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Comment by mrmaddog | Hacker News Reader

If I were in the hospitality industry, I'd be buying adjacent shops next to every Tesla charging station. Having a captive, wealthy audience for ~30 minutes seems like a ripe opportunity, whether it is restaurants, masseuses, or cafes. I'd also offer free valet+ services so patrons would stay in my establishment longer: I'll look over your car, start the charging process (in case there is a queue), and make sure to move it when it is done charging.

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I misread that as "hospital" instead of "hospitality" on my first read, which actually brings up an interesting tangent.

If the Tesla stations make use of and store solar power, would they be a viable backup power source for hospitals? Or are the power requirements for a hospital on backup energy way too large for that sort of thing?

Aren't these stations just connected to the grid and any power is just put back into it to help offset charging costs? I don't think there's any actual storage. Not every Supercharger station has solar panels.

I think solar is too unreliable to be a backup power source for much of anything, especially something like a hospital.

The amount of solar panels you'd need to charge a Tesla at supercharger rates would be ridiculous.

They may have solar panels, but that is just something cute that might make a small dent in the installation's grid power consumption.

However, you are on to something [1], though it's more for cars that are parked for long periods during the day. The point of a supercharging station is contrary to donating your vehicle's power to the grid.

1: http://www.scientificamerican.com/article.cfm?id=how-to-sell...

Are you sure?

"plans are to install on-site grid storage to make them self-reliant with their own energy supply"

Well... let's do the math!

Incident solar radiation is about 1 kW per meter squared. Assume 10% end to end efficiency (including solar -> electric, storage, and actual charging efficiency... this is optimistic, but doable... certainly not the cheapest though). You now need 10 square meters of panel to supply 1 kW. Assume sun is out for 12 hours a day, and for the full 12 hours you get all 1 kW/m^2 incident radiation (this is very very generous). The car has a 60kWh battery. So if we want to find out how much panel it takes for one station to charge one car a day...

60kWh to charge, but 12 hours to charge it up, so you basically need 5kW, which is 50 m^2 of panel. Which honestly isn't -THAT- big. Its a 7 meter square. Now... from my random snooping around, and my own impressions, I would say that a 'large' gas station typically covers something like... 500-600 meters squares (thats 5300 to 6500 square feet). That would be enough to super optimistically charge 10-12 cars a day.

I saw optimistic, because incident solar radiation is not that kind. Can take a looksey here: http://rredc.nrel.gov/solar/old_data/nsrdb/1961-1990/redbook...

If you pick average, annual, and single axis east-west tracking (which I believe is the best bang for the buck), you see on the solar map, the BEST places in the US gets 5-6 kWh/m^2/day, compared to our assumption of 12 kWh/m^2/day.

The feasibility of superchargers being even 90% off the grid is of course completely dependent on the ratio of size of supercharger panel array and rate of cars charging. But given the above, I'm inclined to believe that it is highly impractical for the majority of super charger stations to become actually self reliant, especially in high traffic areas.

A supercharger network is going to have a lot of stations on lonely stretches of highway. Given how few Teslas there are being taken on those trips, you're going to want charging stations in places where there will be very, very little usage.

I can easily see a random station on I-10 near the CA/AZ border being entirely self-reliant...

What's important to remember is the dynamic nature of these improvements. I wouldn't do any development around these short of the standard gas station models. As time progresses I suspect these cars will get greater range and shorter charging times.

And existing gas stations will just grow chargers. These things don't really require a whole lot of infrastructure as I understand it. A standard industrial electrical drop is probably already present (my math says a single charging station will draw 600A). Just drop the station next to an existing parking place and plug it in. The cost is borne mostly by Tesla in producing them as I see it.

I think existing gas stations rely on customers only spending 5-10 mins to keep quantity high, to compensate for lower fuel pricing. Perhaps, in another 5 years, an advance in battery technology will push it down that low, but otherwise I would want to spend the 20 mins someplace with better service, like a grocery store, movie theater, or restaurant.

The model to follow here is oil change stations, like Jiffy Lube. Your car is tied up for 15-30 minutes, so they provide you with free coffee, donuts, TV with cable, wifi, some magazines, and a few nice chairs. All of the above is probably cheaper to add to a gas station than the cost of building a new hospitality facility.

Those places are sufficient for the "5k miles or 3 months" interval. I can endure that a couple times a year. If I was doing this regularly (or with the whole family), I would want more than a free coffee and a magazine. And most existing gas stations that do already have the room to add that already use that space for overpriced chips and candy. I don't see many gas stations I use giving up inventory space to make a lounge. To me, it would make more sense for places that are already equipped to have people stay for 20-30 minutes to drop a couple charging stations out front next to the disabled parking spaces.

If Tesla-class ranges are accepted, I'd think further battery density advances would translate into fewer batteries/lower-weight, rather than maintaining weight and adding additional range. Particularly if charging speed is also advancing, there wouldn't seem to be any call to increase the range beyond what's acceptable. (And using fewer cells would further-advance the charging-time-per-unit-range numbers)

Better to optimize the things people don't like (total charge time) or the things you don't like (high cost of batteries), than to further improve a thing people find acceptable (range).

That said, I wouldn't want to build any business plan that assumes the existence of dedicated charging stations simply because I don't see how they survive long-term.

Dedicated gas stations exist because fuel storage is a large-enough consideration and pumping a fast-enough endeavor that it just makes sense to make fuel pumps a destination in-and-of-themselves.

But if charging stations are a bit of additional electrical work to wire up a handful of spots and charging is going to take a bit of time, why wouldn't every already-viable roadside diner, attraction or hotel just add a few spots (and then a few more, and then a few more...)?

And if you're getting a bit of charge from every other stop you make on a road trip (for snacks, restrooms, meals, attractions, overnights, etc) who needs a 30 minute purgatory at a dedicated charging station?

Even if you needed a charge, choosing a destination that happened to have a charger would seem a more optimal move than choosing a charging station and then hoping it has a destination attached.

It's a good thought, but I think it makes more sense to add Superchargers to existing service stations. I wouldn't be surprised if that's their plan going forward.

Here are two of the three on the East Coast right now: http://goo.gl/oWSbW. It's located on I-95, the busiest highway on the East Coast. There are two separate service areas, one on each side of the highway, both identical, and both with Superchargers. There's a Mobil gas station, 3 or 4 fast food restaurants, restrooms, and a convenience store.

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