Accessing the solar website:

• 10.30: start
• 10.30 - 11.00: project introduction, Materials Matter and Wilderland, PhD intro
• 11.00 to 12.30: Making small solar systems part 1
• 12.30 to 13.30: Lunch break
• 13.30 to 14.30: Making small systems part 2
• 14.30 to 15.30: Discussion - capturing discussion

This workshop is meant to be enjoyable and relaxed. It wants to share information in a usable way and provide hands on experience. If you have any questions or concerns, please feel free to speak up, don’t be afraid to interrupt.

I am not an electrician, nor an engineer, and any of the information provided today should not be used unless you are sure of what you are doing. Don’t connect any of the systems or circuits shown today to domestic installations, or do anything that involves wired sockets. If you reproduce any of the systems shown today, be aware that you do so at your own risk. I would also not making any systems larger that 12V systems unless you absolutely had to. Embrace the smallness! The information that I share today was gathered over a number of years, from a number of sources. In somewhat of a chrono/importance order:

• August 2020 - House building course in Co. Clare - now ‘Common Knowledge’

  

• how-to-build-a-small-solar-power-system from Low Tech Mag

• Mobile solar power, the free book Thank you to all these folx!

• Solar Secondlife Magazine ?! just published ?!

• Low Carbon Methods zine

Working with electicity can always carry risks, but today we are working with 12V systems, which significantly reduce the possibilities of harms. Meanwhile, electrick shocks are possible (can be painful, but not dangerous), as well as possible risks of fire, battery explosion, or component damage. Follow these simple rules and all will be fine:

• don’t touch any components if your hands are wet, or your clothing is wet
• don’t touch exposed parts of positive and negative wires at the same time - don’t do this with a battery either
• don’t let positive wires come in contact with negative wires, this will cause a short circuit, where most issues arise from, component damage, fire, battery explosion.
• use fuses and thick enough cables

• panels
• solar charge controller
• battery
• DC to DC converters
• inverter
• fuses

This workshop is not about the theory of electricity and it’s measurements. If you scratch a little, you will quickly see the narrowness of Colm’s understanding of electricity. The point is that, assuming you are staying with a 12V system, tests and adjustments are easy to make and finding compatible components is somewhat straightforwards. Having said this a few basics can’t hurt. The following is adapted from the Will Prowse Mobile Solar Power book mentionned above.

• Volts: Energy Potential, or the siwe of the force that send the electricity through the wire. Energy potential, or volts is always present, whether the electricity is being sent / used or not. Water hose analogy: Volts are like the pressure of the water in a garden hose.Whether your spray nozzle is open or closed, the pressure is still present.
• Amps: Energy Current, or the amount of electricity going through a wire. The more amps a wire must carry, the thicker the wire must be. Amps are only present when electricity is traveling through a wire or being cosumed by an appliance. Water hose analogy: Current is like rate of flow. It is like the amount of water the hose can carry or hold. If a hose is thicker, it can carry more water.The rate of flow can only occur what water is moving through the hose.
• Watts: The total “power” produced. This is the measurement thant combines Volts and Amps. Water Hose Analogy: How fast you can fill a bucket of Water.
• Fuses: a safety component that stops bad things happening if a short circuit happens. They are meant to be the “weakest link in the chain”, whereby, if something goes wrong in your system, they are designed to heat up and “blow”. This stops the circuit, and then requires your attention.

It can be complex to figure out what size fuse your system needs. We can take the remote.wilderland system for example. From the battery to the DC to DC converter, we should put a fuse in the line. In this case, we have a 12V battery, being wired to a 12V DC to DC converter, that steps down to 5V (this is a common voltage for USB devices). As the plugged in phone will draw between 1.2 and 2A (most draw 1.2, unless they are ‘fast’ chargers), we could put in a 2A fuse and call it a day. But if I plug in another device to the second USB outlet, then that one could also draw between 1.2 and 2A, so I will put in a 5A fuse to have a bit of headroom.

For a long time, south facing panels were the norm, as they produce energy somewhat consistently through the day. But if you know when you will be needing power, you can maybe make some adjustments. East-facing panels will produce peak power at breakfast time, maybe for making hot drinks. West-facing panels will produce power in the afternoon and later evening, maybe suited for TV watching, for example. Another rule of thumb is to set a tilt angle of 30 degrees. Some panels come with mounting systems that allow for tilt adjustment through the seasons. 30 degrees is a good all-rounder.

Two diagrams of systems below, to study, from Will Prowse