Single household domestic water heater design and control utilising PV energy: The untapped energy storage solution

Photovoltaic (PV) panels and electric domestic water heater with storage (DWH) are widely used in households in many countries. However, DWH should be explored as an energy storage mechanism before batteries when households have excess PV energy. Through a residential case study in Queensland, Australia, this paper presents a new optimized design and control solution to reduce water heating costs by utilizing existing DWH energy storage capacity and increasing PV self-consumption for water heating. The solution is produced by evaluating the case study energy profile and numerically maximizing the use of PV for DWH. A conditional probability matrix for different solar insolation and hot water usage days is developed to test the solution. Compared to other tariffs, this solution shows cost reduction from 20.8% to 63.3% This new solution could encourage solar households move to a more economical and carbon neutral water heating method.

Abatement of energy loss by insulating system and designing automatic water heater

The most suitable temperature range for domestic purposes is about 200C to 260C .Besides, both cold and hot water appear to be essential frequently for industrial purposes. In summer bringing down the water temperature at a comfortable range causes significant energy consumption. This project aims at saving energy to control water temperature by making water tank insulated .Therefore applying better insulation system which would reduce the disparity between the desired temperature and the actual temperature and hence saving energy significantly. Following the investigation, this project used cotton jacket to insulate the tank and the tank was placed under a paddy straw shade with a view to attaining the maximum energy saving. Finally, it has been found that reduction in energy consumption is to be about 50-60% which is quite satisfactory. Since comfortable temperature range varies from person to person this project thus combines insulating effect with automatic water heater.

Performance evaluation of an integrated solar water heater as an option for building energy conservation

Since a majority of residential and industrial building hot water needs are around 50 degrees C, an integrated solar water heater could provide a bulk source that blends collection and storage into one unit. This paper describes the design, construction and performance test results of one such water-heating device. The test unit has an absorber area of 1.3 m(2) and can hold 1701 of water, of which extractable volume per day is 1001. Its performance was evaluated under various typical operating conditions. Every morning at about 7:00 a.m., 1001 of hot water were drawn from the sump and replaced with cold water from the mains. Although, during most of the days, the peak temperatures of water obtained are between 50 and 60 degrees C, the next morning temperatures were lower at 45-50 degrees C. Daytime collection efficiencies of about 60% and overall efficiencies of about 40% were obtained. Tests were conducted with and without stratification. Night radiation losses were reduced by use of a screen insulation.

Studies in biogas technology. Part IV. A novel biogas plant incorporating a solar water-heater and solar still

A reduction in the heat losses from the top of the gas holder of a biogas plant has been achieved by the simple device of a transparent cover. The heat losses thus prevented have been deployed to heat a water pond formed on the roof of the gas holder. This solar-heated water is mixed with the organic input for ‘ hot-charging ’ of the biogas plant. A thermal analysis of such a solar water-heater ‘ piggy-backing ’ on the gas holder of a biogas plant has been carried out.To test whether the advantages indicated by the thermal analysis can be realised in practice, a biogas plant of the ASTRA design was modified to incorporate a roof-top solar water-heater. The operation of such a modified plant, even under ‘ worst case ’ onditions, shows a significant improvement in the gas yield compared to the unmodified plant. Hence, the innovation reported here may lead to drastic reductions in the sizes and therefore costs of biogas plants. By making the transparent cover assume a tent-shape, the roof-top solar heater can serve the additional function of a solar still to yield distilled water. The biogas plant-cum-solar water-heater-cum-solar still described here is an example of a spatially integrated hybrid device which is extremely cost-effective.

Fish distribution in a small domestic water supply reservoir: a case study of Kangimi Reservoir, Kaduna, Nigeria

A study of the composition and distribution of fish populations in the inshore, surface and bottom water habitats of Kangimi Reservoir showed that the most abundant family was the Cichlidae followed in order of abundance by the familiesCyprinidae, Schilbeidae, Mormyridae, Mochokidae, Characidae, centropomidae and Bagridae. Though the overall composition of families caught inn the three habitats did not vary significantly (P>0.05) only family Cichlidae showed habitat preference: there was a preponderance of Cichlidae in the inshore water habitat (P<0.05). The families Bagridae and Centropomidae were caught only in the inshore and bottom water habitats while the other families were caught from all habitats and showed no habitat preference. The dominance of primary and secondary consumers indicates high fish production potential under adequate management

Reservoirs for irrigation, water-power and domestic water- supply ; with an account of various types of dams and the...

UANL

Effect of load pattern on solar-boosted heat pump water heater performance

The performance of a solar-boosted heat pump water heater (HPWH) operating under full load and part load conditions was determined in an outdoor experimental study. The system utilised flat unglazed aluminium solar evaporator panels to absorb solar and ambient energy. Absorbed energy was transferred to the water tank by means of the heat pump and a wrap around condenser coil on the outside of the tank. The system COP was found to be in the range of 5–7 under clear daytime conditions and 3–5 under clear night-time conditions. Using part load testing of the HPWH system it was found that concentrating the coils in the lower portion of the tank could increase the efficiency of the condenser coil. It was also shown that there exists a generalised linear relationship that can be used to describe the system COP in terms of the temperature difference between the water in the storage tank and the ambient air.

A study of performance characteristics of domestic water heating equipment, conducted for the Federal Housing Administration under contract no. HA-fh-646 (amendment no. 1) May 10, 1956 /

Mode of access: Internet.

Estimate of self-supplied domestic water use in Oklahoma during 1980 /

Mode of access: Internet.

Status assessment of water use research in turf growth and maintenance.

The strategic objectives of Turf Australia (formerly the Turf Producers Association (TPA)) relating to water use in turf are to: • Source and collate information to support the case for adequate access to water for the Turf production and maintenance sectors and • Compile information generated into a convincing communication package that can be readily used by the industry in its advocacy programs (to government, regulators, media etc) More specifically, the turfgrass industry needs unbiased scientific evidence of the value of healthy grass in our environment. It needs to promote the use of adequate water even during drought periods to maintain quality turfgrass, which provides many benefits to the broader community including cooling the environment, saving energy and encouraging healthy lifestyles. The many environmental, social and health benefits of living turfgrass have been the subject of numerous investigations beyond the scope of this review. However further research is needed to fully understand the economic returns achievable by the judicious use of water for the maintenance of healthy turfgrass. Consumer education, backed by scientific evidence will highlight the “false economy” in allowing turfgrass to wither and die during conditions which require high level water restrictions. This report presents a review of the literature pertaining to research in the field of turf water use. The purpose of the review was to better understand the scope and nature of existing research results on turf water relations so that knowledge gaps could be identified in achieving the above strategic objectives of the TPA. Research to date has been found to be insufficient to compile a convincing communication package as described. However, identified knowledge gaps can now be addressed through targeted research. Information derived from targeted research will provide valuable material for education of the end user of turfgrass. Recommendations have been developed, based on the results of this desktop review. It was determined that future research in the field of turf irrigation needs to focus on a number of key factors which directly or indirectly affect the relationship between turfgrass and water use. These factors are: • Climate • Cultivar • Quality • Site use requirements • Establishment and management The overarching recommendation is to develop a strategic plan for turfgrass water relations research based around the five determinants of turf water use listed above. This plan should ensure research under these five categories is integrated into a holistic approach by which the consumer can be guided in species and/or cultivar choices as well as best management practices with respect to turfgrass water relations. Worsening drought cycles and limited supply of water for irrigation were the key factors driving every research project reviewed in this report. Subsidence of the most recent (or current) drought conditions in Australia should not be viewed by the turf industry as a reason to withdraw support or funding for research in this area. Drought conditions, limited domestic water availability and urban water restrictions will return in Australia albeit in 5, 10 or 20 years time and the turf industry has an opportunity to prepare for that time.

Control of Variable Watermilfoil in Bashan Lake, CT with 2,4-D: Monitoring of Lake and Well Water.

Variable watermilfoil (Myriophyllum heterophyllum Michx.) has recently become a problem in Bashan Lake, East Haddam, CT, USA. By 1998, approximately 4 ha of the 110 ha lake was covered with variable watermilfoil. In 1999, the milfoil was spot treated with Aquacide®, an 18% active ingredient of the sodium salt of 2,4-D [(2,4-dichlorophenoxy) acetic acid], applied at a rate of 114 kg/ha. Aquacide® was used because labeling regarding domestic water intakes and irrigation limitations prevented the use of Navigate® or AquaKleen®, a 19% active ingredient of the butoxyethyl ester of 2,4-D. Variable watermilfoil was partially controlled in shallow protected coves but little control occurred in deeper more exposed locations. 2,4-D levels in the treatment sites were lower than desired and offsite dilution was rapid. In 2000, the United States Environmental Protection Agency (USEPA) issued a special local need (SLN) registration to allow the use of Navigate ® or AquaKleen® in lakes with potable and irrigation water intakes. Navigate® was applied at a rate of 227 kg/ha to the same areas as treated in 1999. An additional 2 ha of variable watermilfoil was treated with Navigate® in 2001, and 0.4 ha was treated in mid-September. Dilution of the 2,4-D ester formulation to untreated areas was slower than with the salt formulation. Concentrations of 2,4-D exceeded 1000 μg/ L in several lake water samples in 2000 but not 2001. Nearly all of the treated variable watermilfoil was controlled in both years. The mid-September treatment appeared as effective as the spring and early summer treatments. Testing of homeowner wells in all 3 years found no detectable levels of 2,4-D.(PDF contains 8 pages.)