Harnessing the power of the Scottish sun

Installation of a Grundfos solar water pump system on a farm in the Scottish Borders is producing excellent ground water flows even in challenging weather.

A remote location and unreliable electricity supply were the primary drivers for a farm run by a large local landowner (Roxburghe Estates) to seek an environmentally friendly water supply solution which harnesses renewable energy sources, with low operating costs.

The water supply is a critical piece of infrastructure on Windywalls Farm in Kelso, Roxburghshire, feeding into a large network supplying farms and residential properties.

Historically, the supply was drawn from a borehole to fill an enclosed reservoir that gravity fed the mains network, which is supported when required by Scottish Water mains supply.

However, the power supply to the electric pump - an air ejection system - was unreliable, with powerlines regularly being damaged.

The driver for this project came in early 2023 when the cost of repair and modernising the electric supply forced the owners to look at alternative options.

Craig Rodger, Managing Director at Holequest Ltd, is a consultant for the Roxburghe Estate. He was tasked with finding alternatives to provide a cost-effective robust water supply.

Following extensive consultation, the Grundfos SQFlex 2.5-2 model was selected for this application.


The SQFlex pump uses renewable energy sources like solar and wind power, and features a built in variable frequency drive that converts DC power from solar panels into AC power for pumping -- resulting in low operating costs. The system is reliable and durable, with features like built-in dry run protection and high temperature protection.

SQFlex offers a choice between helical or multi-stage centrifugal hydraulics and works with any solar water pumping system. It is suitable for various application areas, including commercial buildings (such as schools or hospitals), farms, ponds, lakes and conservation areas, and domestic homes.

Designed using over 75 years of pump experience and over 40 years of solar technology expertise, the SQFlex is built for reliability and durability.

The solar pumping system is designed to work off-grid, withstand different weather conditions, and requires minimal human interference, making it highly reliable in a variety of challenging environments - from the Scottish Borders to the remote Kashmir Valley in northern India.

After the initial feasibility investigations, we decided to go with a Grundfos solar-powered pumping unit, putting the extraction system off grid. The pumping unit is working well and is reducing our client’s reliance on mains water, as well as removing the electrical connection entirely,
Craig Rodger - Managing Director, Holequest Ltd


The SQFlex can be customised to match any application and local conditions, and it is quick and easy to install. As the first solar pumping solution of its kind, the SQFlex has evolved to include a robust range of features and is used in water supply applications around the globe.

For example, in Namibia, the Sandvervaar farm uses a SQFlex solar pump to pump water from a borehole for irrigation and livestock watering, helping the farm to become more sustainable and productive.

Meanwhile in India, in the village of Navargaon, Maharashtra, a Grundfos SQFlex solar pump unit has been installed to provide water to households for the first time. Previously, villagers had to walk long distances through the jungle to fetch water from wells. In the state of Gujarat, Grundfos SQFlex pumps are being used to irrigate crops on small farm - improving the livelihoods of farmers and increasing food production in the region.


Solar energy is a clean, renewable energy source that can help to reduce reliance on fossil fuels and, therefore, reduce carbon while protecting the environment.

This is especially important as, in 2019, water companies in England pledged to reach net zero on operational carbon emissions by 2030. Since then, companies in Scotland and Wales have committed to achieving carbon neutrality across all emissions by 2040, with a pledge from Northern Ireland to deliver the same target in line with UK national requirements, by 2050.

In addition to the environmental benefits of solar energy, there are also financial benefits to installing solar panels. The SQFlex system has been running at the Roxburghe Estate since September 2023, and to date it has been reliable, trouble free and cost saving for the business- equating to approximately £300 per year on electric costs and saving around 290 kg of CO₂ per year.

The Sprouston District Water Supply is now a self-contained supply using solar power. Investigations are underway to assess the feasibility of upgrading the solar panels to incorporate battery storage, with the potential to meet the demand all year round in the future. In addition, the installation of Grundfos SQFlex has removed the need for the mains power supply and mains water back-up.

Due to the project’s success, the client has asked Holequest review the suitability of installing SQFlex pumps at various other locations on the Roxburghe Estate.


Grundfos is pioneering the future of water technology with an expanded range of powered using renewable energy.

According to Market Intelligence Data of the AC and DC Solar Water Pumps, the market is predicted to develop at a CAGR of + 10.1 % between 2023-2029.