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Glossary · Energy industry & energy transition

Cradle-to-Gate

Cradle-to-gate life cycle assessment Carbon footprint product supply chain Embodied Carbon power system

Cradle-to-Gate denotes a system boundary in life cycle assessment. It covers the environmental impacts of a product from the extraction of raw materials up to the point at which the product leaves the manufacturer's factory gate. This typically includes mining, the extraction of biogenic or fossil raw materials, processing, intermediate products, process energy, auxiliary materials, transport to the manufacturer and the manufacturing itself. Not included are transport to the customer, installation, use, maintenance and repair, as well as dismantling, recycling and disposal. The Greenhouse Gas Protocol Product Standard (GHG Protocol Product Standard) therefore describes Cradle-to-Gate as a partial footprint. It extends from material extraction to the point at which an intermediate product leaves the reporting company's factory gate.

The German translation "von der Wiege bis zum Werkstor" (from the cradle to the factory gate) captures the delimitation well. The "cradle" is the beginning of the material chain, for example ore, sand, wood, crude oil, lithium salt, quartz for silicon or steel precursors. The "gate" is the defined exit from the production system under consideration. For a steel beam this can be delivery from the rolling mill, for a battery module the exit from the cell factory and for a solar module the end of module manufacturing. Whether packaging is already included is determined by the respective methodology. The term itself does not say.

A Cradle-to-Gate value therefore describes only a delimited section of the life cycle, not the whole product. It often appears as a Product Carbon Footprint, as a value in an environmental product declaration (EPD) or as Embodied Carbon, i.e. the "grey" greenhouse gas burden already contained in a component. Every value needs a reference unit. Examples are kilograms of CO₂ equivalent per kilogram of aluminium, per square metre of insulation material, per kilowatt hour of battery capacity or per kilowatt of inverter power. Without this unit, the number is worthless. Otherwise a heavy, durable and high-performance product would be equated with a light, short-lived one.

Classification in standards and regulatory frameworks

For greenhouse gas footprints of products, the GHG Protocol Product Standard in principle requires the entire life cycle from cradle to grave for final products. Cradle-to-Gate is permissible for intermediate products, especially when the subsequent use is not known. Use and end of life must not be included in such a partial footprint. The company must disclose and justify the chosen boundary. It must also state the carbon stored in the intermediate product.

For construction products in Europe, the EN 15804 standard forms the framework for environmental product declarations. There, Cradle-to-Gate corresponds to modules A1 to A3: raw material supply, transport to the manufacturer and manufacturing. Since the EN 15804+A2 version, construction products must in principle additionally declare the end of life (modules C1 to C4) and module D. Module D describes credits and burdens beyond the system boundary, for example through recycling. A pure A1–A3 declaration is now permitted only in justified exceptional cases. For products with biogenic carbon, such as wood products, it is excluded. Anyone reading a current construction EPD will therefore usually find more than just the Cradle-to-Gate value and should consider the modules separately.

Not every statutory CO₂ indicator is a Cradle-to-Gate value. The EU Battery Regulation (EU) 2023/1542 prescribes in Article 7 a carbon footprint declaration, namely for electric vehicle batteries, for rechargeable industrial batteries with more than 2 kWh and for light means of transport batteries (LMT batteries). This declaration covers the life cycle including end of life. Only the use phase is excluded, because the manufacturer generally does not directly influence it. The value is stated in kg CO₂ equivalent per kilowatt hour of the total energy that the battery delivers over its lifetime. It is specifically not stated per kilowatt hour of storage capacity. The obligations enter into force in stages and depend on delegated acts and implementing acts. A manufacturing value per kWh of capacity and this mandatory value are therefore not directly comparable.

Distinction from other life cycle boundaries

Cradle-to-Gate is often confused with Cradle-to-Grave. Cradle-to-Grave additionally covers distribution, use, maintenance and end of life. For many products this larger boundary is needed, because most of the impact arises only during use. A gas boiler or a combustion-engine vehicle hardly stands out in manufacturing, but causes high emissions over the years. For wind turbines, photovoltaic modules, batteries or heat pumps it is the other way round: the emissions of the upstream chain can be high, while operation is low in emissions compared with fossil alternatives.

Gate-to-Gate considers only a single production step or a single facility. This helps in assessing one's own process, but says nothing about the burdens from raw materials and intermediate products. Cradle-to-Cradle is not a mere counterpart to Cradle-to-Gate. It refers to a concept in which circularity, harmless materials and reuse are the focus. For reliable comparisons it must be clear whether a figure comes from a standard-compliant life cycle assessment, from a product declaration, from a company-level carbon footprint or from marketing material.

The classification into Scope 1, Scope 2 and Scope 3 is also not the same as Cradle-to-Gate. The scope system allocates emissions to a company. Cradle-to-Gate allocates them to a product along a system boundary. However, the two views are connected: suppliers' Cradle-to-Gate values often serve as the data basis for upstream Scope 3 emissions from purchased goods. A company can therefore have low direct emissions even though its products carry high Cradle-to-Gate values, because it buys energy-intensive intermediate products.

Relevance in the electricity system

In the electricity system, Cradle-to-Gate is important because many technologies cause their emissions not during operation but during manufacturing. A photovoltaic module emits no exhaust gases at its site. Its footprint nevertheless includes emissions from silicon production, glass, aluminium frames, plastics, cell production and transport. A wind turbine requires steel, concrete, copper, fibre composites and electronics. Batteries, transformers, cables, electrolysers and other grid components likewise contain considerable upstream material and energy inputs.

This shifts the perspective. In fossil power plants, most emissions arise during operation and in the supply of the fuel. In renewable and electric technologies, a large share is embedded in the capital goods. This does not make these technologies harmful to the climate, but it requires a different calculation. Anyone who looks only at the emissions from the chimney underestimates the upstream chains. Anyone who looks only at manufacturing values and leaves out electricity yield and lifetime attaches too much significance to a single production value.

For electricity generation, the emission per kilowatt hour generated over the lifetime is therefore usually decisive. A solar module with higher manufacturing effort can perform better if it lasts longer, delivers more yield or operates under good irradiation. A battery with a high manufacturing footprint can make sense if it is cycled frequently, displaces fossil peak load or eases grid bottlenecks. This assessment cannot be derived from Cradle-to-Gate alone. It requires assumptions about the technical lifetime, use, efficiency, load profile and the processes replaced.

Electricity mix, allocation and data quality

An important driver of Cradle-to-Gate values is the electricity mix at the production site. Aluminium, solar-grade silicon, battery cells, hydrogen derivatives and many chemical intermediate products react strongly to the emission intensity of the energy used. The same product can have very different manufacturing values, depending on whether it is made with coal-heavy electricity, with natural gas or with renewable electricity and corresponding process heat. This is also one reason why the Battery Regulation requires information on the location of the plant.

This precision has limits. Life cycle data are often based on averages, databases, industry data or model assumptions. If a process yields several co-products, as in refineries, in the chemical industry or in metal smelters, the burdens must be divided. The methods are not of equal rank here. ISO 14044 specifies an order: first, allocation should be avoided by subdividing processes further or expanding the system. Only then is allocation made according to physical relationships, such as mass or energy content. Only if this is not possible do other relationships, such as market value, come into question. The choice can change the result significantly.

Recycling is also methodologically delicate. It makes a difference whether a product is credited with the benefit of secondary material used, whether future recycling is credited or whether both are mixed. In a pure Cradle-to-Gate footprint, a credit for later recycling has no place. EN 15804 therefore reports such effects separately in module D. They must not simply be added to A1–A3.

For procurement and regulation, this methodological question is central. Grid operators, energy companies, industry and public contracting authorities increasingly compare materials, components and construction methods using product footprints. A low Cradle-to-Gate value can favour a supplier even though use and end of life have not yet been assessed. Conversely, a product with a higher manufacturing value can bring advantages in use that remain invisible within this boundary.

Common misinterpretations

  • Reading a partial footprint as a full footprint: Cradle-to-Gate is sufficient only if use and end of life are negligible or deliberately not part of the question. For metals, building materials and other intermediate products the boundary is often sensible. For appliances, power plants, storage systems or vehicles it is usually not sufficient for overall comparisons.

  • Equating "low in emissions during operation" with "emission-free": For many components of the energy transition, emissions arise before commissioning. What is usually decisive is the ratio of the manufacturing footprint to the electricity generated, stored, transmitted or saved over the lifetime.

  • Comparing the incomparable: Two values can be compared only if system boundary, reference unit, data vintage, regional assumptions, electricity mix, recycling rules and allocation method match sufficiently. A value per kilogram of material is not the same as a value per component. A value per kWh of capacity is not the same as a value per kWh delivered. A global average value from a database can be too coarse for a specific supply chain.

Cradle-to-Gate shows which environmental impacts are already embedded in a product before it is used. The term does not replace a complete life cycle assessment. However, it directs attention to upstream chains, material flows and production energy. In the electricity system this is particularly useful when grid expansion, storage, renewable generation and electrification are to be assessed not only by operating emissions. A value becomes meaningful only with a clearly stated system boundary and an appropriate reference unit.

Sources

Related glossary entries

Edited by eCMS on 11.11.2026 18:12

© 2026 Erik Schmidt. All rights reserved. Quotations with a link to the source are welcome.