Height’s a Breeze

“Anything is possible” says David Fisher, head of the firm, Dynamic Architecture, espousing a philosophy that he sticks to while others raise eyebrows at his mould-breaking architectural model. Though no projects have come beyond design stage, the most controversial part of his plan is that his modular, largely prefabricated high-rises rotate. This was originally conceived as a real estate play so that all apartments could be sold with the same view. But the other more interesting part of Fisher’s concept from an EcoBuild perspective is that they create energy through integrated wind turbines.

Between each floor of these rotating towers is a horizontally stacked wind turbine, so efficient, says Fisher’s engineers, that they can completely power the building.

The Pearl River tower in Guangdong, China, uses wind turbines to power parts of the building. However, the original business plan to make the building net zero energy based on numerous micro-turbines generating energy thrrough wind funnelled into horozontal openings was foiled by government restrictions on selling power back to the grid.

While Fisher’s rotating tower plans were first launched in pre-crisis Dubai, his advisors at CB Richard Ellis advise him now to launch the first tower in a more “serious” location (word says it will be London). However, the Middle East remains the first location where large-scale wind turbines were integrated into a building design. The three wind turbine blades of the Bahrain World Trade Center (BWTC), has made the twin skyscraper complex something of a poster child for green buildings.

At 29m in diameter and with help of the aerodynamic design of the towers funnelling the on-shore breeze in the right direction, the three turbines produce only 12-15 percent of the energy required to run the building. But, at 1300 megawatt-hours per year, supposedly enough to power 300 homes, it’s a start.

The wind plan

While building-integrated wind turbines are not yet common, wind power firmly underlies the plan to reduce cities’ carbon consumption globally. Shanghai’s current total power capacity is about 18,200 megawatts, with wind making up under one percent. A short supply of land means many of the 13 wind power plants the city plans to build by 2020, when they hope to achieve 1,000 megawatts, equalling around five percent of capacity, will need to be built off shore, risking marine life and interrupting flight paths of migratory birds.

Offshore wind farms produce in bulk and are often developed by national power providers or other traditional energy infrastructure players, such as the worlds largest 1000MW Bohai Bay project being undertaken by China National Offshore Oil Corporation (CNOOC) that will be finished in 2020 off the coast of Tianjin. It is three times the size of the current largest wind farm. The coast of China has a potential estimated 750 Gigawatts of offshore wind power with China’s total capacity in 2009 already at over 840 GW (and plenty more demand), this option could provide a solution to the country’s power woes.

However, offshore wind farming brings up environmental issues mentioned above. In addition, along side the logistical infrastructure requirements needed to bring power from turbines at sea, significant amounts of power would be lost in transmission over these distances. Therefore, a way to bring the windmills to land, into the already built up cities, would both produce less negative environmental impact as well as increasing efficiency.

Building the answer

Apart from the building-integrated options such as on the BWTC mentioned above, there are other solutions, though many rely on a smartgrid that allows owners of building level power generation equipment to sell power back onto the grid. The flow of energy would then be multidirectional and encourage building owners to become more involved in energy as a commodity rather than approaching it in terms of cost centre mitigation.

In Cleveland, USA recently an in-town automobile recycling yard celebrated the opening of 120 kW turbine sitting 140 feet (under 50 m) above the yard and visible for miles around. According to Electrical Design Consultants President David Graneto, Pepper Pike, Ohio, the turbine powers lights and equipment in three of the yard’s buildings.

The turbine creates around 7 kW in a breeze of five metres per second and its updated design churns out 120 kW in wind of at least 10 m/s. Alongside the tower are two generators – the smaller for low wind speed and the larger for higher speeds, and a display offering real time tracking allows for effective energy management. According to developers costs for the turbine before incentives was a rather steep US$375,000. At current rates Graneto, predicts an eight to nine year pay back. Though he says that public acceptance of wind turbines on city skylines, particularly because the higher they are the more power they can produce, is one factor holding back a more widespread use of downtown turbines.

The turbine aesthetic

While China has become the worlds largest producer of wind turbines as are used in wind farms or in the example in Ohio above, smaller players are currently developing newer technologies that may prove more efficient. Though discrete in stature, at present their price may still put off players that are working within a heavily subsidised market. Dan O’Connor, Asia Sales Director, Urban Green Energy markets a uniquely and attractively shaped, almost silent turbine (see image above) that is highly efficient. While they are out of budget for many homeowners in the current economic environment, they have now been installed in over 35 countries and with incentives provide a smaller more flexible solution to traditional turbines.

There are even more moderately sized options. Motorwave in Hong Kong creates micro turbines made of plastic in a range of colours that can be arranged in formation to create signs and displays. But according to Lucien Gambarota, Founder and President, enquiries from large scale commercial property management companies interested in retrofitting the turbines still say that despite a lower initial outlay than some other solutions the pay back period would not meet their requirements.

The 50m tower and turbine in Delaware.

Building energy inefficiencies come about because traditionally buildings were built in one location and power came from another. Power is lost along the way. Two completely separate industries together with government, who are now coming to the table with initiatives such as feed-in tariffs, are having to find a way to work side by side. While progress is slow, it is happening.

Early adoptors are providing a valuable service in training building managers, consultants and E&M engineers in what does and does not produce energy efficiently. Over time and as innovation from product suppliers continues, government incentives kick in and the general level of education from the building sector improves then perhaps we might reach a point where buildings can, and will be expected to, power themselves.