Advanced test instrumentation has helped a UK-based solar PV specialist to significantly improve the electricity supply on two off-grid Hebridean Islands.

Renewables specialist Wind and Sun Ltd. has recently completed two new innovative solar PV power installation projects on the islands of Muck and Eigg off the west coast of Scotland to provide additional energy supplies to meet the needs of the growing island communities.

On the Isle of Muck, the newly installed power generation system incorporates both wind turbines and solar PV, with diesel generator back up. As part of the island's new 3.3kV 415V high voltage grid, the solar PV installation comprises a 12 string PV array of 132 REC Solar 250PE 250W modules with an output of 33kWp.

On the Isle of Eigg, installation work was also recently completed on an extension to the islands existing solar PV generating capacity with the addition of a new 6 string, 22.5kWp PV array using 90 REC 250PE 250Wp PV modules.

In both cases Wind and Sun carried out all irradiance testing and electrical commissioning work on the new solar PV systems with the latest Seaward Solarlink PV test kit to ensure compliance with the required MCS and MIS standards.

The Solarlink PV kit combines the comprehensive electrical testing and datalogging capabilities of the PV150 hand held solar tester with the advanced Solar Survey 200R multifunction PV survey meter.

The Seaward Solar PV150 is a dedicated multi-function PV electrical tester designed specifically for solar panel system installation. It performs open circuit voltage measurements (Voc), short circuit current measurements (Isc), earth continuity, insulation resistance and operating current (via AC/DC current clamp) checks.

The required sequence of tests are undertaken with the push of a single button and results can be recorded and stored in the tester for subsequent USB downloading to a PC.

Special wireless Solarlink connectivity between the PV150 and the high performance Solar Survey 200R meter enables real-time irradiance to be displayed and measured at the same time as electrical testing is being undertaken. This means that irradiance, module and ambient temperature can be recorded simultaneously within the PV150 as the electrical tests are conducted.

On the Scottish Islands electrification projects, the specialist test kit enabled Wind and Sun site engineers to eliminate the need for separate testers to be used for different measurements, bringing savings in test times without any compromise on the integrity of the results.

In addition, by recording a reference number against the tests for each string on site, the saved test results could be easily downloaded back in the office for fast incorporation in commissioning reports and other project paperwork.

James Ford, Technical Sales Engineer, of Wind and Sun, said: "Our experience on these projects on the Isles of Muck and Eigg shows that the ability to take combined measurements instead of separate ones greatly improves on-site engineer efficiency and test accuracy.

"For example, variations in cloud cover means irradiance can change very quickly. Taking combined measurements and having automatic referencing means that any errors that could be caused by taking separate measurements on different meters at different distances are eliminated."

As these pioneering island mini grid projects illustrate, Wind and Sun has been at the forefront of the solar PV industry since it was established in 1984. The MCS accredited company combines its role as a distributor of solar PV and wind power products, with specialist technical support, design and installation of specialist renewable energy schemes.

This all round expertise means Wind and Sun is ideally placed to recognise the technical challenges and trends facing the solar PV sector, along with the opportunities that new technology brings.

Steve Wade, Managing Director of Wind and Sun, said: "We believe that there will be an emerging market for operations and maintenance and fault diagnosis of existing solar PV systems in the coming years.

"In this respect, as well as serving as an initial system commissioning tool, we expect the new Seaward test kit to provide useful quick health checks and diagnostic tests on existing PV systems."