Low Carbon Urban Precincts emote visions of local renewable energy generation, vertical farming and energy efficient business and residents using efficient appliances and driving electric vehicles. So do we find the establishment of these precincts elusive? How do we encourage them? How do we measure them?
Creating a low carbon precinct in the City of Sydney
I have been working with a group of industry and government leaders in the development of research on low carbon precincts.The focus on the research is on an existing precinct in the city of Sydney called the Broadway precinct. This precinct includes the University of Technology, Sydney Institute of Tafe, and CentralPark which include residental, commercial and retail The purpose of this research is to look at how we can retrofit such precincts to make them more sustainable. Such retrofits are common on the basis of single buildings, however cross boundary retrofits between building owners have not been successful to date.
What is precinct sustainability?
Sustainability within these precincts (and particularly ecological sustainability) can be driven by energy and water efficiency, deployment of renewable energy, deployment of recycled water treatment plants, fuel switching, local pollutant sequestration, reduction in embodied energy and some form of demand management (which may or may not lead to environmental benefit). At the same time it is critical to view precinct sustainability in the context of total impact on the community more broadly , which brings into focus the impact of any changes in such a community on the wider energy and water macro-grids.
What are Microgrids?
Microgrids are one enabling technology related precinct sustainability. The focus of the work for this research will be on how to best configure microgrids to deliver precinct sustainability in urban contexts. Microgrids can be defined as :
“… electricity distribution systems containing loads and distributed energy resources, (such as distributed generators, storage devices, or controllable loads) that can be operated in a controlled, coordinated way either while connected to the main power network or while islanded (CIGRÉ C6.22 Working Group).”
These grids do not, in and of themselves solve any particular environmental issue. Microgrids need to be implemented with the genuine intent of driving environmental benefit. But what are the mechanisms for influencing these outcomes?
Are there other precinct sustainability initiatives?
Many existing microgrid sustainability projects involve either new precincts, large existing campuses, or islands. The following is a list of campus style microgrid projects, which most resemble the Broadway Precinct :
- Sendai Microgrid Project (and example of a University Microgrid and its impact during severe disruption to the main grid).
- The UC San Diego (UCSD) microgrid project (origionally a high efficiency co-generation plant that is now integrating storage and control systems)
- Santa Clara University Microgrid (Integration of smart meters, solar, microgeneration
- Illinois Institute of Technology Project (a perfect power prototype) (focused on peak load reduction)
- Santa Rita Jail Project (a green prison) (1.6 MW solar with fuel cells)
- LA Airforce Base Project (Vehicle and building integration)
There are also a number of wider microgrid projects such as Beach Cities Microgrid Project which integrate across the boundaries of sites. In Australia you could argue that Barrangaroo and CentralPark are leading sustainability precincts which deploy “behind the meter” electrical and thermal grids. Another key market for Microgrids are islands. Many pacific islands have by necessity implemented simple microgrids (often involing solar integrated with deisel generators). Or for the Rich and Famous why not buy your own microgrid, as per the recent announcement by Richard Branson of his very own island microgrid.
But there are few, if any examples of retrofitting microgrids in urban contexts “accross the fence” which refers to between two building owners.
So why has this not been done?
The challenge with executing on this vision can be traced back to the fundamental drivers of creating such an outcome. To be successful, a retrofit of a precinct for environmental efficiency must navigate one primary barrier – that all stakeholders will require sustainability measures to pass threshold of economic benefit. Many of the campus examples above were government subsidised and involved collaborations with industry as a pilot format.
If the economics can be made to work , there is a second issue. These projects must manage stakeholders who often have self interest in the status quo. There must be a clear governance structure to be able to manage ongoing behavioural aspects and benefit distribution. And then all regulatory barriers must be confronted and managed as well as the related (and substancial) task of working with incumbent grid participants (such as electrical distribution companies). Finally there is significant complexity in managing billing and tarrifs on a local scale
So how do we go about ensuring Microgrids drive sustainability?
So how do we establish such a strategy for managing microgrids to achieve environmental outcomes. Firstly we need a way to contextualize the environmental benefits of microgrids within the myriad of issues outlined above. I have done this by creating formula’s which can demonstrate correlations. Secondly, one can use these drivers to map a number of likely scenarios of microgrid configurations that can solve for the higheset environmental benefit.
The following is an outline of the thinking behind the formulas that I have created below :
1. To measure anything we have to find a common unit of currency. In this case I am using dollars as the universal language. My first formula outlines that in this context the benefits of a particular environmental outcome for a precinct is based on comparing that outcome with others within a time (t) frame, discounted by the time value of money (i) . The Net Present Value (NPV) is a useful measurement for understanding the value of a particular option over the long term (See Formula 1)
2. The Return (Rt) of any given option is based on a combination of Environmental Benefit (Ev) , Economic Benefit (Ec) and Social Benefit (So). Although I am focused in this debate on Ev, this must be given in context of Ec as most decisions will be based primarily on economic outcomes. While this formula is translating all measurements into dollars, the Ec in this context means direct increases in the capital of any key stakeholder in the precinct. This is a function of the finances of residents, building owners, the wider community and the microgrid owner.
3. Once you have an understanding of the Rt we can get down to the business of really understanding the Ev. To do this we have to price (or internalise) the environmental impoact externalities. While such impact goes far beyond greenhouse gases, for the purpose of this exercise we will use the notion of Carbon equivalence as the metric.
4. We can then focus in on the key area of interest for my research which is the environmental benefit at time t of a microgrid. This is based on a formulate of population of the precinct, the affluence, and technology change at any one time. This is then multiplied by the improvements in energy efficiency of the precinct (Ef), the % of renewable energy (Re), the level of fuel switching (ie using generation that is less carbon intensive such as gas fired cogeneration), local carbon sequestration (Ls), embodied energy (Ee) and Demand management. So the question then becomes, how does a local microgrid help to optimise these various mechanisms?
5. There are two key factors that then need to be added. The first, and potentially the largest factor is the impact of behavioral change on all of the factors above (which will impact on affluence, energy efficiency, embodied energy and demand management.) It could also be argued that behavioral change could impact scope 3 emissions (for example in switching modes of transport). The final mediating factor is then the impact of all of these measures on the macrogrid.
By that I mean that if these measures adversely effect large scale generation that has a higher positive environmental impact, then this must be taken into account.