I have used the electric version of the velomobile for roughly 500 kms, so I have been able to ride in different conditions and to make several modifications for improving my seating position.
At this point I was ready to start adding all the solar components:
solar panels
solar MPPT controller
solar shunt
As far as solar panels are concerned, I purchased last December from SUNGOLD Solar in Shen Zhen (China) 2 solar panels of 270Watts each: one for me and one for a friend of mine.
After few discussions we decided to have them delivered by boat to France: air shipment was of course faster but also 100$ more expensive.
Sea parcel was expected to be delivered after 40 days, by end of January.
The parcel (35 kgs !) arrived in the port of Le Havre and I had a very bad surprise: after having already paid roughly 500$ for the solar panels including delivery to my address, they asked me to pay 1100$ more for handling charges, administration fees, VAT, custom duties…
I tried to understand why I had to pay almost the DOUBLE of what I had ALREADY PAID.
It is clear that if we knew this in advance we would have never purchased these solar panels at these conditions.
Long story short, after several days lost in this discussions, I decided not to pay this extra money but to purchase locally 2 solar panels of comparable power.
This was economically quite bad for me but I think I had no other option available.
It is clear that this SUNGOLD Company is not a serious one to purchase solar panels from China.
Then I decided to buy 2 solar panels from a local supplier:
Once I received all the components I was finally able to start the installation process.
A very important type of requirements was:
- to be able to RAISE the solar panels to easily get in/out of the velomobile
- to be able to TILT the solar panels around the carbon fibre boom to optimise the energy production
Here below is the sequence I have followed:
Install the rear support on top of the ‘safety module’ (after having reinforced it with carbon fibre
Test the position of the carbon fibre tube in order to determine the ideal height of the front support
Reinforce with carbon fibre the front boom.
Install the lower part of the front support for the solar panels
Check the ideal position of the carbon fibre tube
Build the aluminium structure to support solar panels
Fix the solar panels to both supports
Install solar controller, solar shunt and finalize all electrical connections
Here I have laid down the carbon fibre tube on the rear support to determine the height of the front support.
I have done the initial simulation with the velomobile opening as a ‘support’.
In my experience the front part has to be 2/3 cm lower due to the rear suspension and aerodynamic efficiency.
Here we can see the simple mechanism I have developed “L shaped” to be able to raise the solar panels to facilitate the entry/exit from the velomobile.
After several tests I was able to reduce the length of both arms from 50cm to 35cm.
At this point I was able to start reinforcing the front boom: I have added 3 carbon fibre layers to increase rigidity.
I have then fixed two short (25cm) aluminium plates, with two bolts to ensure perfect fit.
Then I was able to easily calculate the length of the longer plates, in order to obtain the ideal overall height of the front support.
Here we see the final result, after having fixed with two bolts the upper aluminium plates.
For increasing lateral rigidity I have also added a square carbon fibre plate.
This design is based on the requirement to be able to remove the solar panels with the upper part of the aluminium plates, leaving the lower plates always attached to the boom.
This is typically the case in winter time, when it becomes pretty irrelevant to use the solar panels.
Here we can see the solar panels, already integrated with the carbon boom and fixed on both supports.
The first test of the solar production, with both cables from the solar panels ( 2 x 130w each, installed in series) did give quite good results, around 200w in total.
Then I have also tested two different positions:
solar panels tilted 45° on the right
solar panels raised 40° from the back and further tilted 30° on the right
In both cases solar production was better (still lower than nominal…), roughly 230w.
Once finalized the solar panel position and opening mechanism it was then possible to install the Solar Controller.
Here we see the chosen spot for its position inside the velomobile: I fixed it with a couple of velcro straps.
In terms of connections:
- 2 cables (red and black) are connected to the solar panels as ‘input‘.
- 2 cables are connected to the batteries (yellow and black) as ‘output‘.
This ‘step-up’ controller allows an easy way to change the resulting VOLTAGE (output) through the visual interface.
In my case, having installed 72V battery, I had to enter a charging value of 84V.
In order to monitor the solar panels energy production it is necessary to install a ”Solar shunt”.
This simple device has to be connected as follows:
two cables (red and black) to the BATTERY
two cables (red and black) to the SOLAR CONTROLLER
one cable to the Cycle Analyst COMPUTER
While the installation is pretty straightforward, it was quite tricky to find the best spot inside the velomobile.
After careful analysis I decided to install it below the carbon fibre boom, as close as possible to the solar controller.
In this way it was easy to plug in the (75cm long) cable to the Cycle Analyst computer.
Here on the right we can see:
- the Busbar with all the 6 connectors: the second from the top (red-blue) is the XT60 coming from the Solar Controller
- the USB 3 ports ”mini hub”, very compact and practical to charge my phone and other 2 accessories.
Here we can see see how to go inside my Bülk Urban velomobile and to exit by raising/lowering the solar panels.
It is definitely quite easy and practical: it requires just few minutes to get used !
Great job!
Looking forward to read about your reviews of this setup on the road ! Especially on mountainous paths ?
Keep up the good work !