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SPCC A Casa Amarela
  • Introduction
  • Intro
  • Macieira
  • 001 opening story
  • 002 first weeks of SPCC
  • 003 first informal group meeting
  • 004 SPCC - the start
  • 005 another day, another floor
  • 007 it lives!
  • 006 Rainbow Rooms
  • 008 didn't do shit
  • 009 no water again
  • 010 More work done!
  • 011 waterworks
  • 012 a third of a wall
  • 013 First room
  • 014 One wood wall up and Fuchsia room up!
  • 015 yes officer
  • 016 red room
  • 017 shower
  • 018 hydrant fixed
  • 019 decor
  • 020 orange room
  • 021 Latest News
  • 022 Windows and etc.
  • 023 Electricity!
  • Hydro Pole
  • 024 ARRRRRRRRRRRR
  • 026 squats, social centres, free spaces...
  • 025 squats, social centres, free spaces...
  • 027 Personalitty issues
  • 029 new website look
  • 030 S's Birthday Party!
  • 031 spoils of war
  • 032 water and doors
  • 033 entropy of partying
  • 035 work
  • 034 house meeting
  • 036 yellow room
  • 037 pics
  • 038 visitors
  • 028 an emphasis on exuberance
  • 040 builder gathering
  • 039 progress?
  • 042 Update
  • 043 barbecue
  • 044 tiki bar
  • 045 a valued location
  • 046 teste
  • 047 Gallery
  • 048 first CS guests
  • 049 Chill Out progress
  • 050 tipping point
  • 051 swimming pool
  • 053 the reality of good and evil in all of us
  • 054 Uff
  • 052 Harald's birthday
  • 055 positive derivative
  • 056 Free Shop
  • 057 New era?
  • 058 helpex approved!
  • 060 another party another breakthrough
  • 062 back to basics
  • 063 sunshine AC
  • 064 our DIY photovoltaic system
  • 065 ghetto techno
  • 066 churrasco anti nacionalista + kawak kay sound system
  • 067 dug up roots
  • 068 Christian Louboutin
  • 069 we did it!
  • 070 First RAAAAAAAAAAAAAAAAAAAAAAVE!
  • 072 our first humanure factory
  • 073 blue thursday
  • 074 short stop
  • 075 indulge
  • 076 thank you
  • 077 Kat's account of her stay (and their trip)
  • 078 first request study results
  • 079 humanure
  • 080 Chill Out bar progress
  • 081 low tech hiatus
  • 082 mini rave + kawak kay sound system + free food + free booze
  • 083 free means fun
  • 084 dinner + kawak kay sound system + R's birthday party
  • 085 heat wave hangover
  • 086 Dry toilets, humanure, and closing the sewage loop
  • 087 mild frustration
  • 088 never there when shit happens
  • 089 Enough is enough!
  • 091 good times are back
  • 092 Naked man, pushing shopping cart with a shot gun?
  • 093 Solar panel photos
  • 094 best registry cleaner
  • 095 3ꠁniversᲩo Associa磯 Musical INDUSTRIAL PT / 3rd anniversary of the INDUSTRIAL PT non-profit musi
  • 096 new BFB (Big Fucking Battery)
  • 097 new subwoofer, extra hands
  • 098 hitchhiker gathering craze
  • 099 hitchhiker gathering flash rave + KKSS
  • 100 new work ethics thanks to... work ethics
  • 101 Hitch hikers invasion, part 2, can it be?
  • 102 windmills, swimming pools, cane constructions, gardens and anarcho-syndicalism
  • 059 Nomad Base
  • 103 power struggles, again
  • 104 Big issues, and big decisions to be made
  • 105 solar workshop
  • 106 Today's game
  • 108 parties, philosophies and cultural exchange
  • 107 Flash workshop day + communal dinner + debate
  • 109 fire sculptures and bunker tracks
  • 110 solar energy shortcomings
  • 090 cane frames
  • 111 Hitchhiking gathering and issues gone
  • 112 plumbing fire
  • 113 big brother okupa
  • 114 power
  • 116 holidays and post boomers
  • 117 Return to the squat
  • 118 first google guest
  • 119 on planning
  • 120 Two weeks at SPCC
  • 121 Demolishing is coming!!
  • 122 paintathon
  • 123 A journey
  • 124 why i choose to celebrate the demolition
  • 126 More signs of demolition
  • 127 Baile da Contra Cultura
  • 128 what works, what doesn't work
  • 129 Topographers on site, and kids.
  • 130 the demolition crew and the freeloader crew
  • 131 2 weeks to close the squat!
  • 132 impromptu meeting, couriers and our deadline
  • 134 another paintathon
  • 135 facts, stories and politics
  • 133 THE BIG DEMOLITION PARTY - PAINT THE FUCK UP
  • 136 party people
  • 137 dear spcc
  • 138 Last words
  • 139 How to make a solar panel
  • 141 demolition on its way, but not today
  • 061 About
  • 142 follow up on our characters
  • 143 can't trust a contractor
  • 144 the big demolition party short video
  • 145 new dates for the demolition
  • 146 moving on digitally
  • 147 all gone! SPCC has been cleared!
  • 115 thanks and more
  • 148 SPCC featured in the german Jungle World
  • 150 where you can find me
  • 151 Acts change Facts: Nicolas's movie about SPCC
  • medo e ignorância no controlo policial
  • 152 SPCC featured in the travel comic compilation "Boring Europa"
  • 153 my experience at SPCC featured in an interview about my experience as an engineering student
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139 How to make a solar panel

Previous138 Last wordsNext141 demolition on its way, but not today

Last updated 5 years ago

From: starstuffharvestingstarlight Date: 2010-09-21 23:00:44 Title: How to make a solar panel

here's how i learned to make a solar panel, and what i've been teaching at the workshops.

as for the electrical part, here's a quick overview of the laws we're working with and some rules of thumb. google is your friend, and just google most of this.

1) since the whole setup is DC (direct current), what we need are DC Volts (Voltage) and DC Amps (Ampere). voltage is the "tilt" between your points (higher voltage flows to lower voltage [yields positive current], not the other way around), current is how much charge "flows" per unit of time

2) Power is the way to measure how much any equipment uses in terms of instant energy. a cellphone charger would be around 6W average, a netbook 40W, an LED bulb about 3W, a hairdryer 2000W (not kidding). since we're dealing with DC, we can use P=VI (Power[W]=Voltage[V]Current[A]). this means that, for example, if your cells are 0.5V and give 3A when in the sun, you will get 0.5*3=1.5W

3) Energy is the total energy consumed over a certain period of time (usually in hours). so let's say you used your hairdryer 1 minute. the total energy is 2000[W] 1/60 [h] = 33.(3) Wh. also, let's say you used your LED lamp (3W) for 12h, this is 312 = 36Wh. your LED bulb spent MORE energy than your hairdryer. so more Power doesn't mean more Energy. it always depends on how long you use it.

4) Energy stored in batteries is usually measured in Ah (Ampere hours). Depending on the voltage of the batteries, you can calculate the total power by multiplying. let's say you have a 45Ah car battery (12V). total power is 45*12=540Wh. this means you could power our LED bulb for 180 hours, or run your hairdryer for about 15 minutes. this is the total capacity of your battery. batteries actually are a bit more complicated than this, but as a model this is good enough.

5) Power used in AC (Alternate Current), which is what we have in homes, is comparable to Power in DC. meaning, let's say you have a drill, 500W, and an adapter from 12V to 250V (this is possible, it's called an inverter) that can handle 500W. you would have: 12V 41.(6)A = 500W = 250V 2A . this is a gross simplification, since AC has both peak (250V) and RMS (Root Mean Square), but going deeper would require extra electrical theory. so basically, if your drill is rated 250V/500W, your battery must be able to output 500W/41.(6) amps while you use your drill. depending on the battery, this might or might not be possible. the best is to consult your battery supplier

6) an inverter has a power rating, and that's the most important think you need to know. if your inverter gives 250V 150W you can never use your 500W drill. if Power needed is bigger than Power provided, usually you will fry your inverter, or cause it to go on fault protection mode. same thing with current. if your electronics are rated 10A and you feed (or pull) anything more than 10A, either you'll break a fuse or burn something. if you don't, you just got lucky.

7) when calculating how many batteries you'll need, remember that it's good for your batteries not to be completely drained. so if you have a 160Ah battery and keep it at most 80% discharged, you only have 0.2*160 = 32Ah available. this is about 384Wh of charge. if you just use a 3W bulb, you'll have 128 hours of light.

8) when calculating how many panels you'll need, first calculate how much energy you use (in Wh a day), then double that (or even triple that) for the panel power + battery bank. remember that depending on the time of year and weather conditions, you'll only have a certain fixed value of useful sun hours. if you do the math on Wh/year, you'll have a better estimate of the average, but remember that in winter, you'll need more backup energy, and in summer you'll have surplus energy.

in a D.I.Y. system, you won't be able to use government help, nor connect it to your electricity supply company. remember that for certification and what not, your panels might not get approved, and most of your cheap equipment might be considered "hazardous". our D.I.Y. system with car batteries, cheap inverters and home made panels works, but wouldn't be seen as "safe" by the government.

to find all of this stuff, use eBay, contact the industrial suppliers for panels looking for damaged cells and panels (they still work, they just look ugly and therefore can't be sold), prefer batteries that are recyclable and companies that have battery recycling guarantee (and environmental awareness whenever possible). DON'T BUY FROM CONSUMER STORES! you can build your own system for about 300€ instead of 5000€ like in some stores! it's NOT worth it! also, prefer mono crystalline silicon to poly crystalline silicon to amorphous silicon. in practice, all the shit you hear on the news about "revolutionary solar technology X" is hype. you can't buy any of those technologies, and most companies are for business only.

CHOOSE RECYCLED, USED GOODS INSTEAD OF BUYING! the energy used to make a solar panel will never be output by the panel itself in its whole lifetime. it's ironic, but unless the factory is "green" itself, buying new stuff might cause more harm than good. look up the companies first, and ask what is their manufacturing process, and whether they are green or not. silicon production gives off a lot of pollution and industrial waste. we need better technologies, so see solar as a good way of doing things for the moment, not as the ultimate green salvation. there are many other ways of generating green energy, so look up everything and you might be surprised!

godspeed starstuff ☆★☆☆★★★☆☆☆☆☆

joao@hipercubo.net