Full-facade solar power

March 2010 – Imagine a future where buildings power themselves with the sunlight that falls on the whole façade – no noise, no visual impact, zero carbon emissions. As BLAIR PESTER from Suntech Power Australia writes, new ranges of ‘building integrated photovoltaics’ (BIPV) products make this vision a reality.

Architects and builders around the world are increasingly embracing sustainability and searching for ways to design buildings that are ‘green’, without sacrificing architectural excellence. Suntech has developed several products that enable architects, facility managers and building designers to achieve their greater architectural ambitions in a green way.
With respect to solar design, almost every building has three things in common:

• the need for a weatherproof skin
• the need for electricity
• the presence of energy in the form of sunlight.

It was our goal to combine these three common elements into a collection of building materials that are architecturally minded. The result is a design-enhanced weatherproof skin, or solar façade, that produces electricity for the building from the available sunlight. An example of this is our own headquarters (see description below), which incorporates a 1MW solar façade, supplying 80 percent of the total power demand for the whole building.

PHOTOVOLTAIC POWER
Why choose to integrate a photovoltaic system into your entire building? The benefits are as follows:
Form – highly aesthetic feature of the building
Function – weatherproofing, shading, thermal and acoustic protection
Sustainability – carbon-free electricity generated directly from sunlight
Economic payback – the only type of building material that generates revenue.

Let’s consider these points individually:

FORM
Your architect has the option to use BIPV modules as a striking and highly visible feature of the building, or to make it blend seamlessly into the design. Our see-through products, for instance, have been used as a substitute for tinted windows in an office environment, and come in a range of transparencies including one percent, five percent and 10 percent. A remote display unit, used in conjunction with a BIPV system, allows users to see in real time how much energy is being produced and the amount of carbon saved, making solar design a real talking point for building users.

Blair Pester.

FUNCTION
In the case of BIPV products, the module itself functions as a building material, providing the physical skin of the building, as well as offering shading, weatherproofing, thermal and acoustic protection. This removes the duplication of materials that occurs with standard solar modules, which are mounted on the top of an existing building structure; this efficiency obviously reduces costs and negative environmental effects. Our Just Roof products can be used in place of standard roofing, creating an extremely aesthetically pleasing finish.

SUSTAINABILITY
Our modules make a building more sustainable, and offer architects an opportunity to make a powerful environmental statement. In addition to generating electricity, our thin-film glazing BIPV also dramatically reduces the heat that enters a building, cutting the energy required for air-conditioning. In our experience installing a PV system also leads to a 5-10 percent reduction in energy usage, since occupants are invariably keen not to waste their ‘own’ solar-generated electricity. Solar systems are an excellent form of ‘green marketing’ and in many applications have an important educational function, heightening awareness of environmental issues.

ECONOMIC PAYBACK
In light of substantial increases in electricity costs over the past few years – and predictions that we can expect many more price hikes – companies should really consider the economic benefits of installing a PV system to subsidise each building’s energy consumption. The electricity that is generated by a building can be used or sold back into the grid, making it the only type of building that will pay for itself over time. In most Australian States there are rebates in place to reduce this payback time. Also, remember that most commercial buildings are not occupied during the weekends, and yet they will continue to generate power, allowing you to take advantage of the feed in tariffs. Since building integrated modules displace traditional building materials, only the incremental additional cost of the PV modules needs to be considered.

FULL SOLAR SYSTEM
Incorporating a BIPV system into your building will increase the resale value of your building, reduce cooling costs, improve your Green Star rating and act as a safeguard against rising electricity costs. BIPV facades are aesthetically pleasing and offer you an opportunity to make an environmental statement about your company while reducing carbon emissions and adding a sales point for potential tenants/buyers.
I believe that building integrated products are the way of the future and are achievable today. Why compromise on aesthetics when you install a solar s system?

CASE STUDY – SUNTECH HQ
Suntech’s own headquarters (pictured above), opened in December 2008 in Wuxu, China, features the world’s largest on-grid photovoltaic façade system.
The 18,000-square-metre Suntech Green Energy HQ Building has more than 2570 semi-transparent Light Thru™ solar panels within its facade. The panels, which cover an impressive 6900 square metres, produce a total of 730,000 kilowatt hours per year. Another 1800 roofing panels add 300 kilowatt hours to the total energy production, taking the aggregate annual production to 1,020,000 kilowatt hours. Panels measure 2.2m x 1.12m (façade) and 1.482m x 0.992m (roof).
Suntech’s Light Thru solar glazing product was chosen for its environmental and aesthetic strengths. Suntech chose Light Thru for its ability to generate clean power and contribute to the elegant design aesthetic they envisioned for their office building. The panels form the cornerstone of Suntech’s overall design strategy for an environmentally responsible headquarters.

Blair Pester is distribution manager for Suntech Power Australia Pty Ltd.

More information
Suntech Power Australia www.suntech-power.com
02 9695 8188