When alternative energy is an alternative to a country’s staple resources you can hear the economic and political rumblings a mile off.
Australia’s ongoing transition from fossil fuel power to renewable energy came to a head last September with a power outage in South Australia that left around 1.7 million residents with no power after severe storms. As ABC News reported, SA Premier Jay Weatherill explained that two tornadoes damaged the infrastructure and the power system shut down to protect itself, with backup generators eventually kicking in
Despite questions at the time interconnectors between Victoria and South Australia were not found to have a role in the blackout. This did not stop politicians, including Prime Minister Malcolm Turnbull, leaving themselves open to accusations that they were leveraging “the blackout to initiate misleading debate over South Australia’s progressive use of renewable energy, claiming that its 40 per cent reliance on wind and solar rendered the network unnecessarily vulnerable”.
Indeed, as we know, the federal government’s response to climate change initiatives is often so tepid a recent survey by the Australian Institute found that two-thirds of voters (55% of whom identified as Coalition voters) believed the nation was moving too slowly to embrace renewable energy sources.
Tellingly, one of the conditions for Senator Nick Xenophon to give his support to the government’s lowering of the company tax rate was that, in return, the government will give a $110 million low-interest loan to install a solar thermal plant in Port Augusta to improve the reliability of power in SA (Peter Hartcher, Sydney Morning Herald).
With Labor announcing in April that further to recommendations from a Senate committee it would “retire coal-fired power plants and never fund new ones”, bargaining over the balance of old and new sources of energy is only going to intensify.
How does this play out for an industry looking at alternative ways to power commercial towers in the future considering their environmental impact? What are the energy harnessing technologies, such as some of the highest profile, trigeneration and cogeneration, and others at various stages of development and use?
For Tim Elgood, Sydney Sustainable Buildings Leader at Arup, Australia’s signing of the Paris Agreement on Climate Change (November 2106) without having a real plan of how it can be achieved (such as limiting global warming this century to "well below" 2 deg C and aiming for 1.5deg C) “has created a focus on the renewable energy sector … (giving) a massive momentum in the industry. Yes, there will be challenges but I do not think technology, innovation or creativity are constraints but it might be the regulatory/ governance issues that slow us down.”
A closer look at how things are panning out shows learning, experimentation and frustration.
COGENERATION AND TRIGENERATION IN ACTION
Cogeneration (CHP) heats and powers from a heat engine or power station generating electricity and useful heat at the same time. Trigeneration (CCHP) combines cooling as well with an absorption chiller to generate chilled water for air-conditioning or refrigeration.
To work at their best and produce lower-emissions energy, trigeneration systems must be sized correctly for the energy use of the building for which they are intended, Jay Gualtieri, managing director of environmental consultant Ausnviro told the Fifth Estate newsletter. While the trigeneration system rates well in Green Star “from a design perspective, Green Star is quite bullish on trigeneration; essentially the bigger the system the better”. The problem then is that many of the systems are too large, so “they simply don’t get switched on”.
There are other complications. For instance, the building may have been tuned during commissioning and operations alongside other systems which, if they operate at optimum efficiency, may mean the trigen assumed in the modelling may not start. The Fifth Estate also reported that the increase in gas prices has meant less benefit from using gas than electricity.
The high-profile low carbon 1,400kW trigeneration system at Sydney Town Hall and Town Hall House is expected to cut emissions by more than 40,000 tonnes over its 30 years’ lifetime. The rooftop generation plant, since September 2016, has also regularly exported energy to the grid, according to the City of Sydney. The plant uses seven 200kW Capstone microturbines that can each turn down to a tenth of their total power output, the de-centralised system producing energy locally while meeting year-round demand for electricity.
The high-profile low carbon 1,400 Kw trigeneration system at Sydney Town Hall and Town Hall House is expected to cut emissions by more than 40,000 tonnes over its 30 years’ lifetime. Image: Spotless
Liberty Place, at 161 Castlereagh Street, by Francis-Jones Morehen Thorp (FJMT) took out the Urban Development Institute of Australia NSW Award of Excellence in Sustainable Development, and the Australian Institute of Architects 2016 NSW City of Sydney Lord Mayor’s prize, the award for Urban Design (architect Francis-Jones Morehen Thorp) and commendations for commercial and sustainable architecture. The complex included the refurbishment of the historic Legion House, the first refurbishment designed to meet the Australian Sustainable Built Environment Council’s definition of a zero-carbon building.
The trigeneration system there has two 420Kw gas generators and two 317KwH absorber chillers. Aware of some industry (and property owner) scepticism over the actual operation of trigeneration systems, the developer, Grocon, split the system into the two sets of half size. The gas generators would run at low demand to maximise run time and cooling systems used cooling from absorbers for cooling even when the generators were not running at their peak.
OTHER TECHNOLOGY IN PROGRESS
Meanwhile, another idea for Legion House was to have biomass gasification technology that relied on paper waste from buildings in the surrounding area to create a recycled paper and plantation woodchip briquette feedstock that would be turned into gas to then generate electricity. The greenhouse gases released in the energy production were to equal those absorbed in creating the biomass with Legion House thereby contributing to its operation as a carbon neural building. There were commissioning challenges and it took a while for approval to use briquettes.
Liberty Place by Francis-Jones Morehen Thorp uses a biomass gasification system fuelled by paper briquettes comprising recycled paper from the surrounding buildings.
The University of Technology, Sydney’s Faculty of Engineering and IT (FEIT) building by Denton Corker Marshall is the university’s first building to offset its energy usage from renewables. Partially funded by NSW and federal governments, the $190 million project (opened in 2014) has a cogeneration plant on it roof. Sustainability Matters reported that the plant produced 20 per cent of the building’s electricity, air-conditioning and heating, and includes a vertical axis (rooftop) wind turbine, solar water panels, photovoltaic panels and what are known as solar parabolic troughs or solar thermal concentrators that feed the FEIT’s micro-grid to power its laboratories and classrooms.
UTS' The Faculty of Engineering and Information Technology by Denton Corker Marshall is the university's first building to offset its energy usage from renewables. Image: Denton Corker Marshall
UTS was collaborating with RMIT University, Standards Australia and German thermal system designers Solem Consulting to deliver the first Australian Standard for the industrial use of solar thermal concentrators. It is funded by the Australian Renewable Energy Agency, but the main update Infolink | BPN found was that as of April no such standard was listed on the Standards Australia database.
Architectural consultant Steve King, in his sustainability blog, has acknowledged that in generating power vertical axis wind turbines also “generate noise, vibration and turbulence” so much so that the turbines at London’s Strata Tower, the world's first skyscraper with built-in wind turbines and touted to supply eight per cent of the building’s energy requirements, were observed to be mostly lying idle.
London's Strata Tower is the world's first skyscraper with built-in wind turbines. Image: Wikimedia Commons
Unsurmountable changes can also impinge on a project. Peddle Thorp Architects was to go ahead with a solar powered 60-level skyscraper which was to abut King Street off-ramp at Melbourne’s West Gate Freeway. There were to be solar cells in the glass façade, integrating solar panels into curtain wall technology, and a curved exterior to capture the sun’s rays. Peter Brook, Director at Peddle Thorp International, is clearly frustrated that the project, believed to be a world first, has been stymied by the “Victorian Government’s planning regulations that have made setbacks from freeways mandatory so fewer units could be built than originally planned and to be economically viable. It is a classic case of bureaucracy overrides creativity”. And the irony is that with all the overseas interest it is highly likely to be tried in the other countries in which Peddle Thorp works, especially in Asia and North America.
The original design for the Sol Invictus Tower by Peddle Thorp was expected to house about 3,000sqm of solar panels, with an extra 300sqm on the roof
Another cutting-edge development takes its cue from a building in Hamburg with an algae façade which sequesters carbon and generates biomass for conversion into biofuel. This building has a passive design so the energy loads are lower than a non-passive design, says UTS Associate Professor Sara Wilkinson.
The BIQ tower with algae facade technology in Hamburg. Image: Arup
Part of a UTS team of a scientist, an environmental architect and herself from the UTS School of Built Environment, which is developing a prototype algae panel. A feasibility study highlighted issues around the use of algae in buildings, for example, potential odours, cleaning and maintenance and unknown levels of biomass production in NSW, she says.
The prototype, funded by the City of Sydney, Arup and Lendlease, will be looking at all these to provide empirical data for Sydney. “Algae has the potential to provide biomass and thus biofuel to meet some of the energy needs of some buildings.” Though at this stage that does not include commercial, overall, she is particularly excited by the “great potential to use algae technology to remediate stormwater and grey water on site.”
Elgood also suggested that if we take “the sustainable approach of making the most of what we already have, we should look at what we can do with all those standby generators that sit within buildings waiting for the power to fail. We almost provide a 100 per cent back up power for premium office buildings and the thought of running those generators on bio fuel is technically an option.”
