Solar reflections

Back in 2011 I was taking my first steps into the Solar industry, learning about products, performance, efficiencies.... there was a plethora of brands, some recognisable and some less so, many were even manufacturing in the UK and Europe! Whilst it couldn't be claimed that the industry was new, the installed annual capacity was under 50GW worldwide in 2011, versus an estimated 600GW in 2024.

I'm not sure whether 14 years ago crosses the boundaries into nostalgia or not yet, but nevertheless it was interesting to go back and find old brands & datasheets to compare past and present to really consider how typical spaces have been transformed in terms of their capability and perhaps what this means for repowering in years to come.

A typical 185w monocrystalline module in 2011 had a 14.5% module efficiency, later giving way to PERC technology which could achieve 17.1% from a polycrystalline cell, what seem like relatively small steps were circa 18% improvements. Over the years PERC cells were refined, sliced in half, busbars added... leading to efficiencies breaking 20% in mainstream products.

It's worth mentioning at this stage that my recollection is only concerned with what was produced in volume, typical off the shelf products. I'm aware that at any given point there is a world record breaking module being produced in a lab somewhere, which is breaking the mould for the next generation to become available in mass production.

By the time of more present day modules, TOPCON products are typically 22-23% efficiency, with cell & module sizes standardising across manufacturers, 1134mm width became standard after years of different formats across producers, likewise where module thicknesses were 50mm, reducing to 30mm to optimise shipping the most product.

The very latest modules hitting markets in 2025 will reach 24.8% efficiency, delivering approx. 100 watts more per square metre. Which means on a like for like basis, a 250kWp system in 2011, is now a 426kWp system using the same area, across 20 years that's nearly 3 million kWh more yield from the same space!

Mainstream modules circa 2011, possibly nostalgic if you were there.