Are solar tracking technologies feasible for domestic applications in rural tropical Africa?

That solar tracking improves energy yields from solar harvest systems is not debatable. Nor is the under powering of tropical Africa amidst plenty of energy resources – including solar. This paper presents a review of recent literature on tracking as applied to domestic solar harnessing devices. The purpose is to find basic requirements in design of a suitable solar tracker for the region’s rural homes. It is concluded that Single axis passive trackers possibly will stand better chances of acceptability in the region

The new hydro-mechanical solar tracker: Performance testing with a PV panel

This paper describes work carried out to test the performance of a newly invented solar tracker. It is a gravity driven, bladder-flow controlled, Hooke coupled inclined non polar axis solar tracker. The performance of the tracker when coupled with a PV panel was first modelled in MATLAB® using the Perez anisotropic diffuse radiation and the King cell temperature models. Experiments with two identical 90 Wp panels were done over a 40 day period in outdoor conditions. One PV panel was fixed on optimised slope, the other, was driven by the tracker about a similarly sloped axis. Weather data consisting of total and diffuse radiation, ambient temperature and wind speed was also collected using a Campbell Scientific weather station adjacent the panels. This data was used to simulate performances of the panels in the MATLAB® model. TRNSYS simulations were also done for the two panels. The three sets of results were compared. It was found that the tracked panel yielded 34% more energy than the fixed one and that the experimental results correlated more closely with the MATLAB® models than with TRNSYS ones. Results also indicated that the efficacy of the tracking device could be influenced by the timing of cloudiness during the day and by wind speed

Failed steam traps: First steps to replacement

Current energy, Environmental and Economic concerns are exerting pressure on steam plant managers to reexamine their plant maintenance practices. In South Africa big components of the steam line such as boilers have always received legitimate attention. But the smaller one especially Steam Straps have tended to be taken for granted. A Literature search reveal that up to 55% of steam in some plants is lost through them! In this paper, Industrial experimentation carried out experimentation, current practice of replacing factories- advised to try a mix of old and newer Technology traps in its refurbishment

Are solar tracking technologies feasible for domestic applications in rural tropical Africa?

That solar tracking improves energy yields from solar harvest systems is not debatable. Nor is the under powering of tropical Africa amidst plenty of energy resources – including solar. This paper presents a review of recent literature on tracking as applied to domestic solar harnessing devices. The purpose is to find basic requirements in design of a suitable solar tracker for the region’s rural homes. It is concluded that Single axis passive trackers possibly will stand better chances of acceptability in the region

Re-mapping sub-Sahara Africa for equipment selection to photo electrify energy poor homes

This paper provides a missing integrated guide to budding middle class rural sub-Saharan Africa (SSA) homesteads trying to photo-electrify. It first estimates bare minimum requirements for these homes to start emerging from energy poverty. Guidance is given on optimal selection of the most important device for such homes: the light bulb. Along with other essential devices, this gives a daily electrical load of 500 W h, 42 A h at 12 V DC. Building on earlier experimental work on validating TRNSYS in Cape Town, it extends usage of the software to the rest of SSA, aiming to recommend panel and balance of system component sizes to meet the above load all year round. Use is made of panel slopes derived in a related piece of work to formulate an optimisation model for selecting panel–battery–charge controller combinations. A survey of South Africa-made panels and components is done. Then, a method of solving the model is demonstrated by an example in Uganda which selects from the surveyed components to satisfy two alternative technical objectives of ‘least battery storage’ and ‘smallest panel size’. At each of the other 151 stations in SSA, the model is solved only for the first objective. The overall results are then mapped using MATLAB®. It is concluded that from a ‘smallest battery storage’ perspective, usable battery storage capacities in the region range between 70 and 360 A h, with the biggest being in equatorial/tropical rain forest areas of Congo basin and along the mid-western coastal areas. Panel sizes range between 160 and 275 Wp. The dominant recommendation on charge controllers is 15 A

Modelling annual yields of a solar-tracking solar syphon using ASHRAE’s weather data for tropical Africa

This work is a follow on to previous ones on solar tracking in Tropical Africa by the authors. While the first work showed the necessity to replace current fixed panels/collectors with two slope fixed installations at prescribed angles and times, the second established the need for - and determined the constraining techno-economic factors of tracking photovoltaic panels in rural Africa. This paper covers the introductory part of trackingpassive flat collectors as would be applied in hot water cylinders (domestic water geysers) in these areas