Enabling a New Service Model for Home Solar Energy Systems
2018-08-24

Project Introduction

Turning Big Data into New Income Streams

In the pre-IIoT era, solar panels were often purchased outright or loaned to end users. The upside was that the homeowner kept all the tax credits, but the downside was that the upfront costs were high. An American solar energy company wanted to leverage big data, cloud storage, and reliable wireless communication to make home solar energy systems easier to use and more affordable to the public. They came up with a new solar energy offering: a power purchase agreement (PPA). This contract between the solar energy company and a homeowner allows the solar energy company to install a solar power system on the homeowner’s roof. In exchange, the homeowner agrees to purchase the electricity that is generated by the solar panels from the solar energy company at a fixed rate. This business model benefits homeowners in that they do not have any upfront costs or maintenance responsibilities. For the solar energy company, the PPA model brings in a new revenue stream. In order for this agreement to work efficiently, the solar energy company required real-time and accurate data to ensure the billing information is correct; otherwise, unreliable data transmission will cause them to lose revenue. To enable the PPA business model, the solar energy company required an edge-to-cloud solution.

System Requirements

• The ability to collect power generation and consumption data from 50,000 sites over a wide geographic area, and send this information to the cloud for billing and operational purposes.
• A failover mechanism to switch between Wi-Fi and cellular communication for a high-availability network.
• The ability to maintain devices remotely (e.g., Wi-Fi settings, regular firmware updates, etc.) to eliminate site visits by personnel.

Moxa Solution

Accurate Data Means Accurate Billing. Always Connected with Failover Transmission

For this PPA business model, a reliable networking system is important to ensure the solar energy company has real-time monitoring of the end users energy consumption to ensure accurate data billing. Furthermore, the solar energy company needs the real-time monitoring to balance demand against supply through flexible pricing and other options. IIoT gateways installed in the solar energy system play an important role in this project, as they acquire energy production and consumption data from batteries and inverters via Modbus communication, and then transmit the data to AWS Cloud with a ready-to-run data acquisition platform via wireless networks. In real time, the IIoT gateways enable the solar energy company to retrieve data related to solar energy storage and consumption from sites spread over a large geographical area.

In order to prevent loss of data, the IIoT gateways are designed with a failover mechanism whereby the network communication will switch automatically to the secondary transmission method (cellular) if the primary transmission method (Wi-Fi) fails. When a failure occurs, the solar energy company can fix and update the Wi-Fi settings remotely via their self-developed maintenance applications by leveraging RESTful APIs, which means operators can do all of the maintenance via their mobile devices. Finally, a centralized web-based device management platform (ThingsPro® Server that runs in the AWS Cloud) enables the solar energy company to easily manage many IIoT gateways at multiple field sites, perform firmware upgrades remotely, and upload a program with specific device groups, allowing devices to be monitored remotely.

Why Moxa

• Always connected through Wi-Fi and 4G LTE redundant connectivity.
• Worked jointly with the customer to program customized software and integrate into AWS Cloud.
• 100% of products tested to ensure that they can withstand temperatures from -10 to 60°C.
• Users can manage many IIoT gateways at multiple field sites easily, even the need to upgrade firmware with device group task queue remotely to eliminate personnel site visit efforts.