Energy Efficiency

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Energy Efficiency

Energy Efficiency in Today’s Smart Cities

At the COP28 climate change conference in Dubai in December 2023, a historic agreement marked the “beginning of the end” for fossil fuels. Governments, representing 99% of the world’s governments, agreed to double energy efficiency improvements and triple the renewable energy we use by 2030. To reach these goals means making energy efficiency and renewable energy a top priority for policymakers. This is already taking place as Governments representing more than 70% of global energy demand have implemented new or updated energy efficiency policies in 20241International Energy Agency, “Energy Efficiency”. 2024. https://iea.blob.core.windows.net/assets/f304f2ba-e9a2-4e6d-b529-fb67cd13f646/EnergyEfficiency2024.pdf. While countries will design plans to meet these goals, cities are super important in meeting these goals because they have lots of people and are centres for business and new ideas. Cities can really lead the way in making the changes needed happen quickly2International Energy Agency, “Empowering Cities for a Net Zero Future – Analysis.” 2021. https://www.iea.org/reports/empowering-cities-for-a-net-zero-future.

What is energy efficiency?

Energy efficiency means using less energy to provide the same service or achieve the same level of functionality. Think of it as getting the most out of the energy you use. This means using less energy for things like powering our homes and businesses.

Why is energy efficiency good?

Energy efficiency has lots of great benefits:

  • Reduce energy demand: We don’t need as much energy to get things done.
  • Reduced GHG emissions and other pollutants: It helps reduce harmful gases that cause climate change.
  • Lower bills: You can save money on your energy bills.
  • Increase energy equity: Everyone can have better access to energy.
  • Improve energy security: Our energy supply becomes more stable.

While things like solar and wind power are helpful, making things more energy-efficient is often the easiest and cheapest way to reduce GHG emissions3Environmental and energy institute,”Energy Efficiency”. No date.  https://www.eesi.org/topics/energy-efficiency/description.

How can we be more energy-efficient?

There are many ways to be more energy-efficient:

  • Use cleaner fuels: Switch to cleaner fuels like electricity for cars and cooking.
  • Use better technology: Use things like LED light bulbs instead of older ones and get new, energy-saving appliances.
  • Use materials wisely: Reduce, reuse and recycle things as much as possible.
  • Change our habits: Take the bus or train instead of driving, and turn down the heat in buildings.

How can we quickly improve energy efficiency?

Buildings:

  • Countries with rules about how energy-efficient buildings should be can make those rules even stronger. They can also make sure older buildings meet these rules, not just new ones. This will save energy quickly!
  • Fixing up old buildings, also called retrofitting, to make them more energy-efficient saves energy, creates jobs, makes homes more comfortable, and can save people money.

Appliances:

  • In countries where appliance ownership is high, making energy performance standards stricter and giving people incentives to replace old, inefficient appliances will help a lot.
  • In countries where appliance ownership is still rising, setting high energy efficiency standards is important for the markets not to be flooded by cheap, inefficient appliances. Energy labels on appliances also help shoppers make good choices.
  • In places where people don’t have clean ways to cook (especially in parts of Africa), making sure everyone has access to cleaner cooking methods is a super important way to save energy and improve health.

Industry:

  • Electrification can speed up efficiency progress in factories, especially where high energy intensity is not needed (cement and steel production for example)
  • Setting rules to make industrial motors in factories more efficient and durable can help. Giving companies incentives to upgrade to better motors can speed this up.

Transportation:

  • Countries can encourage people to buy electric cars by offering trade-in deals (where you get money for your old car) or discounts.
  • In many developing countries, encouraging electric motorcycles and three-wheelers is a great way to make transportation more affordable and cleaner.
  • Making rules about how efficient combustion engine vehicles (especially big trucks) have to be is important, too, as these often use lots of fuel4International Energy Agency, 2024.

While a lot of progress has already been achieved regarding energy efficiency, we need to stay focused over the coming years to continue to optimise the benefits of energy efficiency in all sectors.

Watch this video to learn more about energy efficiency:

How to optimise energy efficiency and technology for cooling in cities:

TIP | If in doubt about the difference between energy conservation and energy efficiency, watch this short film:

How is energy measured and how can we quantify our energy savings from energy efficiency?

We measure energy in units of power called watts (W) kilowatts (kW) or kilowatts hours (kWh). W or kW tells you the rate at which something uses electricity, like how much power it’s using at any one time. kWh are different, they tell you the total amount of electricity used over time. To understand the difference between kW and kWh, you need to think about how long an electrical device is running. A kWh measures the energy an electrical device or load uses in kW per hour.

FIG. 1: Typical energy consumption values, NEA5National Energy Action, “How much electricity do my appliances use?” No date. https://www.nea.org.uk/who-we-are/innovation-technical-evaluation/solarpv/how-much-electricity-appliances-use/

Even though different models use different amounts of electricity, the table shows some common amounts. Every appliance should tell you how much it uses in watts (W) or kilowatts (kW) – and remember, 1 kilowatt (kW) is the same as 1,000 watts (W).

Watch this video to understand the difference between kW and kWh and how it helps us understand our electricity bill:

How do we compare the energy efficiency of appliances in our homes?

In 2021 the European Commission introduced a new and stricter energy rating system (energy label) for things like refrigerators and washing machines. They use the letters from A to G. “A” means it’s super energy-efficient, and ‘G’ means it uses a lot of energy. This stricter rating system helps companies continue to make better, more energy-saving appliances.

The application of this energy rating system is mandatory for appliances that use more than 40 watts of electricity. You’ll see them on lots of common appliances like fridges, freezers, dishwashers, washing machines, TVs, computer monitors, and light bulbs6European Commission, “Understanding the Energy Label”. No date. https://energy-efficient-products.ec.europa.eu/ecodesign-and-energy-label/understanding-energy-label_en.

FIG. 2: EU Energy Label example

The energy label indicates a product’s energy efficiency class and also includes information such as noise level, power, size and weight.

To learn more about the EU Energy label and how to use it, watch this video:

Take a look at this Fact Sheet about the EU Energy Label.

How do we compare the energy efficiency of various countries over time?

We often use something called ‘energy intensity’ to measure how energy-efficient a country is. It’s like figuring out how much energy a country needs to maintain its Gross Domestic Product (GDP)7International Energy Agency, “SDG7 Data and Projections, Energy Intensity”. No date. , https://www.iea.org/reports/sdg7-data-and-projections/energy-intensity#abstrac. This metric helps understand how much energy it takes to produce things and if the country is getting better at saving energy over time.

If a country has low energy intensity, it usually means it uses less energy to produce the same amount of goods and services. Conversely, a higher energy intensity suggests a greater energy use for the same economic output, often reflecting less efficiency.

However, there’s more to it. Sometimes, a country might have high energy intensity because it has a lot of natural resources (as observed in Canada and the Russian Federation), or it might have low energy intensity because it has a big service industry or tourism. So, just looking at energy intensity doesn’t tell us everything8Nazim Hajiyev, Vagif Guliyev, Samira Abdullayeva, Esmira Abdullayeva, “Energy intensity of the economy in the context of rethinking growth within a limited planet”. November 2023. Energy Strategy Reviews, Volume 50, https://www.sciencedirect.com/science/article/pii/S2211467X23001967.

Even so, energy intensity is still useful. We can use it to see if a country is improving its energy use over time. Governments and groups use it to plan and check if their energy-saving plans are working.

View this website to learn how your country scores on energy efficiency.

How can digitalisation support energy efficiency?

‘Digitalisation’ describes the growing application of ICT across the economy, leading to increasing volumes of data, rapid progress in advanced analytics, and greater connectivity between humans, devices and machines (including machine-to-machine)9International Energy Agency, “Energy efficiency and digitalisation – Analysis.” 2019. https://www.iea.org/articles/energy-efficiency-and-digitalisation. It can help us use energy more wisely, both in our homes and the energy system as a whole.

Digitalisation offers the potential to increase energy efficiency through technologies that collect and analyse data about how we use energy and propose the best ways to save it.  Sometimes this happens automatically, or sometimes people have to step in and make changes (see Figure 2).

FIG. 3: How digitalisation can improve efficiency through a combination of technologies10International Energy Agency, 2019

Digitalisation is a powerful tool for optimising energy efficiency, especially in busy cities. The density of activities in cities creates economies of scale and scope with a high potential. By increasing the connectivity of buildings, appliances, equipment and transport systems, digitalisation provides a wealth of opportunities to use less energy and react quickly to changes. Imagine the power grid manager being able to briefly pause your dishwasher (or thousands of dishwashers) to prevent power outages11International Energy Agency, 2021.

But remember, all those computers and servers collecting and analysing data also need electricity! If we’re not careful, using more digital technology could actually use more energy. We need to use it smartly to make sure it helps, not hurts12International Energy Agency, 2019.

Have fun and learn about energy efficiency by playing the game:

https://thinkenergy.org/ee-poster/index-esk.html

CASE STUDIES

In Hyllie, a new smart district in Malmö, Sweden, the city has created one of the world’s most energy-efficient neighbourhoods by using a mix of renewable energy and smart technology. Since construction began in 2010, Hyllie has been designed to run entirely on energy from solar panels, wind turbines, biogas from food waste, and even captured heat from buildings and factories. Instead of letting energy go to waste, systems in Hyllie recycle heat from data centres and supermarkets and reuse it to warm nearby homes. A digital system called ectocloud acts like a “brain” for the energy network. It constantly calculates which buildings need heating or cooling and sends the right amount of energy to the right place at the right time. This makes sure nothing is wasted, and everyone gets the energy they need efficiently.

This smart energy system is part of a larger goal: Malmö plans to become a city powered entirely by 100% sustainable energy by 2030. The success of Hyllie has already inspired other parts of the city and even other countries; E.ON, the energy company involved, is now building a similar system in London. Hyllie’s example shows how using clever energy-saving technology can help cities reduce pollution and protect nature, while still being great places to live. It also helps Sweden meet global climate promises, like the United Nations Sustainable Development Goals (especially SDG 11: Sustainable Cities and Communities) and the Paris Agreement, which aim to stop global warming13City of Malmo, 2023, “Climate Smart Hyllie”. Startsida Malmö stad. No date. https://malmo.se/Welcome-to-Malmo/Sustainable-Malmo/Sustainable-Urban-Development/Hyllie/Climate-smart-Hyllie.html.

Bibliography

These articles have been reviewed using AI in order to align the style and length of each article. The research and content are original to the authors noted.

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