"For example, indium is a crucial part of your mobile phone’s touch-screen, but it’s also useful for solar cells. There’s only so much of a supply though and renewables aren’t going to beat the demand of mobile phones – so we’ve already planned for future solar cells to be indium-free.
"Instead of indium tin oxide, we’re now using fluorine tin oxide. While it means we can still make solar cells, without indium it limits our choice on the flexibility of these cells.
"As time moves on, we are seeing more material challenges, more materials that we need to substitute and this is not always as straight forward as the indium case. The biggest fear is that we will have renewable and energy efficient products, all needed to mitigate climate change, competing for materials, thus limiting deployment.
"As consumers, the power lies with us though – we have to vote with our wallets and choose to buy products built with remanufacturing, repair and upgradeability in mind."
When it comes to recyclable design, Dr Davis is something of an expert, with his team developing so-called Active Buildings, that generate their own energy.
Crucially, they’re designed using off-site construction methods – with the houses assembled in place later. Because they’re modular, the houses can be easily rebuilt elsewhere – and components can be easily replaced if broken or in need of an upgrade.
"We need to change the way we see and use materials. There’s inherently a massive benefit in doing that. We know it can be done, the tech exists. We’ve proved it with the Active Buildings. Now we need to shift the onus back to the manufacturers."