Vdc

PV module inputs

Phase

Neutral

Earth

Positive Negative

Earth electrode

Chloride Exide (Kenya) Solar Battery 12 V, 100 AH

Chloride Exide © (Kenya) Solar Battery 12 V, 100 AH

240 VAC output for portable drill, computer, video, slide projector, etc.

240 VAC output for portable drill, computer, video, slide projector, etc.

Earth electrode

Chloride Exide (Kenya) Solar Battery 12 V, 100 AH

12 VDC output for lights

Socket key: I I 3-phase industrial I I 110 VAC industrial I I 230 VAC industrial

I_I sockets and plugs I_I sockets and plugs I—I sockets and plugs for module input for 12 VDC output for 230 VAC output

12 VDC output for lights

Socket key: I I 3-phase industrial I I 110 VAC industrial I I 230 VAC industrial

I_I sockets and plugs I_I sockets and plugs I—I sockets and plugs for module input for 12 VDC output for 230 VAC output interest, since this technology is comparatively unknown in East Africa.

In addition to product information from companies, the Universal Technical Standard for Solar Home Systems, and a technical information package, each student got several copies of Home Power from the EAA collection in Nairobi. The technical standard is intended to provide a basis for technical quality assurance procedures. The document is available for free download, and ETSI (see Access) will also send hard copies free of charge.

Each of the eight students chose a personal design project to complete over the two weeks of the course. These included bush hospitals, rural secondary schools, game park lodges, and a village market centre.

Each student had to produce an overall system design for his particular project, including schematics, detailed calculations for the sizing of PV array and battery bank, and a wiring/cabling diagram of essential parts of the complete installation. On the last day, each student gave a thirty minute presentation to the class, and answered questions from peers. This formed one part of the assessment. The second part was a written test which students were given to complete in their own time at home. EAA awarded completion certificates when all of this work was completed.

Students and instructors stayed in tents which were pitched under thatched bays. When the clouds parted, students got an excellent view of the white glaciers on Mount Kilimanjaro's peak, with cool air, fresh sunlight, and bird songs everywhere. We were treated to scrumptious meals cooked "camp-style." The camp cook, Odero, whipped up pancakes, macaroni and cheese, game meat, fruit salads, chapati, and ubiquitous "ugali" (maizemeal) in an improvised temporary outdoor kitchen.

Complications

Most of the problems had to do with the logistics of delivering equipment from international sources to the remote site. In Africa, this is always tricky and expensive, and it is never fun. For example, due to Trace backlogs, Solagen/BP had trouble delivering the inverter to the site, and a smaller unit (a Trace DR1524) had to be substituted until the right one arrived.

Local screws are always a problem, but the team persevered. (Why do manufacturers never supply spares for that quarter-inch bolt that always falls off the roof?) The PVC conduit was easy to work with once everyone got the hang of it, but there were some compatibility problems with loop-in, loop-out junctions for the lights, and finding boxes for the sockets. There was also a problem with one of the modules, which Solagen fixed when they came down to inspect the installation with a representative of BP Solar Nairobi.

The other complications had to do with making sure that safety codes were followed. In East Africa, many designers and installers do not see a difference between 40 Wp systems and 2 KWp systems. Too often, they design and install using the same minimal codes.

The temporary Trace DR1524 inverter in the battery hut.

We find that proper fuses and interconnects between battery and inverter are often not used. Earthing is done as a last minute thing, if done at all. Between inverters, gensets, and PV power sources, there are often no isolators, or the switches used are not properly rated. And, finally, in the generator/battery rooms where proper connections are so crucial, we often find snake-nests of unlabeled wires. Because the same companies that are not safety conscious also tend not to worry about educating end users, some dangerous situations are created in remote sites where large PV systems are installed.

As an example, we were unable to find proper DC fuses for battery-inverter systems in the Kenya market, and no suppliers have them (though many install inverters!). Suppliers in Kenya often leave safety products out of the system, or substitute the wrong products. This has created many potentially hazardous situations, and has given PV an unprofessional and ramshackle reputation. EAA is working with committed local companies to increase awareness of the need for design standards and codes-of-practice, and to increase the supply and use of safety equipment.

We Visit Later

Three months after the system was installed and commissioned, Bernard and Mark from EAA went down to see how it was doing. Driving across the savanna under a full moon, we got lost somewhere near the site. Fortunately, we were able to use the system lights to find our way. From a distance, the Sollatek 18 watt security lights seem brighter than kerosene pressure lamps.

Students David Omgacho and Peter M. Ngalu from CWMS check array voltage.

We parked, came in through the gates, and found students reading and studying in the chumba under the Sollatek lights. The cooks were making tea in the fully-lit kitchen. In the office, staff were using laptops and printers to produce the next day's class material. Other students were outside playing drums and enjoying lunar energy around a campfire, undisturbed by the noise of a generator!

Site manager Otieno reported that the chumba system had been overused once—the lights had been left on until the LVD cut them off. Afterward they had let the modules give the system a full week's charge before using it again. In short, we found the system in good order, and our measurements showed the batteries and all other parts of the system to be working well. They have not even used the generator yet to top off the batteries. We chalk this success up to good design, careful installation, and—most of all—good user education and discipline.

EAA will be holding occasional two to three week training courses at the bush camp over the next two years. Interested technicians should contact us.

Appropriate Power

Perhaps more than anywhere else, rural Africa needs appropriate power systems. Because of the poor reach of the grid, PV and generators will play a crucial role in supplying this power. This bush camp system is a high-quality demonstration of how PV can appropriately meet these needs, and a training system that enables people from the region to learn how PV works. The system shows that when you get both the technical hardware and the human software (training) right, there is no better power source than the sun.

Access

Authors: Frank Jackson, Green Dragon Energy, 2 Llwynglas, Bont-Dolgadfan, Llanbrynmair, Powys SY19 7AR, Wales, UK + 44 (0)1650 521 589 [email protected]

Mark Hankins, Energy Alternatives Africa, Ltd., PO Box 76406, Nairobi, Kenya

254 2 714623/716287 Fax: 254 2 720909 [email protected]

Instituto de Energia Solar, ETSI Telecomunicacion, Ciudad Universitaria, 28040, Madrid, Spain +34 91 336 72 21 Fax: +34 91 544 63 41 [email protected]www.ies-def.upm.es Source for Universal Technical Standard for Solar Home Systems.

Centre for Wildlife Management Studies, Rod Swatton, PO Box 47272, Nairobi Kenya • [email protected]

Solagen Ltd., Eric Muhanji, PO Box 45679, Nairobi, Kenya • +254 2 441160/1 • Fax: +254 2 444182 [email protected]www.solagen.com

Agency for Personal Service Overseas (APSO), 29-30 Fitzwilliam Square, Dublin 2, Ireland • +353-1-661 4411 Fax: +353-1-661 4202 • [email protected]

Alternative Energy

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