An expanse of dark, reflective panels is the most visible part of every solar PV project, but there are plenty of unseen elements that go into a successful installation.

CleanEarth’s commercial managers, Jamie Johnstone and Ed Lennon, take us through some of the less understood elements that can impact the long-term effectiveness of a solar PV system.

Running the numbers

“Every project starts with some number crunching,” says Ed. “Before you settle on a design you need to review a whole set of variables and understand how they interlink.”

The first step is to match the output of the system to the on-site demand – not just for today but with an eye to the future. “Demand might actually go down over time from greater energy efficiency,” Jamie adds. “Or it might go up as the business expands. You’ve got to factor in that change either way.” You need to look at power consumption over different timescales – time of day, day of the week, time of year – and map that against potential generation at those same timescales.

Jamie and Ed approach their work with a decade of experience each, and have helped to develop a robust model, tweaking the variables to find the sweet spot – a balance of capacity and consumption. This combines with other key factors including available roof-space, client budget, payback period, and ROI.

From spreadsheet to blueprint

With the key parameters defined, a detailed technical design can be drawn up. “It sounds simple to work out a panel layout,” says Ed, “but actually you’re often working around odd-shaped roofs, structural issues, awkwardly placed skylights. Sometimes all the above.” 

The design also needs to allow for the logistics of installing the panels and maintaining them for the lifespan of the system.

“This is where some installers try to make savings,” according to Jamie. “They don’t allow for safe access to the panels and inverters once the system’s in and the scaffolding’s come down. Essentially, you’re betting on nothing going wrong and no cleaning being needed for the next 25 years.”

Not only are logistics key for a design, but the system needs to look right too. While aesthetics may not be the first thing on a client’s mind, it should never be overlooked. The system should fit into the look of the rest of the building, not stand out in opposition.

Long-term returns

In Ed’s view, a project doesn’t end with a completed installation. “It always feels good when a new system goes live.”  he says. “But what’s most important is keeping it at peak performance for years to come.”

The CleanEarth team includes specialists in monitoring and maintenance who keep an eye on generation levels and get alerts for technical problems and dips in performance. They fix faults and do annual inspections to prevent problems occurring in the first place – protecting the asset value of the solar PV system. “The up-front capex is often paid off in three years or less,” Jamie says. “Our aim beyond that is to keep delivering high performance and great returns over the long term.”

Tenacity and focus

The measurable, visible, aspects of a successful project are harder to achieve without a couple of more abstract qualities. “You have to have a mindset of persistence and problem-solving,” Ed says. “When things get challenging, you need to stay focused on the end goal.” Ultimately that’s about the bigger picture of climate change, and not just commercial pressures closer to home. “We need to decarbonise as fast as humanly possible. And that’s it.”

Since 2010 CleanEarth have installed more than 700 solar PV systems and there’s a surprising level of variety across those 700 projects. “There are common themes, for sure, and technology is becoming more commoditised,” Jamie says. “But no two systems are the same and you need to work to get the full potential out of every single one.” 

CleanEarth represents over 40 MW of capacity and saves around 15,000 tonnes of carbon emissions every year, with yet more projects in the pipeline. Every project presents its own unique needs, but with the right expertise they can maintain their peak performance across their lifetime. It just takes the right attitude and close attention to those hidden essentials.