As many of you know, we are doing professional EV van conversions, and one question we get asked almost continuously is "Can't you put solar panels on it?". So we decided to build a prototype and instrument it so we can answer the question with hard data.
We all know it makes more sense to put them where you park your EV, and of course we advise our customers to do so. However, There are a few scenarios where having panels on the van actually makes sense: 1. We produce a variant with an insulated and refrigerated cargo box that runs off the high-voltage pack. This is sold for applications where perishable cargo transport is needed, such as foodbanks where we already have units deployed in 2 states. Given that the refrigeration system is super efficient, it doesn't take that much power, so adding solar to this package could really help autonomy when the van is running the reefer. See: https://youtu.be/-S-DX7gIhcc 2. We are starting to convert camper versions for customers, and this is where you could really use PV. If you are parked and running house loads, the PV can easily handle this, as well as adding a bit of range, rather than just losing range each day. See: https://youtu.be/2ehdwVAH_m8 For the prototype we have custom engineered a low-profile mounting system that lets us mount 1.5kW of high-efficiency panels on the van. The goal was to avoid incurring lots of extra aerodynamic drag, which could negate installing the panels in the first place. Unlike other EVs, we are lucky to have a large rather flat roof on the van to add panels to. I can't imagine it's worth even considering if you are trying to put them on a smaller EV, probably without a large flat surface. Here's the CAD view: Here's the prototype we just finished installing on: (This is an insulated reefer van) I haven't yet fully completed the charge controller yet, but it's going to be a MPPT boost converter to take the ~150VDC output from the panels and boost it to the 300-400VDC needed to charge the EV pack. I have the basic boost stage working on the bench now, but need to implement the firmware for MPPT and also metrology. I'm using a single Wolfspeed SiCFET switch along with a SiC diode to make it as efficient as possible. Of course nobody makes any kind of an off-the-shelf charge controller that can work in this application. There are a lot of complexities, such high-voltage, and needing to preserve chassis isolation and safety. In addition, we have to monitor the BMS over CAN and respect it's charge current limits as well as the user interface to not charge the pack beyond the desired SoC, and have to deal with contactor close requests, etc. It's not easy to solve! I'll make future posts once we have the system in operation and share the data we collect on the system's performance. https://maxwellvehicles.com/ On Tue, Apr 20, 2021 at 3:01 PM Lee Hart via EV <[email protected]> wrote: > nathan christiansn via EV wrote: > > Has anyone successfully integrated solar panels into their EV? If so, > could > > you please share what charge controller you used? > > First, it should be noted that PV panels on an EV are a special case > solution. It's usually better to put them on a fixed structure (garage > roof, etc.), and plug the EV into them when parked. > > That said, I have a small PV panel on my 2001 Prius. It keeps the 12v > battery charged when the car sits for long periods. Without it, the 12v > battery would go dead in 2-3 weeks from all the on-board computers. > > At other times, I've had PV panels on my VW van EV, and my LeCar EV > conversion. Again, they only charged the 12v accessory battery. > > There have also been a lot of custom ultra-efficient EVs with huge PV > panel arrays. These are more for race vehicles than for practical daily > drivers. > > Lee Hart > > -- > A designer knows he has achieved perfection not when there is > nothing left to add, but when there is nothing left to take away. > -- Antoine de Saint Exupery > -- > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com > > -- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210420/38ee7584/attachment.html> _______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
