Moving all or part of SCADA applications to the cloud can cut costs significantly while dramatically increasing reliability and scalability.

Virtually anywhere you look in today's world, there is some type of SCADA system running behind the scenes: maintaining the refrigeration systems at the local supermarket, ensuring production and safety at a refinery, achieving quality standards at a waste water treatment plant, or even tracking your energy use at home, to give a few examples.

SCADA (Supervisory Control and Data Acquisition) refers to a system of hardware and software to control industrial processes and to process real time data from the industrial processes.

Effective SCADA systems result in significant savings of time and money.

Cloud computing provides convenient, on-demand network access to a shared pool of configurable computing resources including networks, servers, storage, applications, and services. These resources can be rapidly provisioned and released with minimal management effort or service provider interaction.

This article describes the state of technology with traditional SCADA Systems and the advantages of moving these systems to the cloud.

The purpose of the SCADA system is to maximize efficiency, provide visibility and minimize downtime. SCADA systems are found in industries such as:

• Energy
• Food and Beverage
• Manufacturing
• Oil and Gas
• Power
• Recycling
• Transportation
• Water Utilities

Traditional SCADA vs Cloud Hosted System

In traditional SCADA, the application is hosted locally and connects to various equipment through a local area network or a private radio network. The local SCADA computer provides alarming, logging, trending and operator interface functionality.

For example in a water treatment plant: the SCADA user interface allows the user to see which parts of the process are active, alert the user if there is equipment malfunction and allow the user to control the equipment.

In cloud hosted SCADA, the SCADA application is running on the cloud, data from the plant equipment are collected at a local communications hub and sent to the cloud for processing. Data collection, storage, analysis, reporting, and mobile access functionality is part of a cloud based SCADA application.

By moving all or part of the SCADA system to a cloud-based environment, SCADA providers and users can significantly reduce costs, achieve greater reliability, and enhance functionality.

Cloud based SCADA has zero up front capital expenditure associated with setting up a data center. There are no operating costs associated with maintaining on-premises IT resources and associated support staff. Operating costs for the IT infrastructure in the cloud is based on a pay-as-you-go model. Numerous studies have shown that the total cost of ownership for a cloud system is significantly lower than operating the IT system on-premises.

Reliability of the cloud based system is higher as the system can be designed with redundancy across multiple geographical locations. When there is a fault in the system, the cloud automatically switches to the backup system in a different location ensuring minimum downtime.

Functionality of the system is enhanced by exploiting a wide range of sophisticated cloud services such as machine learning, analytics, visualization and business intelligence tools.

__One area of industry where Cloud SCADA Technology can bring significant benefits is the renewable energy industry. __

For example the Gannawarra Solar power plant; In April 2018 the Gannawarra Solar Power Plant was commissioned 13 km west of Kerang, Victoria; producing 60MW, energy to power 25,000 homes. The power plant uses 87000 solar panels on 132 ha site. Project cost = $41 million.

The Challenge

In order to maximise revenue, the solar power plant relies on converting the maximum amount of solar energy to electricity for a given set of weather conditions. The solar plant must minimize any reduction in output due to equipment failure or degradation. The energy output of the solar plant can be predicted by correlating the weather forecast with the current capacity of the solar plant. In order to support efficient operations of the solar power generation facility, a SCADA application is required to collect data from the solar plant and local weather station. The data collected is used for the following sample set of objectives:

• Identify damaged solar panels so that they can be replaced quickly
• Measure the performance of the power plant for a given daily solar profile
• Forecast energy capacity for the next seven days given weather forecast information from the Bureau of Meteorology
• Track the preventive maintenance schedule for solar panels

The Cloud Solution

In order to implement a cloud based SCADA system, plant assets can be connected to the SCADA system via a secure low power radio network (LoRaWAN). A “Gateway” is used to receive data from the radio network and forward it to a “Network Server” in the cloud. The Network Server routes messages to the SCADA Application in the cloud.

The diagram above is a simplified block diagram of a solar power plant. The solar panels are organised into PV strings, each string is a row of solar panels in the solar farm. The energy collected by a PV string is collected in a combiner box and used by the charge controller to charge the battery bank. The charge controller also supplies energy to an inverter that converts direct current into alternating current before feeding it into the power grid.

Sensors are placed in the combiner boxes to collect information about the PV Strings to extract information about the health of the solar panels.

Sensors are placed in the battery chargers to monitor the health of the batteries.

Sensors are placed in the weather station on site to collect weather information.

Sensor data is transmitted from low power radio transceivers to one or more Gateways on the solar plant site. The Gateway filters or aggregates data from the radio network and then transfers the data to the Network Server via the local internet connection.

The SCADA Application in the cloud receives sensor data from the Network Server and provides alarming, logging, trending, storage, analysis, reporting and mobile access functionality.

The resulting cloud solution is lower cost, more scalable and reliable than the equivalent SCADA solution based on traditional architecture.

Conclusion

The cloud comes with many attractive benefits, but there are still obstacles that hold companies back from making the jump. This is especially true of applications that deal with high volumes of time sensitive and critical data, where failure has catastrophic consequences. Each industrial application is different and risk assessment must be conducted with application specific needs and priorities in mind. While cloud technology can reliably and cost effectively handle systems requirements for security, performance, and reliability in a non-safety critical function such as solar power plant asset condition monitoring, systems that require more stringent requirements may be less suitable for migration to the cloud.