Energy sufficiency aims at keeping consumption at a sustainable level. Photo: © maxzed /

Energy sufficiency: a necessary complement to energy efficiency

Making the case for energy sufficiency in European policies: the construction of a European sufficiency-based energy transition scenario.

The need to substitute fossil fuels with low-carbon energy resources as soon as possible requires the development of new energy sources such as electric renewables, as well as keeping the level of energy demand under control, so that these new sources can be used instead of fossil sources, rather than in addition. Action to limit energy demand could encompass changes in the amount of energy that is used to provide a given level of services, by improving energy efficiency, and changes in the level of services that use energy, through energy sufficiency.

In the past 20 years, successful energy efficiency policies have enabled progress in the design of more energy-efficient equipment. Cars are a good example of this, with constant progress made in improving the efficiency of vehicles. However, the fact that cars have got bigger and heavier and travel longer distances has kept annual fuel consumption at a high and steadily rising level. This also has consequences for the consumption of resources, with steel demand for cars increasing, as well as the space they require (parking spaces and roads), at the expense of natural areas and, with the shift to electric vehicles, projected high pressure on lithium and cobalt reserves needed for batteries. However, in traditional environmental and climate policy action there has been little room to question whether those increasing trends were tailored to actual needs, or whether they may have been the result of unsustainable consumption patterns, with no reflection on the dimensioning or level of use of the energy service.

Energy sufficiency aims at keeping consumption at a sustainable level through action at the level of the service, such as the size of the car, its sharing or the shift to other modes, or the distances covered. This mostly entails satisfying decent minimum energy service levels for everyone, while keeping the average level within limits that do not endanger the carrying capacity of the Earth. In Northern economies it aims to curb the demand for energy services without negatively affecting the well-being of consumers.

The perception of energy as a simple commodity has nurtured the myth of infinite growth in energy production. Since the first decarbonisation efforts, this view has focused policy-maker’s attention on tapping the potential of low-carbon energy production and efficiency of processes, with little consideration given to changing consumption patterns. The urgency of climate action, the need to get to net-zero greenhouse gas emissions, and rising concerns for biodiversity, resource availability, water and land use issues call for a vision shift towards dimensioning energy services at a just and sustainable level. To achieve this, the overarching purpose of fulfilling services (mobility, housing, lighting, etc.), rather than producing energy, must become central in the analysis of the energy system and its evolution.

Starting energy system modelling with the analysis of energy services lets us question the need for those services and define just levels. As such, it contrasts with the more traditional approach of energy modelling, which aims to achieve decarbonisation by optimising the low-carbon energy supply mix and energy efficiency processes. As our understanding of the climate and delays in the energy transition require more and more ambitious decarbonisation pathways, this traditional approach has reached its limits: classical modellers now try to add lifestyle changes as additional options (e.g. keeping international air travel at the pre-Covid crisis level in the latest IEA Net Zero Roadmap). While this is of course to be welcomed, it does not enable us to fully tap the broader and deeper potential of sufficiency to save resources and reduce impacts – which requires us to question societal needs first and then define sustainable consumption levels on a more systematic, comprehensive and meaningful scale, allowing for societal coherence and consistency.

European governments and the EU have committed to becoming carbon neutral by 2050, and more recently to increase the pathway towards this target through a 55% cut compared to 1990 levels in 2030. Previous decarbonisation strategies that were set for only 80–95% reductions in GHG emissions relied mostly on exploiting energy efficiency and renewable energy. Now, meeting the unprecedented challenge of reaching carbon neutrality by mid-century requires broad and deep changes in production and consumption patterns. By reducing costs as well as the required scale of renewable installations, energy storage and their related impacts on materials and land use, sufficiency can facilitate the achievement of the EU’s renewed ambitious targets.

At the European level, the sufficiency potential remains a hidden resource. Revealing its full potential in order to meet the adequate level of ambition on all sustainability issues requires a high level of detail in the energy demand analysis, which is best done at the national level.

The full integration of energy sufficiency into scenarios requires a concrete description of energy services and their possible evolution in the modelling work. This calls for a more physical approach to modelling, compared to most classical models. Experience shows that most of the models developed and used to build energy and climate scenarios over the past decades tend to focus on representations of economic systems, often with the aim of minimising costs of energy supply and processes, in a way that is not fit to embed specific sufficiency-related assumptions and consistently assess their impact.

In the case of mobility, to implement sufficiency in practice, one could envisage actions that aim to tailor the size of transport vehicles to energy service needs, (e.g. fewer cars in the urban environment), or reducing the distance travelled, particularly for the most energy-consuming transport modes (e.g. cars or planes). This can be achieved through modal shifts towards cleaner modes of transport such as rail or smaller vehicles, or non-energy-consuming uses such as soft mobility, as well as through mutualisation and occupancy with car sharing and pooling, or through an absolute reduction such as remote working.

For buildings, the most common implementation of sufficiency will aim to reduce the floor area that is supplied with energy (e.g. heated m2, or m2/capita), or reducing the temperature for heating. Other sufficiency levers are the reduction of specific electricity consumption needs (particularly through the reduction of the number of appliances through mutualisation, or their size), but also of the needs for other uses of heat (for water and cooking).

Partners in around twenty European countries1  are working together on the integration of harmonised, sufficiency-based, national scenarios into a pathway to meet 100% renewables energy supply and net-zero greenhouse gas (GHG) emissions on a European level by 2050 at the latest.

A first, key building block of the construction of a common sufficiency modelling language was achieved through the definition and prioritisation of a list of sufficiency indicators  that were integrated within a dedicated indicators dashboard used to “translate” national scenarios based on different methodologies, models, scopes, logic and level of aggregation or disaggregation of data, into a common, sufficiency-focused, language.

A contraction and convergence approach  can be applied to energy consumption through dedicated comparison indicators relating to the level of energy services. On the basis of sufficiency assumptions made on key indicators, sufficiency corridors that include minimum and maximum levels corresponding to decent energy consumption levels are discussed in the technical dialogue for indicators based on population (e.g. residential floor area (m2/cap) and passenger traffic (pkm/cap). This enables a search for convergence in living standards . In this complex search for convergence, international literature and the concepts of decency and social justice are referred to: the general vision is rather one of a reduction in excessive energy services, particularly for the most affluent consumers (a good example could be a reduction in the use of SUVs for short-distance travel in urban areas, which can be modelled through a reduction in the distance travelled by heavier cars in urban areas). At a European level, the aim is to define how energy services in different countries and within those countries can converge towards energy service levels that are lower than those of the most affluent countries, such as Luxembourg, but higher than those of catching-up economies, such as Bulgaria. Consumption reduction in the North makes space for fair access and development towards decent energy service levels in the South.

This should ultimately allow assessment and discussion of the kind of ambitious energy consumption reduction target that is needed to meet the other sustainability goals (carbon neutrality and 100% renewables).

Yves Marignac
Stephane Bourgeois
Mathilde Djelali
Nicolas Taillard

1The project is developed on a coherent geographical area that encompasses the EU plus UK, which was still part of the former when the project started, Switzerland and Norway.
2The work on sufficiency-related indicators is being deepened within the framework of the CACTUS project (“Consolidating Ambitious Climate targets Through end-Use Sufficiency”,
3This approach has been documented, for instance, through the calculation of convergence and compression factors in the EUCalc project (Climact, 2019).
4“Minimum consumption standards allowing every individual to live a good life, and maximum standards guaranteeing the chance to live a good life for others” (Fuchs, 2021)

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