One spot weld requires about a comparable amount of a cup of coffee. This is a tangible value and is definitely competitive compared with other joining processes. It is well known that there are other consumers in the system. Few people consciously think about this.
It starts with the welding control. This includes a control system and a power section. The power required in part for welding is provided and buffered in capacitors. The control system is essentially a small computer that also requires permanent power. The systems from Harms & Wende offer possibilities for saving power here. For example, the power section can be switched off when required, while the control system or only the field bus remains on standby. The standby consumption is about 20 W depending on the equipment and can be reduced by using the available possibilities. Most users have this consumption in mind. The further chain is interesting. The mid-frequency systems are operated and run via a central computer. The data is stored in a database and ﬁnds its way to the cloud. The cloud also requires energy. The Internet gobbles up 20 % of the electricity in Germany. A search query on Google requires about 0.4 watt hours of electricity and thus releases 0.2 g of CO2. This happens with an estimated 5 billion search queries per day!
This makes it worthwhile to take a look at this aspect of welding. In a fast-running production, up to 100 MB per hour are generated when extensive welding data is stored. This results in a data volume of 20 GB per year and controller. This can be easily calculated and is quite a lot. To make this size and consumption tangible: per gigabyte and year, the Internet generates approx. 30 g of CO2 or requires approx. 0.1 kWh of electricity. A welding controller thus consumes about 1-2 kWh of electricity per year in the cloud. That doesn’t sound like much at first. But this amount of data adds up and over 10 years 50-100 kWh are consumed. For a large automotive production with several hundred controllers, this is consumption in the range of MWh per year and several hundred kilos of CO2 can be expected. These are considerable quantities.