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| 50559 | Primary, secondary, final, and useful energy: Why are there different ways of measuring energy? | energy-definitions | post | publish | <!-- wp:paragraph --> <p>There are four key ways of measuring energy. These metrics capture the transformations and losses that occur across the energy chain.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The differences between the first stage (‘primary energy’) and the last (‘useful energy’) can be very large. This means it’s important to be clear about which metric is being referred to when people speak about data on “energy”.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>In this post I explain these four metrics.</p> <!-- /wp:paragraph --> <!-- wp:heading {"level":3} --> <h3>Primary, secondary, final and useful energy: the four measures relate to the four stages of the energy chain</h3> <!-- /wp:heading --> <!-- wp:columns --> <div class="wp-block-columns"><!-- wp:column --> <div class="wp-block-column"><!-- wp:paragraph --> <p>In the visualization, I’ve shown the four stages of the chain and provided examples of this pathway for different products.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Primary energy: </strong>Primary energy is the energy as it is available as resources – such as the fuels that are burnt in power plants – before it has been transformed. This relates to the coal before it has been burned; the uranium; or the barrels of oil.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>This is the most widely available statistic and very commonly used.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Secondary energy:</strong> When we convert primary energy into a transportable form we speak of secondary energy<strong>. </strong>For example, when we burn coal in a power plant to produce electricity, electricity is a form of secondary energy. Secondary energy includes liquid fuels (such as gasoline and diesel – which are refined oil), electricity, and heat.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Final energy:</strong> Once we’ve transported secondary energy <em>to the consumer</em> we have <strong>final energy</strong>. Final energy is what a consumer buys and receives, such as electricity in their home; heating; or petrol at the fuel pump.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Useful energy: </strong>This is the last step. It is the energy that goes towards the desired output of the end-use application. For a lightbulb, it’s the amount of light that is produced. For a car, it’s the amount of kinetic (movement) energy that is produced.</p> <!-- /wp:paragraph --></div> <!-- /wp:column --> <!-- wp:column --> <div class="wp-block-column"><!-- wp:image {"id":50561,"sizeSlug":"full","linkDestination":"none"} --> <figure class="wp-block-image size-full"><img src="https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy.png" alt="" class="wp-image-50561"/></figure> <!-- /wp:image --></div> <!-- /wp:column --></div> <!-- /wp:columns --> <!-- wp:heading {"level":3} --> <h3>Each stage of the energy chain results in losses</h3> <!-- /wp:heading --> <!-- wp:columns --> <div class="wp-block-columns"><!-- wp:column --> <div class="wp-block-column"><!-- wp:paragraph --> <p>As the illustration above showed, at each stage of the energy chain, some energy is lost or wasted. The four metrics capture energy losses in the following ways.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Primary to secondary energy:</strong> the conversion of primary to secondary energy can be <em>very</em> inefficient. In thermal power plants – which convert fossil fuels, biomass or nuclear into electricity, up to <a href="https://www.eia.gov/todayinenergy/detail.php?id=44436">two-thirds of the primary energy</a> is wasted as heat. For every three units of energy we put in, you get just one unit of electricity out.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Because primary energy losses are particularly large for fossil fuels, their contribution to energy demand is much higher in primary energy terms compared to the other three ways of measuring energy. This is important to know because it can skew our perception of how much of a contribution low-carbon sources make: in primary energy terms they can appear smaller because they are diluted by the wasted energy that comes along with fossil fuel burning.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Secondary to final energy: </strong>we also lose energy in the process of delivering it to the consumer. This is called a ‘transmission and distribution’ loss. When we transport electricity from a power plant (secondary energy) to homes (final energy), for example, we lose some while transmitting it through power lines.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p><strong>Final to useful energy: </strong>no appliance is completely efficient in providing <em>only</em> the desired output that we want. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>For a lightbulb, the useful energy – what we want – is the <em>light</em>. But bulbs also produce some heat. The useful energy from cars is movement. But engines also produce heat and noise.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Any energy that is not used specifically for the desired use of an appliance is waste.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The energy we need as the end-user is often a small fraction of what goes into the top of the system. We see this in the schematic.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>The world produces a lot of energy, and most of it is lost along the way. The four different measures capture the energy that is available at different stages along this chain.</p> <!-- /wp:paragraph --></div> <!-- /wp:column --> <!-- wp:column --> <div class="wp-block-column"><!-- wp:image {"id":50562,"sizeSlug":"full","linkDestination":"none"} --> <figure class="wp-block-image size-full"><img src="https://owid.cloud/app/uploads/2022/04/Primary-energy-losses.png" alt="" class="wp-image-50562"/></figure> <!-- /wp:image --></div> <!-- /wp:column --></div> <!-- /wp:columns --> <!-- wp:heading {"level":3} --> <h3>Looking at the four stages of the energy chain can help us to identify inefficiencies</h3> <!-- /wp:heading --> <!-- wp:columns --> <div class="wp-block-columns"><!-- wp:column --> <div class="wp-block-column"><!-- wp:paragraph --> <p>There are valid reasons to look at any of the energy metrics individually. But we need to be aware of what the differences mean, because they can be very large. </p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>One good reason why we want to study each of these measures is that they tell us about what options we have to reduce inefficiencies in our energy system.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>A very efficient energy system is one in which primary and useful energy use are very similar. We are currently far away from such a system. The inefficiency losses are often large.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>We can reduce losses from <strong>primary to secondary energy</strong> by transitioning away from fossil fuels because the losses for these sources are particularly high. This reduces the amount of heat lost from converting these raw fuels into a usable form, such as electricity.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>We can reduce losses from <strong>secondary to final energy </strong>by reducing transmission and distribution losses. This means creating more effective energy delivery networks, such as better-integrated electricity grids.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>We can reduce losses from <strong>final to usable energy </strong>by improving the efficiency of final appliances. Lightbulbs today are <a href="https://www.eia.gov/todayinenergy/detail.php?id=18671">much more efficient</a> than they used to be – they convert more energy into light, and less into heat. Car engines have become more efficient. This is especially true for electric vehicles; they convert much more final energy into kinetic energy, and lose much less as heat and noise. On average they lose just 15% to 20%, <a href="https://www.fueleconomy.gov/feg/atv-ev.shtml">compared to losses</a> between 64% to 75% in a gasoline engine.</p> <!-- /wp:paragraph --> <!-- wp:paragraph --> <p>Looking at the energy chain as a whole, we can identify where the largest losses occur, and where interventions can have the biggest impact.</p> <!-- /wp:paragraph --> <!-- wp:separator --> <hr class="wp-block-separator"/> <!-- /wp:separator --> <!-- wp:heading {"level":5} --> <h5>Keep reading at <em>Our World in Data</em></h5> <!-- /wp:heading --> <!-- wp:owid/prominent-link {"title":"","linkUrl":"https://ourworldindata.org/energy","className":"is-style-thin"} /--> <!-- wp:owid/prominent-link {"title":"","linkUrl":"https://ourworldindata.org/worlds-energy-problem","className":"is-style-thin"} /--> <!-- wp:owid/prominent-link {"title":"","linkUrl":"https://ourworldindata.org/explorers/energy","className":"is-style-thin"} --> <!-- wp:paragraph --> <p></p> <!-- /wp:paragraph --> <!-- /wp:owid/prominent-link --></div> <!-- /wp:column --> <!-- wp:column --> <div class="wp-block-column"></div> <!-- /wp:column --></div> <!-- /wp:columns --> <!-- wp:separator --> <hr class="wp-block-separator"/> <!-- /wp:separator --> <!-- wp:paragraph --> <p><strong>Acknowledgments: </strong>I would like to thank Max Roser for useful feedback and suggestions on this article.</p> <!-- /wp:paragraph --> | {
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2022-04-04 09:29:10 | 2024-02-16 14:22:53 | 19R3CYZqGslSjsZ1QPOwIjjVUdvhqMcA_Rx4QTVhPA3Q | [
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Why are there four different ways of measuring energy? And how does each measure help us to understand the energy system? | 2022-04-04 10:29:10 | 2022-04-04 09:30:45 | https://ourworldindata.org/wp-content/uploads/2022/04/energy-accounting-thumbnail.png | {} |
There are four key ways of measuring energy. These metrics capture the transformations and losses that occur across the energy chain. The differences between the first stage (‘primary energy’) and the last (‘useful energy’) can be very large. This means it’s important to be clear about which metric is being referred to when people speak about data on “energy”. In this post I explain these four metrics. ## Primary, secondary, final and useful energy: the four measures relate to the four stages of the energy chain In the visualization, I’ve shown the four stages of the chain and provided examples of this pathway for different products. **Primary energy: **Primary energy is the energy as it is available as resources – such as the fuels that are burnt in power plants – before it has been transformed. This relates to the coal before it has been burned; the uranium; or the barrels of oil. This is the most widely available statistic and very commonly used. **Secondary energy:** When we convert primary energy into a transportable form we speak of secondary energy**. **For example, when we burn coal in a power plant to produce electricity, electricity is a form of secondary energy. Secondary energy includes liquid fuels (such as gasoline and diesel – which are refined oil), electricity, and heat. **Final energy:** Once we’ve transported secondary energy _to the consumer_ we have **final energy**. Final energy is what a consumer buys and receives, such as electricity in their home; heating; or petrol at the fuel pump. **Useful energy: **This is the last step. It is the energy that goes towards the desired output of the end-use application. For a lightbulb, it’s the amount of light that is produced. For a car, it’s the amount of kinetic (movement) energy that is produced. <Image filename="Four-ways-of-measuring-energy.png" alt=""/> ## Each stage of the energy chain results in losses As the illustration above showed, at each stage of the energy chain, some energy is lost or wasted. The four metrics capture energy losses in the following ways. **Primary to secondary energy:** the conversion of primary to secondary energy can be _very_ inefficient. In thermal power plants – which convert fossil fuels, biomass or nuclear into electricity, up to [two-thirds of the primary energy](https://www.eia.gov/todayinenergy/detail.php?id=44436) is wasted as heat. For every three units of energy we put in, you get just one unit of electricity out. Because primary energy losses are particularly large for fossil fuels, their contribution to energy demand is much higher in primary energy terms compared to the other three ways of measuring energy. This is important to know because it can skew our perception of how much of a contribution low-carbon sources make: in primary energy terms they can appear smaller because they are diluted by the wasted energy that comes along with fossil fuel burning. **Secondary to final energy: **we also lose energy in the process of delivering it to the consumer. This is called a ‘transmission and distribution’ loss. When we transport electricity from a power plant (secondary energy) to homes (final energy), for example, we lose some while transmitting it through power lines. **Final to useful energy: **no appliance is completely efficient in providing _only_ the desired output that we want. For a lightbulb, the useful energy – what we want – is the _light_. But bulbs also produce some heat. The useful energy from cars is movement. But engines also produce heat and noise. Any energy that is not used specifically for the desired use of an appliance is waste. The energy we need as the end-user is often a small fraction of what goes into the top of the system. We see this in the schematic. The world produces a lot of energy, and most of it is lost along the way. The four different measures capture the energy that is available at different stages along this chain. <Image filename="Primary-energy-losses.png" alt=""/> ## Looking at the four stages of the energy chain can help us to identify inefficiencies There are valid reasons to look at any of the energy metrics individually. But we need to be aware of what the differences mean, because they can be very large. One good reason why we want to study each of these measures is that they tell us about what options we have to reduce inefficiencies in our energy system. A very efficient energy system is one in which primary and useful energy use are very similar. We are currently far away from such a system. The inefficiency losses are often large. We can reduce losses from **primary to secondary energy** by transitioning away from fossil fuels because the losses for these sources are particularly high. This reduces the amount of heat lost from converting these raw fuels into a usable form, such as electricity. We can reduce losses from **secondary to final energy **by reducing transmission and distribution losses. This means creating more effective energy delivery networks, such as better-integrated electricity grids. We can reduce losses from **final to usable energy **by improving the efficiency of final appliances. Lightbulbs today are [much more efficient](https://www.eia.gov/todayinenergy/detail.php?id=18671) than they used to be – they convert more energy into light, and less into heat. Car engines have become more efficient. This is especially true for electric vehicles; they convert much more final energy into kinetic energy, and lose much less as heat and noise. On average they lose just 15% to 20%, [compared to losses](https://www.fueleconomy.gov/feg/atv-ev.shtml) between 64% to 75% in a gasoline engine. Looking at the energy chain as a whole, we can identify where the largest losses occur, and where interventions can have the biggest impact. #### Keep reading at _Our World in Data_ ### https://ourworldindata.org/energy ### https://ourworldindata.org/worlds-energy-problem ### https://ourworldindata.org/explorers/energy **Acknowledgments: **I would like to thank Max Roser for useful feedback and suggestions on this article. | {
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"rendered": "\n<p>There are four key ways of measuring energy. These metrics capture the transformations and losses that occur across the energy chain.</p>\n\n\n\n<p>The differences between the first stage (\u2018primary energy\u2019) and the last (\u2018useful energy\u2019) can be very large. This means it\u2019s important to be clear about which metric is being referred to when people speak about data on \u201cenergy\u201d.</p>\n\n\n\n<p>In this post I explain these four metrics.</p>\n\n\n\n<h3>Primary, secondary, final and useful energy: the four measures relate to the four stages of the energy chain</h3>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<p>In the visualization, I\u2019ve shown the four stages of the chain and provided examples of this pathway for different products.</p>\n\n\n\n<p><strong>Primary energy: </strong>Primary energy is the energy as it is available as resources \u2013 such as the fuels that are burnt in power plants \u2013 before it has been transformed. This relates to the coal before it has been burned; the uranium; or the barrels of oil.</p>\n\n\n\n<p>This is the most widely available statistic and very commonly used.</p>\n\n\n\n<p><strong>Secondary energy:</strong> When we convert primary energy into a transportable form we speak of secondary energy<strong>. </strong>For example, when we burn coal in a power plant to produce electricity, electricity is a form of secondary energy. Secondary energy includes liquid fuels (such as gasoline and diesel \u2013 which are refined oil), electricity, and heat.</p>\n\n\n\n<p><strong>Final energy:</strong> Once we\u2019ve transported secondary energy <em>to the consumer</em> we have <strong>final energy</strong>. Final energy is what a consumer buys and receives, such as electricity in their home; heating; or petrol at the fuel pump.</p>\n\n\n\n<p><strong>Useful energy: </strong>This is the last step. It is the energy that goes towards the desired output of the end-use application. For a lightbulb, it\u2019s the amount of light that is produced. For a car, it\u2019s the amount of kinetic (movement) energy that is produced.</p>\n</div>\n\n\n\n<div class=\"wp-block-column\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"2033\" height=\"1173\" src=\"https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy.png\" alt=\"\" class=\"wp-image-50561\" srcset=\"https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy.png 2033w, https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy-400x231.png 400w, https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy-800x462.png 800w, https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy-150x87.png 150w, https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy-768x443.png 768w, https://owid.cloud/app/uploads/2022/04/Four-ways-of-measuring-energy-1536x886.png 1536w\" sizes=\"(max-width: 2033px) 100vw, 2033px\" /></figure>\n</div>\n</div>\n\n\n\n<h3>Each stage of the energy chain results in losses</h3>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<p>As the illustration above showed, at each stage of the energy chain, some energy is lost or wasted. The four metrics capture energy losses in the following ways.</p>\n\n\n\n<p><strong>Primary to secondary energy:</strong> the conversion of primary to secondary energy can be <em>very</em> inefficient. In thermal power plants \u2013 which convert fossil fuels, biomass or nuclear into electricity, up to <a href=\"https://www.eia.gov/todayinenergy/detail.php?id=44436\">two-thirds of the primary energy</a> is wasted as heat. For every three units of energy we put in, you get just one unit of electricity out.</p>\n\n\n\n<p>Because primary energy losses are particularly large for fossil fuels, their contribution to energy demand is much higher in primary energy terms compared to the other three ways of measuring energy. This is important to know because it can skew our perception of how much of a contribution low-carbon sources make: in primary energy terms they can appear smaller because they are diluted by the wasted energy that comes along with fossil fuel burning.</p>\n\n\n\n<p><strong>Secondary to final energy: </strong>we also lose energy in the process of delivering it to the consumer. This is called a \u2018transmission and distribution\u2019 loss. When we transport electricity from a power plant (secondary energy) to homes (final energy), for example, we lose some while transmitting it through power lines.</p>\n\n\n\n<p><strong>Final to useful energy: </strong>no appliance is completely efficient in providing <em>only</em> the desired output that we want. </p>\n\n\n\n<p>For a lightbulb, the useful energy \u2013 what we want \u2013 is the <em>light</em>. But bulbs also produce some heat. The useful energy from cars is movement. But engines also produce heat and noise.</p>\n\n\n\n<p>Any energy that is not used specifically for the desired use of an appliance is waste.</p>\n\n\n\n<p>The energy we need as the end-user is often a small fraction of what goes into the top of the system. We see this in the schematic.</p>\n\n\n\n<p>The world produces a lot of energy, and most of it is lost along the way. The four different measures capture the energy that is available at different stages along this chain.</p>\n</div>\n\n\n\n<div class=\"wp-block-column\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"1866\" height=\"1068\" src=\"https://owid.cloud/app/uploads/2022/04/Primary-energy-losses.png\" alt=\"\" class=\"wp-image-50562\" srcset=\"https://owid.cloud/app/uploads/2022/04/Primary-energy-losses.png 1866w, https://owid.cloud/app/uploads/2022/04/Primary-energy-losses-400x229.png 400w, https://owid.cloud/app/uploads/2022/04/Primary-energy-losses-800x458.png 800w, https://owid.cloud/app/uploads/2022/04/Primary-energy-losses-150x86.png 150w, https://owid.cloud/app/uploads/2022/04/Primary-energy-losses-768x440.png 768w, https://owid.cloud/app/uploads/2022/04/Primary-energy-losses-1536x879.png 1536w\" sizes=\"(max-width: 1866px) 100vw, 1866px\" /></figure>\n</div>\n</div>\n\n\n\n<h3>Looking at the four stages of the energy chain can help us to identify inefficiencies</h3>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<p>There are valid reasons to look at any of the energy metrics individually. But we need to be aware of what the differences mean, because they can be very large. </p>\n\n\n\n<p>One good reason why we want to study each of these measures is that they tell us about what options we have to reduce inefficiencies in our energy system.</p>\n\n\n\n<p>A very efficient energy system is one in which primary and useful energy use are very similar. We are currently far away from such a system. The inefficiency losses are often large.</p>\n\n\n\n<p>We can reduce losses from <strong>primary to secondary energy</strong> by transitioning away from fossil fuels because the losses for these sources are particularly high. This reduces the amount of heat lost from converting these raw fuels into a usable form, such as electricity.</p>\n\n\n\n<p>We can reduce losses from <strong>secondary to final energy </strong>by reducing transmission and distribution losses. This means creating more effective energy delivery networks, such as better-integrated electricity grids.</p>\n\n\n\n<p>We can reduce losses from <strong>final to usable energy </strong>by improving the efficiency of final appliances. Lightbulbs today are <a href=\"https://www.eia.gov/todayinenergy/detail.php?id=18671\">much more efficient</a> than they used to be \u2013 they convert more energy into light, and less into heat. Car engines have become more efficient. This is especially true for electric vehicles; they convert much more final energy into kinetic energy, and lose much less as heat and noise. On average they lose just 15% to 20%, <a href=\"https://www.fueleconomy.gov/feg/atv-ev.shtml\">compared to losses</a> between 64% to 75% in a gasoline engine.</p>\n\n\n\n<p>Looking at the energy chain as a whole, we can identify where the largest losses occur, and where interventions can have the biggest impact.</p>\n\n\n\n<hr class=\"wp-block-separator\"/>\n\n\n\n<h5>Keep reading at <em>Our World in Data</em></h5>\n\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/energy</link-url>\n <title></title>\n <content></content>\n <figure></figure>\n </block>\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/worlds-energy-problem</link-url>\n <title></title>\n <content></content>\n <figure></figure>\n </block>\n\n <block type=\"prominent-link\" style=\"is-style-thin\">\n <link-url>https://ourworldindata.org/explorers/energy</link-url>\n <title></title>\n <content>\n\n<p></p>\n\n</content>\n <figure></figure>\n </block></div>\n\n\n\n<div class=\"wp-block-column\"></div>\n</div>\n\n\n\n<hr class=\"wp-block-separator\"/>\n\n\n\n<p><strong>Acknowledgments: </strong>I would like to thank Max Roser for useful feedback and suggestions on this article.</p>\n",
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