{ USAGE_INPUT_DEF : "asks for"
CATEGORY ||--|| ENERGY_MODEL : "calculated by"
CATEGORY ||--o{ PRODUCT_MODEL : "contains"
CATEGORY ||--o{ BASELINE : "has typical units"
PRODUCT_MODEL ||--o{ ATTRIBUTE_VALUE : "has"
BASELINE ||--o{ ATTRIBUTE_VALUE : "has"
ATTRIBUTE_VALUE }o--|| SOURCE : "cited from"
ASSET }o--o| PRODUCT_MODEL : "is a known model"
ASSET }o--o| BASELINE : "or a typical unit"
ASSET ||--o| USAGE_PROFILE : "used like"
ASSET ||--o{ METER_READING : "may have"
SCENARIO }o--|| ASSET : "existing"
SCENARIO }o--|| PRODUCT_MODEL : "candidate"
SCENARIO }o--|| PRICE_ASSUMPTION : "priced with"
ENERGY_MODEL ||--o{ RESOURCE_FLOW : "outputs"
RESOURCE_FLOW }o--|| RESOURCE : "of"
RESOURCE ||--o{ PRICE_POINT : "priced by"
RESOURCE ||--o{ EMISSION_FACTOR : "emits"
PRICE_POINT }o--|| SOURCE : "from"
Category is a hierarchy (Catering › Frying › Open-pot fryer) carrying a functional unit, such as kg of food cooked, litres of chilled storage or m³ of compressed air. The functional unit is what makes a "per unit of useful work" comparison possible across very different products.
Attribute definitions list the performance figures a category needs, with unit, test standard and whether the figure is required. For fryers: cooking efficiency, idle rate, preheat energy, production capacity and oil capacity, measured under ASTM F1361. Values are stored once in a single attribute-value table, each with its source and test method, so new and old products sit side by side.
Product models are specific makes and models from registries (ETL, EPREL, ENERGY STAR, GEMS) or test reports. Baselines are "typical unit of this type and age" records, such as a conventional gas fryer from 2005–2012. Baselines answer the hardest question users face: what is my old one actually using?
Assets are the user's own equipment. An asset points either to a known model or to a baseline, and the user can override any attribute or supply metered consumption, which then takes priority over the calculation. Usage profiles hold the category's usage inputs (hours, throughput, preheats) with defaults offered per business type.
Resources are anything bought: electricity, natural gas, LPG, cooking oil, water, refrigerant. Price points are time series by region, customer size band and tax treatment; emission factors are by year. A scenario pairs an existing asset with a candidate replacement and a price assumption (a historic year, the latest price or a custom forecast), and produces annual flows, costs, carbon, payback and NPV.
{
"category": { "id": "catering.frying.open_pot", "functional_unit": "kg_food_cooked" },
"attribute_defs": [
{ "key": "cooking_efficiency", "unit": "fraction", "test": "ASTM F1361" },
{ "key": "idle_rate", "unit": "kW", "test": "ASTM F1361" },
{ "key": "preheat_energy", "unit": "kWh", "test": "ASTM F1361" },
{ "key": "production_capacity","unit": "kg/h", "test": "ASTM F1361" },
{ "key": "oil_capacity", "unit": "L" },
{ "key": "fuel", "unit": "resource_id" }
],
"usage_input_defs": ["food_kg_per_day", "hours_on", "days_per_year",
"preheats_per_day", "oil_changes_per_week", "oil_topup_l_per_day"],
"energy_model": {
"id": "fryer_fstc_v1",
"outputs": {
"fuel_kWh": "days * (food*0.368/eff + preheats*preheat + idle*max(0, hours - food/capacity - preheats*0.25))",
"cooking_oil_L": "52*oil_capacity*changes + days*topup"
}
},
"baseline": { "id": "fryer.gas.conventional.2005_2012", "fuel": "natural_gas",
"cooking_efficiency": 0.35, "idle_rate": 4.10, "preheat_energy": 4.69,
"production_capacity": 27.2, "oil_capacity": 25,
"source": "ENERGY STAR CFS calculator, conventional gas fryer" }
}
For a commercial fridge the energy model is simpler (rated kWh/day × a usage factor), the resources are electricity and occasionally refrigerant, and the functional unit is litres of storage. For a motor it is rated power × load factor × hours ÷ efficiency, and the functional unit is kW of shaft output. The pricing, carbon, payback and comparison layers are untouched. Every result also records which inputs came from the user, from a baseline or from a product test, so the tool can show how confident each answer is.
Daily fuel use follows the method used in independent fryer testing (ASTM F1361) and the ENERGY STAR commercial kitchen calculator. Energy to cook the food is the food weight × 0.368 kWh/kg, the standard figure for frozen chips, divided by the fryer's cooking efficiency. Preheat energy is added once per preheat. For the rest of the time it is switched on, the fryer idles at its idle rate; a preheat is assumed to take 15 minutes.
If you know your existing fryer's metered consumption, tick the box and enter it; that replaces the calculation for the existing fryer only. Oil use is a full change of the vat each time oil is discarded, plus daily top-ups for oil absorbed by food.
Simple payback is the net cost of replacing divided by the yearly saving. Net present value discounts the yearly saving over the expected life. Both hold prices flat at the chosen period. Carbon is reported for the energy used at the fryer only.
The UK Energy Technology List does not yet include fryers; its foodservice category covers combination and convection ovens and dishwashers. The models offered here are from the ENERGY STAR certified commercial fryers register (version 3.0 specification), which publishes independently tested cooking efficiency and idle rate. They are brands sold in the UK, but the register lists North American model numbers, so UK and CE-marked versions should be checked with the supplier. The register does not publish preheat energy or hourly capacity per model, so typical values for efficient fryers are used for those two figures.
Typical older units use the conventional-fryer assumptions in the ENERGY STAR commercial food service calculator: gas 35% efficient with a 4.1 kW idle rate, electric 75% with 1.05 kW.
Prices are averages across all non-domestic consumers. Smaller businesses usually pay more per kWh than this average and very large users less, so entering your own tariff gives a more accurate answer. Standing charges are left out because replacing a fryer does not change them. Periods published before 2023 were reported excluding Climate Change Levy; the main CCL rate for that year (electricity 0.775p, gas 0.465p in 2021–22 and 0.568p in 2022–23) has been added. Late-2022 prices reflect the government's Energy Bill Relief Scheme discounts. Early figures are as first published and may since have been revised.
Maintenance and labour for oil changes, savings on kitchen extraction and cooling, water, waste oil collection, and the carbon footprint of producing cooking oil.