How much does the amplifier volume affect the amount of power required? Does the volume needed for an outdoor concert, such as the one on October 19, draw significantly more power? These questions will be answered through the use of a kill a watt meter. This tool measures the amount of watts used by a device. I will measure the watts used by the sound system at different volume settings.
I borrowed a 100 amp hour battery and inverter from Interstate Battery so I could test out the sound system to see how long the battery would last. For the off-the-grid concert, I will need 5-6 hours of power. This first test went well. Since I was using the sound system in my house, I did not turn up the volume as loud as will be necessary for the concert. However, I am optimistic that a solar panel or bicycle generator will be able to charge the battery sufficiently to maintain power for the enire length of the concert. During the battery test, I measured and recorded the voltage of the battery every 30 minutes.
Start: 12.83 v 30 min: 12.73 v 1 hour: 12.72 v 1.5 hour: 12.71 v 2 hours: 12.70 v 2.5 hours: 12.69 v 3 hours: 12.67 v 3.5 hours: 12.65 v 4 hours: 12.63 v 4.5 hours: 12.62 v 5 hours: 12.60 v 5.5 hours: 12.58 v 6 hours: 12.56 v The battery would be considered to be 75% charged at 12.65 volts and 50% charged at 12.45 volts. Thus, after 6 hours, the battery was still over 50% charged. For two reasons we are going to power our sound system with a battery. The first reason is the reliability and consistency of a battery. Since one of our goals of the event is to provide high quality entertainment, we want to make sure that the power will not immediately fail even if one of the alternative energy generating sources fails. Also, I feel that by experimenting with a battery, I am modeling how one might use alternative energy in a home. A person may want to use electricity when it is not sunny or windy, or when they are not pedaling a bicycle generator. Therefore, energy storage is an issue. I want to demonstrate that net metering is a way to use the power grid for storage, while disconnecting from the power grid will require a battery for energy storage.
The purposes of this event are to entertain and to educate. We intend to raise awareness about alternative energy sources and to educate people about ways in which they are impacting the environment and how they can reduce that impact.
I am working on figuring out how to power the sound equipment for the off-the-grid concert. The mixer takes 30 watts, 120 volts, 60 Hz and the amplifier takes 170 watts, 120 volts, 60 Hz. I could purchase a 300 watt generator. Supposedly with a buck-boost converter (whatever that is - I have some more learning to do) and then a 500 watt inverter, I could have enough power for both the mixer and the amplifier. Or maybe I should do a separate generator for each - just to be safe. The original plan was to run the mixer and amplifier off a car battery and then be using 1 or 2 generators to charge the battery. How long could a car battery power the 2 pieces of sound equipment? Another option would be to use a battery for each and then have one generator charging each battery. In that case, do I need the 300 watt generator? If I can run off batteries, then should I just go with alternators? This video makes an alternator system look fairly do-able. Bicycle Generator with Alternator
July 14, 2014
We are making progress on plans for the October 19 off-the-grid concert. Musicians will include: Eliza Gilkyson, Common Folk, and Brutal Bear. There will be a poetry reading by local poet, Molly Traffas. LED Light Source, Wichita Rain Barrels, and Interstate All Battery Center will have booths demonstrating environmentally friendly products. May 19, 2014
The date of the off-the-grid concert at the Arboretum has changed to October 19, 2014. Eliza Gilkyson is already scheduled to perform at the Arb at 4 pm that day. In addition we plan to have local bands performing at 1, 2, and 3 pm. There will be speakers presenting on topics such as beekeeping in a GMO world, climate change, drought-tolerant landscaping water issues, and composting. We also hope to have an environmental poetry reading. I enjoy listening to the music show e-town and am inspired by all of their environmental elements. One day I was eating lunch with my friends at the Bartlett Arboretum and, out of the green, I commented, "I think we need to do an off-the-grid concert. I want to do something really cool like e-town does." There were two replies at the table:
Robin: "Sure, we could do it October 26. Let's have Brutal Bear perform and Mike's Celtic band and..." She took me seriously and immediately began planning the event! Pam: "I think that should be your final project for your program!" So now I have a great challenge before me. Mark your calendars for October 26 for a fun off-the-grid concert at the Bartlett Arboretum. There will be plenty of pedaling opportunities at the event. In the meantime, I will be researching how other venues do off-the-grid concerts. I need to learn about the electrical requirements of a sound system and every single item that needs to be plugged in for the concert. Then I will figure out how to generate the necessary current for each of those items. |
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