How primary energy is measured has changed across our charts

Some of the most popular charts on Our World in Data are about energy production and consumption : how much energy countries produce, how they compare per person, and what sources this energy mix comes from.

《我们的数据世界》中一些最受欢迎的图表是关于能源生产和消费的：各国生产了多少能源、人均能源比较情况以及这种能源组合的来源。

But when people talk about “energy”, they’re not always talking about the same thing.

但当人们谈论“能源”时，他们谈论的并不总是同一件事。

There are different ways of measuring energy, from the very top of the chain — for example, coal going into a power plant — to the final link in the chain — the light that eventually comes out of a lightbulb.

测量能量的方法有多种，从能量链的最顶端（例如，进入发电厂的煤炭）到能量链的最后一环（最终从灯泡中发出的光）。

The differences between the first stage (primary energy) and the last (useful energy) can be very large, so it’s important to be clear about which metric is being referred to when people speak about data on “energy”.

第一阶段（初级能源）和最后阶段（有用能源）之间的差异可能非常大，因此当人们谈论“能源”数据时，明确所指的指标非常重要。

In a previous article , I walked through the four different ways of measuring energy.

在上一篇文章中，我介绍了测量能量的四种不同方法。

I’ve included the main visualization below.

我在下面包含了主要的可视化。

On Our World in Data, we present data on both primary energy and secondary energy in the form of electricity generation .

在我们的数据世界中，我们以发电的形式提供一次能源和二次能源的数据。

We would like to present final and useful energy too, but international datasets on these metrics are, unfortunately, not openly available.

我们也想提供最终和有用的能源，但不幸的是，这些指标的国际数据集尚未公开。

But even when it comes to primary energy , there are differences in how this is calculated.

但即使涉及一次能源，其计算方式也存在差异。

Recently, the methodology used by our main data source changed.

最近，我们的主要数据源使用的方法发生了变化。

In this article, I want to explain this change and how it affects our charts on this topic.

在本文中，我想解释这一变化以及它如何影响我们有关该主题的图表。

The main difference in the calculation of primary energy comes down to how we account for the energy wasted when we burn fossil fuels.

一次能源计算的主要区别在于我们如何计算燃烧化石燃料时浪费的能源。

If you put coal into a power plant, around two-thirds of its energy value is wasted as heat, and only one-third is converted into electricity.

如果将煤炭投入发电厂，其能源价值的大约三分之二会被浪费为热量，只有三分之一会转化为电力。

For gas, roughly half is wasted, and half is converted to electricity.

对于天然气来说，大约一半被浪费，一半转化为电力。

So to get 1 kilowatt-hour (kWh) of electricity out, you need to put in the equivalent of 3 kWh of coal and 2 kWh of gas.

因此，要产生 1 千瓦时 (kWh) 的电力，您需要投入相当于 3 千瓦时的煤炭和 2 千瓦时的天然气。

I’ve sketched this in the diagram below.

我在下图中描绘了这一点。

This is not the case with non-combustible sources, such as solar, wind, and hydropower: they just deliver electricity.

太阳能、风能和水力发电等不可燃能源的情况并非如此：它们只是提供电力。

We just see 1 kWh of electricity output; there’s no upstream fuel input or waste along the way.

我们只看到1千瓦时的电力输出；沿途没有上游燃料输入或废物。

That means that 1 kWh of electricity from coal, 1 kWh from gas, and 1 kWh from solar will look very different when measured in primary energy terms.

这意味着，以一次能源衡量时，1 千瓦时的煤炭发电、1 千瓦时的天然气发电和 1 千瓦时的太阳能发电看起来会有很大不同。

It would be equivalent to 3 kWh of coal, 2 kWh of gas, and 1 kWh of solar.

这相当于 3 千瓦时的煤炭、2 千瓦时的天然气和 1 千瓦时的太阳能。

Expressed as a share of primary energy, coal would make up half of our energy mix, gas one-third, and solar one-sixth.

以一次能源的比例来表示，煤炭将占我们能源结构的一半，天然气占三分之一，太阳能占六分之一。

Even though the electricity we get out — and can actually use — is split evenly between coal, gas, and solar, each makes up one-third.

尽管我们发出的电力（并且实际可以使用的电力）由煤炭、天然气和太阳能平均分配，但各占三分之一。

Our main data source for primary energy is the Energy Institute’s Statistical Review of World Energy .

我们的一次能源主要数据来源是能源研究所的世界能源统计回顾。

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It historically presented data on primary energy using the substitution method .

它历来使用替代法提供一次能源数据。

This method attempts to account for the inefficiency of fossil fuels by converting renewable and nuclear energy into their “fossil equivalents”.

该方法试图通过将可再生能源和核能转化为“化石能源”来解决化石燃料的低效率问题。

In other words, it asks: if this electricity had been generated from fossil fuels instead, how much fuel would have been used?

换句话说，它问：如果这些电力是由化石燃料产生的，那么会使用多少燃料？

To get this figure, it divides renewable and nuclear electricity generation by a typical thermal power plant efficiency factor, which is around 38% to 41%.

为了得到这个数字，它将可再生能源发电和核电发电除以典型火力发电厂的效率系数，该系数约为 38% 至 41%。

So, if a country generates 100 terawatt-hours (TWh) of electricity from solar, that amount is divided by 40% to get a “fossil equivalent” of 250 TWh.

因此，如果一个国家通过太阳能发电 100 太瓦时 (TWh)，则将该数量除以 40% 即可得到 250 TWh 的“化石当量”。

This means renewable energy figures are all inflated by a factor of around 2.5.

这意味着可再生能源数据全部夸大了 2.5 倍左右。

The net effect of this is that non-fossil fuel sources are measured as the amount of fossil fuel inputs they would have substituted .

其净效应是，非化石燃料来源按照其替代的化石燃料投入量来衡量。

This has two impacts:

这有两个影响：

The Energy Institute no longer publishes primary energy data based on the substitution method.

能源研究所不再发布基于替代法的一次能源数据。

Instead, it’s based on the physical energy content method, giving a measure of total energy supply .

相反，它基于物理能量含量方法，给出总能量供应的度量。

In our charts, we still refer to this as primary energy.

在我们的图表中，我们仍然将其称为一次能源。

The physical energy content method does not make any adjustments to solar photovoltaic (PV), wind, and hydropower generation.

物理能含量法不对太阳能光伏（PV）、风能和水力发电进行任何调整。

100 TWh of solar electricity generation is included as 100 TWh of primary energy (rather than 250 TWh in the substitution method approach).

100 TWh 太阳能发电计入 100 TWh 一次能源（而不是替代法中的 250 TWh）。

It does still make adjustments for other renewables — geothermal, concentrating solar, and biomass — where heat is an input (these have thermal efficiency factors applied to them).

它仍然对其他以热量为输入的可再生能源（地热、聚光太阳能和生物质）进行调整（这些可再生能源应用了热效率系数）。

It still measures fossil fuels in terms of their raw, calorific value — how much energy is produced when burned (including wasted energy).

它仍然根据化石燃料的原始热值来衡量化石燃料，即燃烧时产生的能量（包括浪费的能量）。

Nuclear power generation is treated slightly differently.

核能发电的处理方式略有不同。

It still uses a thermal equivalent conversion.

它仍然使用热当量转换。

This is because nuclear plants operate like a thermal plant: fission heat is the input for steam, which turns a turbine to generate electricity.

这是因为核电站的运行方式类似于火力发电厂：裂变热是蒸汽的输入，蒸汽驱动涡轮机发电。

To get the total nuclear energy supply, the electricity output is divided by the average thermal efficiency of nuclear, which is around 33%.

为了得到核能供应总量，用发电量除以核能的平均热效率（约为33%）。

So, 100 TWh of nuclear power generation would equate to around 300 TWh of physical energy input.

因此，100 TWh 的核能发电相当于约 300 TWh 的物理能源输入。

Almost all of our charts on primary energy now use this physical energy content method in line with the data source; if you have previously followed or used these metrics, you might notice a change in the numbers.

现在我们几乎所有的一次能源图表都使用这种与数据源一致的物理能量含量方法；如果您之前关注或使用过这些指标，您可能会注意到数字的变化。

In the chart below, I’ve shown how 100 TWh of coal, solar, and nuclear power compare under the substitution method versus the physical energy content method.

在下图中，我展示了 100 TWh 的煤炭、太阳能和核电在替代法与物理能量含量法下的比较。

We send two regular newsletters so you can stay up to date on our work and receive curated highlights from across Our World in Data.

我们定期发送两份时事通讯，以便您及时了解我们的工作并接收来自“我们的数据世界”的精选亮点。

This is purely an accounting change; nothing physical in the energy system has changed.

这纯粹是会计变更；能量系统中的任何物理现象都没有改变。

It applies to the entire historical series of primary energy, not just the most recent year.

它适用于一次能源的整个历史系列，而不仅仅是最近一年。

That means the methodology applied to the data is consistent across decades.

这意味着应用于数据的方法几十年来都是一致的。

Explore global data on where our energy comes from, and how this is changing.

探索有关我们的能源从何而来及其变化的全球数据。

This was previously published as the BP Statistical Review of World Energy.

该报告此前曾作为《BP 世界能源统计评论》出版。

This is not the case for some other, smaller renewable energy sources, such as geothermal.

对于其他一些较小的可再生能源（例如地热能）来说，情况并非如此。

Our articles and data visualizations rely on work from many different people and organizations.

我们的文章和数据可视化依赖于许多不同的人和组织的工作。

When citing this article, please also cite the underlying data sources.

引用本文时，请同时注明底层数据来源。

This article can be cited as:

这篇文章可以引用为：

We are a live site and we keep our work maintained.

我们是一个活跃的网站，我们会保持我们的工作。

So our articles are often changed, including the data.

所以我们的文章经常改，包括数据。

You can browse previous versions of this work here.

您可以在此处浏览此作品的先前版本。