In an era of escalating energy costs and growing environmental concerns, the importance of energy efficiency has never been more pressing. As consumers, we have the power to drive the energy transition forward by making informed choices that reduce our energy consumption and enhance our quality of life. This report contains practical energy transition solutions through energy efficiency and aims to provide practical insights and ready-to-implement measures tailored for ordinary consumers.

Energy efficiency is not only the most accessible and cost-effective way to begin the journey towards a sustainable future, but it is the fundamental step on the energy transition path. By consuming less energy and using it more wisely, households and small businesses can achieve significant savings, increase their independence from volatile energy markets, and contribute to environmental sustainability. This foundational step sets the stage for further advancements in distributed energy sources and renewable technologies.

Our goal at NEAH is to demystify energy efficiency, presenting it as a basic yet powerful measure that anyone can adopt. From simple behavioral changes to sophisticated digital solutions, the potential for energy savings is vast. By understanding the economic feasibility and practical steps required to implement these measures, consumers can make informed decisions that align with their values and needs.

We will explore various facets of energy efficiency, from passive measures in building design to the innovative Energy Efficiency as a Service (EEaaS) model. We will delve into the role of digital solutions and artificial intelligence in optimizing energy use, and highlight the importance of a systematic approach to energy management. Our aim is to equip you with the knowledge and inspiration to take control of your energy consumption, paving the way for a more sustainable and comfortable future.

Why does energy efficiency precede other measures? Energy efficiency is an essential component of any transition to sustainable energy supply. This is justified both technologically and economically.

The most obvious reason to reduce energy consumption without compromising the quality of life (for households) or the quantity and quality of produced goods (for industrial enterprises) is the savings on energy costs. As energy prices continue to rise, the motivation for energy conservation will only grow.

If a facility is connected to a fossil fuel source, reducing consumption means reducing CO2 emissions and harmful atmospheric pollutants. Even with renewable sources, there's still motivation to conserve energy: the less we consume, the more consumers can be connected to the same source, thereby improving energy availability and quality of life with the same energy consumption. After all, increasing energy efficiency means achieving the same or better results with less energy or getting more results from the same amount of energy.

Energy-saving measures are especially feasible where there is an energy deficit since financing the saving of one kilowatt-hour is cheaper than building a new source to generate the same kilowatt-hour.

It's important to understand (considering the entire energy chain from generation, transmission, and distribution to end consumption) that energy efficiency measures at any link in the chain affect the others. If a facility consumes less, there will be less load on the distribution network and lower operational costs, and less generation capacity will be needed.

Conversely, irrational energy consumption and losses at the end-user level, such as households or businesses, lead to extra expenses in energy production and distribution. This means more fuel and other material resources, labor, and time will be collectively spent.

To summarize, our first step should be to improve energy use efficiency; otherwise, any other measures will involve expenses for losses and unproductive energy costs. It's economically unviable to strive for increased production or higher household energy availability if energy is wasted irrationally. We must first eliminate these irrational expenditures.

The good news is that the range of energy efficiency measures for consumers is broad, well-developed, and technically feasible. In most countries, there are also financial incentives to encourage energy-efficient modernization.

In the following sections, we will detail the directions and specific measures for reducing energy consumption, focusing on the building sector without touching technological processes.

According to the IEA, buildings account for 30% of global final energy consumption and 26% of global energy-related emissions for their operations. This is due to the need to provide us with a sufficient level of comfort and quality of life. The goal is to move away from irrational energy use and take measures to reduce consumption without compromising comfort.

Several major expense categories and thus, energy-saving opportunities, are important here:

• Energy costs for creating the microclimate (heating, cooling, and ventilation)
• Consumption of household appliances, including cooking and electronic devices
• Lighting

Before consuming energy, it is necessary to ensure that possible passive measures for comfort are implemented, which do not require energy and help reduce its use.

Since the main expense is heating and cooling, it is primarily necessary to ensure that natural conditions help retain heat in the cold season and coolness in the hot season. This can be achieved through strategic landscape architecture that utilizes natural features—terrain, wind patterns, etc.

In temperate and cold climates, it makes sense to build houses so that they are maximally heated by the sun and less chilled by the wind (by planting trees or creating other barriers), placing windows on the southern side, and using glazed galleries and balconies as heat accumulators.

In hot climates, conversely, the location of the building on the site, trees, and other structures can reduce heat gain from sunlight.

The next important point is the insulation of the building envelope (walls, ceiling and roof, floor and basement, windows, and doors). This includes using low thermal conductivity materials, installing energy-efficient windows with double or triple glazing in cold climates, and using coated glass that lets light through but blocks heat in hot climates.

Light-reflecting paint helps deflect solar heat, while dark paint attracts and retains it. Mechanical external window shading (blinds, awnings, pergola grilles) works best to prevent indoor heating from the sun.

Using the wind rose and window and door placement in the house can ensure natural cross-ventilation to maintain coolness, while proper placement of supply and exhaust vents can organize natural ventilation, bringing in fresh air without excessive energy consumption.

A great solution is heat recovery systems—heat exchangers to use the exhaust air's heat to preheat incoming fresh air in winter and cool it in summer.

To spend less energy on heating and cooling, it is necessary to reduce heat loss or, conversely, cool air loss through the building envelope—walls, windows, doors, floor and basement, ceiling, and roof.

Minimizing the thermal permeability of the building envelope can be done in several ways. More complex and expensive but more effective measures include thermal modernization and insulation of the building's envelope. Cheaper options include sealing gaps, using curtains, rugs, and other simple insulation methods.

Let’s describe the possible directions of building thermal modernization, which also ensures reduced energy consumption during their subsequent operation.

As mentioned earlier, it is important that the building envelope is less permeable to heat and cold.

Energy-efficient wall materials have low thermal conductivity (also called high resistance to heat transfer), which reduces energy consumption for heating and cooling.

Various types of insulation are widely used. These can be mineral fibers, such as fiberglass or mineral wool, which have high insulation and good anti-condensation properties. Insulation is used in both boards and rolls, providing flexibility in construction and allowing easy consideration of structural features.

Another effective material is extruded polystyrene foam (XPS). It has high density and insulation properties, making it a popular choice for external walls and building foundations. XPS is easy to install and has good moisture and rot resistance, but it is quite flammable and should be considered.

Another option is polyurethane foam (PUR), which is characterized by high insulation and low weight. It is widely used in sandwich panels for walls and roofs, providing effective insulation and structural strength.

It is also worth mentioning mineral boards, such as gypsum board with added mineral fibers or cement-fiber boards. They not only provide good insulation but also have high fire and sound insulation, making them a versatile choice for various types of building walls.

In addition to traditional insulators, energy-efficient materials based on wood are also widely used in modern construction. One such material is cross-laminated timber (CLT), which consists of layers of wood bonded under high pressure and heat treatment. CLT has high strength, deformation resistance, and good insulation due to its multilayer structure. CLT boards are used for building walls, floors, and roofs, ensuring not only energy efficiency but also quick assembly and environmental safety due to the use of renewable wood.

When using energy-efficient materials for walls, it is important to consider not only their insulation properties but also compatibility with other structural elements, as well as environmental and fire safety and durability. Combining various materials and technologies allows achieving an optimal level of energy efficiency and creating buildings that effectively retain heat or coolness, ultimately reducing operational costs and improving the building's lifecycle.

Thermal modernization measures are not cheap but are often feasible. The pay-off period depends on the climate (the more need for heating and cooling, the more sense to make the building envelope thermal resistant); the current materials used (the less thermal resistance, the easier to pay back investments); the price of modernization; and the energy tariff.

If the bills are too high, and you suspect the envelope is not isolated enough, consider conducting an energy audit of the house. It will show the potential for savings.

We recommend investigating market variants for the materials and the full pack of services. In Central Europe, it is possible to save up to 60% on heating and cooling after such modernization. On average, 20-30% of thermal energy is lost and can be saved in this way.

Reducing the permeability of the building envelope, which is important for all latitudes, involves installing modern windows. This will prevent the leakage of cool air in summer (or in hot latitudes) and heat in winter, especially in cold climates.

It is recommended to install double-walled glasses with reflective coatings. They consist of two glass panes separated by a gap, creating an insulating layer of air or gas between them. The gap provides thermal insulation, reducing heat transfer between the interior and exterior of a building.

The addition of a reflective coating on one or both glass surfaces further enhances energy efficiency. The reflective coating reflects a portion of incoming solar radiation and outgoing thermal radiation, helping to regulate indoor temperatures. This feature helps to reduce heat gain during hot weather and heat loss during colder weather, contributing to improved heating and cooling efficiency and reduced energy consumption.

According to estimations, changing windows could decrease the energy bill by 4-10% in Central Europe.

The roof and ceiling are significant sources of heat loss and gain in buildings, which is why proper insulation is crucial for maintaining energy efficiency. Different insulation materials and techniques can be used to enhance the thermal performance of roofs and ceilings.

For pitched roofs, attic insulation is a common method. This involves installing insulation materials such as fiberglass batts, mineral wool, or blown-in cellulose between the roof rafters. In addition to traditional insulation materials, reflective foil or radiant barrier insulation can be used to reduce heat transfer from the roof, particularly in hot climates.

For flat roofs, rigid foam insulation boards, such as extruded polystyrene (XPS) or polyisocyanurate (PIR), can be used. These boards are installed on top of the roof deck and covered with a protective layer, such as roofing membranes or gravel.

Proper insulation of the ceiling is also essential to reduce heat transfer between the living spaces and the attic or roof space. This can be achieved by adding insulation materials such as fiberglass batts, blown-in cellulose, or spray foam insulation between the ceiling joists.

By improving the insulation of the roof and ceiling, significant energy savings can be achieved. Proper insulation helps to maintain a stable indoor temperature, reducing the need for heating and cooling and ultimately lowering energy consumption and costs.

Insulating the floor and basement is essential for preventing heat loss and maintaining energy efficiency, especially in cold climates. Different insulation methods and materials can be used to enhance the thermal performance of floors and basements.

For floors, insulation can be installed beneath the floorboards or within the floor structure. This can be done using rigid foam boards, such as extruded polystyrene (XPS) or polyurethane foam (PUR). Alternatively, mineral wool or fiberglass batts can be used between the floor joists.

For basements, insulating the walls and floors is crucial to prevent heat loss and moisture infiltration. Insulation materials such as rigid foam boards, spray foam insulation, or insulated concrete forms (ICFs) can be used to improve the thermal performance of basement walls. Additionally, installing a vapor barrier can help prevent moisture issues and enhance the overall energy efficiency of the basement.

By insulating the floor and basement, significant energy savings can be achieved. Proper insulation helps to reduce heat loss, maintain a comfortable indoor temperature, and lower heating and cooling costs.

There are various ways to organize a system that regulates the microclimate in your home, and below are the most applicable options for heating and cooling systems. Regardless of the method used, there are general recommendations:

• Adjust the microclimate not for the entire house but only in rooms where people are present to reduce costs.
• A programmable or even adjustable thermostat can help schedule heating by the hour. Lowering the set temperature by just 1 degree (or increasing it in the case of air conditioning) can save a significant amount of energy—estimated to be 1-3%, depending on factors like climate and insulation.
• Install a heat recovery ventilator to utilize outgoing heat.
• If possible, carry out thermal modernization of the building—replace or repair windows and doors, add insulation to walls, floors, and ceilings.
• The choice of heating and cooling methods can also play a significant role.

The following systems are most commonly used to create a microclimate:

To reduce energy loss when using household appliances, several principles should be followed:

• The energy consumption of an appliance can vary significantly depending on its energy efficiency class; always choose higher-class appliances according to the energy label.
• Proper operation and timely maintenance (cleaning filters in AC units, heating elements in water heaters and washing machines, etc.) ensure that appliances do not consume excess energy.
• Even the most energy-efficient appliances consume energy in standby mode, which should be avoided whenever possible.
• Optimizing the load (e.g., dishwashers or washing machines) and selecting the correct operating mode, as well as carefully using settings for specific tasks, contribute to reducing irrational consumption. This applies fully to electronics as well—screen brightness, hibernation and sleep settings, and battery operation mode.

To save energy on lighting, remember these basic points:

• Passive measures: use natural light, large windows, translucent walls, light-colored interior walls, light wells, and keep windows clean.
• Use energy-efficient lighting devices, preferably LED, as they are the best in terms of energy efficiency and closest to the solar spectrum, which is comfortable for the eyes. It is recommended to choose LED lamps and fixtures from reputable brands to avoid negative effects such as light flicker and degradation of LEDs over time.
• Zonal and local lighting according to needs, the ability to adjust the number of lights on and their brightness (dimming).
• Use occupancy or motion sensors to automatically turn off lights where there are no people.

By following these principles, you can be sure that energy in the building will not be used inefficiently.
In addition to the passive measures mentioned above, important areas for energy saving include automation and smart management, as well as the use of renewable energy sources (detailed in sections below).

When discussing energy efficiency, it is essential to mention financial and service models for implementing energy-efficient measures, significantly expanding their applicability. This group of opportunities can be united under the term "Energy Efficiency as a Service" (EEaaS).

Often, users lack the necessary competencies and the readiness to invest to independently understand the opportunities, choose the most suitable one, and implement measures to reduce energy consumption at their facility. EEaaS models solve this problem by outsourcing energy efficiency improvement. Responsibility and risks, including financial ones, are taken on not by the energy supplier or the consumer, but by a third party – a professional market participant with specialized competencies in energy saving.

EEaaS is sometimes mentioned in the context of public-private partnership (PPP) models since both involve a professional third party that identifies and implements a set of activities and raises funds for them. However, PPP necessarily involves a public party (state or municipal), which is not the case with EEaaS. In contrast, EEaaS implies a specific scope to optimize energy consumption, while PPP can be applied to a wide variety of project types.

Typically, such contracts are tied to improving energy performance, where the contractor guarantees a certain amount of savings and enhancement in energy performance, with payment often linked to achieved results.

The benefits of EEaaS models include:

• Relieving the energy consumer of non-core functions related to optimizing energy consumption, which require engineering and other competencies.
• Involving external professional expertise from specialized companies in energy efficiency projects.
• Attracting external financing for energy efficiency projects.
• High motivation for project success, as the contractor's payment depends on it.
• Comprehensive implementation of measures from auditing and analyzing the situation at the facility to implementing energy-efficient measures and professionally operating the new technical solution.
• Using the most modern technologies, including energy consumption monitoring and data analysis.
• Continuous search and use of energy consumption optimization opportunities.
• High scalability with regulatory support (legal framework).

The main idea of service models, as mentioned above, is to transfer responsibility for optimizing energy consumption, along with the risks of such a project, from the owner to a specialized company. There is a significant variety of such contracts. The most common are listed below, though it is often difficult to draw a clear line between different types of contracts.

Digitalization in the field of energy saving, as in other areas, opens up new opportunities for more efficient activities. It's not just a change in technology but a rethinking of the ways to manage energy. Modern digital solutions provide more precise, efficient, and flexible management of energy consumption across all areas—from households to large enterprises and entire cities.

Data has become a primary resource in the digital age, often called the "new oil," as data analysis allows for identifying dependencies, forecasting supply and demand, optimizing processes, and making informed decisions. The availability, quality, and reliability of data directly impact the quality of decisions made.

This differentiates modern digital solutions from previous methods based on experience, intuition, and assumptions. At the same time, the digital revolution has brought its own challenges, such as ensuring data security, training personnel in new technologies, and adapting to the rapid pace of changes.

The start of the digital revolution in energy saving is linked with the advent of automation—the use of technology to perform routine tasks without direct human intervention. In the context of energy management, automation means applying systems that independently regulate energy consumption based on pre-set parameters or data analysis.

Automation in energy saving offers several advantages. For example, automated systems can optimize energy consumption in real-time based on needs and environmental conditions. Unlike regular accounting data, which we receive monthly or at best once a day, automation provides timely responses based on the actual situation. This allows for reduced energy costs, increased resource efficiency, and decreased negative environmental impact.

Examples of automated solutions in various fields include smart thermostats for regulating heating and air conditioning in homes, lighting control systems based on motion or presence sensors, and automated processes in industries to optimize energy consumption on production lines.
This not only simplifies processes but also reduces the likelihood of errors due to human factors, allowing for the early prevention of emergency situations, which is crucial in the field of energy supply and consumption.

With the development of digital technologies, systems of energy production, transmission, and consumption do not just react to pre-set parameters but can adapt and optimize their functioning based on accumulated experience and data.

The principles of digital solutions in managing energy flows can be summarized as follows:

• Data Acquisition. Obtaining operational and reliable data series is crucial, for which modern digital solutions are also used. Data acquisition takes a significant portion of resources but pays off later through increased energy efficiency by applying digital technologies based on processing these datasets. For enhancing energy efficiency at home, it's important to establish reliable data accounting and storage. Today, there are new digital solutions "beyond the meter" that allow detailing the consumption patterns of individual large appliances.
• Data Analytics. Using big data and analytics to identify energy consumption patterns, determine optimal operating modes, and forecast energy consumption. Some electricity suppliers use such tools—we can find them on our paper bills, mobile apps, or personal energy consumer accounts. Charts and comparisons allow us to see, for example, whether energy consumption is increasing compared to the previous month or year. There are also more complex models that consider factors such as weather, season, the number of residents in a building, etc.
• Modeling and Optimization. Creating mathematical models of energy consumption processes to optimize system operations and resource management.
• Artificial Intelligence (AI) and Machine Learning. Applying algorithms and AI technologies for automatic system learning and decision-making based on data.
• Integration with Other Systems. Interaction of digital energy management systems with other smart devices and systems to create comprehensive solutions.

Most of these opportunities are usually implemented by energy suppliers, EEaaS providers, or management companies.

Applying these principles allows for creating intelligent systems capable of adapting to changing conditions and effectively managing energy consumption in real-time across various objects.

To understand the capabilities of digital methods for reducing energy consumption, one needs to understand how cross-cutting technologies (cross-cutting technologies, enabling technologies) work.

Why do smart technologies empower individuals to reduce energy consumption?

Let’s look at the most familiar technologies and their applications:

The solutions and technologies described above apply not only to households but also to businesses. Various types of businesses are more susceptible to different energy-saving technologies. For instance, hotels, business centers, and other companies with buildings as their primary asset focus on building energy management solutions. Enterprises implementing technological processes seek energy-saving potential in optimizing equipment operation. Transport companies focus on vehicle and logistics management (route optimization, fuel management systems, etc.). It is essential to identify the most significant energy consumers and focus on optimizing their operation.

Among the most widely used measures are:

• Technologies for accounting and monitoring energy consumption, as well as data analysis and decision-making based on it.
• Automation solutions based on SCADA systems and other capabilities, including AI integration.
• Monitoring operational parameters of equipment and ensuring it operates in standard calculated modes.
• Ensuring flexible regulation and management of operating modes.
• Using secondary energy resources, such as waste heat (ventilation with heat recovery, using data center or cooling system heat, or exhaust gases in industry for some production needs).

Overall, the most comprehensive progressive approach to energy savings in business is implementing an energy management system per ISO 50001:2018 standard, ensuring a comprehensive systematic approach and continuous energy performance improvement. This allows identifying and analyzing energy-saving potential, optimizing energy costs, planning investments in energy solutions, and reducing the company's environmental footprint.

Smart Home
A smart home is a set of technological solutions based on hardware devices and software integrated to automate and control various home and system characteristics, making the dwelling more comfortable for residents. Resource efficiency is a significant characteristic of a smart home.
The primary goal of a smart home is to increase comfort, security, and resource efficiency. A smart home consists of various components, including:

• Smart devices and sensors (lights, thermostats, sockets, motion sensors, smoke and gas sensors, surveillance cameras, etc.).
• Control systems (central controllers, hubs, or smart speakers that connect all devices and allow control).
• Security systems—surveillance cameras, security sensors, alarms, etc.
• Control interfaces—mobile apps, voice assistants, remote controls, and device interfaces.
• Communication channels (often wireless, with various technologies).

How is the increased efficiency of a smart building achieved?

Here's how various functions of a smart building are implemented:

Different smart home models vary in functionality, scale, supported devices, and manufacturers. When choosing a smart home provider, consider the following aspects:

• Device compatibility (check which devices and protocols the technology is compatible with).
• Functionality (assess which functions and control scenarios the system provides; some may be lacking, while others may be redundant).
• Security (how data and devices are protected from unauthorized access; look for encryption and multi-factor authentication support).
• Expandability (consider the possibility of adding new devices and functions to the system over time).
• Reliability (check manufacturer reputation, customer reviews, and warranty conditions).

Some users prefer to order and install a comprehensive smart home system. Others opt to assemble a smart home piece by piece, choosing different devices from various manufacturers and integrating them using universal controllers or hubs. However, for effectiveness and correct operation, a smart home system needs to be customized to specific conditions, features, and preferences.

A properly configured home device management system, including heating, air conditioning, ventilation, and lighting, can significantly reduce energy consumption. The exact figures depend on the scale and configuration of the smart home, as well as the behavior and habits of the residents.

Building Energy Management Systems (BEMS)
For commercial real estate, there are BEMS (Building Energy Management Systems) products. This technology integrates various equipment and software to ensure optimal regulation and operation modes of systems, which leads to comfort and reduced energy consumption. BEMS solutions either implement control actions themselves or enable operators to make decisions on managing building engineering systems by analyzing data from heating, ventilation, air conditioning, fire protection, security systems, and the power distribution network.

Today, BEMS systems are increasingly indistinguishable from IoT-based platform solutions. Modern technologies allow for integrating diverse data and building scenarios and energy consumption algorithms based on them, providing recommendations to operators:

• Energy consumption across various engineering systems and equipment and their load patterns
• Behavior of residents and their energy consumption patterns
• Tariff menu (to use energy at a lower rate and sell excess energy to the grid if renewable energy sources are available on the premises)
• Demand response programs from energy suppliers (for rewards for load reduction during peak hours)
• External factors affecting energy consumption (depending on the season, day of the week, time of day, weather, etc.)

Various input data are processed in real-time, and operators work through web interface dashboards containing visualization, mnemonic schemes, and so on. Custom reports and access through mobile applications are usually available.

Local Energy Communities
Local Energy Communities represent a group of homes, businesses, or other energy consumers who come together for joint energy production, consumption, and management. They aim to achieve greater autonomy, independence, cost reduction, and improved energy supply system resilience.

Here are their main characteristics:

Smart City
A more complex structure is a smart city—an urban area that uses a multitude of cross-cutting digital technologies to improve the lives of residents, enhance infrastructure, and optimize all processes, including modernizing public services. A critical feature of a smart city is ensuring ecological sustainability and high adaptability to climate change; sustainability is a mandatory characteristic and goal of a smart city. Energy-efficient technologies play a significant role in this.

Smart Citizen: What Depends on Us
Process optimization and improved resource management efficiency are integral parts of modern technologies. However, they are closely linked to consumer responsibility and self-awareness. Modern smart cities are based on creating a model that involves public participation and enables social inclusion and community engagement, and a Citizen-Centric Approach. This means each of us can contribute to increasing comfort and efficiency, including energy efficiency, in cities through our actions and decisions.

A "smart citizen" actively uses digital technologies and services to enhance their comfort, safety, and resource use efficiency and actively participates in urban life:

• Using technologies and digital literacy. Mobile apps, e-government platforms, smart devices at home and on the street for managing energy consumption, transportation, security, and health.
• Participating in public life. Through online platforms for feedback, discussing urban issues and initiatives, voting, and surveys.
• Environmental awareness. Understanding environmental issues, comprehending one's impact, and using technologies and opportunities to reduce one's environmental and carbon footprint.

There are plenty of good examples. One of them is Vienna, which has partnered with the local Wien Energy company, allowing citizens to invest in local solar plants and work with the public to address gender equality and affordable housing issues. This model has spread worldwide, including in Vancouver, where 30,000 citizens co-created the Vancouver Greenest City 2020 Action Plan.

Overall, the formation and development of smart cities, improvement of life quality, and resource optimization depend on each of us and our active role.

Conclusion
Digital solutions are a powerful tool for improving life quality, enhancing convenience, and increasing resource management efficiency.

Summarizing the benefits of their use:

• Resource savings and increased efficiency through identifying potential, making informed decisions, and improving management flexibility
• Reduced environmental impact, both in terms of pollutant emissions into the air, discharges into water bodies and soil, waste generation, and greenhouse gas emissions
• Assisting in adapting to climate change in human habitats (buildings, cities)

However, using digital solutions for energy conservation comes with challenges:

There is no doubt that digital technologies will continue to develop, providing new opportunities for optimizing energy management at all stages, expanding the possibilities for mutual integration of various systems and services, and enhancing solutions through experience exchange and best practice dissemination.

When planning to implement smart technologies to reduce energy consumption, we recommend acting thoughtfully:

We hope you are already inspired and have a plan of action for the near future, which will undoubtedly bring you significant results in reducing energy consumption and enhancing comfort.

As in other fields, energy efficiency in mobility refers to the ratio of useful output (measured in kilometers traveled, passengers transported, or goods moved) to the energy consumed, expressed in terms of fuel volume, kilowatt-hours, kilojoules, or other units.

Therefore, improving energy efficiency can mean either increasing the useful output with the same or lower energy consumption, or reducing energy consumption for the same or greater useful output.
For passenger cars, fuel efficiency is usually measured in liters per 100 kilometers. In the United States, the reverse measure—miles per gallon—is used.

Fuel consumption for internal combustion engine (ICE) vehicles in the combined cycle
(according to the Office of Energy Efficiency and Renewable Energy under the US Department of Energy)

(To calculate the metric for electric vehicles, a conversion factor is used to translate the fuel economy from kWh/100 miles into miles per gallon of gasoline equivalent (MPGe))


For public transport, an indicator showing energy consumption per passenger-kilometer is used, for example, MJ/pkm (MJ/pkm) - how much energy is required to transport one passenger one kilometer. In aviation, it is measured in kilograms of fuel per passenger-kilometer or per ton-kilometer. In maritime transport, it is measured in tons of fuel per ton-mile (carried cargo and distance traveled).

It should be noted that energy consumption is influenced by many factors - the type and quality of fuel, the weight of the vehicle and its load (cargo), speed, weather conditions (wind, road surface moisture), the quality of technical maintenance (tire pressure, optimal operation of units), and human factors such as driving style.

Therefore, the basic measures for reducing a car's energy consumption, regardless of the energy source, include:

• Timely and quality technical maintenance and repairs, including maintaining proper tire pressure.
• Passive measures, such as protection from the heat of the sun in hot climates - a white car color, storing the car in shaded parking areas to reduce the need for air conditioning.
• Avoiding the use of air conditioners or heaters with open windows.
• Using high-quality fuel for internal combustion engine (ICE) vehicles.
• Warming up the engine before starting the trip (the colder it is, the longer the warm-up period) as driving with a cold engine consumes up to 10% more energy.
• Smooth driving without sudden acceleration and braking, which requires increased energy consumption.

Energy efficiency in transportation is primarily important for the rational use of fuel and energy, controlling carbon footprints, and reducing energy costs.

However, there are additional factors that are significantly impacted by increased energy efficiency in mobility.
First, air quality in cities. Vehicles running on fossil fuels emit significant amounts of pollutants, such as nitrogen oxides (NOx), hydrocarbons, and particulate matter. These emissions negatively affect human health, causing respiratory and cardiovascular diseases. Improving the energy efficiency of vehicles, especially transitioning to electric and hybrid technologies, can significantly reduce these emissions, improving air quality and reducing respiratory and lung diseases.

Second, noise levels, especially in large cities, which can cause stress, sleep disturbances, and other problems. Increasing energy efficiency - optimizing the number of vehicles and electrifying them - reduces noise sources and creates a more comfortable and healthy urban environment.
Third, it’s not just about controlling energy costs for transportation, but understanding that reducing transportation service costs can lower the prices of goods and services where transportation accounts for a significant share.

As in other areas, energy efficiency in the mobility sector goes hand in hand with reducing the environmental footprint, that is, harmful emissions (vehicle emissions are the most influential negative factor on urban air quality), decarbonization (reducing greenhouse gas emissions throughout the lifecycle), more flexible consumption models (e.g., car-sharing), and digitization (development of autonomous vehicles, sharing platforms, and various transport services).

According to IEA data, the transport sector accounts for one-third of all CO2 emissions in end-use sectors, with the lion's share coming from road transport. In turn, the majority of emissions from road transport (almost half) come from passenger cars.

From 1990 to 2022, emissions from transport grew annually by 1.7%, with transport sharing this top spot with industry, and aviation being the main contributor to this growth.

To meet the Net Zero Emissions (NZE) scenario, transport emissions must be reduced by 3% annually until 2030.
The transport sector relies on oil products for 91% of its final consumption. Therefore, improving fuel efficiency, competing fuels, and other measures to reduce the environmental and carbon footprint of transport are extremely important.

Trip and Flight Optimization
The first type of measures involves the rational use of transport and avoiding unnecessary trips. These measures include:

- Prioritizing the consumption of local goods with a short transportation distance.
- Minimizing trips and using modern communication technologies (remote work, video conferences).
- Optimizing routes using navigation systems (avoiding traffic jams and choosing the shortest route).
- Regulating traffic (choosing optimal speed limits, the number of open lanes, and signal timing at traffic lights).
- Using various modes of transport (combining public and private transport, bicycles, car-sharing, using trains instead of planes, etc.).

Choice of Transport Mode
It is essential to emphasize the importance of choosing the type of transport to improve efficiency and reduce the environmental and carbon footprint of trips.

Air travel is the most carbon-intensive type of trip, so replacing it with any other mode is justified in terms of climate. Public transport is more efficient than private, as it transports more passengers with less fuel and emissions. It is better to use the metro, light rail, trams, trolleybuses, or buses instead of private cars.
Car-sharing and ride-sharing are also more energy-efficient than private cars because such assets as cars are less idle, reducing the number of vehicles on the roads and their total energy consumption. In ride-sharing, fewer individual trips are made, as one car replaces two or three.

Using individual mobility means, where possible, such as bicycles and scooters, also improves trip energy efficiency and has additional benefits - fewer traffic jams and cleaner urban air.

Size and Weight
An important factor affecting fuel and energy consumption is the weight of the vehicle. Modern manufacturers are working to use lightweight but strong materials such as aluminum, carbon fiber, and composites. This reduces the mass of vehicles and, consequently, their energy consumption. A small car with a small engine is more energy-efficient than a large heavy car with a large engine. In urban environments, small cars help reduce greenhouse gas emissions.

According to the IEA, in 2022, ICE SUVs emitted over 1 Gt CO2, far greater than the 80 Mt net emissions reductions from the electric vehicle fleet that year. Battery electric SUVs often have batteries that are two to three times larger than small cars, requiring more critical minerals. However, electric SUVs significantly reduce emissions compared to ICE vehicles.

Design Features
For all types of transport, technological advancements that improve engine efficiency are essential.
Moreover, some types of transport use regenerative braking technology, where the energy released during braking is reused for acceleration.

Another factor is aerodynamics, and designers are working on reducing air resistance, which improves fuel economy. This includes car body design and the use of special kits and spoilers. While this factor is less dependent on consumers, choosing vehicles with good aerodynamics is still advisable.


Fuel Type
The types of fuel and energy consumed by vehicles affect their energy efficiency and environmental and carbon footprint.

Gasoline and Diesel
These fuels are the least environmentally friendly despite stricter regulations on fuel octane ratings in developed countries. The overall efficiency of internal combustion engines is low, and emissions of harmful substances and greenhouse gases from burning petroleum products are high.

Electric Vehicles (EVs)
According to BNEF New Energy Outlook 2024 (BNEF NEO 2024), direct electrification via batteries is the most efficient and economical path to decarbonizing road transport. The EV fleet grows to 1.5 billion vehicles, and no new internal combustion engine vehicles are sold after 2034 (net zero scenario, BNEF NEO 2024).

Electric vehicles are much more energy-efficient. Unlike ICE vehicles, they use energy directly. While ICE vehicles lose 75-85% of energy, EVs lose only 10-12%, considering regenerative braking. EVs also have zero emissions at the point of use.

The development of charging infrastructure and increased battery range due to technological advancements contribute to the growing popularity of EVs. However, the source of electricity matters greatly in terms of carbon footprint, as there is a huge difference between a kWh produced by a coal power plant and one produced by a solar station.

In cold climates, operating EVs may pose challenges due to reduced battery capacity at low temperatures, so it is advisable to check supplier and dealer data and user cases in your region.

The convenience of using EVs also depends on the availability of charging infrastructure, which is already well-developed in most major cities and even on intercity routes, growing rapidly and thus not posing a problem in most regions.

Environmentally conscious consumers remain concerned about the disposal of used car batteries. Recycling technologies exist, and their practical availability is increasing, making them more common.

Another issue is the EV sector's dependence on rare earth metals and whether the market will grow, EVs will become cheaper, and the technology will develop, offering more choice and benefits to consumers. This should not concern the average user, as battery recycling, new technologies, and new supply chains aim to address this problem.

When choosing a car, it is helpful to refer to the country's eco-labeling system, usually accompanied by fuel economy figures for different cycles - typically combined, urban, and extra-urban.

In any case, EVs and electric transport are more environmentally friendly in urban environments and therefore preferable compared to gasoline or diesel vehicles - this applies to passenger cars, light commercial vehicles (LCV), heavy trucks, and buses.

Hybrid Vehicles
A compromise type of transport that combines gasoline and electric engines in one vehicle. This model improves fuel economy and reduces emissions while avoiding issues with a lack of refueling stations or operation in cold temperatures. However, hybrid vehicles can be considered a transitional type of transport, and with the development of technology and infrastructure, the use of EVs is expected to increase.

Many questions arise for those concerned about their carbon footprint, particularly regarding the comparison of greenhouse gas emissions over the lifecycle of different types of vehicles. This greatly depends on the vehicle's usage activity and size. The International Energy Agency (IEA) has released a calculator that allows for modeling various scenarios of electric vehicle (EV) usage compared to ICE and hybrid vehicles, showing emissions at different stages of the lifecycle. According to IEA data (see the IEA EV lifecycle calculator), a typical medium car with a petrol (gasoline) engine driven 42 km per day will be responsible for life-cycle emissions of 54.1 t of CO2-eq over a 15-year lifetime in the Stated Policies scenario. An equivalent plug-in hybrid EV would produce 36.9 t, or 32% less over its lifetime. An equivalent battery EV with a 300 km range would produce 25.0 t, 54% less over its lifetime than a conventional internal-combustion vehicle and 32% less than an equivalent plug-in hybrid EV. Despite higher manufacturing emissions associated with producing the battery, the battery EV's cumulative emissions are lower than those of its internal-combustion equivalent after 2 years. Using such a calculator, we can clearly see how environmentally beneficial it is to replace an internal combustion engine vehicle with an electric or hybrid vehicle. We also recommend familiarizing yourself with the materials from the US Department of Energy, debunking the most popular myths about electric vehicles.

Hydrogen Transport
There are more and more examples of using hydrogen as a transportation fuel, but experts do not predict its widespread use for passenger vehicles, but rather for long-haul trucking applications. For heavy-duty trucks and maritime transport, hydrogen as a fuel is a solution for decarbonizing freight transportation. Hydrogen fuel is increasingly used in trains, making a trip in such a train greener than in a regular one.

Other Fuels
Synthetic fuel, according to forecasts, will not become widespread in the coming years due to price and scale (Synthetic fuels do not arrive at scale in time or at a price point needed to have a material impact). Overall, in the passenger car sector, the main trend is the transition to electric vehicles. Their market is quite developed and continues to evolve in terms of model variety, manufacturers, and efficiency, and today, each of us can make a conscious choice in favor of a green and sustainable future.

As mentioned earlier, air travel is characterized by a very significant carbon footprint. Its decarbonization follows traditional paths such as minimizing flights, optimizing routes, developing new efficient engines, reducing weight, and improving aerodynamics. Specific measures include the use of sustainable aviation fuel (SAF) and the electrification of aircraft. Battery-powered planes will be used in the next decade for small aircraft flying limited distances of a few hundred kilometers. This transition may affect consumers through higher air travel prices due to surcharges for eco-friendly fuel. As technologies develop, they will become cheaper and more convenient, reducing the negative impact of flights on the environment and climate. However, the first measure remains conscious travel.

For any type of transportation, intelligent transportation systems hold great potential. They allow for managing traffic flows, optimizing the number of vehicles, routes, and loads. In cities, this includes developing public transportation schemes, creating park-and-ride facilities for private cars, creating transportation hubs for transfers, and managing traffic through signal control systems. In suburbs, it involves setting speed limits and reversible lanes to alleviate congestion. Modern intelligent transportation systems use big data and real-time analysis with artificial intelligence technologies.

Conclusion
Technologies are rapidly evolving, providing us with more choices, and these choices of sustainable and green solutions are becoming increasingly economically justified. Labeling systems and the open publication of vehicle efficiency and emissions metrics are designed to help us make informed choices. Today, each of us can plan our trips with efficiency principles in mind, which will help reduce our environmental and carbon footprint.

The main opportunities for increasing energy efficiency as a basic measure of the energy transition were discussed above. However, the most effective approach is to improve energy efficiency on a systematic basis. And the most widely applicable method for this is the implementation and operation of an energy management system, as suggested, for example, by the international standard ISO 50001:2018.

The principles and requirements of the standard make it possible to ensure continuous improvement of energy performance of any object or facility, from a household to a public organization, from a small business to a large manufacturing enterprise, taking into account its specifics.

In short, the cornerstones of the implementation of an energy management system are:

• Systematic (comprehensive, integrated) approach
• Cyclicity
• Process approach (рrepresenting what is happening in a facility as a series of interrelated processes)
• Working in team, engaging people (family mates, neighbors)
• Relying on data rather than assumptions (modern techniques allow to accurately measure success and calculate savings achieved, carry out monitoring of energy consumption to make informed decisions using digital technologies).

By following this principles, it is possible to work in a truly systematic and comprehensive manner, without missing anything and taking into account all significant factors, achieving continual improvement in energy performance and making informed decisions according to the prevailing conditions.

As we conclude this report on energy efficiency, it is clear that reducing energy consumption is not only feasible but also highly beneficial for all stakeholders. Households can enjoy increased comfort and lower energy bills, while small businesses can achieve greater operational efficiency and cost savings. Policymakers and bureaucrats can tick off important goals related to energy security and environmental commitments, while green and tech enthusiasts would revel in the reduction of carbon footprints and the adoption of cutting-edge technologies.

The journey towards energy efficiency starts with small, manageable steps that collectively make a significant impact. By embracing energy-efficient practices and technologies, we can create a ripple effect that extends beyond individual savings to broader societal and environmental benefits. The distributed energy revolution offers immense opportunities, and by starting with energy efficiency, we lay a solid foundation for further advancements in renewable energy and autonomous energy systems.

We at NEAH encourage you to explore the measures outlined in this report and consider how they can be implemented in your own context. Whether it's upgrading your home insulation, adopting smart energy management systems, or exploring new mobility solutions, there are numerous ways to enhance energy efficiency and reap the rewards. The time to act is now, and by making informed choices, we can collectively drive the energy transition towards a brighter, more sustainable future.

For more tips on household energy management check out the Cut Your Bill course – it contains practical measures for reducing your energy consumption and saving money along the way!

Even small changes (like using LED lighting) can have a significant impact. To better understand and track the changes in your household, you can use our Greener Me planner – download it for free!