11 nov 08 | Globe and Mail
A building with an energy all its own
By Jay Somerset
New design frontier aims to make structures more than zero users of energy but power plants in their own right.
Fritz Lang likely never dreamed of this for his futuristic city in Metropolis: Offices and retail centers that harness the earth, wind, sun - and even people - to generate energy for their own needs, to share with adjacent buildings, or to sell to the power grid.
It may seem the stuff of a filmmaker's fantasy, but some architects believe buildings that require zero energy from public utilities - and might double as power plants in their own right - will become common over the next decade.
"This is a realistic goal," says Birgit Siber, project architect at Diamond and Schmitt Architects Inc. in Toronto. "Mechanical engineers anticipate net-zero buildings within the next five years and big-box buildings are the perfect candidates because of their large roof area and low energy requirements. So there's no reason why they can't start generating energy beyond their own needs."
It's a goal that already has been embraced by a Toronto-based furniture retailer.
"We'll be off the grid in 10 years," predicts Gerrit de Boer, president of Idomo Furniture Co. Ltd.
"We've got 72,000 feet of pipe in the ground," he says, referring to a 66-hole geothermal field that cost $1-million to install beneath his office and retail facility in north Toronto. It is designed to cover heating and cooling needs and provide free, renewable energy once it pays for itself "in about eight to 10 years," he says.
But geothermal energy is only the beginning for Mr. de Boer. There are plans for a photovoltaic solar array atop his 200,000-square-foot mixed-use building to convert sunshine into electricity.
On a much larger scale, a 1.1-million-square-foot mixed use project in Abu Dhabi is being designed from the ground up to not only power itself but provide surplus energy to surrounding buildings.
Chicago-based Adrian Smith + Gordon Gill Architecture is designing Masdar Headquarters, which will make use of virtually every type of renewable energy, from geothermal to wind turbines to green roofs, says Bob Forest, a partner at S+G who is in Abu Dhabi overseeing construction.
The building will sit in the heart of Masdar City, a 2.3-square-mile community that is being designed to be the world's first zero-carbon, zero-waste city fully powered by renewable energy, once it's completed in 2016, Mr. Forest says. "For a part of the world that made its fortune from oil and fossil fuels, this is all the more impressive."
Designing for renewable energy is always site-specific, Mr. Forest says. "In the desert, you've got lots of sunshine, so your building should be molded around capturing sunlight. We're not sure about adding wind turbines yet because there isn't much of a breeze."
Putting a wind turbine on top of a building might make sense elsewhere, even in a downtown core, adds Richard Williams, vice-president of architecture at HOK Canada. But the effectiveness "is dependent on geography," he says. "You need prevailing winds to get high [energy] returns."
Like the desert, cold-climate countries such as Canada tend to get a lot of sun, so solar, not wind, might be the dominant design consideration.
"The solar energy that falls on the roof of a typical building far exceeds its energy requirements," says Dr. Andreas Athienitis, Concordia University Research Chair in the department of building, civil and environmental engineering and chairman of the Solar Building Research Network, a group of professors from 11 Canadian universities. "That means there's potential for that building to achieve, on average, zero-net energy consumption."
But, certainly the dream of designing office towers and retail centers as self-standing power plants has its limits.
HOK is building a federal government office in Charlottetown that features photovoltaic panels that will contribute between 8 and 10 per cent of the building's energy needs, which will "reduce the amount of energy taken from the grid but certainly not even near the level of being net-zero or even an energy exporter," Mr. Williams says.
"At a certain point you run into the laws of physics," says Paul Szaszkiewicz, principal and director at Diamond and Schmitt, adding that a building not only has to be heated or cooled and lit, but the equipment within it, such as computers, needs to be powered. "The infrastructure needs to go beyond the support of the building and into the support of the tenants."
Instead of attempting standalone, energy-positive buildings, the better approach is to come up with building designs that "can integrate power needs with neighbors and district utilities," Mr. Szaszkiewicz says.
Not only is this a more realistic approach to commercial construction, it's already being done.
When Diamond and Schmitt designed the engineering and computer science building at the University of Toronto, architects realized they could recover 93 per cent of the heating requirements from an adjacent boiler plant at the university. "This is heat that had been wasted blowing out the smokestack," says Don Schmitt, a principal partner at Diamond and Schmitt.
Energy tradeoffs are especially plentiful in urban areas where the pool is much larger, "whether it's heat recovery on a smokestack or solar energy," Mr. Schmitt says.
In Britain, building engineers are even testing the possibility of harnessing power from pedestrian footsteps. Floors embedded with "heel-strike" technology generate power when compressed by footprints. "There are a number of possibilities here," Mr. Williams says, "but the technology isn't generating the volume of power we need [for commercial buildings.]"
While some of this may seem exotic building design, there's still a case to be made for old-fashioned tried and true energy saving techniques.
"We need to avoid becoming too enchanted with high-end technology," Mr. Schmitt warns. "Energy efficiency - retaining heat and managing it - comes back to a really robust building envelope."