California-based CyboEnergy, a subsidiary of control and automation company CyboSoft, has developed what it calls a “mini inverter” with benefits of both central inverters and microinverters. At its booth at Intersolar 2015, the company showed how its CyboInverters can operate in either on-grid or off-grid mode. A time-based grid power injection feature also allows energy to be stored in batteries and sent to the grid during peak power hours to help grid stability.
We followed up with CEO George Cheng to find out more.
Solar Power World: What is your background, how did you come to be in the solar industry?
George Cheng: In 1994, I cofounded CyboSoft, a control and automation company. The Model-Free Adaptive (MFA) control technology developed by CyboSoft for controlling physical processes is a major breakthrough. The MFA control products have been deployed on a large scale in building control, oil and gas drilling, pH control, industrial automation and equipment control. We are always exploring important things that we can do to make a difference. In my view, our world is facing at least the following critical threats:
• Global warming and climate changes
• Ever increasing pollution to the environment in air, water, soil, and food
• Shrinking natural resources and explosive growth in world population
• Aging society with healthcare needs and out of control cost
It is profound to see that automatic control is very much related to these critical issues. For instance, control difficulties slow down the adoption of renewable energy. So, we saw the need and opportunity to enter the solar industry.
SPW: Tell me more about CyboEnergy. How was it founded and what kinds of products does it offer?
GC: CyboEnergy was formed to apply CyboSoft’s control technology to the renewable energy industry. We developed on-grid, off-grid and on/off-grid solar power inverters with multiple input channels to provide flexibility and seamless integration of DC sources including solar, wind and batteries. A CyboInverter has four input channels, each of which has its own control and maximum power point tracking (MPPT) to eliminate partial shading problems and maximize power production.
Because a multi-channel power inverter is a multi-input-single-output, high-speed, nonlinear system, it is very difficult to use a traditional proportional-integral-derivative (PID) controller or model-based method to control it. CyboSoft’s model-free adaptive (MFA) technology enables us to control the CyboInverter to synchronize with grid AC with four varying DC sources, and meet the stringent UL1741 / IEEE 1547 standards. The multi-channel CyboInverter was awarded the 2013 Global Product Differentiation Excellence Award by Frost & Sullivan.
SPW: Let’s focus in on your on/off-grid solar inverter. What does it offer solar contractors, that other models don’t?
GC: Climate change is becoming more catastrophic and power grid shutdowns are more frequent and severe, resulting in loss of production and personal hardship. On-grid inverters are designed to deliver power to the grid but cannot run as off-grid inverters to power AC loads, yet off-grid inverters cannot send power to the grid when the grid is on so the solar energy is wasted. The on/off-grid CyboInverter combines both functions in one inverter to offer grid flexibility.
The inverter can offer solar contractors the following benefits: (1) the ability to do “plug-and-play” installation for small to large on-grid solar systems with backup power, (2) seamless integration of solar, wind, hydro and battery for grid power balancing and AC power arbitrage, and (3) exceptional economic benefits for both customers and solar contractors.
SPW: There’s lots of inverter options out there. What’s industry response to the model been, and how do you compete with other major players?
GC: Response for the on/off-grid CyboInverter has been very positive. On the market, a few string inverters also have the ability to provide backup power when the grid is down but they lack the key functions including panel-level MPPT, immunity to partial shading and ease of installation. In addition, the “Rapid Shutdown” requirements by NEC2014 will be enforced, which will make string inverter based systems much more costly to install. On the other hand, microinverters are too small to provide sufficient power to run AC loads in off-grid situations.
Our go-to-market strategy is to work with key partners that integrate CyboInverters to offer unique and useful systems in certain market segments. For instance, WindStream Technologies’ SolarMill was recently featured on the NBC Today show. A typical SolarMill has three solar panels and one wind generator, which are connected to four input channels of a CyboInverter. This unique and useful system can harvest both solar and wind energy for small to large installations. CyboInverters are delivered by WindStream as part of SolarMill for their on-grid customers in the global market.
SPW: Where is the inverter deployed? What types of applications is it best for?
GC: CyboInverters have been deployed in on-grid and off-grid solar systems around the globe. The family of CyboInverter products are well suited for: (1) on-grid solar systems with ease of installation, excellent power production, and best system per watt price, (2) on-grid solar systems with backup power capability, (3) on-grid systems with solar, wind, hydro and battery inputs for seamless DC source integration, energy storage, grid power balancing and AC power arbitrage, (4) small microgrids to provide electricity to schools, clinics, stores, homes, factories, farms, etc., in rural parts of the world, (5) off-grid PV solar heating and cooking, and (6) AC coupling when integrating with large off-grid battery inverters.
Since there are no comparable products on the market, we have just released an On/Off-Grid Solar Power System Design Guide, which can be downloaded from our website. This guide provides a systematic approach with design rules that can help customers and installers to design on-grid and on/off-grid renewable energy systems with battery storage to provide backup power when the grid is down. These systems are very useful for homes and facilities, especially those where backup power is a necessity but not available, including: nursing homes, clinics, data centers, hotels, stores, etc.