- Werner Weiss and Monika Spörk-Dür, 7 May 2018
The installation of solar thermal demonstration projects is an important part of the SOLTRAIN programme’s activities. On the one hand, the installations allow the SOLTRAIN community to apply knowledge gained during the training courses, and on the other hand, to show and demonstrate different solar thermal applications from small-scale systems for single family houses to large-scale systems in industrial applications.
The systems also serve as best-practice examples in order to facilitate broader market uptake.A cumulative 221 solar thermal systems with a combined collector area of 2,393 m² had been installed by end of December 2017 in the six SOLTRAIN partner countries.
638 tons of avoided CO2 emissions
The annual solar yield of all solar thermal systems is 1,834 MWh. This corresponds to electricity savings of 2,017 MWh/a and 638 tons of avoided CO21*), and the figures for the individual countries can be seen in the table below.
The avoided electricity cost corresponds to ZAR 4.3 million based on city of Cape Town tariff in 2015 of 213.90 c/kWh including VAT.
At COP21 (United Nations Climate Change Conference), which took place in December 2015 in Paris it was agreed to respond to the global climate change threat by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels, and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. This can be reached by switching from a mainly fossil fuel-based economy to an energy supply system based on renewables, and the figures outlined above demonstrate the contribution of SOLTRAIN to the COP21 Agreements.
Table: Annual solar yield and corresponding electricity savings as well as avoided CO2 emissions of all solar thermal systems by end of December 2017, which were funded by ADA and OFID and installed in phase I - III of the SOLTRAIN project.
based on oil equivalent 1*)Dr. Edwin Matlotse, 7 May 2018
University of Botswana’s Clean Energy Research Centre (CERC) hosted a successful SOLTRAIN Conference at the University of Botswana (UB) Conference Centre in Gaborone in early February. The event included tours of solar thermal installations in the Gaborone.
The conference kicked off with an address by the UB VC, Prof. David Norris, welcoming participants from institutions and companies from Lesotho, Mozambique, Namibia, Zimbabwe and South Africa. He expressed thanks to the SOLTRAIN community and assured the project sponsors that his institution would continue to support their efforts going forward.
In his address, Minister of Environment, Natural Resources Conservation and Tourism, Honourable Tshekedi Khama, emphasized the reality of climate change and lauded the practical activities that the SOLTRAIN project espouses which go beyond policy. He acknowledged the positive impact that SOLTRAIN activities had in the SADC sub-region, and expressed his thanks.
Mr. Matthias Radosztics, from the Austrian Embassy, emphasised that climate change is on our doorstep and needs effort from everyone in order to mitigate its negative impacts. He commended the SOLTRAIN country partners for coming together at the event and for taking the opportunity to reflect on project outcomes as well as to share experiences and ideas on taking SOLTRAIN forward.
Mr. Werner Weiss of AEE-INTEC highlighted the cumulative contribution of SOLTRAIN to the COP21 agreement in terms of GHG emissions (please see below for a more detailed article on this). Further, Mr. Kudakwashe Ndhlukula of SADC Centre for Renewable Energy and Energy Efficiency (SACREEE) also thanked the project sponsors and outlined ways in which the country partners might sustain efforts when the project draws to a close.
Other notable contributions included Mr. Nico Snyders, from Namibia’s Ministry of Mines and Energy, sharing Namibia’s solar water heating experiences with their national housing programme which is assisted by up to 50% grants from the SOLTRAIN project. Ms. Karin Kritzinger of Stellenbosch University spoke the SOLTRAIN student bursary scheme and Mr. Ivan Yaholnitsky (BBCDC) and Mrs. Helvi Ileka (NEI), provided their perspectives relating to their institutions’ co-operation on their solar baking project.
Another highlight of the conference was delivered by the Director of Energy and Environment Partnership for Southern and East Africa (EEP), Mr. Wim Jonker Klunne, who provided an outline of EEP’s funding relating to the participating countries’ roadmaps and their respective implementation.Ivan Yaholnitsky, 7 May 2018
In December, BBCDC put up a large advertising sign in Mohales Hoek at the site of BBCDC’s solar energy sales operation. The sign is just next to the main southern highway and enhances the exposure of SOLTRAIN and our solar energy products and services. We call it a ‘Green Lantern’.
In one of their recent newsletters, The Climate Reality Project gave these four suggestions for action on Climate Change, drawing on the work of professional psychologists studying change processes in a systematic way:
- Connect the climate crisis to what’s happening in real communities to reduce psychological distance.
- Make climate action a group experience to promote social norms.
- Talk about what we’re gaining, not what we’re losing, to avoid loss aversion.
- Give your friends real ways to take action to prevent “environmental melancholia.”
I think they are useful, especially in regard to the broader mission of the SDGs and future work of SOLTRAIN in Lesotho and regionally.
We hope the Green Lantern fits this pattern. We need to get SOLTRAIN into each and every far flung community in Lesotho, and demonstrate that cost effective lifestyle and hygiene solutions are available and feasible. Positive social activities and processes will drive adoption and innovation. It is true that we need to lead with benefits and qualitative enhancements rather than costs.
Finally, we need to provide opportunities for more participation. When a solar water heater is put up on a roof, it should not be done by one or two people. Rather assemble a crowd and let everyone pitch in. Throw a party with hot dogs grilled in a solar cooker. Music and food create lasting memories. I call on my colleagues and friends in SOLTRAIN to embrace the above. Let us go out and win it. The Green Lantern is meant to herald of much better times. Hope for humanity.SOLTRAIN Administrator, 7 May 2018
The project demonstrated an innovative and unconventional solar energy system that garnered the world’s attention according to NUL’s Mr Anadola T’siu, the designer of the system.
This was not the first time the project had received accolades. In 2016, it won second prize at the International Conference on Solar Technologies & Hybrid Mini Grids to Improve Energy Access held in Bad Hersfeld, Germany, at which it was recognised for its potential for alleviating energy poverty in rural Lesotho.
Dimitri Kerkentzes, Deputy Secretary General of the Bureau of International Exhibitions, lauded the project as a concrete example of the core values of both Expo 2017 Astana and Expo ’90, to promote sustainability and environmental protection. Mr. Shinya Kubota of the Expo ’90 added that the project fully embodies the harmonious coexistence of nature and mankind, the fundamental principle of the Expo ’90 Foundation.
The solar energy system offers traditional water heating for general use, space heating (including under floor heating and wall radiation heating) and can also generate electricity using the Organic Rankine cycle, thus eliminating the need for unsustainable and expensive storage batteries.
A published paper on the system can be found at this link. https://www.researchgate.net/ publication/318344342_Construction_and_ Performance_Evaluation_of_A_Low-Cost_Flat- Plate_Solar_Energy_CollectorHelvi Ileka and Rudi Moschik, 7 May 2018
The Namibia Energy Institute (NEI), at the Namibia University of Science and Technology together with AEE-INTEC, have installed the first photovoltaic water heater (PWH) in Namibia using a special DC/AC element for heating the water. The installation is for research purposes under the SOLTRAIN project.
Through SOLTRAIN, NEI has already installed 62 solar water heaters (SWH) at low cost houses in Windhoek’s Otjomuise township between December 2015 and March 2016.
In addition, measurement and verification systems were installed at six houses, four of which had SWH installed while the other two used electrical geysers, and data has been collected and analyzed at these houses since 2016. The installation of PWH now takes the research a step further.
The PWH installation consists of six solar PV modules with a cumulative 1.59kWp capacity which are connected directly to a resistive element for heating a 300l tank using direct current (DC) without an inverter. The element is also able to operate from the house mains AC supply as a backup for when there is not sufficient sun to power the element with solar.
The PWH system was installed at one of the houses which was previously monitored using a standard electrical geyser. Another house, which also used an electrical geyser and which was also previously monitored, was equipped with a thermosyphon unit consisting of a 300l tank and 4m2 collector. Both systems were designed based on the hot water demand per person in the respective houses as analyzed for one year.
This provides a comprehensive research platform for the comparison of SWH and PWH in Namibia, the results of which will be highly informative for both the housing and energy sectors in the country. In addition, the pilot project also be aims at exploring the possibility of adopting the photovoltaic water heating system in off-grid areas where it could be used to provide basic electricity needs including the provision of hot water.
Senior Shimhanda, a Master of Environmental Engineering student at NUS, with a specialization in renewable energy systems, is working with NEI as an intern to work on the pilot project as part of his final research to complete his Masters thesis. He was directly involved in the installation of the two systems and monitoring equipment, and will also collect and analyse the data.
According to Shimhanda, “it is essential to conduct a techno-economic analysis of the existing water heating systems in the Namibian context in order to determine the best domestic water heating technology between SWH and photovoltaic water heating. The outcome of the research will help prospective Namibian consumers choose the most efficient and cost effective solution between SWH and PWH”.
Shimhanda added that the research into the SWH and the PWH aims to answer the following questions:
- Whether existing water heating systems are viable technically and economically
- Their possible impacts on the environment
- The initial capital costs and operation costs of each water heating system
- Which technology is more cost-effective in terms of performance and economic benefits and;
- Which technology is more efficient and less prone to intermittent weather fluctuations.
Mr Nicolas Marembo, the owner of the PWH system who also contributed to its cost, was trained on the functionality of the system and reports that he is happy with the system so far.Andrew Obok Opok, 7 May 2018
Botswana’s first solar thermal system subsidized by SOLTRAIN was commissioned in February this year. SOLTRAIN’s partner in Botswana, the Centre for Clean Energy Research, University of Botswana, actively guided and supported the project through the phases from inception to installation and commissioning. The beneficiary of the project is Mara-u-Pula Secondary School, which is a premium Senior Secondary School located in the proximity of Gaborone Central Business District.
With a price tag of close to 18,000 Euros, the project timeline took roughly three months from the time of submission of application for the SOLTRAIN subsidy to installation and commissioning, and the design and installation was done by Botswana-based company, So Solar (Pty) Ltd.
Technical Description of the systems
The installation consists of two pumped solar thermal water heating systems. The first is for the boy’s boarding house which was a refurbishment. This system was sized to provide hot water for 65 students and consists of a 2000 litre tank with a heat exchanger and an electric heater as backup. It was designed to operate with a 90% solar fraction and is powered by 16 flat plate collectors in combination of series and parallel. Due to roof orientation, the collectors face north west and consequently, a modest addition to the collector area was needed to compensate for the orientation away from north. The pumped system supplies 1800 litres per day on average.
The second system is installed at the girl’s boarding house and is designed to meet water demand for 65 girls. It consists of a hot water tank of 2000 litres and is powered by 12 flat plate collectors, also connected in a parallel and series arrangement. The collectors face north for optimal solar gain.
To comply with SOLTRAIN requirements, the systems are equipped with remote monitoring capabilities to enable their performance to be tracked on a continuous basis. A number of parametersarecapturedandrecorded,including collector inlet and outlet temperatures, storage tank heat exchanger temperatures across the primary and secondary loops, mass flow rates for the heat transfer media, water glycol mixture for the input and output of the collector circuit and the mass flow rates for the heat exchanger system. More importantly, the solar radiation resource available at the site is monitored continuously to enable the yield, efficiency and economic performance to be evaluated over a desired time-horizon.
Site Visit and Quality Assurance Training
The completion and commissioning of the Mara-u-pula system coincided with two important SOLTRAIN events in Botswana, namely, SOLTRAIN’s annual two-day conference held in early February, and SOLTRAIN’s Quality Inspectors: Solar Water Heating training course which took place after the conference. Conference delegates were taken on a site visit to the installation where they experienced the contribution that SOLTRAIN is making in practice towards promoting and developing capacity in the field of solar thermal systems in Botswana.Puleng Mosothoane, 7 May 2018
SOLTRAIN ran a technical tour late last year and invited representatives from solar companies, academic institutions, the public sector and those who had previously attended SOLTRAIN training sessions to participate.
The 37 participants were treated to a number of interesting site visits which included a range of solar technologies, including BBCDC’s now famous solar cooking technologies.
The technical tour was followed by a dissemination course for 38 participants run by Mr Sehloho Holomo from BBCDC and Mr Anadola Tsiu from the National University of Lesotho, both of whom had attended previous SOLTRAIN train the trainer courses.
Another technical tour will be run in late June this year with another dissemination course happening shortly thereafter.Dr Karen Surridge, 7 May 2018
The SOLTRAIN project aims to tackle water heating energy needs and create opportunities through addressing the solar water heating sector across six partner countries in the Southern African Development Community (SADC), namely, Botswana, Lesotho, Mozambique, Namibia, South Africa, and Zimbabwe, through training, awareness raising, performance monitoring and demonstration systems.
The SA government has realised that a low carbon economy can bring benefits and in particular it will support climate change mitigation measures. The Government has already committed to reducing carbon emissions in South Africa by 34% by 2020 and 42% by 2025 depending on certain conditions. In order to meet these emissions reduction targets, several strategies will need to be used towards meeting this goal.
On the 6th February 2018, SANEDI hosted the launch and discussion of the “Solar Thermal Technology Implementation Plan for South Africa” as part of Phase III of the SOLTRAIN programme. This plan outlines what needs to be achieved in order to meet the SOLTRAIN visionary target to have ½ m² of net solar thermal collector area for every member of the population by 2030 in South Africa.
It is split into 5 “Roadmaps” that essentially outline projected installations needing to be met in order to achieve the goal:
Roadmap 1: High Pressure Residential Solar Water Heating
To grow the installed area to ~12 000 000 m² by 2030, requires a growth rate of 21% per annum on annual installations
Roadmap 2: Low Pressure Residential Solar Water Heating
The South African government has committed to install 600 000 units over two years. For the purposes of this roadmap, it is presumed that this commitment of 300 000 units per year will be sustained up to 2030, to produce a total installation number of 5 200 000 units
Roadmap 3: Industrial/Commercial/ Multi- Family Residential installations for Solar Heating and Cooling
If this market is grown with 40% per year on total installations, there will be 48 848 m² of solar collectors installed by 2030
Roadmap 4: Unglazed Swimming Pool Solar Water Heaters
If this market is grown with 35% per year on total installations, there will be 527 630 installations, or 10 522 598 m² of solar collectors installed by 2030, which represents 65% of the current number of swimming pools in South Africa
Roadmap 5: Passive Solar Thermal (PST) heating/cooling of buildings
It should be noted that solar thermal buildings include at least one day’s integral thermal storage as a result of the prescribed interior thermal mass (SANS10400XA).
Over 50 people from across sectors (industry associations, science councils, private sector, government departments, academic institutions, municipalities, NGOs and State- owned entities) attended this launch and shared in a presentation of the document as well as a lively panel discussion to explore roles in support of the implementation plan for Industry, Government and R&D sectors. Key to achieving this is a focus on awareness and marketing, institutional issues, workforce development (in terms if training and education) and research and development. Valuable points to this end were raised during the panel discussion:
- Knowledge sharing is key and important information must reach decision makers as well as the general public, just as important is coordination between sectoral role players, what is a possible mechanism to achieve this?
- How is government support obtained for this sector and which government department/s should endorse this?
- How is SWH linked to industrialisation and development of the industry in South Africa and what is needed in terms of support by the government? And how can this link to the Special Economic Zones or Industrial Parks initiatives
- What is the local potential for evacuated tube technology in terms of job creation, possibilities of a municipal/government tariff levee, the local and export value chain?
- Should there be research and development with an RRR (reduce, reuse, recycle) focus for the sector?
- How do potential users know what is a good system? Should market competition define this?
- How to approach solutions to testing and certification (energy efficiency rating B) challenges? How to make component testing easier?
- Technology reputation is key to a successful implementation
- Defining a strategy, coordination, knowledge management, awareness, systemic approach and an implementation plan, broader vision
- How to identify and exploit any competitive advantages for South Africa in this sector?
- How to avoid peaks?
- Consider incentives vs. rebates
- How to address and achieve system simplicity?
- The Sustainable Energy Society of Southern Africa (SESSA) has a company list of certified installers and is an instrument for public awareness
- Consider the implications of using PV to reach the defined targets
- Consider the concept of heat ESCos (Energy Service Companies)
It was suggested that SOLTRAIN might explore the possibility of compiling a study on “lessons learned” that focuses on what strategies should not be repeated, showcasing together with learning of successes and failures and how to maintain stability in a solar water heating roll out programme. A further study, might explore the heat technology, area vs. yield, competitive advantages and systems for commercial and industrial application, and to a large extent this is being addressed the Solar PayBack Project being implemented by SANEDI (https://www. solar-payback.com).
In addition to the above, it should be noted that the National Solar Water Heating Programme is in the process of being moved to Central Energy Fund (CEF). One of the sub-programmes under this, the Repair/Replace programme, which is at an advanced stage, has been delegated to the DoE-IPP Office. Additional information, in regard to the NSWHP current status and objectives, can be accessed at https:// solarwaterheating-programme.co.za
Following the launch of the implementation plan document several key stakeholders representing industry, government, research and development were hosted on a site visit to explore some of the SOLTRAIN systems installed in the Gauteng area during SOLTRAIN phases 2 and 3. The aim of this tour was to showcase different types of systems at different scales and their deliverable performance.
Achieving this vision will require an effective, long-term and balanced policy effort to allow for optimal technology progress, cost reduction and ramp-up of industrial manufacturing for mass deployment. The South African Government will need to provide long-term targets and stable supporting policies to build confidence for investment in manufacturing capacity and deployment of solar thermal systems.Monika Spörk-Dür, 31 January 2018A specialised course for a restricted number of experts was held in Stellenbosch at the end of November, giving insight into state-of-the-art design, simulation, planning and installation of advanced high quality solar thermal systems for industrial applications in Southern Africa. The training course was carried out in co-operation with SOLTRAIN and the Solar Academy of the IEA Solar Heating and Cooling Programme, and was hosted and organized by the SOLTRAIN project partner, CRSES, from Stellenbosch University.
The course accepted 50 participants, of which about 12 were planners from the solar thermal industry. The remaining participants comprised SOLTRAIN partners, researchers and members of public institutions. The course was lectured by SOLTRAIN coordinator, Werner Weiss, from AEE –Institute for Sustainable Technologies (AEE INTEC) in Austria, and by Christoph Brunner, head of the Department of Industrial Processes and Energy Systems at AEE INTEC, Austria.
The feedback of participants was unanimous in that they derived great benefit from attending the course, and expressed great interest in any future SOLTRAIN courses.Geraldo Nhumaio, 31 January 2018The new Counsellor and Head of Cooperation of the Austrian Embassy in Mozambique, Mr Hubert Neuwirth, visited the Faculty of Engineering of the Eduardo Mondlane University (FEUEM) in late November in order to get acquainted with the SOLTRAIN activities in Mozambique. After the briefing at FEUEM and after being shown the SOLTRAIN demonstration trailer, Mr. Neuwirth was pleased to visit one of the SOLTRAIN I demonstration systems installed at Ndlavela, a health centre within 7 km of Maputo's peri-urban area.
Due to Mr Neuwirth's time availability, a visit will be re-scheduled so that he can also tour the Psico-Social Rehabilitation Center where a 1 000 l Briefing about the SOLTRAIN activities in Mozambique. From left to right: Hubert Neuwirth (ADA), Madeleine Salinger (ADA), Muarapaz (EDM), Deputy-Dean for Research and Extension, Faculty Administrator, SOLTRAIN Coordinator. solar thermal system was installed as part of SOLTRAIN I, as well as the 2nd trailer in the possession of a vocational school. Both locations are within 7 km radius of downtown Maputo.Angelo Buckley, 31 January 2018The Centre for Renewable and Sustainable Energy Studies (CRSES) at Stellenbosch University undertook a project to install two solarpowered, water-heating systems at the Mariendahl farm. Mariendahl serves as Stellenbosch University’s experimental farm and is located approximately 14km north of Stellenbosch.
Although both systems are solar powered, they are powered using two different technologies. The one system is powered by solar thermal energy and is referred to as a solar water heating (SWH) system. The other system is powered using photovoltaics (PV). The project was funded by Stellenbosch University through the SOLTRAIN initiative. The SOLTRAIN initiative is managed by AEE-Intec in Austria and funded by the Austrian Development Agency (ADA) and the OPEC Fund for Industrial Development (OFID).
The initial stage of the project included the modelling and simulation of each of the systems to identify suitable sizing. This simulation modelling was followed by a detailed financial analysis to investigate the feasibility of each system and the detailed designs with the assistance of AEE-Intec. The systems should substantially reduce the electricity consumption of the residents as less grid electricity will be required for water heating. The aim of this project is to compare the systems, their performance and cost effectiveness.
A 2.4 m2 flat-plate collector with a 200 l hot water storage was designed and installed on one of the houses and the other with a 1.5 kWp PV system. The PV system powers a DC/AC element for heating the water in a 200 l hot water storage tank identical to the tank used in the SWH system. The DC/AC resistive element, a relatively new technology on the market, allows DC electricity from the PV system to directly power the resistive element without the needed of an inverter. The element is also able to operate with AC electricity from the grid which serves as a back-up for when solar energy is insufficient. The SWH system is also equipped with a back-up AC resistive element.
The PV and SWH systems are expected to provide 60% of each residence’s hot water needs. Both systems are equipped with monitoring equipment that allows CRSES and AEE-Intec to monitor and evaluate the performance of the systems. This will allow for a detailed technical and financial comparison of the types of technologies based on system operation, project costs and the cost of energy.Ivan Yaholnitsky, 29 January 2018On Oct. 24, Stephen Lelimo and Ivan Yaholnitsky accepted an Emirates Energy Award in Dubai, United Arab Emirates, on behalf of Bethel Business and Community Development Centre (BBCDC). BBCDC was recognized in the category of Education and Capacity Building and received a cash prize of 21,780 USD and Certificate.
The Emirates Energy Award was part of a Green Economy Summit which ran in late October, and and which received broad exposure on social and global media. The sponsors of the award covered BBCDC’s travel and accommodation, and the program included a world class expert’s panel on RE transition and clean energy.
The UAE is setting impressive and urgent targets for decarbonisation of its energy supplies. BBCDC is greatly honoured to receive this award and grateful to the organizers and people of the United Arab Emirates. BBCDC will use the cash prize to purchase an electric utility vehicle and bolster the solar energy program with a working model of a clean transportation system.
The vehicle will facilitate inexpensive driving lessons and reduce energy costs for local transportation. The prize will also enable additional investment in education and programs at BBCDC.
BBCDC’s submission for the EEA included the contribution from OFID, AEE-Intec and the Austrian Development Agency, and summarized BBCDC’s work on solar energy for the last two decades.Givemore Kanyemba and Samson Mhlanga, 29 January 2018The National University of Science and Technology, Zimbabwe’s SOLTRAIN partner, exhibited at the Schools Climate Change Education and Awareness Campaign Fair under the theme Change the Mind, Not the Climate at Hillside Junior Primary School, Bulawayo in the latter part of November. Other organisations present were the Zimbabwe Climate Change Coalition, Edgars, and various primary and secondary schools.
The objectives of the exhibition included making children aware of climate change, its causes and effects, and to make children aware of the various means of mitigating global warming by using less electricity and promoting the use alternative, renewable sources of energy at their homes. It also sought to expose children to alternative, more sustainable technologies and to influence future policy and decisions by the children when they take positions of influence later on in life.
The event included presentations from Mr Zvaita (Programme Director of Zimbabwe Climate Change Coalition), Mr Sibanda (Deputy Provincial Education Director), Mr G Chirinda, (SOLTRAINNUST Representatives) and an Edgars Representative. Mr G Kanyemba and Mr A Mnkandla manned the SOLTRAIN stand for practical demonstrations.Fenni Shidhika and Helvi Ileka, 29 January 2018Under the Southern African Solar Thermal Training and Demonstration Initiative (SOLTRAIN), partners are expected to transfer technology and exchange information. Namibia Energy Institute (NEI) in collaboration Lesotho’s Bethel Business and Community Development Center (BBCDC) demonstrated a solar bakery at the Windhoek Industrial and Agricultural Show (WIAS) at the beginning of October. The parabolic oven was transported from Lesotho and was on display for the whole week, with the main objective being to raise awareness from bakery entrepreneurs in the country in order for those who are interested in the solar baking to submit proposals for co-financing under the SOLTRAIN project as demonstration systems.
Another objective of the collaboration was for Namibia to learn from Lesotho on how to construct the solar bakery, so that Namibia can start designing and manufacturing their own solar bakery. Participants from Lesotho shared their knowledge by demonstrating how the solar bakery works by baking a variety of bread and muffins. Normal standard bread pans as well as traditional pans from Namibia were also tested in the solar oven and were found to fit properly. Malte Schien, an Intern student from Germany who assisted BBCDC in the construction of the solar bakery, shared this knowledge of constructing and operating the solar bakery with staff and interns of NEI, members of the public and members from the Renewable Energy Industry Association of Namibia.
Members of the public who attended the WIAS were amazed at how the solar bakery worked and how well it baked bread and muffins. The demonstration of the solar bakery was done in conjunction with a cook-off competition organized by NEI under the Namibia University of Science and Technology (NUST). The competition was focusing on using different sustainable cooking methods including cookers using energy from the sun and wood efficient stoves. Various institutions participated in the competition and companies from industry such as Amusha Consulting and RDJ Consulting showed interest in knowing more about the design and manufacturing of the solar bakery. NUST and the University of Namibia students and lecturers also indicated that they would like to introduce the solar bakery at their institutions for research projects.
According to Namibian census data from 2011, the main domestic energy source for cooking was wood and charcoal. The census indicated that 86 % of all rural households and about 20% of all households in urban area were still using wood for cooking. Women and children do heavy work in gathering wood all the time, resulting in health problems and absence from school. In addition, traditional cooking methods cause health problems through smoke inhalation, especially in women and children. The introduction of clean cooking technologies to the communities will reduce some of these health risks and will improve the livelihood of people in both urban and rural areas.
In sunny weather conditions, the parabolic oven reached an ideal baking temperature of 180⁰C and took approximately 35 minutes to bake a batch.Puleng Mosothoane, 29 January 2018Bethel Business and Community Development Centre (BBCDC) updates us on some solar innovations that they have recently undertaken relating to a new collector manifold for an aging solar water heating system and, a heat exchanger design.
New 20 heat-pipe collector manifold
An average solar radiation of 6kWh per square meter per year provides enough solar thermal energy for Leotho's BBCDC to rely on solar water heating for its hostel’s hot water requirements. Having been early adopters, some of the installed infrastructure is already 15 years old and recently needed some maintenance. At the same time, Lesotho’s very cold winters present challenges due to freezing, resulting in the rupturing of pipes within the aging infrastructure.One of the girl’s hostels had a 200 litre galvanized tank and 4 square meter flat plate collector made out of galvanized pipes installed.
This year, the BBCDC decided to replace the galvanized pipe collector with a 20 heat-pipe collector manifold. Since the new heat pipes are freeze resistant up to -32°C, freezing should no longer be an issue. The heat pipes also have a higher efficiency than the galvanized pipe collector, meaning that more hot water will be produced.
The new collector was installed by second year Solar Technology students at BBCDC.
The BBCDC is also experimenting with its own heat exchanger to deal with sub-zero temperatures and the damage caused by freezing. It is made out of copper pipes and copper sheeting which is soldered together. The collector is filled with freeze-resistant heat exchange fluid which in turn heats water in the storage tank. The heat exchanger is highly insulated so that all the heat in it is transferred to the water to be heated. The dimensions of the heat exchanger are 50cm x 7cm.
On the day it was tested, the loop from the collector with the heat exchange fluid reached 65°C, while the loop going to the tank reached 56°C. On the test day, the solar radiation averaged at 800 watts/m2, and in 4 hours the heat exchanger managed to heat 20 l of water from 20 to 50°C.
A 2m2 copper pipe flat-plate semi-closed collector was used in the testing. More tests on the heat exchanger will be conducted.