Embedded energy generation: designing the buildings of the future

A growing number of building projects, from public buildings to modern homes, have energy generation incorporated into their design in stylish and innovative ways. But what are the benefits of this and how does it challenge designers?

10mw tower

The Strata SE1 tower in London is home to approximately 1,000 people and is one of the tallest residential buildings in the city. Completed in 2010, it is one of the first buildings in the world to incorporate wind turbines as part of its structure and included energy efficiency in its initial designs in 2005.

Since then, a number of projects worldwide have announced ideas to follow a similar route, with energy generation and sustainability at the forefront of considerations. One of these is a huge circular wind turbine, the Dutch Windwheel, in Rotterdam, Holland, that includes apartments, a hotel and rollercoaster. Its designers claim that it could be the first of its kind, with the turbine sitting in the centre and surrounded by two rings.

Currently under construction in Jakarta, Indonesia, is the Pertamina Energy Tower, designed by Skidmore, Owings & Merrill. This will generate wind power via a funnel at its summit. It will be 530m high and feature solar shades to allow natural light in.

Another notable development is the 10MW Tower, a concept design in Dubai produced by Studied Impact, an architecture and design company that focuses on the environment. It incorporates three renewable energy generation systems: a 5MW horizontal axis wind turbine, a 3MW concentrated solar power armature and a 2MW solar updraft tower. At 50 storeys high, the tower has been designed to produce 10MW of power, which would be ten times its needs, and is intended for office, retail, hospitality and residential use.

Studied Impact estimates that the yearly output of the building would be approximately 20,000MWh and will zero out its carbon footprint in less than 20 years. The wind turbine is designed atop of the tower, while the south side includes heliostatic mirrors.

All of these present their own benefits and challenges. Gary Peters spoke to Robert Ferry, co-founder of the Land Art Generator Initiative and Studied Impact, to find out more.

Gary Peters: Where did the idea for the 10MW Tower come from?

Robert Ferry: While living in Dubai, I had the opportunity to be a part of Masdar City's Project 1 planning and early implementation. That experience within the broader context of the climate, economy and energy infrastructure of the United Arab Emirates contributed to a sense of urgency with regard to developing new ways of thinking about architecture and city planning.

The 10MW Tower is one in a series of concept designs, alongside the Almeisan Tower and the Positive Impact House, developed for the UAE that explore what responsibility new architecture has towards contributing to a sustainable city.

Living space in big cities like London is gradually shrinking.

By designing buildings that not only achieve net-zero energy, and water, goals, but go beyond that threshold to provide clean energy and clean water to the surrounding city, we can reduce our dependence on large centralised facilities that are typically located a great distance from population centers - this distance contributes to an inefficient use of resources.

The eventual goal would be a self-sufficient city that functions much like a sustainable forest - a complete urban ecosystem that is self contained without waste or want for external infrastructural support, and that leaves open land areas between population nodes to undisturbed nature.

GP: What challenges have you encountered to date?

RF: In most places the cost of energy and water is subsidised to some extent and does not reflect the cost of extraction and generation on the environment. Dubai is an extreme example of this, but it is prevalent to some extent in almost all jurisdictions.

There are certainly efficiencies to be seen if we can produce more energy at the point of demand load. Why build a power plant and a building if you can do both at the same time? The solar power that strikes the facade no longer contributes to air conditioning load, but is rather turned into electricity. Doing so makes the building self regulating for temperature and reduces dependence on electricity consumption, [which is a] win-win.

The integration of concentrated solar power and other energy systems into buildings is a challenge, but it also is an opportunity to celebrate these technologies as artistic contributions to urban space. I like to call this 'style' of architecture 'sustainable expressionism', as we are seeing the impact of these on-site energy systems on the formal expression of architecture that meets Living Building standards (a campaign to promote sustainable building).

GP: Could you talk me through the design process, including the look of the concept?

RF: The exterior is shaped by the solar path across the site. The idea is to maximise the number of heliostatic mirrors that are able to reflect light onto a central collector where heat exchange makes steam to power a turbine.

The height of the building is a product of the physics of solar updraft technology. Inspired by the height of so many buildings in Dubai, it occurred to us that solar updraft tower technology could be integrated with high-rise buildings in a way that took the heat gain away from the interior by allowing it to rise within a double skin facade, gaining speed along the way to actually run a turbine.

"Onsite renewable energy systems are just as fundamental to the conception of the design, particularly because they require proper orientation to the sun or the wind."

The integration of the wind turbine is probably more problematic for a number of reasons, [as] the design does not allow it to rotate into the wind, vibrations will be difficult to isolate from the building and Dubai's winds are very intermittent. But the turbine would be able to capture the seasonal winds that blow to and from the desert, and is oriented to do so.

GP: How challenging is it to incorporate energy generation at the design phase, rather than retrofitting?

RF: Early in the design phase is the absolute best time to incorporate energy generation systems into architecture.

As is the case with any design / engineering problem, it is critical to understand all of the desired outcomes before putting pen to paper. You wouldn't begin to design an aeroplane before first understanding how the air will flow around it.

Onsite renewable energy systems are just as fundamental to the conception of the design, particularly because they require proper orientation to the sun or the wind. This relationship to natural forces means that these technologies are exposed or expressed on the exterior and they therefore drive early conceptualisation of the form of the design.

Similarly, the design should not proceed to concept sketches until a careful analysis of the site and its microclimate has been performed. The data collected in the research phase of the design process will inform decisions related to passive energy conservation measures that can heat and cool the building without the need to rely on active systems. Such design responses can include overhanging eaves, light shelves, mass capacitance - thick walls of earth, for example, or trombe walls that can store solar energy, chimney effects, etc.

If you have not considered these aspects from the very beginning it is nearly impossible to implement them into a design at a later stage. Such a design process will lack efficiency and suffer in performance.

GP: How important is the concept of incorporated energy generation, moving forward?

RF: I'm of the opinion that buildings owe it to their users and to the environment to be holistically designed as living buildings that function like a tree, generating their own resources and handling their own waste.

Cities full of buildings like this will see a decrease in demand for new infrastructures. As such, governments should be doing all they can to incentivise this kind of building.

GP: There are other similar projects in the works, including a circular wind turbine that doubles as an apartment block and hotel in Rotterdam, and the Pertamina Energy Tower. Do you think we will increasingly see more of these in the future?

RF: Yes, there will be a greater proliferation of these buildings in the future as energy generation infrastructure becomes more integrated into city planning.

The Pertamina Energy Tower is aiming for net-zero energy, which is a great achievement for a high-rise building. The concept behind 10MW Tower is that it is a net producer of energy for the surrounding city, still more ambitious yet.

GP: What, if any, obstacles do you think are in the way of more architects following a similar path to you?

RF: [The] 10MW Tower is a speculative concept without a paying client, so that does pose a challenge to architects. But seriously, I do think that we will see forward-thinking developers starting to incorporate this kind of design. It will start to make 'dollars and sense' as the cost of renewable energy technologies continues to drop.