We continue to develop resources related to the COVID-19 pandemic. See COVID-19 initiatives on Appropedia for more information.

Changes

Jump to navigation Jump to search

CCAT MEOW

291 bytes added, 13:04, 8 November 2012
no edit summary
<gallery>
Image:MEOW_V2_Paint_Job.jpg|Fig 2: Sean Armstrong and his kids having fun repaintingImage:CCAT_MEOW_hardware.jpg|Fig 2a: The previous hardware panel (2005).Image:MEOW New Hardware Construction.jpg|Fig 2b: The CCAT Crew mounting the new components.Image:MEOW New Panel.jpg|Fig 2c: New batteries, inverter, and charge controller successfully mounted (2012).Image:MEOW V2 Paint.jpg|Fig 2: Sean Armstrong and his kids having fun repainting the MEOW.
</gallery>
===The PV Rack===
The PV rack turned out to be one of the most difficult components to rebuild. Although the bandits did not take the PV rack, in their mad dash efforts to remove and steal our valuable PV panels, they did manage to leave the rack system horribly mangled and more-or-less useless to us. Due to a lack of mechanical and structural expertise, our preliminary designs for the new rack weren’t fully functional (each panel weighs roughly 40 lbs. and must be able to safely travel down the highway at speeds of 65 mph; headwinds encountered on the highway must also be considered). In the name of safety and a long lasting system, we decided to work with local professional John Davis at Solar Racks to build the new PV rack. For John’s efforts, we traded him a couple of 60 W monocrystaline PV panels that had been lying around the CCAT house and had not been put to use in some years; because we are a worthy NGO, John also gave us a good deal on materials. By working with John we were able to give several students the opportunity to work in a metal working shop and receive hands-on experience with building solar racks (*ADD PHOTOS*).   <gallery>Image:MEOW Rack Jerome.jpg|Fig 3: HSU student Jerome filing one of the beams in John's shop.Image:MEOW Rack Dustin.jpg|Fig 3a: HSU student Dustin doing some precision metal cuttingImage:MEOW Rack Jess.jpg|Fig 3b: HSU student Jess making sure it will all fit together.</gallery>
The final design for the rack was a stationary flat-mount (i.e. 0° tilt) rack. This design was ultimately chosen for three reasons. The first reason is that a flat mount simplified the design and minimized materials cost. Second, we figured that a flat-mount rack would be much safer than a tilted or adjustable rack for the mobile system. The logic here was that if we were to make an adjustable rack, we would run the risk of someone accidentally leaving it 45 degrees during transport (which is likely since CCAT has a very high turn around rate of employees who don’t always know the finer details of how the systems at CCAT work). Additionally, the rope and pulley system used for the adjustable rack on the MEOW V1 was not devoid of problems: the rack required the careful attention of two people to raise and lower the panels and the rack [http://www.appropedia.org/CCAT_MEOW_rack reportedly bowed at critical points]. The third reason we went with the flat mount is that our analysis showed we would only lose 59 kWh/year (6%) in energy production as opposed to a tilted rack system (41°), and would lose 116 kWh/year (12%) with an adjustable rack. We decided the risks and costs of a tilted/adjustable rack didn’t outweigh the benefit of the additional 6%/12% electricity we would receive.
62

edits

Navigation menu