In almost all charging projects, load management comes to the fore. A few years ago, it was possible to try to solve the issue with a massive center and connection, but this causes very significant costs both in the construction and use of the infrastructure, for example in the form of power payments.

Load management should always be thought of according to the object, taking into account not only technical issues and costs, but also the life cycle of the system. The important thing is to think about the solution in such a way that in the future you will not end up in a situation where you have to make new big investments or change equipment. Many environments have been built where problems may arise in the future. Not right away, but within 5-10 years, if there will be plenty of electric cars on the property. At worst, the problems are such that the devices have to be replaced in their entirety, and the situation with regard to infrastructure has not been considered long-term enough. Many contractors are used to thinking about "correction factors", the idea of ​​which is that the power equalizes automatically for several users. In car charging, however, this idea is not properly realized in practice. We have already seen locations where electricity consumption has increased 3-4 times, as electric cars have spread quickly due to positive experiences.

When the choice of contractor and system is often made on the basis of price, it is of course a big temptation for the bidder to ignore issues that might cause problems only within approx. 10 years. Knowledge and practical experience with the systems is also new, in fact there are few destinations where there are very many people charging fully electric cars in relation to e.g. parking spaces. We have experience in a few places where electric cars have spread quickly and almost every place has a charger (the majority are still fully electric cars). The surprise is the need for peak power, which has really increased many times over, and the originally thought "practical" maximum power without load management has been quickly exceeded in some places. Load management has therefore become mandatory even for large main connections. However, once you have prepared for this, it does not cause any problems. Spot pricing and optimization further increase charging at the same time and the importance of load management is emphasized. The power fee should also be taken into account here. When charging at the same time, charging becomes very expensive due to power charges. In this case, optimization and load management become even more important and require a versatile system.

As with charging, the best starting point for load management in all areas is an OCPP-based background system and charging stations that are truly compatible with it at the device level. In our opinion, the system as a whole should be such that it works at least in the future also in the new 2.01 or 2.1 versions. In addition, it cannot be emphasized that by choosing truly OCPP compatible devices, you will not end up in a lock-in situation where you cannot change the device manufacturer/network service. Load management is also broadly defined in the OCPP standard for numerous different options. By selecting compatible charging stations directly at the device level (not the manufacturer's API), all options will also be available in the future for network service and load management. This is especially true for larger objects. In smaller systems, of course, you can also think of committing to one good device or operator and if new and better services come along, the devices are still electronics with a useful life and you can exchange them for newer technology. There are also differences between destinations, and for certain environments there are devices suitable for that destination, where the properties, e.g. in terms of load management, are sufficient or very suitable. In any case, infrastructure should be carefully considered.

What load management options are there in practice? The first choice is whether load management is implemented at the device level locally or as a network service. Both have their good points, the online service is characterized by its flexibility, no commitment to a single device (OCPP), easy and inexpensive configuration and installation, possibilities for changes in new situations/when installing new devices, and in the future especially the possibility of various optimization solutions. Independence from the internet connection/network service, speed in certain special situations, especially in cabled solutions, reliability and multi-level support in the latest systems speak for the local. In practice, a meter/load management device is always connected to the local system, resulting in a dynamic system that also takes into account other loads in real time. This may be essential in e.g. geothermal sites or other sites where the load fluctuates very strongly or "spikes".

In many cases, a meter and a local controller can also be connected to the network-based system, which can be used to enhance the existing network-based load management. In our opinion, this is often the best solution from a technical point of view, because this way the best aspects of both options can be used. The cost is usually a bit higher and requires more from the online service. Our system is a Woltti SmartMeter, which is based on a local ModBus meter or network analyzer (as well as local systems) and a local controller, which separately sends data to the network service. In the future, P1/HAN measurement and Shelly Pro measurement in small areas will also be possible. In the future, optimization will be an important part of the charging system, and therefore grid-based load management is also essential if there are future plans for e.g. spot price optimization, solar electricity or battery systems.

New independent online services have now also entered the market, an example of which is Enegic. In practice, it is a data transfer component that can be connected to the P1/HAN port, which is connected to the API interface of the charging device via the manufacturer's cloud service. Again, there are pros and cons to this. The system is flexible, but always binds to both the Enegic system and the charging device's API service. In smaller sites, the benefits in the form of lower costs can be significant, and in small sites it can be a very good option. The data transmission here is WLAN, which is usually not recommended for housing association/company systems. Its malfunctions always usually require a visit to the site. If you wish, you can also connect Enegic load management to the Woltti system.

The data transfer of the charging devices to the backend system is the part that is worth investing in and where most of the errors occur. In practice, according to experience, the best options are ethernet cabling or each device's own SIM connection. WLAN/ ZigBee/ other wireless systems are more error-prone, and even if they are implemented with high quality, even in the case of a rare error, you usually have to find out the matter on the spot. This is expensive and also always takes time, when the system does not work as agreed. In addition, building and maintaining networks is reasonably demanding and requires expertise and high-quality equipment.

Hybrid systems have recently gained great popularity because the starting threshold and cost are often low for slow charging. In slow charging, the load management always cuts off the charging completely and in practice the positions "alternate". Cars "waking up" after taking turns is sometimes a problem, and that's why in Woltti load management, the basic charging (11/22kW) flexes first. Woltti SmartSchuko can be installed one device at a time, because each device has a SIM card. This makes installation even easier and enables flexibility and reliable operation. The choice of charging devices is also important, there are big differences in, for example, the scope of the OCPP protocol. Plug-And-Play is an important feature that ensures that the installation goes quickly and the functionality of the devices is the best possible.

Load management is therefore a broad and complex entity. It is worth spending time on its solution, so that the solution will also work well into the future. There is also a significant difference between the sites, and that is why you should think about the system according to the site.