> =A0According to the BBC science page, 90 % of current solar panels will > last at least 30 years rather than the considered standard of 20. > This claim is from the EU Energy Institute, and they predict that 40 > year life PV panels will be on the market shortly. YMMV - see below. > According to their research Italy (which has high electricity costs) > will reach grid cost parity in 2010 and the less sunny parts of Europe > by 2030. Elsewhere the leading CIGS panel maker define grid parity as about $1/Watt with panel at $US0.80/Watt =A0and infrastructure at $0.20. You can get panels FOB China now for $US1.70/Watt. maybe less? Excellent insolation and other climate data at www.gaisma.com > > As a personal aside, I fail to see why scientists advising governments > don't take the emphasis of alternative power reaching baseline > generation for grid distribution and turn it into micro generation > either at individual dwelling or street level - which IMHO is far more > achievable with current technology, leaving current base load to drive > the very high, but short usage items in the home. That's what grid tie can achieve where the administration allows and is done in some places. AFAIK the UK installed (NZ designed) Whispergen Stirling cogen units work on this basis with heat being used in premises and mains power being available for grid use. A fraught issue is the cost per unit that such energy is paid for at. Suppliers would like to pay wholesale bulk charges at best, homeowners would like to receive at least retail rate (which is effectively what you get if your meter allows bidirectional energy flow) and in some cases home owners get in excess of retail rate due to subsidies / incentives. =A0PV panel longevity: PV panel longevity, after best practice is used, depends heavily on the quality of the "EVA" adhesive used to bond the panels. The typical "sandwich" is =A0 =A0 =A0 =A0 =A0 =A0 =A0Low iron Glass - EVA - PV Silicon - EVA - Tedlar. The Tedlar backing sheet (may be other material) serves both as sealer and important antireflective coating. Up to several % efficiency gain can be achieved from inobvious reflection property manipulation. The EVA "quality" depends on manufacturer, and material from Asian sources without 'technology transfer' from more capable manufacturers (or who care less) *MAY* have a lower lifetime. This doesn't HAVE to be the case but in enough cases is. Highly reputable manufacturers will quote the sources of their glass, PV material, EVA and backing sheets. Also relevant are lamination times and temperatures. EVA crosslinking takes about 20 minutes at typical press temperatures and where time is money there is no doubt the tendency to minimise time in the lamination press. Cross linking above or below about 80% affects panel life and/or performance. In an Asian factory where I spent some time a while ago, the manager told me that he used only German sourced EVA from a=A0specific manufacturer in order to achieve maximum panel longevity. I was reading a Chinese-manufactured EVA material spec literally a few days ago and they had two grades - one was quicker laminating than the other and contained the bracketed note "(mainly for use in China)." Conclusions, possibly erroneous, may be drawn :-). I have seen reports of panels lasting well over 30 years and I have a 50 Watt panel of about that vintage which still performs OK despite partial water intrusion in one area. (I got it"broken" - a connection had corroded where it entered the panel and was repairable.) I've also heard of EVA starting to fail at under 20 years. The actual silicon PV material does have a long term degradation mechanism but it is slow. Typical industry claims overall are 5% loss at 10 years and 10% more up to 25 years total. I've seen some recently offering (AFAIR) 5% total at 25 years, but I have no idea whether this is based on any factual basis. =A0 Russell McMahon =A0 Applied Technology ltd =A0 New Zealand -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist