Connecting SOLIS Solar Tonneau Cover to Main Battery

[JRT]

I used the standard watts = amps X volts with a .97% efficiency factor that I've used for sizing panel needs on sailboats.

So we can go back to 32amps X 240v X. 97 = 7,449.6 watts of panels. Now that said I using 240v because I'm not aware of a way to decrease volts and still maintain a realistic recharge time, especially if we want to consider this to recharge our packs. Just rough math and principles I'm familiar with for solar setups for sailboat demands.

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[hturnerfamily]

coming into this interesting idea and conversation a little late, but my own thoughts are:

- no matter how enticing the idea is, these panels would provide such a small, tiny, output that it pales in comparison to any real-world application for EVs...
camping? yes. 12v needs? yes. EV charging? No.

- secondly, and more importantly, EVs can't 'charge' while you are driving them, and, even if you are only considering the application for 'while parked', you will have no method to 'attach' this solar/battery output to your EV, unless it has a 120v or 240v output outlet. You would then need to use your 120v mobile EVSE, which would take FOREVER even to add simply 1 MILE to your range - likely the battery storage won't, itself, even hold THAT much. You would wind up being very depressed at all the price your paid for 'extra' power, only to find that either you NEVER need it, or, if you did, you'd take MUCH LONGER to get anything effective, versus some other mode of help.

- third, and this is the big one: the price for this 'power' is EXTREMELY high, no matter WHAT the need is for. Solar panels are EXPENSIVE, in ANY form, for the little power they provide, as compared to the REAL power that we need. Add the wiring. Add the battery storage. Add now the WEIGHT of all this extra 'stuff'.... and, well, you're already now going to LOWER your range on your EV before you even leave.

No, it's an enticing idea, but, like others have said, if Manufacturers thought they could 'one up' the competition by putting solar panels on roofs of EVs, THEY'D BE DOING IT ALREADY.

I like the idea, too, of just adding a high-powered output ALTERNATOR to the truck, and send that 'charge' to the battery pack, but, alas, if that was such a 'simple' idea, manufacturers would also already be doing that.... they don't.

I also like the idea of just 'carrying around' a heavy large FUEL-consuming GENERATOR, too, but as others have found, since you now are adding all this WEIGHT to your already heavy truck, you are, again, simply artificially LIMITING your Range from the get go. No. No again.

 

[hturnerfamily]

and, NO, there's no way to 'connect' any external power source to your High=powered Battery Pack... except thru your charge port.

 

[BEVolution]

This always seems interesting for remote/off-grid charging. https://knowledge-center.solaredge...._inverter_integrated_ev_charger_datasheet.pdf

 

[tearitupsports]

You can buy 10,000 watts worth of solar panels for your house for $3500 (not including inverters or installation). In TX that can produce nearly 14000 kWh / year. That would be 25000 miles / year even with bad driving and charging losses. It would be a much more worthwhile investment for the money.

 

[chl]

As I recall one Japanese car manufacturer offered a solar roof option on its plug in hybrid....... Have to ask, "How's that working out for them?". You will never see your ROI on a trickle charger.

But then there is Aptera (if they ever get to a final mass market vehicle):
https://aptera.us/vehicle/

My 2012 Leaf has a small solar panel on the roof - to trickle charge the 12v battery. It does that just fine.

 

[chl]

My observation is that solar farms are designed for where they are installed. By us, most solar panels face south. Some solar farms have various panels at slightly different angles. Not one tracks anything.

We were in Vermont in April. Most of the solar installations I saw (which were smaller than around here), including residential ones, were setup to track the sun. Likely because they were so much further north, and the terrain is steep.

Tracking the sun uses energy because the tracking is not passive and requires spending energy on motors. So generally it is used with large commercial photovoltaic (PV) and concentrated solar power (CSP) solar installations.

CSP solar is generally solar power generation with mirrors concentrating the rays to heat a fluid and run a turbine (like conventional carbon or nuclear run power generation):

"...CSP is used to produce electricity (sometimes called solar thermoelectricity, usually generated through steam). Concentrated-solar technology systems use mirrors or lenses with tracking systems to focus a large area of sunlight onto a small area. The concentrated light is then used as heat or as a heat source for a conventional power plant (solar thermoelectricity). The solar concentrators used in CSP systems can often also be used to provide industrial process heating or cooling, such as in solar air conditioning.

Concentrating technologies exist in four optical types, namely parabolic trough, dish, concentrating linear Fresnel reflector, and solar power tower.[35] Parabolic trough and concentrating linear Fresnel reflectors are classified as linear focus collector types, while dish and solar tower are point focus types. Linear focus collectors achieve medium concentration factors (50 suns and over), and point focus collectors achieve high concentration factors (over 500 suns). Although simple, these solar concentrators are quite far from the theoretical maximum concentration.[36][37] For example, the parabolic-trough concentration gives about 1⁄3 of the theoretical maximum for the design acceptance angle, that is, for the same overall tolerances for the system. Approaching the theoretical maximum may be achieved by using more elaborate concentrators based on nonimaging optics.[36][37][38]

Different types of concentrators produce different peak temperatures and correspondingly varying thermodynamic efficiencies, due to differences in the way that they track the sun and focus light. New innovations in CSP technology are leading systems to become more and more cost-effective.[39][40]

In 2023, Australia’s national science agency CSIRO tested a CSP arrangement in which tiny ceramic particles fall through the beam of concentrated solar energy, the ceramic particles capable of storing a greater amount of heat than molten salt, while not requiring a container that would diminish heat transfer.[41]..."

https://en.wikipedia.org/wiki/Concentrated_solar_power

Not worth it for home installs because it would use more energy than would be gained from tracking probably.

 

[chl]

My observation is that solar farms are designed for where they are installed. By us, most solar panels face south. Some solar farms have various panels at slightly different angles. Not one tracks anything.

We were in Vermont in April. Most of the solar installations I saw (which were smaller than around here), including residential ones, were setup to track the sun. Likely because they were so much further north, and the terrain is steep.

And for home installs, tracking is generally not use, but an optimum slant angle for the panels is set based on the latitude. At the equator, zero degrees.

The ideal angle for a solar panel installation is close to or equal to the latitude of your home.

The best tilt angle varies throughout the year as the earth moves around the sun, so a best year-round angle is used. (The Earth is tilted on its axis of rotation by 23.45° - only at the spring and fall equinoxes is the declination angle equal to 0°.)

Here is an on-line calculator by zip code:

https://shopsolarkits.com/pages/solar-panel-tilt-angle-calculator

HERE is one that uses latitude:

https://www.solartap.com/blogs/solar-101/solar-panel-angle-calculator

 

[chl]

Sadly, that's probably true about helter-skelter angles and compass directions.
If I were involved I'd be sure they were at least angled/pointing south (in the northern hemisphere).
Ideally I'd have them installed with adjustable frames so I could change the angle 4 times a year to maximize the return on investment.

It could add $50 per panel, but probably worth it in added output in the long run.

They say one could "gain up to 25% more solar panel efficiency by tilting your panels towards the sun instead of laying them flat.Especially beneficial over winter months when there is less sunlight. ..."

https://www.amazon.com/Adjustable-Solar-Mounting-Brackets-Folding/dp/B00KV30GIC/ref=sr_1_13?dib=eyJ2IjoiMSJ9.scdz8dk_mrOV-_8vTB6W0rMScNIDP_CCiRZiHAtbuciYRYXPB1_KkFNi4B869n5_-3vQgbRKX9pdSk6P_sf31XHQnPB8Zf2fJdPsVvs__TvSWO5R7ENz_zIgJ1ujN2RMZt-33aXzYZTefnG2JcMHn88-Bb7vhN3jVEQRUT7IeUNK5nvtgea5sLdmbRvhYlkyF03l5VKpqM_aSKrtDieBKnzMYAttdcRRl2D01PRlqbE.5mvuBpVB4uBKoq3pGdXImEb2fa1rdITXNqjEpSRcEbs&dib_tag=se&keywords=solar+panel+frame&qid=1720476284&sr=8-13&th=1

Yes, that tonneau cover solar is woefully inadequate, and the weight with the battery it comes with probably makes it even worse, maybe even adds a lot of drag..

EDIT: see also for angles

"A common rule of thumb for fixed arrays is to set the tilt angle to the latitude of the system's location to maximize the system's total electrical output over the year. Use a lower tilt angle favor peak production in the summer months when the sun is high in the sky, or a higher tilt angle to increase output during winter months. Higher tilt angles tend to cost more for racking and mounting hardware, and may increase the risk of wind damage to the array.
For an array installed on a building's roof, you may want to choose a tilt angle equal to the roof pitch...."

https://pvwatts.nrel.gov/

 

[Runaway Tractor]

Further substantiating my point that anyone selling solar panels on a car or pickup truck as anything more than maintenance trickle charging the LV battery is a liar or a delusional activist. The tech to provide meaningful HV power in a compact form simply does not exist yet.

 

[chl]

Indeed, you have a good installation. No question about that.

My background is electrical engineering and law, patent law, so I sometimes fall into that trap, but if engineers are good at anything, it is compromising to make something work, even if it has duct tape all over it.

I am lucky in that I have a large area of south facing roof on my house, built in 1969, a split-level.
I have a lot of east and west facing roof as well, but the south roof is 480 sq ft.

Although I may not need them, panels on the east and west roofs could be raised at the north edge and spaced so they don't shade one another, to improve output.

My only problem is shade from trees at certain times of the day.

So I guess the 25% more if at optimum angle is correct based on your numbers, I wondered about that number.

I inherited a house on the island of Montserrat from my parents - built for retirement, didn't expect the volcano to come alive - which also has a lot of south facing roof, 2 wings of the house have it, and I have a big yard with a lot of unobstructed south face.

The only problems are:
1) the utility there is owned by the Gov't and they don't let anyone grid-tie for net metering even though they have rolling black-outs frequently due to lack of capacity (running on 2 diesel generators since the volcano erupted in 1997)

2) the duty on solar panels is large making it twice as expensive as it should be

3) there are no solar installers there, the neighboring island Antigua has them, and even runs most of their airport on solar! I contacted one of the installers there and he tried to get permission to come over (a 15 minute flight) and do an install but had no luck with the red tape and gave up,

4) everything has to be shipped a heck of a long way adding to the cost, so it's a DIY expensive project and

5) because they have a volcano they think they can have geothermal energy easy peasy - Oxford University in coordination with the UK Government has been pushing Geothermal for 14 years, they bored some wells at a cost of millions of pounds, none were suitable for energy generation, they have no way of responsibly handling the toxic waste water that comes with geothermal, but still they persist in the boondoggle, when solar and wind would be simpler and better - the trade winds almost always blow there and the solar flux is great at that latitude.

But someday somehow I will do it.

 

[marc_hanna]

The site says they can generate up to 650 watts. I don’t see how that is possible. If they had 100% coverage on a 4’ x 8’ box they’d still only have an output of ~500 watts. So they’re claiming about 30% great efficiency than the best pv panels on the market today. Based on the images on their website, they don’t have 100% coverage.

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