Most installed lighting systems are outdated and have poor energy efficiency. Therefore, there is an urgent need for smart LED lighting systems that are energy efficient, easy to install, and inexpensive. In this article, a leader-follower smart office lighting control system based on Internet of Things (IoT) technology is proposed to satisfy the goal of saving energy through the coordinated operation of a system counter and an infrared (IR) human movement sensor (passive infrared (PIR) sensor). When no one is present in the space, all indoor LED lights are turned to low-light mode. Otherwise, all indoor LED lights are turned to high-light mode together. In addition to change the brightness of LED lights in the same area at the same time to save energy, the parameters of the LED lights can be set directly through microcontrollers via the IoT and the internet. If a general 15 W T8 LED tube (noninduction light) is replaced with the proposed leader-follower office lighting system (assuming that the office is occupied for 10 hours a day and that the hourly low-light mode is 20 minutes), then the power-saving rate is as high as 28.13%.

Reducing residential and industrial electricity consumption has been a goal of governments around the world. Lighting sources account for a large portion of the whole energy/power consumption. Unfortunately, most of the existing installed lighting systems are ancient and have poor energy efficiency. Today, many manufacturers have introduced light-controlling systems into the current market. However, existing light controlling systems may not be successfully applied to buildings, streets, and industrial buildings due to high costs and difficult installation and maintenance. To combat this issue, this article presents an easy-to-install, low-cost, Master-Slave intelligent LED light-controlling system based on Internet of Things (IoT) techniques. The benefit of using the proposed system is that the brightness of the LED lights in the same zone can be changed simultaneously to save in energy consumption. Furthermore, the parameters of the LED lights can be directly set. Moreover, the related data are collected and uploaded to a cloud platform. In this article, we use 15 W T8 LED tubes (non-induction lamps) as a case study. When the proposed system is installed in a zone with few people, the energy-saving rate is as high as 90%. Furthermore, when 12 people pass by a zone within one hour, its energy-saving rate can reach 81%. Therefore, the advantages of using the proposed system include: (1) the original lamp holder can be retained; (2) no wiring is required; and (3) no server is set up. Moreover, the goal of energy saving can also be achieved. As a result, the proposed system changes the full-dark mode of the available sensor lamp to the low power low-light mode for standby. Further, it makes the sensor lamps in the same zone brighten or low-light way simultaneously, which can quickly complete large-scale energy-saving and convenient control functions of intelligent LED lighting controlling system.

Today, the world’s electricity consumption is growing rapidly, and therefore energy demands are also increasing. In the past few decades, various measures have been taken to improve equipment and system design to increase production and transmission efficiency and reduce power consumption. This article proposes a novel Internet of Things (IoT)-based temperature control power extender with two working modes of cooling and heating to solve power shortages. The power is turned on or off accurately and in a timely manner through a temperature-sensing element, thereby avoiding unnecessary power consumption to achieve the goal of energy-saving. This can directly power on or off the power extender through the Internet. It can also use a 2.4G Wi-Fi wireless transmission to transmit, for example, real-time temperature information, the switch status and the master–slave mode. Related data can be controlled, collected and uploaded to the cloud. Each proposed power extender’s temperature setting in a large-scale field can be set uniformly, and no staff is wasted to set the temperature separately. Taking a general industrial electric fan as an example, if it is changed to drive with this temperature control extension cable, and assuming that the industrial electric fan is activated for 900 s per hour, its power-saving rate is 74.75%.

In general, the sensor lamps in the corridors, stairwells, or toilets of buildings will change from completely dark to full brightness when someone passes by. It will make the human eyes feel very uncomfortable, and when the sensor lamp is completely dark, the whole corridor and stairwell will be dark, making women and children feel insecure at night. If the lighting is changed to be sensor-less, there is a serious problem of wasted energy. To solve this dilemma, we developed a new type of “LED sensor lamp with low-light mode” that changes the original “full dark mode” to “low-light mode”. As such, when someone approaches the sensor lamp, their eyes will not be uncomfortable with the momentary illumination. Furthermore, when no one passes by, the sensor lamp will stay in low-light mode, so that people returning home at night no longer have to go through dark corridors, thereby achieving safety, aesthetics, and energy-saving purposes. This new sensor lamp’s power consumption in low-light mode is only 1/10 of the high-light mode, but its brightness can be up to half of the high-light mode, making it very suitable for parking lots, corridors, stairways, or toilets of buildings. It only requires the replacement of the lamp but not the original lamp socket, yet the basic brightness can be maintained. Take the general 15W T8 LED lamp (sensor-less) as an example: if it is replaced by this new type of sensor lamp, and the place where it is installed is rarely passed by people, the power saving rate will be as high as 90%. Assuming that there are 12 passers-by per hour, the saving rate is still 81%.

Currently, the 1st generation and 2nd generation solar water heating tanks’ design is unsatisfactory in the current use situation. When hot water is used with the hot water being consumed, thus cold water will be added into the same tank at the same time, resulting in a significant drop in the temperature of the hot water in the tank and making it necessary to use an additional electric heating rod for reheating. To address this shortcoming, a 3rd generation solar water heating tank was designed to improve the situation. In other words, a “movable dividing disk” is added inside the tank to completely isolate the hot water from the cold water so that the entire tank of hot water can be 100% utilized. However, when the hot water is exhausted, the 3rd generation solar water heating tank must adopt an electric heating rod to reheat the entire tank of water or make an additional small heating tank. To solve this problem, this article develops the 4th generation intelligent energy-saving solar water heating tank, in which a “fixed dividing disk” is installed inside the water heating tank to create a cold-water heating zone of about 10% of the total capacity for local heating. This allows for an efficient and faster hot water supply, saving about 90% of energy when the first tank of hot water is used up and a separate electric heating rod is used for heating.

Ships have many uses in human social life and can be used for various purposes, such as the transportation of people and goods, military affairs, and scientific research. Generally, major ship accidents rarely occur because ships’ design and construction are completed in strict compliance with relevant regulations and international standards (Pan et al., 2020).