killoran@XN.LL.MIT.EDU (Mike Killoran) (04/10/90)
Greetings, I have an application which will use about 7Watts at 5Volts. I would like to have this in operation 24 hours a day for as long as possible unattended. My thinking up to this point has been to use batteries, replacing these as needed. However, solar might become an interesting alternative depending on the difficulty. Since this has to operate at night, I assume the solar array will have to produce enough energy to power both the device during the day and charge batteries at the same time which will discharge into the device at night. How do I figure the best batteries and the size of an array needed for this application taking into account inefficiencies of solar cells, batteries, etc.? This will be in a HIGH sunlight area. Sorry if this is asking for a simple answer to a complex problem, but at this point I am just trying to see if this idea will pan out. Thanks, Mike Killoran
henry@utzoo.uucp (Henry Spencer) (04/10/90)
In article <1790@xn.LL.MIT.EDU> killoran@xn.UUCP (Mike I. Killoran) writes: >... Since this has to operate at night, I assume the solar >array will have to produce enough energy to power both the device during >the day and charge batteries at the same time which will discharge into the >device at night... Remember to consider (a) worst-case weather conditions reducing sunlight, and (b) the limited life of most rechargeable batteries. It does sound like a practical idea, though. -- Apollo @ 8yrs: one small step.| Henry Spencer at U of Toronto Zoology Space station @ 8yrs: .| uunet!attcan!utzoo!henry henry@zoo.toronto.edu