Energy and Meteorology Portal

Energy Efficiency

Energy efficiency is the ability to perform the same work with the least possible amount of energy, this implicitly requires reducing energy waste. Energy efficiency brings a variety of benefits: reducing greenhouse gas emissions, reducing demand for energy imports, and lowering costs from the household to the wide-economical level. Energy efficiency is the cheapest and often the easiest measure to curb fossil fuel consumption.

There is a need to enable greater efficiency in energy demand and use. Energy efficiency results from technological improvement, regulation, behavioural changes and innovation. This is often achieved in response to changes in policy and improving regulatory frameworks (including standards) and education. Changes in consumption can come about through individual and collective behavioural changes and adaptation of technologies at different scales. Considerable efforts to improve energy efficiency must also come from international bodies, governments and local authorities regulating and incentivising the sectors that require higher energy inputs, principally in developed countries or countries with economies based on manufacturing products for exportation, as they tend to have high emission intensity.

There are enormous opportunities for efficiency improvements in every sector of the economy, whether it is buildings, transportation, industry, services or energy generation. Improving efficiency in the sectors with higher energy demand (see for example the proportion of energy demand by sector in Europe, Figure 1), is meant to have a bigger impact on reducing the total energy consumption of the region.  

Energy Efficiency fig1

Figure 1. The proportion of energy use by sector in Europe for 2018. Source: Eurostat


Information about the weather has been vital since the very beginning for maritime and aerial transport, not only for security reasons but also for energy efficiency, as routes get modified according to wind speed and weather conditions in general in order to minimise fuel usage. There are also other instances where W&CSs are providing vital information for transport. For example, captains of cargo ships modify the load according to Sea Surface Temperature as the surrounding water temperature affects the functioning of their engines (which can be up to one or two thousand tonnes). Warmer water reduces engine efficiency, in such cases, the load is reduced to compensate for this extra exertion of the engine, to decrease fuel consumption. As there are around 90,000 cargo ships world wide deployed for three-quarters of the year, the fuel saving can be of cumulative significance.

Regarding land transport some NMHSs like UK’s MetOffice, offer services for route optimisation, helping to maximise efficiency by reviewing operations and deployment according to climatology. This is particularly relevant for lorries moving heavy loads travelling upwind, which can increase fuel consumption. A similar service is provided by the MetOffice to rail companies.


The energy efficiency for households can be improved at three different levels:

Energy efficiency at this level can be achieved through behavioural change, which includes:

  • Deliberate decisions to limit personal energy use (e.g. turning off lights, setting thermostats at lower temperatures in winter and higher temperatures in summer).
  • Choices about the source of energy being used (e.g. from renewable sources).
  • Choosing to use electricity at times of the day when renewable energy is more abundant.
  • Use of technology like smart meters to monitor own consumption and patterns or devices like a programmable thermostat that uses weather forecast data to automate the household heating/cooling systems, lights, blinds, etc. which will also reduce energy bills.

At a building or office facilities level, a combination of smart technology and good energy-efficient building design can greatly increase the thermal stability of the building reducing the need for high-energy strategies like HVCAs (Heating, ventilation and air conditioning). An energy-efficient design uses a combination of passive (insulation materials, blinds, orientation of the building) and low-energy strategies (e.g. night ventilation, evaporative cooling, radiative cooling and earth tube cooling for tropical climates) (Rojas et al 2019). Furthermore, the use of heating/cooling systems can be optimised by microclimate measurements outside the buildings by small weather stations, ensuring the efficiency of the facilities while managing the comfort of their occupants.

Some cities are implementing centralised systems to provide heating to different district buildings via an underground network. Such is the case of Espoo, Finland, where the heating is distributed to different buildings according to information coming from a network of sensors monitoring the microclimate (wind, temperature and precipitation) in different parts of the city (Figure 2). This fine-tuning of heating delivery according to specific local conditions can have a massive impact on the ability to gain energy efficiency, as these weather variables will impact how much, when and where is the energy produced, delivered, and consumed (Jaakkola, 2021). 

Another example is Canberra, Australia, a city with ~400,000 inhabitants, which now uses 100% renewable energy, sourcing it from solar and wind power plants, along with solar panels on houses. In addition to achieving 100% renewable electricity, the government has also committed to reaching net zero emissions by 2045 (Cass, 2019).

Globally, at least 834 cities in 72 countries, covering 558 million people had committed to increasing the contribution of renewable energy in at least one sector (transport, buildings, heating and cooling) by the end of 2020 (REN21, 2021). And for all those cities that depend on renewables, W&CSs are key not only for operations but also to fine-tune energy use of buildings in line with weather conditions.

Figure 2. Espoo city transformation 2014 – 2029. Source: Fortum, 2022


While industry may see energy efficiency as a ‘tool’ to reduce carbon emissions, it is also important to highlight its co-benefits as, when energy-efficient measures get implemented, production performance, quality, and competitiveness are also improved (UNECE, 2018). Although some industries have started to install solar or wind farms on their own land, there is still a long way to go to fully integrate environmental and social dimensions into the industrial systems before they can become sustainable and energy-efficient systems. Nevertheless, there are initiatives like the Eco-Industrial Parks aiming to address these issues.

Eco-Industrial Parks (EIP) aim to minimise energy consumption, GHG emissions, pollution and waste production by upgrading industrial processes. They also seek to create symbiotic relationships between the factories of the EIP, aiming to reuse and recycle the waste generated by other companies, and ideally, cities or broader regions can enter this symbiotic relationship by providing waste as a resource for EIPs or benefiting from EIP waste streams such as residual heat. The idea of EIPs was developed under the Circular Economy principles, aiming to reduce waste and energy by reusing and recycling materials. Although these are emergent practices, China provides the best example of scaling up this idea at a national level – with more than 55 operational EIPs and 52 under development – where the use of energy and resources has been effectively reduced. However, there is still a need to expand the sustainability criteria and social aspects to increase the effectiveness of EIPs (Hong and Gasparatos, 2020).

On a global scale, UNIDO has implemented EIP pilot projects in six countries under the Global Resource Efficient and Cleaner Production (RECP) Programme since 2015 (China, Colombia, India, Morocco, Peru and South Africa), with the intention to upscale and expand resource efficient and cleaner production activities. The aim is to move beyond the borders of EIPs and incorporate them into sustainable cities (UNIDO, 2018).

Energy Distribution

Specifically, in the context of smart grid technology, weather forecasting plays a critical role, for instance, in the management of renewable power resources according to resource availability. Also, to optimize energy networks the use of precise, real-time local weather data and modelling is key. Ideally, the users will no longer use energy at any time of the day but will synchronise their behaviour according to energy availability and price rates.