ResslynHalvik
Cosmic Mongoose
How long does it take to recharge a TL14 12-space grav vehicle (VHB26) from a medium (20kg) advanced solar panel array (CSC23 p119)?
Recharging vehicle from CSC solar panel
- Thread starter ResslynHalvik
- Start date
Limpin Legin
Emperor Mongoose
Rules-as-written appears to say that the answer depends on the time of day and weather conditions. Up to the referee to determine, perhaps.
MonsterX
Emperor Mongoose
don't forget the stellar luminosity, axil tilt of the planet, latitude, atmosphere, distance from the primary - oh, secondary too, and tertiary if applicable. Plus the tilt and facing of the panels - vis a vis all relevant stellar bodies. There should a formula (WBH update)!
Let's assume we don't want to actually calculate that but will be satisfied with some rough number. A typical mid-size car with a 400 km range might have 60-100 kwh battery, and a solar panel in that weight range might deliver 500kw in optimal conditions. So 120 hours of charging from zero to full.
However, today's panels are about 20+% efficient in terms of how much of the energy that lands on them they convert to electricity, so by TL 14, it is probably getting close to 100%, which means it might end up be x5 as efficient. Fully charge in about a day if the sunshine is constant. However, I would suggest using more than one panel for this job.
How many kilowatts does a grav vehicle need? Can't help you there, I'm afraid.
Limpin Legin
Emperor Mongoose
Or be pseudo-scientific and use some random weather dice.
MonsterX
Emperor Mongoose
I forgot that if you assume the panel is folding up and you have some ultra-light ultra-strong material that gives you more surface are for weight, you could actually get more surface area than a 20kg panel of today would have. That kind of panel is less that m2 The panel's power is limited at absolute maximum to the energy of the sunlight striking the panel - regardless of technology. You can expand the area if it is very thin and light and therefore fit in the 20kilos.
ResslynHalvik
Cosmic Mongoose
Ah, no-one else.knows either. Ta!
AnotherDilbert
Emperor Mongoose
Months? Years?
Earth solar irradiation is roughly 1 kW/m3 at the ground, in direct sunlight, close to the equator, without any shade, cloud, or haze.
A light grav vehicle like an air/raft might need a few MW to fly by earlier editions, e.g. MT.
So, to charge as quickly as you deplete the batteries, i.e. 1 h of fly time for 1 h of charging, you would need a few thousand m3 [~30000 sqft] of solar panel at perfect conditions, or perhaps ten times that at less than perfect conditions.
A portable solar panel of, at a guess, a few m3 will give you very roughly 1 kW, or perhaps 10 kWh per day, under less than perfect conditions, with a high-tech very efficient panel. Perfectly suitable to power a campsite with lights and charge portable computers. Not enough to provide much in the way of heat or cooking, perhaps a microwave oven.
Much less charging a 100 kWh car battery or 10 000 kWh air/raft battery...
Look at current solar charged "power stations" with solar panels plus stands to position the panels ideally and compare to the 100 kg TL 7 version. You'll get a few kW under ideal conditions from a quick check...
By CSC a solar panel should give as much power as a "hydrocarbon generator" (CSC, p118) at 25 kg at TL-5. By current standards that would be something like a small 2 kW Honda unit, say "Honda EU22i".
By earlier editions a Dton of ship fusion power plant will produce in the region of 100 MW depending on TL, in the same order of magnitude as a square kilometre of solar panel. That will charge an air/raft in short order...
Solar panels works much better in space, without having to fight gravity, atmosphere, clouds, shade...
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MonsterX
Emperor Mongoose
We don't have to guess. Assuming optimal conditions: Days for 100kwh battery (1 day if there is no night time and conditions are perfect - which could in fact be the situation). Months for 10000kwh. 1 day theoretical minimum for 1 x 1 m solar panel (about 40 kilos), assuming constant direct sunlight and 100% efficency. Obviously depending on the weather, and obviously the actual number would be different, almost certainly less (could in theory be more in a thin atmosphere, brighter sun). Out by Jupiter, I am sure your math would work ok though.
You 100 MW one-ton fusion power plant example is enough to power a medium sized city.
AnotherDilbert
Emperor Mongoose
Without ideal conditions, I have to guess.
Regarding TL12-15 batteries, I have to guess.
Currently 1 kW might not be enough to charge a car battery ever, as it can easily need more than that to temperate the battery. 11 kW is generally enough to charge a car overnight.
Presumably a CSC medium solar panel is roughly 2 kW nominal, much less under non-ideal conditions. I can only guess how fast that would charge a car battery, on a different world, with a different atmosphere, under a different sun.
Yes, and not enough for even a small starship. According to CT & MT a Scout or Free Trader needs (and produces) 500+ MW.
ResslynHalvik
Cosmic Mongoose
CSC says a medium solar panel can power a large house or recharge a light vehicle.
AnotherDilbert
Emperor Mongoose
Sure, but that is not even remotely coherent with the stats for generators or solar panels. Pick any interpretation you wish.
This is obviously a disadvantage of the consistent avoidance of real world power units.
EDIT: Sorry, checking, an average home in the US consumes 10000 kWh/year, an average of 1-2 kW electrical power for 24 h a day, but that would not include heating, cooling, or cooking. Peak consumption is presumably a lot more.
But sure, a fridge and some lights should be doable.
An old (inefficient) small house in Sweden with electrical heating (and no aircon, since Sweden) would consume triple that per year, with wider swings in the momentaneous consumption, up to perhaps 20 kW. A 2 kW generator would be hilariously underpowered, much less a solar panel buried under snow...
I suspect someone forgot to account for the difference between average consumption and momentaneous consumption...
Light vehicle?
With a 0.25 kW motor and a 0.16 kWh battery a 1-2 kW power source should easily charge it.
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If I were confronted with this question mid-session I would roll for it. 1d6 hours under ideal circumstances, 2d6 hours with any kind of inclement weather. "Ta!"
I must have an old version. Mine only has the language about "equal to a hydrocarbon generator." But a 12 space vehicle is definitionally Light rather than Heavy. So it can be done RAW, we just don't know how long it takes RAW.
I must have an old version. Mine only has the language about "equal to a hydrocarbon generator." But a 12 space vehicle is definitionally Light rather than Heavy. So it can be done RAW, we just don't know how long it takes RAW.
MonsterX
Emperor Mongoose
No it does not need that to "temperate" the battery, whatever that means. 1 kw of power will charge your car, in winter when it is -30 (if that is what you mean by "temperate"). Maybe not your car. But it works fine for my car anyways.
Condottiere
Emperor Mongoose
It's an interesting question, without an easy answer.
Optimal conditions could include a pivotable solar panel that can track the sun, for maximum exposure.
Possibly, you could position mirrors, to increase sunshine directed at the panel.
Optimal conditions could include a pivotable solar panel that can track the sun, for maximum exposure.
Possibly, you could position mirrors, to increase sunshine directed at the panel.
AnotherDilbert
Emperor Mongoose
Most cars heat or cools the battery to around 20 ˚C, where the battery chemistry works best. Sometimes it's called preconditioning the battery. That takes power.
See e.g.:
https://recharged.com/articles/ev-b...#when-you-should-precondition-your-ev-battery
Have you tried? Even a regular wall socket can give a lot more than 1 kW.
Anstett
Emperor Mongoose
I have only driven EVs since 2014.
You can hear the battery conditioning running, especially in late summer Florida, while it charges.
A 110 outlet in the garage can output enough Kw to recharge about 40 miles of range every 12 hours or so.
{just a stupid variance of references there}
220 and higher obviously charges much faster, etc.
You can hear the battery conditioning running, especially in late summer Florida, while it charges.
A 110 outlet in the garage can output enough Kw to recharge about 40 miles of range every 12 hours or so.
{just a stupid variance of references there}
220 and higher obviously charges much faster, etc.
