Introduction
When MarinaCo, a Dutch Marina, approached us in 2022, they had the wish to obtain more control over the electricity usage of their customers. At MarinaCo, boat owners can rent work space in one of two indoor workspaces. They can work there on their boat and make use of the electricity net free of charge. Unfortunately, during the 2022 price surge, this model proved to no longer be sustainable and MarinaCo was eventually forced to charge their customers for electricity. Because they haven't had the facilities to attribute individual energy usage, the only possibility was to raise the stalling fee, thereby distributing the price increase evenly among everyone. This was obviously not a fair solution, as customers who use little amounts of energy now subsidized customers who used a lot.
The solution was to install a smart electricity system. MarinaCo conducted initial market research for options but couldn't find a solution suitable for their situation. So they approached LIFE electronic, and we gladly took on the task. To get it done, we first had to deploy a networking infrastructure. Then we could design and develop the electricity system. By installing a network on the terrain, we also enabled MarinaCo to increase their security with internet-connected CCTV cameras. This case study explores in detail how the system was designed, developed, and deployed.
The large marina shed. Winter storage full of boats.
Task Description
The task was to develop a smart electricity meter and control system that gives MarinaCo fine-grained control over who is allowed to make use of the electricity net as well as fine-grained accounting of individual energy usage. Multiple challenges had to be overcome to achieve this goal. First of all, it obviously needed to satisfy the functional requirements of MarinaCo. It also had to be user-friendly, so that all of their customers would be able to use it. Their customer base is a wide variety of people, not all of them tech-savvy enough to use, for instance, a complicated smart phone app. Thirdly, there was no network installation. So we had to come up with a network design that was feasible for the local situation and extensible enough to allow for future extensions. And lastly, it, of course, should not cost a fortune.
The Solution
Touch-Screen User-Interface. Qr Code Scanner visible in lower right.
To create a working and user-friendly solution, we developed and integrated multiple components. For the user-interface, we decided to use a touch-screen kiosk with an integrated QR code scanner. Each customer receives their own account and associated QR code(s). By logging in with the code, a person can use the interface to unlock one of the 40 electricity plugins that are distributed over the terrain. Once a plug is unlocked, all energy consumed via this plug is attributed to the customer's account. The display shows up to date usage information to the customers as well as historic records.
To administer the system, MarinaCo employees can use their own admin codes to log into the administrator interface. There, it is possible to create, edit, and delete customers, file invoices, set the electricity price, and more. An on-site database securely keeps track of all usage, giving valuable insights into overall consumption patterns.
To control the plugs, we developed a custom PCB with an STM32 microcontroller and a WizNet ethernet adapter. The microcontroller can control up to eight plugs. Usage is recorded via a Modbus-enabled electricity meter, and the plugs are controlled by a 12V relay, switched on and off via the uC. The Ethernet chip provides the board with connectivity via the common networking protocol. We also developed a WiFi-based version of the chip, based on the ESP32, but MarinaCo decided to only deploy the Ethernet version.
Ethernet (left) & WiFi (right) version of control board.
In total, we deployed six of the PCBs, each mounted in a DIN-Rail case, together with the relays, meters, and necessary cabling. Each of those so-called control boxes connects to a central control server that we wrote using the Go programming language. The server communicates with the controllers through a simple, but cryptographically secure, communication protocol and enables control and management via a REST API. The API is subsequently used by the Kiosk computer to power the user interface. The user interface has been developed in C++ with QT6 in order to provide a snappy experience for the users.
Controlbox with 6 plugs in main marina shed
Network Design
The Data Network
As mentioned earlier, MarinaCo had no digital facilities, so we had to come up with a network design that would make it possible to connect all the controllers to a central server. Additionally, we wanted to provide internet access via 4G, deploy a hidden wireless access point for maintenance tasks, and allow for additional extensions, such as CCTV cameras. The situation was as follows: There are two marina sheds on the terrain. One large one, in which easily more than 40 boats can be worked on simultaneously, and a smaller one, in which more long-term work is being done, usually on a small set of larger boats. MarinaCo asked us to place four control boxes with six plugs in the larger shed and two control boxes with eight plugs in the smaller one. The display had to be placed near the main entrance of the large shed. Additionally, they wanted us to install three security cameras, covering all the main entrances. Inside the individual sheds, we distributed standard UTP Cat5E cables. To connect the two sheds with each other, we used a Ubiquiti Nanobeam 2AC point-to-point WiFi radio. In each shed, we installed two Ubiquiti Edge Switches, which provide excellent PoE+ support plus 24V passive PoE for the Nanobeams. The cameras are connected and powered by the Edgeswitches. Internet connectivity is provided by a consumer-grade Huawai 4G modem, which also provides WiFi access to the network via a hidden SSID. We divided the network into two VLANs for increased security. All components related to the electricity system are in one VLAN, and cameras, internet, and WiFi are in the other. This logical separation provides increased security. The cameras are Reolink 810A and can be accessed remotely via the Reolink Smartphone app from any of the MarinaCo staff members. They have night-vision capabilities, smart people and vehicle detection algorithms, and automatic alerts. The alerts are enabled after working hours, when the terrain is usually empty.
NanoBeam A at large marina shed & NanoBeam B at small shed (look for little white dot)
Feedback & Evaluation
LIFE electronic successfully designed, developed, and deployed the whole system, except for laying the cables and mounting the hardware at their designated places. This was done by the owner of the terrain himself, and we are very grateful for his help.
The first version of the system was deployed in early 2022 and is thus in production for one year. During this time, it proved to be stable, and we acquired very positive feedback from MarinaCo and their customers. It appears to be very easy to use, even for older people who are usually not so tech-savvy. Choosing QR codes as a login mechanism proved to be a great decision. Since the pandemic, people have become so used to QR codes that it doesn't require any explanation anymore regarding what they are and how they work. In 2023 and early 2024, we extended the system further by connecting the smaller shed and installing the cameras.
In summary, our work consisted of the planning, design, and deployment of this complex system. We procured all components, designed and developed the hardware and software across the whole stack, installed and configured the network, setup and configured the cameras, and provided after-deployment support.