96 research outputs found
Development of microencapsulated phase change material for solar thermal energy storage
In this paper a novel microencapsulated phase change material (MF-3) has been developed and tested for solar assisted hot water storage systems. Even though the morphology of the sample was affected by the type of emulsifier used for fabrication it recorded the highest energy storage capacity of 126 kJ/kg with encapsulation efficiency of 97.4% as compared with other developed samples. For the purpose of assessing its thermal effectiveness it was theoretically evaluated in a compacted fixed bed TES unit and found to be capable of achieving a higher energy storage density as well as relatively smaller physical storage size than water based system. Despite the overall effective thermal conductivity being slightly less than water, its value was still about twice as high as most current PCM storage units. Experimental evaluation is therefore strongly encouraged
Performance and operational effectiveness of evacuated flat plate solar collectors compared with conventional thermal, PVT and PV panels
The concept of an evacuated flat plate (EFP) collector was proposed over 40 years ago but, despite its professed advantages, very few manufacturers have developed commercial versions. This situation suggests both technical difficulties in manufacturing a competitively-priced sealed for life panel and a lack of awareness of the bene fits of such panels. This paper demonstrates an evacuated flat plate simulation that closely models experimental efficiency measurements. Having established the validity of the model, it compares published data for a commercial EFP collector with predictions for an optimal design to investigate whether any further efficiency improvement might be possible. The optimised design is then evaluated against alternative solar energy devices by modelling a number of possible applications. These comparisons should inform choices about solar options for delivering heat: EFP collectors are well-suited to some of these applications. Evacuated flat plate collectors are a possible alternative to concentrating collectors for Organic Rankine Cycle power generation. The annual output for all the modelled collectors was found to be a quadratic function of delivery temperature: this enabled a novel optimisation of ORC source temperature. Predictions for concentrating and non-concentrating ORC plant are compared with a PV/thermal alternative. The ORC output is significantly less than a PV panel would achieve; applications needing both heat and power are better served by PVT panels. This is an original and novel result
CTA Project Completion Report: Promoting Agritourism development Across ACP Small Island developing States and Africa
Building on the steps taken during the previous years, this project aimed to strengthen the intersectoral linkages between agriculture and tourism, promoting the sustainable use of healthy local foodstuffs by the tourism industry. It worked to create an enabling policy environment for agritourism development and to also leverage funds, investments and public partnerships to promote agritourism and its associated value chains, and in this way improve agricultural productivity, incomes and wellbeing. In order to achieve these goals, CTA worked together with regional and national institutions focusing on agriculture, tourism, trade and health, with producer organisations and the private sector
Effects of different working fluid use on the energy and exergy performance for evacuated tube solar collector with thermosyphon heat pipe
High density polyethylene spheres with PCM for domestic hot water applications: Water tank and laboratory scale study
Industrialization and environmental sustainability in Africa: The moderating effects of renewable and non-renewable energy consumption
African countries have become interested in economic transformation through revamping their manufacturing sectors. However, the environmental effect of industrialization is an issue of great concern, with the need to maintain a sustainable environment in line with sustainable development goals. This study investigates the effect of industrialization on environmental sustainability in Africa, taking in to consideration the moderation effect of renewable energy and non-renewable energy consumption. Data was collected for 46 African countries from the Global Footprint Network, World Development Indicators of the World Bank and the Food and Agricultural Organization from 2000 to 2022. Robust panel fixed effects regression and generalized least squares methods were used to analyze the data. The empirical results showed that value added in manufacturing has a negative and significant effect on environmental sustainability. However, when interacted with renewable energy consumption, manufacturing exerted a positive effect on load capacity factor, indicating that the environment will be sustainable if manufacturing sector activities are powered by renewable energies. This suggests that renewable energy has the ability to propel industrial growth in Africa while sustaining the environment. The moderating effect of non-renewable energy and manufacturing is positive in the fixed effects regression and negative for the generalized least squares estimates. This suggest that fossil fuel consumption, particularly clean fossil fuels or natural gas can still drive African manufacturing without considerably harming the environment but continual use of it in to the long run will make the environment unsustainable. From the above results, this study recommends that for sustainable industrialization to take place, Africa should grow her manufacturing sector by extending the range of manufactured products from light to heavy manufactures while ensuring that renewable energy remains the major source of industrial energy supply
Performance analysis on a novel micro-channel heat pipe evacuated tube solar collector-incorporated thermoelectric generation
D DI IS ST TU UR RB BA AN NC CE ES S O OF F T TH HE E 9 90 0 K KV V E EL LE EC CT TR RI IC CA AL L N NE ET TW WO OR RK K A AN ND D T TH HE E 3 38 80 0/ /2 22 20 0 V V D DI IS ST TR RI IB BU UT TI IO ON N S SY YS ST TE EM M I IN N T TH HE E D DO OU UA AL L
ABSTRAC
- …