Back to knowledge
JRC

Zero emission electric cars

An electric car uses electric power instead of an internal combustion engine powered by liquid or gaseous fuels like diesel fuel, gasoline, LPG or methane. It has been increasingly recognized that electric cars provide an opportunity to reduce global GHG emissions [3] and greatly increase air quality.  

Even though the emissions by a vehicle determine only a part of total emissions related to mobility (apart from emissions during production of energy, production of a vehicle and its shipping and maintenance etc.), the transformation to net zero emission electric car fleet, combined with green electricity, could reduce CO2 emissions 10–12 times comparing to fossil-fuel vehicles [5]. Their widespread adoption also may help to decrease noise pollution in cities [6].  

The adoption of electric car accelerates – the share of battery electric vehicles sales reached 5.4% in 2020 and 9,1% of new vehicles in 2021, while plug-in hybrid respectively 5,1% and 8,9%. A rapid growth is expected in major markets [2], although in some markets sales already reached high percentages (e.g. 80% of new sales in Norway or 30% in the Netherlands), proving that these vehicles are mature for most applications. However, a broader adoption of electric cars still faces several obstacles.  

The main challenges for electric car adoption are high purchase costs in the lower vehicle segments, the still insufficient charging infrastructure in some parts of Europe and their charging time on longer trips.  

The purchasing cost of an electric car shall not be confused with its Total Cost of Ownership (TCO) that includes the purchasing price, but also running costs, repairs, taxes, maintenance, depreciation and resale values. While purchasing cost can be still unaffordable for lower-income customers, also due to the increases in the prices of critical minerals which are crucial for battery (in particular cobalt and lithium [4]), the TCO can be already equal or lower than an internal combustion engine for customers driving high yearly mileage.  The range of electric cars can cause ‘range anxiety’ in drivers mainly due to lack of awareness of recent improvements in performance (most current vehicles have running ranges from 300 to 500km) and deployment of recharging infrastructures (in fact, in some countries this problem is much less perceived than in other). Whoever has access to a private garage or parking place at home or at the workplace can easily cover 90% of the needs by installing a wallbox there, while public infrastructure is essential to allow other users to charge.  

A parallel deployment of vehicles and their infrastructure is essential to accompany the growth of this market, but an increased popularity of electric cars can in principle also create an overload risk for existing electricity grid in the unlikely case that all vehicles charge at peak time, but work is already underway to support the balancing, demand-management and resilience of a ‘smart’ grid via Vehicle to Grid (V2G) features. Thus, electric car mass-market requires some investment in grid infrastructure to meet this increased demand (World Economic Forum, 2022).  

Therefore, new solutions need to be developed such as: 

  • Reduce initial cost and improve convenience by improving battery energy density and reducing the cost per kilowatt-hour (kWh) of batteries (cost already decreased by almost 90% in last decade, with a 7-fold increase in density) [1]; 

  • smart and flexible charging in public parkings, i.e. schedule charging based on power constraints, price and priority, selling unused energy back to the grid; 

  • smart energy management, improving electric cars charging and stationary load management, reducing the risk of grid overload and using electric cars as grid energy storage; 

Source: https://afdc.energy.gov/vehicles/how-do-all-electric-cars-work 

 

In order to speed up electric cars adoption, cities can implement different measures, including provision of free or preferential parking for electric cars, developing a wide range of publicly available chargers (mostly low power, but including also a small share of fast chargers), facilitating the installation of private charging points in residential and office buildings (right to charge) offering access to priority lanes for electric cars (e.g. limited to shared electric cars fleets), introducing zero-emission zones, electrifying the municipal vehicle fleets, simplifying administrative processes to build charging points, providing local subsidies for electric cars purchase or tax write-offs for companies or citizens willing to install charging points, facilitating zero emissions car-sharing schemes, multimodal integration with public means via park & ride or long distance travel. 

MATURITY:  

Zero emission electric cars are widely available on the market (nearly 100 models in most segments in 2022) and offered by the majority of car manufacturers. The large sales shares achieved in some markets confirm their technological maturity, and that of the deployed infrastructure, although some teething problems can remain. The specific technologies which can help electric mobility achieving mass market penetration in all EU markets are related to cost, charging technologies (e.g. low cost and high efficiency low power, ultra-high power and wireless charging).  Most of these technologies are already at large demonstration phase and further investments are required to make them ready for commercial deployment on a wide scale [1]. Moreover, further developments are required in the area of batteries to optimise the trade-offs between cost, range, durability and ultra-fast charging capability via new chemistries) and higher efficiency in order to increase autonomy of electric vehicles and increase their capability to cover long distances with no or little time penalty in comparison with today’s cars.  

While today’s numbers don’t pose significant problems to the grid even in countries with high sales, technology to manage charging needs to be validated and deployed proactively. 

CO-BENEFITS
KEYWORDS
PRE-CONDITIONS & ENABLING CONDITIONS
CONSTRAINTS/BARRIERS FOR IMPLEMENTATION
DRAWBACKS/ADVERSE IMPACTS OF THE SOLUTIONS after implementation
EXTERNAL LINKS
IMPACTS (Indicators + DNSH)
INSTRUMENTS/Processes for implementation
EXAMPLES

In this collection

Grey water treatment (including Nature Based Solutions) and reuse

Greywater is the wastewater generated in households or office buildings without serious contaminants, such as water from baths, sinks and washing machines. Greywater can be separated from blackwater (water from toilets or kitchens) and then treated on-site for direct reuse in toilets recharge or irrigation. Greywater is a relevant secondary source of water and nutrients. Many studies have analysed the environmental, economic, and energetic benefits of the reuse of greywater [1][2][6][7]. Greywater treatment systems can be introduced in new buildings or in existing buildings with retrofitting measures. There are different greywater treatment systems: diversion and filtration, diversion and treatment (using chemicals), or nature-based solutions (NBS). 

 

Traditional greywater treatment 

Greywater treatment by mechanical systems is typically based on filtration or treatment with chemicals. In filtration, the aim is to remove impurities using filters, with typically a few or several filters in a row in order to guarantee good results. In a purifying process done with chemicals, the aim is to add chemicals that bind impurities, which are then removed from the water, for example, by filters. The mechanical treatment can start with a settlement tank, where coarse particles settle in the bottom of the tank and are then removed. After that, the greywater flows through filters, typically first gravel and sand and then biological filters like wood or peat. Last, if needed, ultraviolet light or chemicals are used to remove potential bacteria. 

Green roof and greywater treatment [7] 

 

Grey water recovery system [10] 

The first filter is a biofilter, which removes the fats and oil. The sand and gravel filter removes small particulates and other impurities. 

 

NBS-based greywater treatment 

Nature-based solutions (NBS) applications are typically constructed wetlands, green roofs, and green walls [1][2][3]. 

 

Several studies have shown that NBS-based greywater treatment has high removal performances [1][5], indicating the suitability of these systems in treating domestic greywater. Planning and design parameters should be carefully considered when implementing NBS; high residence time of water can be especially important for grey water treatment efficiency (see e.g., [1]). To optimize the removal processes in NBS, appropriate plant species and substrates (as growing material), optimal hydraulic parameters, and suitable operating conditions are needed.  

 

The decentralized process consists of several stages: (i) greywater separation, (ii) storage, (iii) treatment by innovative NBS as multi-level green walls/green façades, or by mechanical systems as multi-layer filters and activated carbon, and (iv) final disinfection using commercial O3/UV systems (Ozone and Ultraviolet).  

MATURITY:  

 

Some building-level solutions for grey water treatment and reuse (including nature-based) are commercially available, for example:  

 

  • Aqua Gratis is a technology to capture and reuse the bath and shower water for flushing toilets. The solution is at the stage of initial market commercialisation. The technology development of Aqua Gratis was funded by the EU. 

  • REDI gives a solution for single-family houses, where the treated greywater can be used for watering the garden. 

  • Disinfection can be done with commercially available solutions, e.g. with ozone and ultraviolet (UV) light. 

 

Some examples of pilots are: 

 

  • Greywater treatment with nature-based solutions for indoor or outdoor modules in multi-level green walls/green façades was carried out in Houseful. The project tested also ozone and ultraviolet light for disinfection.  

  • Water management systems and how to monitor and collect water condition information for urban water management platforms were piloted in UNaLab. 

  • Green walls and constructed wetlands were piloted in NAWAMED, with a focus on grey water treatment from a public building, a parking area, and a refugee camp. 

  • A service model for grey water treatment with NBS was tested in Houseful. The service model considers a leasing contract and a payment fee per m3 of water treated and reused. 

 

The nature-based grey water systems have been tested in a rather short period of time (e.g., some months to 1–2 years). Since the operating time of grey water treatment should be closer to 15-20 years, a further full-scale testing is still needed. [1]. 

Passive building design strategies: building orientation, passive heating and cooling

Passive building design means providing passive heating, passive cooling, and natural ventilation to maintain comfortable indoor conditions with no need for energy, by taking advantage of location (climate), orientation, massing, shading, material selection, thermal mass, insulation, internal layout and the positioning of openings to allow the penetration of solar radiation, daylight, and ventilation in the desired amounts [1–8]. When duly applied, passive design strategies are a designer’s first opportunity to increase a building’s energy efficiency, without adding much less front-end cost to a project as compared to active design strategies. Efficient passive design results in smaller heating and cooling loads (so that the building’s mechanical system – if any – can be downsized) and smaller electric loads for lighting through the use of daylighting design strategies.  

 

Beyond local climate, building orientation is a key aspect for passive design. The most energy-efficient designs are facing south or north to allow better solar energy management and better quality of daylighting. Building shape is also very relevant in the design, as an elongated and narrow plant (with south or north facing façade) allows for more of the building to be receive daylight. Shading strategies properly combined with other passive design strategies are also required, especially in hot climates [9,10]. Since the main difficulty in designing natural ventilation systems driven by buoyancy and wind is the simultaneous estimation of ventilation airflows and indoor temperatures, solar chimneys are used [11,12]. A solar chimney is a vertical shaft utilizing solar energy to enhance natural ventilation. 

 

Passive heating can be achieved by capturing the heat from the sun inside the building. Tweaking the window-to-wall ratio and the building exposure to the sun, all the while controlling for the thermal mass, heat flows and insulation allows to effectively store, distribute and retain the heat. The thermal mass defines the capacity to absorb, store and release heat. Heavyweight construction materials like concrete, brick and stone exhibit large thermal mass that can be used to effectively store the heat over peak hours and release it overnight. 

Passive building design. Figure from

 

Passive cooling is a set of design strategies to reduce heat gains and favour heat dispersion. Many methods exist and include using solar shadings as well as designing openings in such a way to allow good ventilation (such as solar chimneys). Shading can either be operable (external louvres, blinds, and deciduous trees) or fixed (e.g. eaves, overhangs, fences and evergreen trees). 

 

 '

Shading devices for north-facing openings. 

Figure from https://www.yourhome.gov.au/passive-design 

 

Passive design strategies are rated in different standards, such as PassivHaus (Passive House), BREEAM, LEED or WELL. 

 

The literature shows that today there are many net-zero, nearly-zero energy, and certified Passive House buildings worldwide, in different climate or geographic regions. Most are in Europe and North America, followed by New Zealand, Kore, Japan, China, and India [1]. Literature also shows that is it possible to achieve at least the Passive House energy standard of performance in all climate zones [13]. 

 

MATURITY:  

 

Although individual passive techniques are already commercial, their holistic implementation in buildings is still at TRL=4-6. 

Citizen Participation Platforms

E-participation [1][2][3][4][5] enables citizens to use digital technologies or platforms, e.g., combination of geographic information systems (GIS), Web 2.0 and mobile technologies (including video, mobile messaging and Internet access), for communication, engagement and deliberation on policy or planning challenges.  

 

Engagement and participation are vital tools in climate adaptation and environmental decision making as these entail increased community acceptance, support for climate actions, and provide new insights based on local knowledge [12]. Citizens can be consumers as well as producers of useful data for policy development and decision making (WeGovNow, Smarticipate, AI4PublicPolicy). 

 

There are multiple degrees of citizen participation ranging from passive, i.e., being simply informed, to responsive, i.e., contribute to consultation, to active, i.e., being fully empowered by having final decisions delegated to them (see Arnstein’s ladder [6]) [7]. In e-participation initiatives, both top-down (i.e., issues identified by public authority) and bottom-up (i.e., citizens led initiative) approaches can be applied. As multiple actors (i.e., different departmental units) are involved in the provision of e-participation, cross-organizational issues related to ownership and accountability may arise [3].  

 

Technologies supporting government processes (GovTech) can add great value to participatory processes (e.g., access to sensor kits, web portals and data), as shown by examples of Madrid (Decide Madrid), Bristol (Bristol Approach to citizen sensing – e.g., air quality, solid fuel burning etc.) [7], and Brussels (Curieuzenair). E-participation is usually considered part of e-government [5]. 

 

E-Government (or Electronic-Government) [1][2][8] refers to the application of Information and Communication Technologies (ICT) to government functions and procedures with the objective to increase efficiency of government agencies, enhance delivery of public services, and facilitate low cost and faster public engagement with public authorities. A comparative survey [8] of global e-government performance of municipalities highlights the best e-governance practices. It uses five categories of measures: privacy and security, usability, content, service and citizen and social engagement. For citizen and social engagement category Shanghai, Auckland, Seoul, Madrid, Paris, and Lisbon are ranked top cities for year 2018-19. 

 

Open Governance [9] is about transparency of and access to government data and decision making process so that innovative forms of collaborative actions (i.e. bottom-up and top-down) can be applied to solve policy problems, raise awareness, increase public participation, change behaviour, promote e-democracy, and revolutionise traditional service provision [10][11]. It is closely associated with open government data that can provide new insights about issues and services as well as offers the opportunities to participate, comment and influence plans and policy agenda to foster greater citizen participation. 

 

 

E-participation solutions range from responding to planning e.g., top-down to bottom-up urban regeneration [Smarticipate] or policy challenge [WeGovNow] or reporting a local problem (e.g., Bristol’s FixMyStreet); or bottom-up budget planning (e.g., Helsinki’s participatory budgeting) or accessing open data (e.g., Hamburg’s Transparency portal).  

 

There are several e-participation initiatives where various ICT tools are used to deliver different public services. For instance,  

Cross border e-governance initiatives such as [ACROSS], [DE4A] and [GLASS] go beyond one city’s public administrative level (even at EU level and beyond [iKaaS]) and deal with cross-border interoperable, mobile [mGov4EU] and privacy-aware public services.  

MATURITY: 

 

Many e-government and e-participation tools are available at higher TRL and are already being used by municipalities for public services and e-participation, e.g., open source Consul platform is being used in 35 countries by 135 institutions; Similarly, Organicity tools are used for over 35 experiments in various cities. 

 

Some of the example solutions fall under validation and demonstration category such as DUET and Smarticipate.  

Comments ()

Authors

EIT Urban Mobility
VTT
CEREMA
JRC

Last update: July 24, 2025

Tags

Air qualityClimate resilienceEnergySustainable fuelTransport and mobility

Tags Climate Transition Map

Under license CC BY-NC-SA
This license allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator. If you remix, adapt, or build upon the material, you must license the modified material under identical terms.