DC Microgrid/Solar

Most DC grid installations we've talked about so far use solar power as their main energy source. So even though it's not directly part of the microgrid, here's a small collection of information on solar energy

Getting cheap solar panels

Used solar panels are ideal for us. There are a few places to get them

• Used-Solar has an ebay shop. They ship panels, or you can pick them up in Leipzig. We got our panels for CCCamp19 from them
• SecondSol is an online market place for used and new solar gear
• eBay & eBay Kleinanzeigen

NOT getting cheap solar panels

• AWM Wertstoffhof Plus
• eds-r (that place where the Wertstoffhof brings their panels to)

Charge Controllers

Charge controllers connect the solar panels to the battery (and sometimes also to the load). There are cheap ones from China that work decent enough, and proper expensive ones. Also, there are OpenSource projects.

• Cheap charge controller from China, works well enough for its price, great for getting started
• LibreSolar, open source MPPT with 10A or 20A, and a 20A PWM controller (also on OSE wiki: BMS
  • All connected together in a Goal Zero Yeti like box: SolarBox (GitHub)
• SMBS4080 older opensource project, for lithium batteries. Newer versions apparently availble but not sure if they are opensource [1]

Project ideas

• Integrated box with solar SunCrafter

Guerilla-PV cum Zombie-Mode

• Be simple, reliable, idiot-proof
• have enough stored energy to run for 1 week in cloudy weather

On no-Zombie:

• Have Grid-Tie-Inverter to offset all the things wasting power in standby.
• charge battery for Zombie
• not discharge battery over night (unless battery + PV has enough power that we don't care)

On Zombie

• Run in island-mode (inverter with no grid tie) from battery to run smartphone, laptop, radio and fridge.
• continue to charge battery from PV when there is enough power

Needs

• PV panel (used?)
• something to charge battery from PV
• maybe something to charge battery from grid?
• battery (run down lead-acid car-battery?)
• Inverter being able to tie into grid
• Inverter being able to run stuff stand-alone
• ???
• Profit!