It's a photovoltaic (PV) wall. And at 7,700 sq m it's the biggest one in the world that uses Copper Indium Diselenide (CIS) for the PV material.
What's the big deal?
Most commercial applications of PV so far have used crystalline silicon. CIS is 'thin film' technology and is supposed to work better in our less-than-constantly-sunny climate.
What's the building?
It's called OpTIC Technium and it's in St Asaph. It's an incubation unit to encourage budding 'optronics' (optics/electronics ventures).
So why PV?
Client Welsh Development Agency wanted a sustainable building, that would get an 'excellent' rating under the BRE's BREEAM assessment method. The building also has recycled water for flushing the toilets, natural ventilation in its public areas and waste slate, used a bit like dry stone walling, on lower portions of some walls.
How much did it cost?
£440,000 from a total contract value of around £10m.
Who's building it?
Shepherd Construction is the main contractor under a JCT 98 contract. PV Systems is the specialist firm that sourced the PV panels from California and manufactured the subframes used to mount the panels on the sloping walls.
Why California?
Well, that's the thing. Initially PV Systems had sourced panels from Antec, which had a factory in Germany. That went out of business, so it went to BP Solar but just as PV was about to place the order, they shut the factory down. So finally they went to Shell Solar.
Did this cause problems?
Yes. The original panels would have provided a waterproof facade, whereas the Shell ones didn't. The steel frame was already being made. So the project manager and QS from Bucknall Austin got everybody together for a brainstorming session.
They came up with the idea of extending the standing seam roof all the way to the ground and then mounting clips on that to support the PV panels. Alumasc, the manufacturer of the roof sheet, had to modify the clip because the roof slopes at 70% which meant that the clips are taking more vertical load than expected. There is also the added force of uplift as the wind whistles down the gap between panels and the roof sheeting.
The cost of this adaptation to accommodate the change in the type of panels was £80,000 Fortunately for Shepherd, the PV element had been tendered on a provisional sum. "I don't think we would have taken it on otherwise," confides project manager Tim Waters. "It would be too high risk."
So after all that, will the wall supply all the building's electricity? Not even close. This power-hungry optronics industry requires huge amounts of electricity – around 2.5 megawatts. The wall, on the brightest of days, will produce 85kW.
Source
Construction Manager
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