Village:Energy
The idea is that we create a metropole containing villages / people with tents that all use 42VDC (+/- 8V) as only power source. (On the island maybe?)
WHY?!
- Because power hacking is COOL!
- DC grids are HOT!
- <50(60)VDC is relatively safe.
- You can connect your:
- Wind generators
- Solar cells
- Woodgas generator
- Electrical bacteria soup
- Hamster wheels
- Fitness gym equipment
- Pocket fusion generator
- INSERT YOUR POWER IDEA HERE
HOW MUCH POWER? 1.21 JIGOWATTS!
Benadski has a plan and some stuff prepared already. Contact him for the details in the RevSpace IRC channel, or read on.
Alternative power SHA2017: brainfarts benadski
Example grid left:
- red: power central, no user ends. except maybe for a few big power suppliers
- yellow: interconnect / user tap point
- green: user tap point. tap points are for delivering power too
Contents
The grid must be:
- Safe
- ELV (a voltage not exceeding 42.4 Vac peak or 60 Vdc) is safest thing fiddling with
- Grid cable strands individually fused at least on positive rail, negative: earthed.
- Fuses must all be DC rated 60V+ for a DC ELV grid!
- High current side not accessible for end users
- Accessible
- Not too expensive converters for delivering / using power to / from grid.
- Connecting should be painless for end users.
- High power connections for villages must be available
- 24/7 powered
- Power transformer(s) for power when alt-power is depleted (no sun / wind etc.) ←Benadski already has a 15kW power supply!
- Small battery backup (not more than 15 minutes?), also doubles as stabilizer.
- Maybe other kinds of backup solutions, like bio-gas / wood-gas generators?
- Simple and robust
- Cables must be able to handle more power than needed
- A shorted or disconnected cable should not affect the rest of the grid
- Smart and anonymous? (not really my expertise, but interesting)
- Should a user need more power temporarily, let her/him access the power grid somehow to get some more? Can this be made non-traceable / anonymous?
- Let the network warn people when power demands are too high / voltage is low?
- Voltage dependant power, users can control when they use power just looking at the grid voltage. A converter can auto-start when there is plenty of power for instance.
Numb3rs and sort of facts:
(all are sucked out of my thumb): ←I know, I know that's not an English expression (yet!) But used in many other countries, so: adapt! :P
- 42VDC? (range 34-50V, some safety to make sure >60V will never be reached) (42V is 7 6V batteries in series)
- 2A per user (enough for charging laptops, having blinkenlights etc.), average use under 0,667A
- 16A per village (to power a fridge, 4 laptops and lots of lights and/or audio), avg 6A
- Power generation, 32A max. 4 connections totaling 64A max. per power node. ZB: 32+19+1+12
- 300 users * 0,667A + 10 villages * 6A = 260A. 260A * 42V => 11kW average usage, estimated peak 15kW.
- Cables should handle about 25% of max. current => 52A, fused at 50A slo-blo
- 4x6mm2 can probably handle the current, but there cannot be a yellow/green conductor carrying current.
- 5x10mm2 is better, earth wire is now used for earth only. Voltage drops are lower, less losses. 5x16mm2 is awesome but very expensive...
- PTC fuses are excellent for user end protection, but must be pre-fused. One 16A per 8 2A outputs should do the trick
- Battery backup / stabilizer: 7x6V 10Ah at every corner of the grid. Decouples below 35V, starts charging again above 42V. Maybe bigger one at the center of the grid, 12Ah or higher
- We need a big load for destroying excess power when >48V (or store it somehow, see below)
- The whole concept / ruleset must be open and accessible online at least one half year before the event.
Wild ideas next!
- Water tower for storing energy and big-ass stat display. (Energy capacity fairly low)
- Big crane structure lifting / lowering a concrete weight or an old car to store / deliver power.
- Woodgas generator
- Biogas generator (from local biological waste like dead food, NOT from feces and/or pee) ←This could create horrible stench, use with care!
- Electrical bacteria farm (http://www.nwo.nl/en/research-and-results/cases/bio-batteries-in-the-seabed.html)
- Bicycle gym with generators (near showers please!)
- Design nice converters people can buy for little money (open hardware):
- >36V => 19V / 12V / 5V for powering stuff, with grid status outputs ←Benadski already has some (30+!) >38V to 12V20A converters for the power lurkers. These will be installed inside the yellow/green tap points.
- 5..42V => 36..48V (auto optimum point detection) for delivering power to the grid.
- 48..120V => 36..48V same as above. for the awesome solar frontier panels for instance.
- Data over power, for general grid stats or other cool things.
- Use the motion of people to generate power somehow. (children's playground power / walkways)
- Store excess energy in water heating for dish washing / showering, pre-heated water needs further heating before it's used.
- Limited number of alt-power tickets for participants will make sure people can participate. No disappointments. But I don't like limitations... What to do?
`High' voltage DC interlinks (a.k.a. decentralized nanogrid)
For anything past ~ 20 meters, low voltage DC becomes effictively unfeasable. Meaning, you could wire up maybe to tents but not really set up any larger energy sharing structure. However, there are bidirectional converters between 48 VDC and 380 VDC that would allow creating a proper grid with minimal required architectural input. As AC cables are safe for these DC voltages as well, this would allow for essentially a plug and play type of grid.
So what needs to happen to get this implemented?
- Buy/beg/borrow some of these devies
- FInd a simple DIY way of wiring up proper fuses/spark detectors
In this case it woul be cool enough just to have two 48 V systems connected over a single 380 VDC line, as the worlds first prototype of a truly decentralized DC grid.
Sounds interesting? Want to work on this? More feedback? Contact DokterBob and/or look at this hackpad with prior research and at this article
