20201229 rC3 Meetup

EventGrid // DC MicroGrid Meetup Day 3

Introductions

skipping people who were at yesterday's meetup

• Martin: Libre Solar
• hk: modular battery based on 18650s in euroboxes, with DC-DC charge controllers for each box. Has a lot of 18650 batteries for use in a battery system.
• ecki: built own BMS, started PWM DC-DC Controller, using same TI chip as libre.solar, slightly smaller in terms of power. No documentation (yet?)
• Jeremail: Has a small setup with multiple dc-dc-converters

LibreSolar DC Grid

DC Grid for Rural electrification

• today: tiny home systems, >=50W, usually proprietary
  • Interconnect those systems?
• Test run in UK, w/ 4 participants
• Another Project planned in Ruanda
• Some of the developments are supposed to go back into Libre Solar
• Solar charger 12V/24V, grid 48V
• Working on new version of the 20A controller, potentially available ready built then. ETA maybe Jan/Feb 2021 - Martin will post costs in Telegram channel if anyone would like to order one. The more orders, the cheaper it will be, although there is no minimum order.
• Plans for a bigger charge controller (120V input) for wind generators (https://windempowerment.com/) -> Send a message to Martin if you want to be involved
• Has some 400WH second-hand e-scooter batteries he wants to use but has not had time yet.

DC-DC-Converter by Zoe and Elen

• https://fully.automated.ee/raccoon.html
• Not available yet, but maybe/hopefully for MCH? -> https://twitter.com/tachiniererin/status/1343955837258248192
• Maybe ask them for an earlier version?

Old AltPwr Website

tiefpunkt tried to recover the old-old altpwr Website from the Internet Archive. Partial success:

• Website mirror
• GitHub repo if you can help fix some broken links

Festival Grid

Power metering using tasmota-compatible smart home devices. Were funded by Prototype Fund.

• Website
• Might be also possible for 48VDC
• Worth to take a look, for MCH?

Portable power-mesh nodes

• based on hk's battery modules
• Goal Zero Yeti do some "meshing" which is more a daisy chaining, but isn't very efficient. The systems do communication between each other, probably via the charging cable.

Jeremail's setup

Could e-bike batteries be used so that an entirely new battery system does not need to be created and the focus can be on connectivity and DC-DC converters/chargers etc? Bought a few hundred bosch lawnmower 9s2p battery packs, and have no BMS!

MCH Prep

Monthly/bimonthly meetings to prep for MCH

• Make a list of stuff people can bring
• tiefpunkt will set something up and post it in the telegram group

Wind Energy

• Chewie has a setup: blog post
• Braking: by shorting the generator
• tiefpunkt read a book about microgrids recently, with a pretty good section on WECS: epub pdf

Misc notes

• DC-DC converters usually one low-voltage side, one high-voltage side, so it's easer to have a 48V grid with a 24V battery. Adapting a 48V battery to a 48V grid is much harder.
• Open source DC-DC converter for "small" power sources?