Solar power plant drives environmentally friendly business success
Supervisory control system provides real-time monitoring of massive solar network, cutting energy costs—and reducing emissions—at intermodal transit facility in Bologna, Italy.
The Bologna Freight Village, also known as Interporto Bologna, is a testament to how businesses can be both financially successfully and environmentally responsible.
The freight village, one of 22 such operations scattered across Italy, was founded in the early 1970s as a joint venture between several government agencies and private companies. The initial purpose was to reduce traffic congestion in and around the city of Bologna by coordinating the movement of goods from a single location and using multiple modes of transportation, including trucks, trains, and airplanes.
The village’s infrastructure includes a regional airport, a food center, warehouses, and exhibition and conference centers. In addition to achieving its primary goal of reducing traffic congestion through more efficient transportation planning, the village has become an economic engine for the surrounding region, attracting both national and international companies.
As time passed, however, the village’s management became increasingly concerned about the amount of energy its operations were consuming.
Logistics and energy infrastructure
In 2006, management started researching ways to reduce both the cost and environmental impact of its energy use. Ultimately, management decided to install a solar power system. With some financial assistance from the Italian Ministry of the Environment, a solar power plant consisting of more than 1,000 photovoltaic panels was installed, at a cost of 1.3 million euros, or $1.7 million US.
In its infancy, the solar plant produced roughly 236 MWh of power each year, reducing the freight village’s annual petroleum consumption by 50 tons. This success inspired management to expand its reliance on solar power. To date, the village has invested a total of 5 million euros ($6.5 million US) on a solar-power network that includes 18,300 individual solar panels mounted atop 9 freight center warehouses with a combined 4.3 million sq ft of roof space.
Through 2012, this network had produced more than 4.52 GWh of electrical power—and its expansion continues. An additional 86,000 sq ft of freight center rooftop space is currently being outfitted with solar panels.
The control system
The solar panel network was developed by Rebernig Supervisoni Srl, an Italian solar energy engineering company. The goal from the beginning was to create a state-of- the-art solar facility that would provide maximum user control and low-cost energy. To reach these goals, the network was designed with a Movicon 11 supervisory control and data acquisition (SCADA) system, which logs and displays process data from the solar panels.
The SCADA system monitors numerous parameters, including:
- The electric current generated from over 900 solar panel strings
- Operating and functional status of the solar system’s 200 power inverters
- The amount of energy produced by each solar panel
- Data from temperature and radiation sensors.
The distributed control system includes monitoring stations located along the warehouse rooftops for gathering and processing data. The data logging component resides in a centralized server to enable constant viewing of the system’s functional status and easy analysis of historical data.
Seventeen industrial routers installed in the network are connected to the main server through a 3G wireless connection. Communication with the solar panel devices, the I/O slave, and other control units is established through an Ethernet and serial bus link.
Data collected by the solar monitoring stations flows to the supervisory system built with a server from the Movicon 11 SCADA/HMI software platform and the MySQL database.
The industrial routers have been configured for gathering data by implementing protocol conversions (i.e., proprietary protocols such as those for solar inverters are converted to the TCP/IP Modbus standard protocols). The Movicon system also collects and processes production data from its network sensors in real time so staff can respond to current weather and environmental conditions for optimal solar panel performance.
The Movicon system includes intuitive user interfaces which provide total system control and monitoring. Staff can make adjustments using the user interface to optimize the performance of the various systems and/or promptly handle critical situations such as inverter malfunctions, damaged string box fuses, or substation disconnections.
The most essential process data can be managed in real time through graphical display screens. These screens are equipped with various smart graphics to display real-time information and recorded data so operators can perform historical and statistical analysis. This architecture was made possible by using an all-in-one supervision system capable of synthesizing—with zero margin for error—data derived from heterogeneous systems.
All operating data is displayable through web interfacing so staff can review and analyze data remotely. Access to the system is protected by log-in using password and user name with assigned privileges based on job responsibility.
In the final analysis
The collaboration between Rebernig and Movicon has been impressive, enabling the Bologna Freight Village network to produce low-cost renewable energy through a system that is easy to manage. Adding to the overall success of the project was the fact that it was completed on time and on budget. As they say in Italian—Fantastico.
Scott Ludwig is general manager at Progea.
This article is part of the April 2013 CFE Media supplement, Industrial Energy Management. See other articles in that supplement linked below.