BP’s solar subsidiary is on the hunt for Britain’s shiniest grass to help make the most of new double-sided solar panels that can harness light reflected off the ground.
Lightsource BP hopes the “bi-facial” solar panels will boost the amount of renewable energy generated at its solar farms and could make them more economic in gloomier parts of Northern Ireland and Scotland.
At a test site outside Belfast the company found that the b-facial panels can increase electricity output by almost 15% – but this can be much higher if the ground beneath the panel is particularly reflective.
Lightsource BP is using the findings from its experiment to work with a seed company in Norfolk to find the “most reflective” grass type to grow underneath the solar panels.
Chris Buckland, the technical director of Lightsource BP, said the team tested the panels for almost a year on “lush Northern Irish grass”, which helped to reflect light on to the back-facing panels.
The grass helped to produce an extra 14% of electricity, he said.
The same panels positioned over white floorboards produced almost 30% more electricity than traditional panels and once the floorboards were removed to reveal dried, brown grass the output plummeted “to low single-digits”, he said.
Buckland believes that most customers will want to keep grass beneath their panels, rather than boards or gravel, which would require occasional cleaning.
“We’re working with a seed company in Norfolk to trial test fields of different grass types to find a species of grass with the most solar potential to recommend to our customers,” he said.
“What will be important is that the grass stays green throughout the year. We are fortunate here in the UK because the grass is a perennial variety and quite tightly packed.
“What we don’t know at this stage is whether the best grass will prove to be a wide-blade cattle grazing grass or a finer golf course variety. We’re not there yet.”
Lightsource hopes to use the new solar technology advances to install solar projects in less sunny areas because the two-faced panels work particularly well in cooler climates.
In a trial, the company is using “tracker panels” that, like sunflowers, tilt through the day to follow the track of the sun, which are “very useful in sunnier areas”.
The London-based solar giant, in which BP holds a 43% stake, is expanding quickly after it won the backing of the oil giant in 2017.
It is already Europe’s largest utility-scale solar developer and more than $3bn (£2.4bn) has been invested across almost 2GW of solar projects around the world.
Last week it announced plans to buy 1.9GW worth of solar projects in Brazil from the independent renewables developer Enerlife, for an undisclosed sum.