One众所周知的分析claims that Bitcoin consumes more than 40 Terawatt hours per year. That is more energy than we here in Ireland consume in a year. This makes sense – bitcoin operates by getting proof of work. To complete a transaction the miners in the network perform a series of operations. These consume power. But most of the work of the miners yields no useful results to those outside the network. Yet the miners earn currency for doing so. So it makes economic sense but they are using a lot of power doing number crunching of little utility.

工作证明是如何建立比特币系统的创始原则之一。然而，能源使用的规模是意外的后果。这是一个开始关注一些人，并让他们寻找alternatives。After all, you can still have a working cryptocurrency even if you got rid of a large fraction of the miners.

As I read about the power consumption of crypto currency mining networks I wondered where else the laws of unintended consequences might come to play. One area that springs to mind is the tens of billions of IoT devices expected to be in the field in the next few years. Would even a small power draw per device add up to something to worry about? After all, we are dealing with a lot of devices. To find out I thought I’d take a look at some of the numbers.

您的连接设备实际使用了多少功率？

Trying to figure out a power consumption for all these devices is difficult. Some will be battery powered. Some may harvest energy from ambient sources. Still, others will use mains supplies.

An example is a modern smartphone’s battery. It can store around 5Whr (sometimes减）可能需要每隔一天收取费用。这给了912.5WHR的年度能耗。但在我的经验中，能源效率是大多数IOT和IIT设备的关键。大多数人将瞄准低于几十多瓦的电力水平。所以，让我们平均说出他们将消耗30mW。这意味着每年的每个设备都需要〜315WHR能量（〜1.1 MJ）。

That’s not a lot over a year. But if we have 40 billion devices out there does it become significant?

拥有40亿台电源的设备。由2005年最终用户消耗的电力为16,806TWHRWikipedia。所以我们的新连接设备的数字是世界电力供应的0.07％（至少在几年前的电力）。小部分，但仍远非零。

这是什么意思？

所以，它看起来我们不会很快就无法为IoT / IIOT革命找到权力。但我们还需要从这些设备中融合和维护所有数据。这种简单的分析不是那种功率需要的因素。它也没有将其加工成有用的可操作的响应。在某些领域进行测量时，力量也是一个基本限制。拍摄衡量点没有意义，其利益超过了所需的力量的成本。

So making sure you process data at the most energy efficient location is important. Often this means processing at the edge of your IOT network. Designing your device with the lowest energy footprint remains key. But so too does understanding the end to end solution. To reduce the power it is crucial to have a good end to end architecture while still designing efficient IOT devices.