Introduction: Pop-up Solar Generator: SunZilla 3.0

The pop-up solar generator SunZilla is a renewable energy source that is portable and modular. It’s a plug-and-play system that is easy to set up and doesn’t need any experts to be built from scratch. Its modularity makes it possible to adapt the system to your energy needs, especially when they change over time. We provide you all the necessary information to build and assemble a SunZilla system on your own. For the moment, there are still components in the system that are not open source, and these have to be bought off the shelf. We are working on to find open source solutions for these different parts. You are very welcome to help us. We want to empower people by providing modular and open source micro energy solutions. We all know that renewable energy sources make people more independent, but we are also convinced that they are key to decentralized and truly democratic energy production and consumption. We believe that energy grids can be built from the bottom up, step by step.

SunZilla 3.0 is easy to set up and decommission.

Here's a photo of our team at POC21 with our previous prototype, SunZilla 2.0 (not documented here):


SunZilla 3.0's design is published under the CERN Open Hardware License


SunZilla 3.0 Technical details:

  • Solar peak Power: 140W
  • Maximum AC-output of pure sinus inverter: 350W (700W peakload)
  • Effective battery storage: 600 Wh

Examples of what you can do with it:

  • Solar peak power: 140W
    • Sunny day
      • charging 25 Smartphones continiuosly
      • running one small fridge (60l) AND 2-3 Notebooks • running a water pump and purification 200L /d
    • Cloudy day
      • charging 10-15 smartphones
      • running one small fridge OR 2 Notebooks
    • running a water pump and purification 80-100L/d
  • AC Output
    • Maximum AC-output of pure sinus inverter: 350W (700W peakload)
      • Running light for 8 rooms
      • Charging 25-30 Smartphones at the same time
  • Battery storage
    • effective storage capacity: 600Wh
      • charging arround 100 Smartphones
      • using 4 Notebooks during 6 hours
      • lighting 4 rooms for 4 hours
      • cooking 1⁄2 hours with one portable electrical cooking stove
  • time to fully charge battery when empty
    • Sunny day
      • around 5h when no other consumption
      • around 10h when charging around 10 Smartphones at the same time
    • Cloudy day
      • around 10-12h consumption
      • around 20h when charging 10 smartpohnes at the same time

Step 1: What You're Building

When complete, the system consists of:

  • 1 Battery-Box
  • 1 Solar Box
  • 1 Inverter / Socket Box

We used Euro norm boxes as containers for the different parts. They're easy to transport, come in a range of standardized sizes, and can be stacked on top of each other. Here we use the 1/4 and 1/8 box. For future prototypes we will design the housing boxes by ourselves, keeping the main dimensions of the Euro norm boxes.

Step 2: What You'll Need

SKILLS

  • Basic crafting skills, such as drilling metal, screwing, cutting metal etc.
  • (PCB) soldering
  • Wood crafting or laser cutting and/or CNC

We recommend that you follow a tutorial that explains CNC and/or laser cutting usage, and a tutorial that explains how to prepare wood.

PEOPLE

  • Minimum 2 people

TIME

  • 8 h for soldering and connecting the wires, plugs, sockets etc.
  • 8 h for preparing the boxes and building the inner structures
  • 8 h for building the folding mechanism

MATERIALS (COSTS IN EUROS)

You can download a detailed PDF of the required materials below. NB We do not actually recommend that you use the Weipu sockets and plugs, as we found that they easily slip out of the boxes.

Very roughly, the required materials are:

  • Black Euro-Boxes: 80€
  • 4 Solar modules (à 35 Watt): 200€
  • Inverter victron phoenix 24/350: 153€
  • Charge Controller: blue solar 100/15: 115€
  • 2 Batteries Agm 38 yuasa: 180€
  • Connectors, cables: 100€
  • Material: Screws, Aluminium profiles, etc.: 200€

TOOLS

  • Drills
  • Drilling machine (drill press)
  • Wrenches
  • Soldering station
  • Pliers
  • Aluminium file
  • Centre punch
  • Rubber and metal hammers
  • Ruler
  • Set square
  • Marker pen
  • Mitre saw (for aluminium)
  • Milling cutter
  • Silicon pistol
  • Countersinking cutter

Step 3: Preparing the Aluminium Profiles

Refer to the above Materials List PDF for a full list of required aluminum profile sizes and, shapes (L, T, or Square). You can buy aluminum profiles pre-cut to the right sizes. Otherwise, you have to cut them first according to the material list. Once you have them in hand, the first step is to file the ends of the profiles to deburr them, as shown in following picture.

Afterwards, the holes can be marked and drilled through the profiles. For the precise location and size of the various holes in the specific profiles, refer to the technical drawings in the below PDFs.

To drill the holes you have to mark their position with the metal marker and the ruler.

Afterwards, the marked positions need to be punched with the centre punch and then the holes can be drilled with the drill press.

After the holes are drilled they also need to be deburred by a countersinking cutter.

For the 4 x 150mm long square profiles, you should use the .PDF technical drawing "Folding Mech.- slides.pdf". NB the length is incorrectly indicated as 200mm in the technical drawing. These will be cut open on one side like this:

Step 4: Inverter Box (1/8 Pallet Euro Norm Box)

To make sure that the inverter can´t move around inside the inverter boxes, an inner mounting structure is required. The inverter attaches to the mounting structure, fixing it in place. The mounting structure is fabricated using laser cut wood structures. The .DXF source files for the laser cutting can be downloaded below.

When using the files with the laser cutter, refer to the laser cutter tutorial.

The inverter and its mounting structure fit inside one of the 1/8 EURO norm boxes, which have external dimensions of 230mm (H) x 400mm (L) x 300mm (W), and usable internal dimensions of 208mm (H) x 370mm (L) x 270mm (W).

One piece of plywood measuring 800mm (L) x 600mm (W) x 10mm (th) is sufficient to laser cut parts for both the inverter and battery boxes' internal structures (see next step).

NB, we have used the Victron Phoenix-Inverter-350 with a spec of 350 VA, 24 V and dimensions of 72mm (H) x155mm (W) x237mm (D). If you use a different inverter, it will probably have a different form factor, and you will likely have to adjust the .DXF files accordingly.

If you don't have access or prefer not to use a laser cutter, the inner structures can also be built by hand using normal wood crafting techniques with a jigsaw and wood drills. Therefore, the .PDF technical drawings of the structures can also be downloaded below.

Step 5: Battery Box (1/8 Pallet Euro Norm Box)

To make sure that the battery can´t move around inside the battery boxes, an inner mounting structure is required. The batteries are held in place by the mounting structure, and no physical attachment is required. As with the inverter box, the battery box mounting structure is fabricated using laser cut wood structures. The .DXF source files for the laser cutting can be downloaded below.

When using the files with the laser cutter, refer to the laser cutter tutorial.

The batteries and their mounting structure fit inside one of the 1/8 EURO norm boxes, which have external dimensions of 230mm (H) x 400mm (L) x 300mm (W), and usable internal dimensions of 208mm (H) x 370mm (L) x 270mm (W).

As mentioned in the previous step, one piece of plywood measuring 800mm (L) x 600mm (W) x 10mm (th) is sufficient to laser cut parts for both the inverter and battery boxes' internal structures.

NB, we have used Yuasa NP 38-12B batteries with a spec of 12 V, 38,5 Ah, and individual dimensions of 170mm (H) x 197mm (L) x 165mm (W). If you use different batteries, it will probably have a different form factor, and you will likely have to adjust the .DXF files accordingly.

If you don't have access or prefer not to use a laser cutter, the inner structure can also be built by hand using normal wood crafting techniques with a jigsaw and wood drills. Therefore, the .PDF technical drawings of the structures can also be downloaded below.

Step 6: Solar Box (1/4 Pallet Euro Norm Box)

In the case of the solar box, the inner structure is constructed using square aluminium profiles.

Having already drilled holes in the prepared square aluminum profiles as specified in the "mounting system" technical drawing PDFs (see step 3), this step is about assembling them to form the inner structure of the solar box.

Materials for this step:

  • 4 x Squared aluminium profiles, 732 (l) x 25 (w) x 2 (th)
  • 2 x Squared aluminium profiles, 200 (l) x 20 (w) x 2 (th)
  • 2 x Squared aluminium profiles, 515 (l) x 20 (w) x 2 (th)
  • 3 x Squared aluminium profiles, 560 (l) x 15 (w) x 2 (th)
  • 4 x Squared aluminium profiles, 370 (l) x 15 (w) x 2 (th)
  • 14 x Hexagonal bolts, M6 x 50 (l)
  • 14 x Self-locking nuts, M6
  • 28 x Washers, M6
  • 4 x (Wing) bolts, M6 x 40 (l)
  • 8 x Wing nuts, M6
  • 4 x (Wing) bolts, M6 x 30 (l)

The positions can be seen in the following technical drawings. The profiles can be screwed together with bolts, washers and nuts. Detailed steps are outlined below.

First, connect the 25 mm wide vertical profiles with the 2 long 15 mm wide horizontal profiles, like you can see in the following photos.

Then attach the short horizontal profiles to one of the already connected sides.

Finally, connect the two parts.

So that you get the following structure in the end:

Step 7: Preparing the Solar Box Lid

Take the ¼ EURO norm box with lid.

For the mounting system of the solar panels holes in the lid of the solar box are required. In this way the square profile of the mounting system can move in and out of the box.

To do this holes first close the lid of the box with the mounting system inside give it a light knock with a rubber hammer on the lid surface where the tops of the mounting structure contact the inside of the lid. The plastic of the lid will dent outward forming square marks showing the position of the vertical profiles of the inside structure.

Now you can drill holes in the middle of the marked squares and cut them out with a cutter. Be as precise as possible.

Step 8: Box Joins

Materials for this step:

  • 8 x Bicycle spokes, around 150 mm long
  • 1 x Plywood, Min. 1200 (L) x 400 (W) x 18 (th)

To physically anchor the the boxes together, the joins need to be added. The joins hold the boxes in place on a wooden foot structure. This structure can be CNC-milled with the provided .DMX source file, which you can download below. You can also old-school wood-craft them, following the .PDF technical drawing, also downloadable below.

After milling the foot structure, put the boxes in their places and drill 4 holes through the outside bottom rim of each box and the underlying wooden structure. Using these holes, the different parts are connected by a bent bicycle spoke. The shape of the spoke can be seen in the following figure:

The height of the “mouth” of the bent spoke depends on the thickness of the wooden foot (see diagram). It should 2-4 mm less than the added thickness of the box and the wooden foot. To bend the spoke, start from one side of the spoke and do one bending after the other by holding the spoke with pliers and bending then the longer end of the spoke with your hand in the shape you like.

Step 9: Solar Module Frames

Materials for this step:

  • 6 x Hinges, 24mm (l) x 20mm (w) x 1mm (th)
  • 4 x L-Aluminium profile, 558mm (l) x 20mm (w) x 2mm (th)
  • 4 x Squared aluminium profile (better rectangular profiles with 20mm x 8mm), 150mm (l) x 20mm (w) x 2mm (th)
  • 4 x T-Aluminium profiles, 560mm (l) x 15mm (w) x 15mm (h)x 2mm (th)
  • 4 x T-Aluminium profiles, 435mm (l) x 15mm (w) x 15mm (h)x 2mm (th)
  • 2 x L-Aluminium profiles, 545mm (l) x 15mm (w) x 15mm (h)x 2mm (th)
  • 4 x L-Aluminium profiles, 420mm (l) x 15mm (w) x 15mm (h)x 2mm (th)
  • 24 x Hexagonal bolts, M3 x 8mm (l)
  • 24 x washers, M3
  • 24 x Self-locking nuts, M3
  • 36 x Countersunk bolts, M5 x 10mm (l)
  • 36 x Self-locking nuts, M5
  • 36 x washers, M5
  • 8 x Wing bolts, M6 x 20mm (l)
  • 4 x Semi-flexible mono-crystalline PV-modules, in this case, we've used the SUPERFLEX SGM-FL-35W, 12 V, 35 Wp

The PV-module needs to be drilled.

You can find the positions and diameter of the holes in the .PDF technical drawing which you can download below. For marking those of the PV-modules use a marker pen. For drilling use a metal or wood drill. Two of the 20mm-L-profiles need to have a slot cut along one side; the position of the slots is shown in the .PDF technical drawing downloadable below. These slots will allow the angle of incidence can be adjusted. To slot the profile you should use a milling cutter.

After drilling, connect the profiles on the backside of the modules with the M5-10mm countersunk bolts, nuts and washers. Take care to place the washer on the side of the nut.

The frames for the solar modules are made of T- and L-profiles, as shown here:

(ABOVE) The 4 solar panels with frames

And they are connected with hinges so they can be unfolded.

(ABOVE) Fixed hinges at framed solar panels

(ABOVE) Folded Solar Panels

When the panel assembly is unfolded, it is held open and flat using the 15 cm long squared aluminium profiles that were cut open on one side. These slide on over the T-profiles from a corner of the unfolded assembly and sit in place halfway up the side of the assembly, as shown.

(ABOVE) The cut square and T-profiles both fit together.

You already drilled fastening holes in the T- and L-Profiles according to the instructions in Step 3 “Preparing the Aluminum Profiles”. The holes to attach the hinges in the L-profiles are different, because they need to be placed according to the hinges you have, and this will vary. To mark the position, place the hinge 5 cm from the end of the profile not on the side of the other holes, like you can see it in the following picture. Then mark the holes with a metal marker.

For an explanation how to mark and drill holes in aluminium profiles, refer to Step 3.

Step 10: Solar Module Cables

Materials for this step:

  • 1 x Female M4-plug
  • 1 x Male M4-plug
  • 3 x Heat shrink tubes (short), for 4 mm² cables

After the solar modules are connected to the folding mechanism, their cables need to be connected and fixed. The first step is to bring the cables to the backside of the solar panels. Drill holes as you can see near to the connection box of the panels. Afterwards you can push the cables to the other side.

The cables need to be soldered in series as you can see in attached wiring diagram. So you connect the positive pole of one panel with negative pole of the following. To do so you have to lay the cables in some cases through the profiles in between. So that they are not squeezed when the panels are folded. Therefore, drill a hole through the profile and push the cable through. Protect the cable and hold it in position in the hole with small piece of rubber. Insulate the soldered connections with the heat shrinking tubes. At the end you have to connect the appropriate M4 plug at the positive and the negative pole, respectively.

Step 11: Sockets and Switches

Materials for this step:

  • 2 x LED (Green)
  • 1 x Switch, DC
  • 6 x Female Connector WEIPU SP21 (These are what we used in our prototype, but we actually do not recommend to use the Weipu sockets and plugs as they easily slip out of the boxes)
  • 1 x DC-switch
  • 1 x ¼ EURO norm box, with lid, 742mm (H) x 600mm (L) x 400mm (W) (Usable: 732mm (H) x 570mm (L) x 370mm (W)
  • 2 x 1/8 EURO norm box, with lid, 230mm (H) x 400mm (L) x 300mm (W) (Usable: 208mm (H) x 370mm (L) x 270mm (W)

The order of the different pins of the plugs and sockets can be found in following photo. Connection one is for 1st communication (blue cable), two is minus, 3 is plus and no 4 is the 2nd communication (black cable).

Switches and sockets To insert the switches, sockets and the LEDs to the boxes, first the holes on the outside of the box need to be drilled and/ or cut for the switches and sockets respectively. Use 22mm- Drill to drill the holes for the sockets and a 5mm drill for the LEDs. For the switch and the AC-socket, first mark the position and the dimensions of the switch, then drill a small hole inside this dimensions and finally cut the hole out with the cutter.

Once the holes are done, the sockets can be attached into them, by placing them from the outside with the thread ahead into the hole and then screw them tightly with the nut from the inside. The switch also needs to be inserted into the hole from the outside with the contacts ahead. Afterwards, the connection between the switch and the box needs to be made waterproof with silicon.

All these components should be located in the upper third of the boxes, and centred in the façade. In the case of the solar box, they should be horizontally centred on the longer side, where there the two horizontal profiles of the inner structure (as in the below diagram). For the battery- and inverter/socket-box, they should be horizontally centred on one of the shorter sides.

Step 12: Electronics

(ABOVE) Parts and cable for communication / 4mm² power cable being soldered

**** NB, This section explains how to wire up the the communication for the SunZilla 3.0. Since this aspect of the design is currently in development, we're including it here. HOWEVER, you can skip this step for now. ****

Materials for this step:

  • 2 x Gel Battery, 12 V, 38,5 Ah, 170mm (H) x 197mm (L) x 165mm (W)
  • 1 x Fuse, 20 A, DC
  • 1 x LED (Green)
  • 1 x Resistor, 2 kOhm
  • 1 x Switch, DC
  • 2 x Female Connectors, WEIPU SP21 (These are what we used in our prototype, but we actually do not recommend to use the Weipu sockets and plugs as they easily slip out of the boxes)
  • 1 x Fuse Holder
  • 1 x MPPT-Battery charger, here we used a Victron- Blue-Solar-Charge-Controller-MPPT-100-15
  • 4 x Semi-flexible mono-crystalline PV-modules, here we used SUPERFLEX SGM-FL-35W, 12 V, 35 Wp
  • 1 x Female M4-plugs
  • 1 x Male M4-plugs
  • 2 x Female Connector, Weipu SP21
  • 1 x Sinus – Inverter, here we used a Victron Phoenix-Inverter-350, 350 VA, 24 V
  • 2 x Female Connector WEIPU SP21
  • 1 x LED (Green)
  • 1 x DC-switch
  • 4 x DC-plugs (male), Weipu SP21
  • 10 m Flexible cables, 4 mm², 1000V
  • 10 m Flexible cables, 0,25 mm² (for signal transmission for later extension)

For this step, please refer to the wiring diagram PDF, downloadable below.

All energy connections are made using Cables of 4 mm² cross sections. Communication or signal lines (such as LED-Lines) are made using cables of 0.25 mm².

You need to create at least two cables to connect the 3 modules.

Components within the “Accessible Components” category have to be mounted in such way that they are accessible from outside the box. All the other components are inside the box.

To connect the solar panels when mounted with the MPPT-charger, run a cable out of the solar box and connect the appropriate M4 solar plugs at the endings.

General soldering tips: Use a clean tip. Wait for the soldering gun to be heated up (300-400° C). Attach a bit of solder to the tip, then touch with the tip the desired object and wait until it is heated up and the solder merges with the object. Add the second object to the heating point. Add solder to get a proper thermal connection.

Do not hold or block the two objects mechanically with the soldering iron because when the solder connects both objects you want to remove the iron. Wait for the solder to cool down. Try to pull the objects to see if soldering joint is firm.

Use a stronger or two soldering irons if you want to solder big or longer cables.

Use red cables for all PLUS-Connections and black or blue cables for all MINUS-Connections.

Be sure to always solder PLUS on pin number 3 and MINUS on pin number 2 for the power connection (thick cables) and for data connection (thin cables) black cable on pin number 4 and blue on bin number 1.

Before you connect and start your system, check the electric wiring for proper connections and short circuits. Set Multimeter to “Continuity tester” Mode. Touch with one lead of your multimeter the other lead, a sound will occur if multimeter is operation correctly.

Start one lead at Pin 1 of female connector. Touch with other lead at Pin 1 of other female connector. If soldering was successful, a sound will occur. Touch with second lead all the other Pins. If sound occurs, circuits contain short circuit – check for that before you set up the system!

Go on with the check to try all combinations.

Step 13: Ventilation

All boxes need vents. Be sure to use splash proof ones. We used here bent copper water pipes which can be fixed with a nut from the outside of the box.

Step 14: Sealing

To prevent the electronic components from corrosion and damage the boxes need to be splash-proof. Therefore, the lid needs to be sealed with silicon+ on one side of the lid. The lid needs to be open therefore until the silicon is dried. First clean the surface with a cleaning cloth and alcohol from dust and grease. Then apply the silicon with the pistol as shown in the photos. Let them dry fully before closing the lid again. Otherwise you will close the box for ever! The holes around the mounting profiles can be sealed with some old bicycle tube, which is wrapped around the profile and fixed with some wire. Take care to always press this tube tight to the lid after the solar panels are mounted.

Step 15: Coding

Visualisation - Raspberry Pi

Coming soon...

Regulation/ Control Mechanism

Coming soon...

Step 16: Assembly Manual With Safety Instructions - IMPORTANT

IMPORTANT: Download the PDF "SunZilla Prototype 3.0 SETUP MANUAL.pdf" below.

This manual explains how to commission and decommission the SunZilla 3.0. and includes imporant safety information. PLEASE DO NOT ATTEMPT TO USE THE SUNZILLA 3.0 UNTIL YOU HAVE READ THIS MANUAL!