Bishops Square
When architects Foster and Partners decided to put the largest office-based solar installation in London on the roof of the Bishops Square development in Spitalfields, they knew that they needed a public display to help demonstrate the benefits.

The solar array at Bishops Square. - the largest installation of its kind in London!
Most roofs are only used for one purpose: for keeping out the rain. The urban environment - with all its underused roof area - is perfect for the collection of solar energy. Solar electricity has many advantages over electricity from conventional power-stations; it reduces environmental impact dramatically and, because it's generated locally, it cuts out the significant distribution losses that are otherwise incurred on the way from the power-station. And of course the fuel - which is simply daylight - is free.
We worked with renewable energy specialist solarcentury, architects Foster and Partners, and developers Sir Robert McAlpine to deliver a street-level experience communicating the benefits of the thirteenth-floor solar installation to an audience of people working in Bishops Square, shoppers and passers-by.

Up close to one solar panel on the roof of Bishops Square.
The context
The display was to be sited outside the main entrance to Number 1, Bishops Square in the heart of the City of London, mounted inside standard site signage designed by Fosters. The site would be visible from more than 100 metres away, and it needed to have impact even from that distance.

When it opens in September 2005, 4,000 people will work in the office, and many more will pass the site while commuting, shopping and so forth. The audience will get many repeated exposures to the display - many people will see it four or five times a day - and we set out to create something that was immediately informative without feeling brash or tiresome after a few months.
We needed to explain a natural phenomenon in a modern urban context, and find a representation that would feel connected to natural processes, changing slowly with the weather, with a feeling of constancy and dependability, while also speaking to the pace and language of city life. We wanted to open up the story of renewable energy beyond ecogeeks like us, and refer to energy in terms that people can understand, rather than just KWH and KG of CO2. Of course, we were also determined to minimise the power consumption of the display itself.
The design
The core idea of the display is simple: Every moment of the day, photons are raining down like little packages of free energy all over every city in the world - if people want to use it, they need only decide to collect it. The main animation shows a constant 'rainfall' of energy that relates to the amount of power being generated from minute to minute. A sunny day brings a torrential downpour of energy, a winter's evening will produce a light shower.

Most of the time, this is what the display shows. Live data showing power production scrolls across the display at moderate intervals. Every 8 minutes or so, the display cuts to an informative animation telling a simple story about energy use - how the generated power relates to cups of tea, digital cameras, and laptop computers for example. Information is also presented in standard units like Kilowatt hours for those lucky people who understand them.
The build
We started by refining the animation to have the right character, while minimising energy use. This was tested internally as simple animations matching a number of possible energy conditions (the animations were designed to change depending on the weather, the time of day, and the total cumulative output of the panels).

Testing the LED panel in the studio.
During this time, we modified the pacing of the animations quite significantly. We conceived and developed the intercut animations to allow us to use two different major 'characters' in the communication: the slow, natural character that runs most of the time, and the quick, fun modern character that shows up in the intercut animations.
This allowed us to get the best of both worlds in a way that would offer immediate impact, while engaging audiences over a long period. This approach would allow incremental improvement in respect of user feedback. These tests were approved by the client, and we moved on to develop the software that would draw these animations in real-time, depending on the performance of the panels.
We used our existing morePower software to communicate with the solar controller on the roof, and we built a small, very low power computer with a custom operating system to run the display. We also designed and built some custom hardware to handle communications with the controller and the display interface.
