Quantifying the influence of residential water appliance efficiency on average day diurnal demand patterns at an end use level: A precursor to optimised water service infrastructure planning (original) (raw)
Impacts of water efficient appliances on the design of the water supply infrastructure
Water efficient appliances are proven measures of reducing householders' peak water demand on cities' mains water supply network and consequently provide benefits to the water provider, in terms of augmentation deferrals and reduced sized infrastructure. However, while acknowledged in the literature, the actual benefits have not been thoroughly investigated and quantified. The paper aims to demonstrate how the installation of water efficient appliances would affect the design of the water supply network. Using an updated methodology incorporating end-use data from smart water meter, peak day water demand profiles were developed for the baseline scenario (Scenario A), representing the typical building code mandated for new dwellings constructed in the region of Queensland, Australia, and for households fitted with higher efficiency water appliances (Scenario B). Hydraulic model runs were conducted for both scenarios over various planning horizons to determine the scheduling o...
2009
The traditional use of long-term average consumption records and "peak factors" to determine water network design criteria ignores allotment-scale diurnal water use patterns which impact upon detailed network dynamics. The diversity of allotment-scale diurnal water use patterns directly impacts on network dynamics. Demand management and/or rainwater tanks are likely to impact upon water supply network diurnal peak flows. Results presented in this study suggest that rainwater tanks with mains water trickle top-up produce different diurnal "mains water" use patterns that significantly reduce peak demand of the network; which subsequently impacts upon water supply network design criteria and provides opportunities to offset water infrastructure costs. Therefore there is a need to investigate the impact of diurnal patterns and source control measures, such as demand management and rainwater tanks, on water supply system peaks and network design criteria.
Resources, Conservation and Recycling, 2011
In response to increasing water demand, Miami-Dade County, FL, USA implemented water conservation incentives for the residential customers. These incentives include rebates and unit exchange programs for showerheads, toilets and clothes washers. In this study, impacts of the water conservation incentives on water demand were analyzed. Water savings and water use trend shifts of the customers were evaluated during the first four years after the implementation of water conservation practices. About 6-14% reduction in water demand has been observed during the first and second years. The water savings continued during the third and fourth years at a lower percentage. Water savings for water use efficiency measures were about 28 (10.9%), 34.7 (13.3%) and 39.7 (14.5%) gallons per household per day for the showerhead, toilet, and clothes washer programs; respectively. Adoption of more than one type of water efficiency appliance contributed to additional saving in residential water use.
Implications of resource-efficient technology on peak water demand and water-related energy demand
2012
This paper uses a detailed water end use data registry generated from the South East Queensland Residential End Use Study (SEQREUS) to examine (a) peak hourly and daily demand, and (b) water-related energy demand. The impact of water-efficient fixtures and appliances, as required by current building codes in Queensland, is also explored. The four peak demand days selected had increasing peak day factors of 1.3, 1.5, 1.6 and 1.7. The range of these values is slightly lower than those used in the Department of Environment and Resource Management (DERM) guidelines where the peak day factors range from 1.5 to 2.3, suggesting that the frequency and volume of peaking factors may be lower than those that are currently being used for network distribution design; due likely to the high penetration of water-efficient technology and growing water conservation awareness by consumers. This type of knowledge can facilitate the optimisation of infrastructure design and sizing and inform the subsequent deferral of such assets. In terms of water-related energy demand, it was found that the hot water components of showers, and to a lesser extent, taps and clothes washers were the most influential. Shower energy consumption for electric cylinder hot water systems (HWS) and solar electric-boosted HWS was 810 and 351 kWh/p/year, respectively. The type of hot water system was significant in dictating the volume of energy-related carbon emissions, with the results confirming the significant impact that electric storage water heating has on total household energy consumption and related carbon emissions. Substantial savings can be achieved by substituting water (eg, high star rating clothes washers and shower heads) and energy (eg, solar hot water system) efficient appliances in the home. Knowledge on the end uses that are influencing peak water and energy demand can: 1) facilitate the optimisation of infrastructure design and sizing and inform the decision process regarding subsequent deferral of these expensive assets; and 2) underpin future sustainability codes for new buildings.
Identifying Residential Water End Uses Underpinning Peak Day and Peak Hour Demand
Journal of Water Resources Planning and Management, 2013
Accurate and up-to-date peak demand data are essential to ensure that future mains water supply networks reflect current usage patterns and are designed efficiently from an engineering, environmental, and economic perspective. The aim of this paper was to identify the water end-uses that drive peak day demand and to examine their associated hourly diurnal demand patterns based on over 18 months of water consumption data obtained from high-resolution smart meters installed in 230 residential properties across South East Queensland, Australia. Peak day (PD) to average day (AD) ratios between 1 and 1.5 were driven by both external and internal end-uses. However, as the PD:AD ratio increased above 1.5, demand was driven largely by external water usage (i.e., lawn and garden irrigation). Peak hour ratios (i.e., PHPD: PHAD) ranged from 1.3 to 3.0 for the four peak demand days. At the end-use level, the individual end-use category PHPD:PHAD ratios were in the range of 0.7-3.3 for all end-uses, with the exception of external or irrigation. The ratio for this latter end-use category was typically very high, at over 10 times the average irrigation demand. Comparisons with historically based, but currently used, peaking factors used for network distribution modeling suggest that the degree and frequency of high peaking factors are lower now, due to the high penetration of water-efficient technology and growing water conservation awareness by consumers.
2009
The traditional use of long-term average consumption records and "peak factors" to determine water network design criteria ignores allotment-scale diurnal water use patterns which impact upon detailed network dynamics. The diversity of allotment-scale diurnal water use patterns directly impacts on network dynamics. Demand management and/or rainwater tanks are likely to impact upon water supply network diurnal peak flows. Results presented in this study suggest that rainwater tanks with mains water trickle top-up produce different diurnal "mains water" use patterns that significantly reduce peak demand of the network; which subsequently impacts upon water supply network design criteria and provides opportunities to offset water infrastructure costs. Therefore there is a need to investigate the impact of diurnal patterns and source control measures, such as demand management and rainwater tanks, on water supply system peaks and network design criteria.
Article Seasonal Demand Dynamics of Residential Water End-Uses
2015
Water demand prediction by end-use at an appropriate spatial and temporal resolution is essential for planning water supply systems that will supply water from a diversified set of sources on a fit-for-purpose basis. Understanding seasonal, daily and sub-daily water demand including peak demand by end-uses is an essential planning requirement to implement a fit-for-purpose water supply strategy. Studies in the literature assume that all indoor water uses except evaporative cooler water use are weather independent and do not exhibit seasonal variability. This paper presents an analysis undertaken to examine seasonal variability of residential water end-uses. The analysis was repeated using two sets of data to ensure the validity of findings. The study shows that shower water use is significantly different between winter and summer, in addition to irrigation, evaporative cooler and pool water end-uses, while other water end-uses are not. Weather is shown to be a significant determinant of shower water use; in particular it affects shower duration which increases with lower temperature. Further analysis on
MIND OR MACHINE? Examining the drivers of residential water end-use efficiency
Water (Australia)
Essentially, there are two overarching demand management strategies employed to achieve efficient water consumption in the residential sector. These are: targeting water use behaviour change ("mind") and promoting the use of water-efficient technologies ("machine"). Using detailed water end-use data and qualitative methods, this paper describes the role that each of these strategies has played over the last few years, using data from 250 residential properties located in the south-east corner of Queensland.
Characterizing maximum residential water demand
Urban Water, 2012
The design of water and wastewater supply systems is traditionally based on maximum water demand which is a function of multiple factors. Understanding these factors and how these affect maximum water demand will lead to the estimation of appropriate peak design factors for a more cost effective design of water and wastewater supply systems. This paper describes the maximum water demand of four separate residential suburbs in Greater Melbourne, Australia with populations ranging from 1000 to 20,774. The study involves the analysis of water consumption data recorded at five-minute intervals over one year. The effects of population and the sampling interval on the peak factor have been analysed. From a set of data collected at five-minute intervals, further data sets at 10, 20, 30 and 60 minutes have been derived. New equations to estimate the peak flow demand for a small number of the population have been developed. Results also show that at five-minute intervals, a more accurate peak design factor has been estimated.
Journal - American Water Works Association, 2013
The intrinsic link between water and energy is well documented (USDOE, 2006). Water is required to produce electricity and energy is used to intake, treat, distribute, and use water, and to collect, treat, and dispose of wastewater or reuse treated wastewater. The California Energy Commission (2005) disaggregated energy use associated with urban water systems into water conveyance, treatment, and supply (20%), end use (75%), and wastewater collection and treatment (5%). Most of the energy use associated with the urban water cycle is direct use by the customer, largely in heating water for end uses such as showering and washing clothes. The percentage of energy use attributable to end uses is likely greater in other states such as Florida, where the energy use associated with water conveyance from source to water treatment is significantly lower than in California. A recent report for the Water Research Foundation (Leiby & Burke, 2011) includes water-demand management as a best practice, recognizing that reduced demands may result in reduced treatment and distribution needs, saving energy inputs. The predominance of the energy associated with water end uses serves as the impetus for this work, which is to present a parcel-level model of the water and energy savings associated with water conservation practices. Existing water use models evaluate water savings at the aggregate level. Jacobs and Haarhoff (2004) devised a residential end-use model that addressed not only demand for potable water but also hot water, wastewater flow, and concentration of total dissolved solids in wastewater. This approach requires significant data inputs, relies on average values for a given service area to determine end uses, and does not allow for targeting of individual users or clusters of users most suitable for water conservation. The Least Cost Planning Demand Decision Support System model, a proprietary end-use model, has similar limitations in its lack of fine spatial data on water users and limited ability to target customers for water conservation (Maddaus & Maddaus, 2004). Several models have been proposed to address the variability in indoor water use and demand-management options using probabilistic techniques. Rosenberg (2007) uses probability theory to derive a normalized performance function for evaluating conservation options. Blokker et al (2010, 2011) generate probabilistic demand estimates through simulation of end-use parameter probability distributions of various end-use parameters but do not explicitly use this model to develop optimal demandmanagement strategies. Other models estimate only energy use. Aydinalp et al (2004) modeled hot-water energy use in the residential sector using neural networks, but the effect of water conservation was not investigated. The same limitation exists in the work of Widen et al (2009), which modeled hourly electricity use through simple conversion schemes, mean appliance and water-tap data, and general daylight availability distributions. Clark and Males (1985, 1986) presented the Water Supply Simulation model, a hydraulic model that provided valuable insight into spatial pricing and costing, conservation policies, operating improvements versus increased capital expenditure, user-class subsidization, fire protection capacity, and water quality. Spatial costing incorporated operation and energy costs associated with withdrawal, treatment, and distribution, as well This article presents a parcel-level methodology to estimate the water and energy savings associated with indoor water conservation best management practices (BMPs). By estimating fixture water savings at the parcel level for 64 public-supply land use sectors, this approach facilitates targeting customers for water conservation by calculating their net benefits for each end use (savings in charges for water, wastewater, and energy, minus cost of water conservation BMPs). The inclusion of energy savings, primarily through reduced hot water use, is shown to be a significant benefit. The modeled end uses are male-only toilets, mixed-use toilets, urinals, faucets, showerheads, clothes washers, and prerinse spray valves. This article concludes with a simplified optimization formulation that determines the best fixture choice for every end-use device so that net benefits at the parcel level are maximized. These individual fixture results are then aggregated to the parcel or any desired aggregate scale (e.g., utility).