Smarter Water Solutions: Variable-Speed and Solar Submersible Pumps Redefine Efficiency
/Discover how variable-speed and solar-powered submersible pumps—like the Grundfos SQ, SQE, and SQFlex—are transforming residential, agricultural, and off-grid water systems with reliability and smart control.
By Michelle Segrest, Reporting for Empowering Pumps & Equipment
For more than two decades, the shift toward smarter, more sustainable pumping systems has reshaped how water is delivered to homes, farms, and communities around the world.
What began as an innovation in compact design has grown into an era defined by variable-speed control, solar integration, and intelligent monitoring.
Few product families embody that evolution better than Grundfos’s SQ, SQE, and SQFlex submersible pump lines. Launched 25 years ago, these systems set a new standard for efficiency and adaptability—and they continue to shape how end users approach water supply challenges today.
“We don’t rest on our laurels,” says Tom Drew, Global Business Development Manager – Solar at Grundfos. “We’ve upgraded the electronics, simplified installation, and enhanced control features, but much of the innovation was already there from the start. This product line was cutting-edge when it launched—and it still is today.”
Inside the Technology: Compact Power Meets Intelligent Control
At just three inches in diameter, the Grundfos SQ and SQE submersible pumps are designed for small or restricted wells without compromising performance. Each model is built with motor protection and wear-reducing features that extend lifespan and minimize maintenance.
Core Design Advantages
Soft start and overload protection reduce stress on the motor.
Dry-run protection automatically stops the pump if water levels drop too low.
Low amp draw minimizes power requirements, reducing overall operating costs.
Permanent magnet motors deliver consistent, high-efficiency output.
The SQE series builds on this foundation with integrated electronics and variable-speed drives (VSDs) that automatically adjust motor speed to maintain constant pressure—ideal for homes or businesses with fluctuating water demands.
Imagine a typical household where a child is bathing, a parent is watering the garden, and the dishwasher is running—all at once. Without constant-pressure control, pressure would fluctuate. The SQE solves this problem automatically, keeping flow steady and consistent.
Solar Integration: Powering Off-Grid Water Access
While the SQ and SQE are perfect for traditional installations, the SQFlex takes the concept even further by combining high efficiency with solar adaptability.
The SQFlex pump can run on solar panels, grid power, or generators, offering unparalleled flexibility. Its wide voltage range allows operation from sunrise to sunset—even on cloudy days—with minimal energy loss.
Because it runs directly from solar power, it delivers reliable access to water where electricity is limited or unavailable, reducing reliance on fossil fuels and expensive infrastructure.
“In areas where electricity isn’t readily available, the solar pump provides an efficient way to get access to water—especially for the cattle ranchers we serve,” says Darrell Ferguson of Ferguson Water Well in Edna, TX. “Even on cloudy days, the SQFlex outperforms anything else we’ve used.”
Real-World Applications Around the Globe
From small towns in Texas to wildfire-stricken California and remote cattle stations in Australia, Grundfos pumps are solving water challenges in diverse conditions.
Reliability on the Ranch
In the American Midwest, farmers and well-drilling professionals rely on the SQ series for irrigation, nurseries, and residential lawns. Lightweight and easy to install, these pumps save time and money on every job.
“The reliability factor alone makes this the best choice for me,” says Robbie Eshee, President of R&D Water Wells. “We rarely have to pull an SQ pump out of the ground—it just works.”
Rebuilding After Disaster
Following California’s 2021 River Fire, the Quabner family lost their 100-year-old home and access to clean water. Through a grant supported by Grundfos and local partners, they received a new water well powered by an SQE pump—a solution that was both sustainable and life-changing.
“It feels like a fresh start, a new chapter in our lives,” says homeowner Misty Quabner.
Powering Off-Grid Communities
In rural Australia, Grundfos installed SQFlex solar pumps across a million-acre cattle ranch where there was no grid power for miles. The system delivers dependable water for livestock without maintenance or fuel costs.
And around the world, Grundfos teams have replaced thousands of obsolete windmill systems with compact, solar-driven pumps—offering a safer, more efficient solution for remote wells.
Smarter by Design: Installation and Connectivity
Beyond the pump itself, Grundfos has continued to refine how its systems integrate with modern infrastructure.
For solar setups, the SQFlex connects directly to DC power or through the Grundfos CU202 controller, which provides preconfigured programs for irrigation and tank-filling applications.
When upgrades are needed, users can simply download new firmware through the Grundfos app via Bluetooth connection—no technician required.
Because the pump’s design allows for a smaller, more economical well size, installation costs are lower compared to traditional 4- or 6-inch systems. That affordability, combined with long-term reliability, makes these pumps a favorite among residential and agricultural users alike.
Engineering for Sustainability and Social Impact
Grundfos’s innovation isn’t just about technology—it’s about global access to clean water. Through the Grundfos Foundation, the company contributes a portion of every sale toward its initiative to provide safe drinking water to more than 300 million people worldwide by 2030.
From solar farms to humanitarian projects, these efforts reflect the broader goal of using technology to balance performance, affordability, and environmental responsibility.
“With the SQFlex solar version, we’ve solved problems all over the world,” says Drew. “It’s tested, it’s proven, and it’s never been duplicated.”
The Future of Pumping Is Intelligent, Connected, and Sustainable
Today’s water systems demand more than just flow—they demand efficiency, adaptability, and smart control.
As the industry continues to embrace Industry 4.0 and the digitalization of infrastructure, systems like the Grundfos SQ, SQE, and SQFlex show what’s possible when innovation meets reliability.
For homeowners, farmers, and engineers alike, these pumps represent more than a product—they represent a smarter way to move water.
Michelle Segrest is president of Navigate Content Inc., and has been a professional journalist for four decades. She specializes in creating content for the processing industries and has written books about Modern Manufacturing best practices. If you have an interesting efficiency, maintenance, and/or reliability story to tell, please contact her at michelle@navigatecontent.com.
