Questions and Answers - Photovoltaic Training Session 4

PV TRAINING – DESIGN, CONSTRUCTION, OPERATION AND MAINTENANCE

Q&A SESSION 4 September – October 2010 http://www.leonardo-energy.org/node/5948

takam pascal 2: Could we bypass a module in case of its breakdown greenproc: when is a laboratory certified?

If you bypass a module, the voltage in the string varie and this could originate a wrong working of the inverter. (different voltages in parallel strings) When it respects the in force standard of a country. You must verify if your country has a standard about it, and besides exists an entity that can issue the certification according this standard

chibunna: what does panel yellowing mean and how to overcome that

It is a problem that can come from the deterioration of the plastic protections of the photovoltaic cells. These elements are called: EVA and TEDLAR. It can be produced a phenomenon of yellowing of this plastic elements concretely. In this case, if it is the EVA, (which wraps the cells), its transparent color changes into yellow, and it does not allow the flow of light in a clean way. If the plastic elements (EVA or TEDLAR) degenerate much can happen that the oxides enter even inside the cells, oxidizing the silicon and producing the yellowing of the own cell and its degradation. This fault has to be inmediately communicated to the manufacturer. You cannot correct this fault by your own It is not recommendable to use sun trackers in these environments except in the case that the manufacturer authorizes it. The elements of motorización of the follower in this type of environments can be affected, as well as the elements of positioning (end course detectors and others) No, we haven´t got any plant in India

Amr ELHUSSEINI 2: How reliable is sun trackers in dusty, sandy weathers

Sachin: Does Generalia plan to start operations in India? Elmer Enerio: Advance Q: The 1MWp PV Plant in the Philippines had major panel replacements for about 3,000 units. There were visible cracks in the surface of the panels. Is this a common and expected future defects for most PV panels? With these number of unit replacements, this is considered a major maintenance issue. Pat Byrnes: What legislation applies to maintenace of PV Systems in Spain?

This percentage of cracked panels is not usual . For instance, our solar plant in Toledo (Spain) have 8,000 panels. After 4 years working constantly, we have had only 6 cracked panels. Please, contact your supplier for inquiries.

It doesn´t exist in Spain at present, but nowadays there is an ongoing code that will gather a set of maintenance operations

alvaro: is pannel cleaning to be foreseen Except zones with important pollution, the in the maintenance plan losses for dirt are not so high. If the zone is rainy, our experience says to us that we must not clean panels. If there is very few rain or the zone has a strong conditions of dirt, can clean them periodically. Please, analyze the production in a dirty string and in a cleaned one to verify the losses in bouth cases.

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[email protected]: how to keep module cool in hot areas

Recommendations: 1. You can use thin film modules halving the thermal losses compared to the crystalline panels. (Losses: Thin film 2 % each 10 º. Crystaline: 4 %/10 º), but you will need more land surface because his efficiency is lower/2. Keep a reasonable distance between panel and roof 3. If it is possible, avoid valleys and choose locations with high altitude [email protected]: For small plants say Solar trackers entail a major surveillance & 3kw, which design of solar tracker is maintenance. In a 3 kW facility we don´t best suited? recommend its use Ministry of Electricity and Energy Please, get the PV webinar number 5 to see Egypt: could we discuss a feed in tariff and understand a financial model with model for this kind of projects at the last Spanish and German cases session? Avikul: what about lower temperatures? No problems with panels, very good for canada we have sub-zero ... performance. For inverters, please read briefings talking about its operation temperatures, and protect this element putting it into a small building alex nyembo kalenga: is it necessaty to The manufacturer doesn´t cover all the insure the all system? because the panel incidences, as thefts, fires or meteorological manuffacturer gives already 20 to 25 problems years guarranty.

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