Geasy Related Resources
How much energy can optimal control of domestic water heating save?
Three strategies for optimal control of domestic water heating is explored: matching the delivery temperature in the hot water, matching the energy delivered in the hot water, and a variation of the second strategy which provides for Legionella sterilisation. Our results demonstrate a median energy saving of between 8 and 18% for the three strategies.
Potential legionella growth in domestic water heating systems in South Africa
Legionella is a genus of pathogenic bacterial mesophiles that cause a range of diseases collectively referred to as Legionellosis, with immuno-compromised individuals being particularly susceptible. The high energy usage of electric water heaters (EWH) cause cost-sensitive users to employ energy-saving initiatives, such as scheduling and lower temperature set points which may allow Legionella to flourish – although its prevalence is probably higher in the downstream pipes.
An analysis of behaviour and understanding of electric water heaters
This paper aims to investigate: the awareness of energy savings measures for electric water heaters (EWHs); whether or not consumers are implementing suggested measures; and if consumers understand and effectively control their EWHs’ energy usage. The results indicate that: convenience is a key factor in consumers’ willingness to implement curtailment actions; users don’t understand the energy consumption of their EWHs; and they don’t know how to control their EWHs efficiently.
Saving on household electric water heating: What works best and by how much?
This paper addresses this problem by comparing some of the commonly employed approaches to reduce the energy usage of electric water heaters, including schedule control, change in set temperature, use of thermal insulation, and reduction in consumed volume. The results show that for the consumption profiles and use cases evaluated, schedule control is the most effective, followed by the insulation of the cylinder and piping. Combined, these two interventions save up to 25%.
Sustainability through Intelligent Scheduling of Electric Water Heaters in a Smart Grid
Water heating is responsible for 32% of domestic energy use. Given the usage patterns, the capacitive nature of water heaters, and the standing losses when hot, these devices are good candidates for schedule control to affect energy savings. The smart grid experiments performed demonstrate a 29% energy saving, comprised of reduced standing losses and usage enthalpy.
Recognition of consumption patterns for heating schedule optimisation
This paper presents an alternative to the invasive and expensive solution of using water flow meters. The results show that the approach is able to detect usage events with an accuracy of 91%. Despite the challenges related to thermal inaccuracies, event durations are estimated to within 2 minutes accuracy 79% of the time.
Dropula Related Resources
A correlation of school fees and governance as it relates to sustainability in water resources management at schools
Water scarcity is increasingly staking a claim next to energy as a threat to the sustainability of large cities, especially in developing countries with limited resources. The recent crisis brought on by Cape Town’s “Day Zero” drought created the impetus to expand on existing research on water demand management to include analysis of school usage patterns and key determinants thereof. We find that poor schools use substantially more water, partially because of poor maintenance, with mean water efficiencies of poor schools around 50% and 80% for affluent schools.
Results from a water-saving maintenance campaign at Cape Town schools in the run-up to Day Zero
We evaluate the impact of a plumbing maintenance drive at 196 schools during the drought of 2017/2018 in the Western Cape. We gave plumbers a list of typical easy-gain repairs. We then analysed the cost-benefit of these repairs, using data on the minimum nightly flow (MNF) as recorded by Dropula units. We found an average of 28% reduction in MNF within five days of the reported maintenance date. The once-off R1.22 million spent resulted in a saving of R1.90 million/month.
Understanding and affecting school water behaviour using technological interventions
The aims of the study was to characterise water consumption patterns for a school, and to quantify the effects of the technology-driven interventions on behavioural change. Three interventions were implemented using smart meter data: posters, playing cards, and daily presentations. The interventions were able to reduce water consumption of the school by 44% when compared to the use of a school in the same town where the interventions were not implemented.
Case study of household behavioural response to Cape Town’s “Day Zero” using smart meter data
We look at how changes in water use were affected by official announcements and by public engagement with this news via the social media activity and internet searches. We found that the introduction of Level 5 restrictions had a perverse effect on consumption, possibly due to confusing messages. The most dramatic change in behaviour appears to have been instigated by a media storm and consequent user panic after the release of the City’s Critical Water Shortages Disaster Plan in October 2017. However, contradictory communication from national and provincial government eroded some of this gain.