|
Recycled
water powered by renewable energy | |
|
Citiwater
Carbon Neutral
Water Recycling Project |
|
 Aerial photo
of the Cleveland Bay Purification Plant |
|
Introduction to the Carbon Neutral Project Energy and Greenhouse Analysis |
|
|
Introduction to the Carbon Neutral Project The Citiwater Carbon Neutral Water Recycling Project proposes to recycle up to 20ML of water per day from the Cleveland Bay Purification Plant (CBPP). Under this arrangement, Private Partners with will assist in the development of a water recycling plant (for example, using reverse osmosis technology) Another driver for this project is to improve the security of Townsville's water supply by reducing the demand on raw water. At present, in the event of an extended drought Ross Dam running dry, water can be pumped from the Burdekin into the Ross Dam. Pumping water over this distance has a significant energy cost and also results in large amounts of water loss through evaporation and evapotranspiration. For example, it is calculated that 28 ML of water would be diverted from the Burdekin region to provide 20ML in Townsville. The water recycling option helps to offset the need to pump water from the Burdekin. However, it too comes at a high energy cost and greenhouse emissions (through use of coal fired mains power). For this reason it is proposed to provide the energy necessary to run the water recycling plant with renewable energy. An number of renewable energy sources have been investigated including a prefeasibility assessment of the wind resource at the Cleveland Bay Purification Plant Site. The Citiwater Carbon Neutral Water Recycling project is soon going to Expression of Interest by which the business community will have the opportunity to offer their goods and services.
Preliminary energy and greenhouse analysis
.In Queensland, production of mains electricity is mainly done using coal power. There are significant greenhouse emissions associated with producing energy in this manner. Furthermore, because Townsville is some distance from the large power stations in Gladstone, it is likely that the greenhouse emissions associated with mains power in Townsville are higher (due to distribution loss) than the Queensland average. The average greenhouse intensity of mains power in Queensland is:
source Australian Greenhouse Office Factors and Methods V3 By multiplying the greenhouse intensity of mains power with the total amount of mains power used, it is possible to calculate the greenhouse emissions associated with the provision of water in Townsville. Concentrating only on the energy associated with pumping water from the Burdekin and the option to recycle treated waste water we find the following figures:
These figures suggest that every kilolitre of water produce in Townsville has a greenhouse signature of approximately 1.4kg CO2e per kilolitre. Other sources of energy demand in the water management system include:
A full analysis of the greenhouse signature of Townsville water would include all the above energy sources and determine the carbon intensity of mains power in Townsville rather than relying on the State average. The Citiwater Carbon Neutral Water Recycling Project is seeks to provide a more energy efficient means of deliver water to Townsville, and also to produce this water without adding to greenhouse emissions through use of mains (coal) power. Potential renewable energy sources
Waste Water Treatment Infrastructure
Expression of Interest An EOI document is soon to be release by the Townsville City Council inviting private sector to Express its Interest in the project.
A preliminary assessment has been made of the wind resource of Townsville with a view to possibly using wind power to run the water recycling equipment. Council commissioned CSIRO Wind Energy Research Unit to undertake a prefeasibility study on the winds at the Cleveland Bay site. This was achieved by extrapolating the wind from a scientific wind monitoring station operated by the Australian Institute of Marine Science in Cleveland Bay. The wind data for the year 2000 was combined with regional terrain data (i.e.. elevation). Computer software called WASP 7.2 combined these data to produce an extrapolation of the wind speeds from the wind meter site to the Cleveland Bay Purification Plant Site. This data indicates that the average wind speed at the CBPP site is approximately 6.9m/s. While this is less than the average wind speeds associated with the southern Australian wind farms (i.e.. Bass Straight and Great Australian Bight) this is nonetheless a valuable resource potential yielding 4.3gigawatt hours of electricity per annum (assumes use of REpower MM70 2MW wind turbine).
|
|
 |
Wind Speed and Direction This table shows that the predominant wind direction at the CBPP site is from the south east (trade winds) and that other stronger winds predominantly blow from between east and south. From East to South through North, the winds are typically much lighter. |
Average Wind Speed in Each Sector This graph shows the direction of the wind and the average wind speed from each direction. |
|
 |
Average Wind Speed for Two Hourly Intervals This table considers the wind strength in relation to the time of day |
|
Wind Speed Probability Distribution This table shows the average probability distribution of wind speeds. |
|
|
Mean Annual Wind Speed This table shows the mean annual wind speed across Towsville and covering the CBPP site. The two crosses at bottom right of the image are the proposed locations for wind turbines at the CBPP site. This data shows that the annual average wind at the site is 6.9m/s.
|
Mean Annual Energy Yield This table shows the mean annual energy yield from the CBPP site. This table shows the power curve of a 2MW REpower MM70 wind turbine with a hub height (center of the blades) of 65m above ground. The data suggests that an MM70 wind turbine could produce 4.3Gigawatt hours annually on this site.
|
|
