Clarity Solar charging
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Not in any meaningful way, no.
With a 100% conversion rate, one can expect to get about 1kW of continuous power from one square meter of solar panel space. This assumes you're at the equator, at noon, on a perfectly clear, humidity-free day, with a 90 degree angle to the sun.
Some of the best photovoltaic (PV) panels today are about 15-20% efficient, and one can almost never count on perfect weather or Sun angle.
Then there are conversion losses (and storage requirements) to get a DC to AC inverter to provide the necessary 120V AC for an EVSE.
You could completely cover the skin of a Clarity with PV, and you still aren't going to get there.
Today, and for the foreseeable future...
...ain't going to happen.
Some of the best photovoltaic (PV) panels today are about 15-20% efficient, and one can almost never count on perfect weather or Sun angle.
Then there are conversion losses (and storage requirements) to get a DC to AC inverter to provide the necessary 120V AC for an EVSE.
You could completely cover the skin of a Clarity with PV, and you still aren't going to get there.
Today, and for the foreseeable future...
...ain't going to happen.
You’re going to need a very large battery to store at least 13Kwh of sunshine so there’s enough to fully charge the car. (Thousands of dollars) You’ll need to know the average amount of sunshine you get each day to figure our how many solar panels you’ll need. (Thousands of dollars) Then you’ll need......
Or get a Tesla power wall+ solar roof.
For approx. $1,000, I have two portable 120w solar panels and one 576 Wh LiOn portable battery for power outages/storms/camping/road trips/etc. (in addition to a generator). Here in south Texas, it takes about 4 hours of summer sun to charge it up (140-160w peak). This setup also does pass-through power while charging. I’ve haven’t tried plugging it into the car..... yet........ Hmmm.
Or get a Tesla power wall+ solar roof.
For approx. $1,000, I have two portable 120w solar panels and one 576 Wh LiOn portable battery for power outages/storms/camping/road trips/etc. (in addition to a generator). Here in south Texas, it takes about 4 hours of summer sun to charge it up (140-160w peak). This setup also does pass-through power while charging. I’ve haven’t tried plugging it into the car..... yet........ Hmmm.
The lowest rate the Clarity should accept charge is 6amps (J1772 standard if I’ve read it right). At 6amps x 120V = 720W so about eight 100W solar panels might do it, but it would require about 24 hours of sunshine to charge the car and that’s hoping for a good conversion of solar power. So maybe two or three days or longer to fully charge the car. Plus I haven't found a 6A charger that I thought would reliably work, and you would need a good battery and charge controller to at least stabilize the voltage. I thought you might be able to use the OEM charger with 15 panels, again requiring multiple days. I didn’t want to leave 15 panels laying around my car for a couple days while I walked off to do something else, and that’s a lot of money to spend on something that doesn’t really work. So I haven’t tried it.
So I think charging the car off solar is feasible, but not with a portable solar setup. Something roof mounted on a house should work (mentioned above), but that’s a different setup. I did see a YouTube video once where they charged a Tesla off portable solar. It was a trailer of solar panels that opened up for more surface area. If I remember it was to charge up electric tools at a job site and they did a few minutes of car charging just to see if it would work.
Having less than 800W doesn’t really work at all, except to charge a battery that would then deliver that wattage for a short time to charge the car in bursts. It would take a long time. In any case you’re adding the weight of an additional battery to the car and eventually that needs to be figured into the equation that you’re hauling more weight.
So I came to the conclusion of no solar charging at my wife’s work. There’s no electrical plug in available, so she just drives home on gasoline … the solution is I drive the car to my work where there is a 48A level 2 charger available. She drives the old gasoline car.
I hope this is helpful and not just disappointing.
So I think charging the car off solar is feasible, but not with a portable solar setup. Something roof mounted on a house should work (mentioned above), but that’s a different setup. I did see a YouTube video once where they charged a Tesla off portable solar. It was a trailer of solar panels that opened up for more surface area. If I remember it was to charge up electric tools at a job site and they did a few minutes of car charging just to see if it would work.
Having less than 800W doesn’t really work at all, except to charge a battery that would then deliver that wattage for a short time to charge the car in bursts. It would take a long time. In any case you’re adding the weight of an additional battery to the car and eventually that needs to be figured into the equation that you’re hauling more weight.
So I came to the conclusion of no solar charging at my wife’s work. There’s no electrical plug in available, so she just drives home on gasoline … the solution is I drive the car to my work where there is a 48A level 2 charger available. She drives the old gasoline car.
I hope this is helpful and not just disappointing.
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638 Posts
This would be perfect when camping, assuming you could carry the equipment.
Or...you put 5kW+ of PV on the house roof, with a couple of Powerwalls (or equivalent), and charge at home from solar.
I've been doing this for over twenty years, starting with EV-1s in 1997.
There's simply no practical way to get any significant amount of charge for an EV from a portable setup that wouldn't itself severely effect range and performance of the vehicle...
...No matter what Aptera is trying to tell us...
I've been doing this for over twenty years, starting with EV-1s in 1997.
There's simply no practical way to get any significant amount of charge for an EV from a portable setup that wouldn't itself severely effect range and performance of the vehicle...
...No matter what Aptera is trying to tell us...
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230 Posts
I have a 7.3kw solar system on my house. I have asked for a quote to add 4 panels (335 watt Sunpower EQ). 4 panels will average 200 kw per month more than currently. 17 kw per charge 3-4 times per week is 200-300 kw used. I had a Prius Prime previously and that was 6.8kw per charge 7-10 times per week so the additional production should still keep me at a net zero electric bill.
Point of clarification: Instantaneous Power is measured in kilowatts (kW). Energy produced over time (or stored in a battery) is measured in kilowatt-hours (kWh).
For this example, the four Sunpower panels together can theoretically produce 1.34kW (4 panels x .335kW each) of instantaneous Power, and over a month can produce an average of ~200kWh (5kWh per day x 30 days) of Energy.
It's a subtle distinction, but an important one.
I have a 6.6 kW solar and 2 PowerWalls from Tesla. During sunny periods when temperatures are mild, I can actually get some of the energy to charge my car, but most of the time the solar doesn't even offset my house's power consumption, let alone the car.
An example of a high quality solar panel is the ones that Tesla sells. They are 340W peak output with a 97.5% efficient inverter. They are 5.7 ft long and 3.3 ft wide. They would probably fit in the Clarity if you put the back seat down, but I haven't physically tried fitting them.
Back of the envelope calculations, you'd probably need about 8-10 of those on an average day (i.e., if you aren't at the equator at noon on a cloudless day with the panels exactly angled to maximize insolation). They might fit in the car, but they are going to weigh about 300 lbs. The car can handle the weight if you have 1-2 passengers and no other cargo.
Assuming you design or can find a custom inverter that directly converts the DC of solar panels to 240V AC, current state of the art devices of this sort would take up the front seat of the vehicle, or you might get lucky and be able to fit one in the foot well of the back seat.
So if you had a Clarity, $8000-10000 of solar panels and a $2000 piece of high-density power electronics, you could conceivably unload these solar panels, set them up in your average North American locale with less-than-ideal sunlight and less-than-ideal orientation of the panels, and get enough amps at 240V to mostly keep the car charging during the day. Setting this up would probably take at least 20 minutes, probably closer to an hour unless you had help; would occupy a surface area on the ground comparable to the footprint of a house; and would be completely useless if there were any nearby object casting a shadow (a building, a tree line, etc.) unless you somehow bring a bunch of heavy metal struts with you to put the panels up above the shadow (strap them to the roof of the Clarity maybe?)
Suffice to say, this is not a suitable or sustainable solution for most commuters. If you assume an ideal case -- you are at the equator at noon with no clouds -- that cuts down the number of panels you'd need to about 3 of these 340W panels. They'd still weigh almost 100 lbs, take up most of your cargo volume, and require a hefty inverter.
These sizes and weights do not really describe a "portable" setup, but the purpose of this thought experiment was to demonstrate that it probably is just barely possible to do this with current technology. But the realities of our lives probably prevent this from being something you'd actually want to do, even if you had the money to buy the equipment, just due to the size and weight of the panels.
Solar is pretty ideally suited to rooftops. In many parts of the world you can minimize your usage of the dirtiest power generators on the grid by installing rooftop solar. That's because the baseload often has a combination of renewables (e.g. hydro) and nuclear, while peak power demand is often satisfied by coal or liquid petrolem (e.g. diesel or oil) power plants. This will allow you to recharge your Clarity while knowing that your kilowatt-hours are not having a large carbon footprint. If you really want to maximize how clean your power is, set your EVSE to charge late at night, when usage is at its lowest. People are asleep, so the usage is low.
The idea of having the ability to power your car from the sun "on the go" is extremely attractive, and trust me, I'd love it if we could do that. But for the time being, to charge your Clarity with renewables you need to plug into an EVSE at a facility or house that has a fixed installation of some kind of renewable energy (usually solar, but wind, hydro and geothermal are also possible).
If you find yourself running out of EV range and consuming a lot of gasoline, the Clarity is probably not the ideal vehicle for you. You could get a BMW i3 Rexx, an EV, or keep an eye out for new PHEVs in the future with a bigger battery. Or try to get some kind of EV charging (even if it's just from the grid) at the various places you go, to minimize the amount of gasoline miles.
Good luck!
An example of a high quality solar panel is the ones that Tesla sells. They are 340W peak output with a 97.5% efficient inverter. They are 5.7 ft long and 3.3 ft wide. They would probably fit in the Clarity if you put the back seat down, but I haven't physically tried fitting them.
Back of the envelope calculations, you'd probably need about 8-10 of those on an average day (i.e., if you aren't at the equator at noon on a cloudless day with the panels exactly angled to maximize insolation). They might fit in the car, but they are going to weigh about 300 lbs. The car can handle the weight if you have 1-2 passengers and no other cargo.
Assuming you design or can find a custom inverter that directly converts the DC of solar panels to 240V AC, current state of the art devices of this sort would take up the front seat of the vehicle, or you might get lucky and be able to fit one in the foot well of the back seat.
So if you had a Clarity, $8000-10000 of solar panels and a $2000 piece of high-density power electronics, you could conceivably unload these solar panels, set them up in your average North American locale with less-than-ideal sunlight and less-than-ideal orientation of the panels, and get enough amps at 240V to mostly keep the car charging during the day. Setting this up would probably take at least 20 minutes, probably closer to an hour unless you had help; would occupy a surface area on the ground comparable to the footprint of a house; and would be completely useless if there were any nearby object casting a shadow (a building, a tree line, etc.) unless you somehow bring a bunch of heavy metal struts with you to put the panels up above the shadow (strap them to the roof of the Clarity maybe?)
Suffice to say, this is not a suitable or sustainable solution for most commuters. If you assume an ideal case -- you are at the equator at noon with no clouds -- that cuts down the number of panels you'd need to about 3 of these 340W panels. They'd still weigh almost 100 lbs, take up most of your cargo volume, and require a hefty inverter.
These sizes and weights do not really describe a "portable" setup, but the purpose of this thought experiment was to demonstrate that it probably is just barely possible to do this with current technology. But the realities of our lives probably prevent this from being something you'd actually want to do, even if you had the money to buy the equipment, just due to the size and weight of the panels.
Solar is pretty ideally suited to rooftops. In many parts of the world you can minimize your usage of the dirtiest power generators on the grid by installing rooftop solar. That's because the baseload often has a combination of renewables (e.g. hydro) and nuclear, while peak power demand is often satisfied by coal or liquid petrolem (e.g. diesel or oil) power plants. This will allow you to recharge your Clarity while knowing that your kilowatt-hours are not having a large carbon footprint. If you really want to maximize how clean your power is, set your EVSE to charge late at night, when usage is at its lowest. People are asleep, so the usage is low.
The idea of having the ability to power your car from the sun "on the go" is extremely attractive, and trust me, I'd love it if we could do that. But for the time being, to charge your Clarity with renewables you need to plug into an EVSE at a facility or house that has a fixed installation of some kind of renewable energy (usually solar, but wind, hydro and geothermal are also possible).
If you find yourself running out of EV range and consuming a lot of gasoline, the Clarity is probably not the ideal vehicle for you. You could get a BMW i3 Rexx, an EV, or keep an eye out for new PHEVs in the future with a bigger battery. Or try to get some kind of EV charging (even if it's just from the grid) at the various places you go, to minimize the amount of gasoline miles.
Good luck!
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610 Posts
I am on the order list for the new Ford EV truck in 2022.
This truck has the ability to power external devices including a house for a few days (Ford intelligent backup power) of up to 9.6KWh.
I figured if I ran out both EV & fuel in my Clarity, I can plug her into the 220V outlet of the Ford truck and charge her up!
Ford F150 Lightning EV truck
Just a point of clarification. If you use the max capability of the fully-optioned version, the Ford Lighning can source up to 9.6kW (not kWh) of instantaneous power through all outlets and the bidirectional EVSE. The energy available (in kWh) is dependent on the size of the traction battery (100kWh+ on the extended range version), reserve amount set, and overall efficiency of the system. If you use the average daily household electricity consumption of ~30kWh, the Lightning can backup a house for about three days. I'd argue that you'd probably get several more days, as most folks would reduce usage to the bare minimum during a grid emergency. When I do calculations, I use 10kWh per day for my Powerwalls for three refrigertors. I don't depend on AC use during Summer months, nor require the use of sump or well pumps that can really suck the electrons.
Be sure you check with your local utility. In most locations, the utility only allows charging the batteries from PV, and disallows charging the batteries from the grid, if that's a capability you were expecting.
I've got 5kW of PV and 27kWh of storage. It's great (but relatively expensive) insurance. While the PV has an effective ROI of about eight years, the storage doesn't pencil out to much savings at all, so I just treat it as a sunk cost. Keep in mind that a battery system has a round-trip efficiency hit of somewhere around 10%. Thermodynamics Laws and all that.
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Yep, if you have reliable electricity, the cost of battery backup has to be zero. Of course many of us are a bit more environmentally conscious and are doing it for more emotional reasons over economic.
Yup. Also, some utilities will give you a grant (30% from SCE at the time I got mine) with the stipulation that you'll pull from the battery instead of the grid for a certain minimum number of peak hours per year. Then, you're not a net load, and any PV production goes to further support the grid. It helps the utility to not need to run relatively expensive, dirty and inefficient peaker plants, so they share the savings with the consumer. Win-win.
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