Just worked out that the tax department OWES me money for an old return where I expected to owe THEM money. Decided to celebrate with a late night Solar Dish-Stirling writeup. Some people have no life :-). After a century++ of gestation the Stirling Engine seems about to break through into mainstream use. Maybe. Solar Dish-Stirling engines! These people in various guises and takeovers claim to have spent $500M over 30years to get this far. 5? of their units have been operating at Sandia for many years. They have come close to shutting down a number of times AFAIK but some enthusiastic dreamer seems to always come up with a few more 10's of millions to keep the dream alive. And, at last, the 'dream' has got as far as an 'energy farm' with 60 of these 25 kW units being installed. Here's an aerial view of their live Solar Dish-Stirling installation in Maricopa, Arizona. http://bit.ly/MaricopaSolarStirling The substation 'just over the fence' will not be there by mistake. A total of 63 towers are visible (7 x 9) with 37 dishes mounted and one apparenbtly under construction. 4 of the 37 dishes are visbly not "on sun" and about 4 more present a different visual effect to the rest so may be pointing off angle somewhat for some reason. Each "station" mounts a 25 kWe (electrical OUTPUT) Stirling Engine at the focus of a 40 foot dish. All the pictures you could want http://bit.ly/TesseraSolarImages (Gargoyle images) Extremely good idea of the installation http://www.ntrplc.com/uploads/images/av/SunCatchers-Looking-N= orth-Image.jpg Good video http://www.youtube.com/watch?v=3DqN2Wcy2khuE&NR=3D1 But, 60 x 25 kW =3D 1.5 mW is very small on a power generation scale - about the same output as a good wind turbine - which may well run for many many more hours per day on a good site. BUT, if the following occurs, that will change: Their site says: "In late 2010, Tessera Solar North America will break ground on two of the world=92s largest solar plants =96 both in California. Working with San Diego Gas & Electric and Southern California Edison, our Imperial Valley project and our Calico project will produce a combined 1,600MW of clean, renewable energy. Together, they will use over 64,000 SunCatcher=99 units...Solar energy at a scale the world has never seen." 64,000 dish Stirling units ! :-) That's going to be worth seeing. If it happens. I suspect that quite a lot hangs on the success of the Arizona site. If/when that happens a certain Stirling decrying good-friend of mine will have to eat his hat (you know who you are :-) ). Efficiency is awesome compared to what's available with most other technologies. On a (very*) good day they have delivered 31.25% conversion solar to grid!. * Very good is full sun and extra cold day. Normal is slightly below this level. (Note that efficiency comparisons between differeing technologies are often not too relevant. eg What does it matter if Solar PV gets 15% and Stirling gets 30% if the all up lifetime cost of power from the Stirling installation is higher? (Or vice versa). ie delivered cost per kWh ovver lifetime is the primary measure. Environmental and other aspects will also feature to various extends. (Land use, area, toxicity of components, recycling, pollution, water use etc). eg water use for dish Stirling is low - used only for mirror cleaning - all air cooling is used. Whereas eg trough concentrator requires water cooling with higher overall water usage. BUT Here's some opposition to their Colorado San Luis plant plans http://www.saveslv.org/2010/02/last-decembers-public-meeting.html 8000 dish Sanluis 1041 application http://slvrenewablecommunities.blogspot.com/2010/07/tessera-solar-final-app= lication-meeting.html Availability of the Maricopa plant is said to be 97%. They claim 55 - 60 MWh/year output from a 25 kW unit or over 2000 hours/year at full output =3D > 6 hours/day of full sun equivalent. Here's the month by month insolation for Phoenix, Arizona. Insolation, kWh/m=B2/day 2.98 3.78 5.06 6.53 7.37 7.54 6.99 6.21 5.46 4.30 3.30 2.74 =3D 5.2 kWh/m^2/day mean or 5.2 sunshine hours per day at 1 sun. They say: Prototype Systems of today=92s SunCatcher=99 System have been operating for more than two decades. During this time the critical elements of the system, the PCU, and dish concentrator have been redesigned for greater efficiency and performance. It has recorded an aggregate hundreds of thousands of hours of on-sun testing on all sub-systems, and over 50,000 hours of complete system on-sun testing at Sandia National Laboratories in Albuquerque, New Mexico. The SunCatcher=99 has furthermore been modified and optimized for large scale manufacturing and deployment. I have trouble believing that these systems can be cost effective. As does my friend. But it seems that they must be. Apparently any way. Simplistically: 60,000 kWh/year say at say 10 cents/kWh - high by wholesale standards =3D $6000 pa. 5 year life no DCF etc =3D $30,000 value. 10 year life =3D $60,000 value. Super simple DCF at 5/10/20 year life and 5/10/15 % interest rates - no operating costs or maintenance, power at 10 cents/unit. Interest rate=09 Years 5 10 15 5 27000 25000 22000 10 48000 40000 32000 20 77000 53000 38000 Realistically maybe $40,000 break even value. Can you buy one of these for that much ? Lower energy value lowers result. _____________ View over the fence video - you don't see too much - but what you do see would have looked like SciFi not too long ago http://www.youtube.com/watch?v=3DvG0xIBc3l9U This promo video This annoying but useful video with animations and artists impressions has some shots of the Maricopa plant being built. Contains some good views of people working on the hardware - you could learn quite a lot from these brief glimpses. http://www.youtube.com/watch?v=3DBDBFdbKcl84&feature=3Drela= ted ? http://www.youtube.com/watch?v=3DBDBFdbKcl84 Tessera website http://www.tesserasolar.com/ US http://www.tesserasolar.com/north-america/ International http://www.tesserasolar.com/international/index.htm (looks similar at top level) --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .