need solar power for 2 weeks with HVX & Firestore

[Dean Sensui]

Here’s something I came up with recently as there was a possible job coming up that would require field power. Some of these things can run off DC but most would require AC power. Either through an inverter or through a generator.

But it’s a list of what each device required in terms of total watts. Watts is easily calculated:

Watts = Volts X amps

Amps = watts/volts

Portable production power requirements

MacBook Pro: 85 watts
Seritek 1SE2 enclosure: 48.5 watts
Dolgin battery charger: 25.2 watts
Panasonic battery charger: 24 watts
MyPower MP3400: 60.04 watts

Total: 242.74 watts
(110VAC at 2.21A)
(12VDC at 20.22A)

6-hour charge = 122 Amp-hours

West Marine 400 watt inverter, 8617482
$39.99

Honda E1000i portable generator
120VAC 7.5A.
29 pounds
0.6 gallons = 3.8 hrs at rated load, 0.157 GPH

At 2.21A load probably get 6 -7 hours run time.
About .6 gallons/day to charge batteries & run laptop.
1 week = 4.2 gallons. 25.2 pounds.

Generator rental rates, Hawaiian Rent-All (Dec 2006):
Honda 1000 $35/day
Honda 2000 $47/day

Dean Sensui — Imagination Media Hawaii

[Tony Cope]

Thanks for posting this info again… I remember reading it in a prior post, but couldn’t find it.

This is what I know about the system I had linked to…
22 Watt high-efficiency PV panel (monocrystalline)
Sealed, maintenance-free battery (18 AMP hrs)
300 Watt AC inverter with one AC plug

What seems good is that it includes an AC inverter as well as the ability to charge the battery from a wall AC outlet or car DC plug. What I’m hoping to do is make use of the base farm (with a large scale solar power) every 2 or 3 days — and then hope to get through 2 or 3 days at a time shooting on batteries (10 batteries for the HVX, 4 batteries for the Firestore, laptop batteries…) and then use this system or something like it to run the external hard drive when dumping footage as well as charging batteries when needed… using the solar panels to try and keep the Solar battery topped off.

I might get this system and try it out a bit at the office – so I’ll know what I can expect from it… I am planning on shooting HD… but I guess I can fall back on shooting on DV tape if it comes to that.

Thoughts?

Thanks,
Tony

[Dean Sensui]

Tony…

Doing the math, it’ll take 54 amp-hours to provide just the camera battery chargers and another LiIon battery charger for enough power over 6 hours. That will charge three camera batteries, and one small lithium-ion battery for an on-camera light.

109 watts divided by 12 volts equals 9.1 amps. Multiplied by 6 hours is 54.6 amp-hours.

Your solar power system can provide only 18 amp-hours of power, assuming a perfectly sunny day with no trees throwing shadows or clouds. Way short. You’ll need three systems like this, operating on perfectly sunny days, to charge three camera batteries and a small light.

To charge 10 batteries will take more than three times that in solar battery power and storage.

At which point a small gas-powered generator starts to make much more sense. It’ll cost less, weigh less and take up much less space. Take a look at the notes regarding estimated fuel consumption and the weight of the gas needed for a given period of time.

You might also want to re-consider the Firestore.

P2 cards proved their durability during the Iditarod. It’s easier to protect a camera against a rain storm than it is to protect a camera AND a Firestore. Also, the Firewire connector may or may not be rugged enough to tolerate a deep tropical environment.

The Firestore 100 I had also interfered with my wireless mic system (Audio Technica ATW-100). It was a problem that neither I nor Matt McEwen could quite figure out. The only solution was to get the Firestore as far away from the wireless receivers as possible. That meant more cabling and a complicated setup where I couldn’t just put the camera down and walk away. I had to unmount stuff from my belt first.

Less equipment means less to go wrong.

I’ve used both the Firestore and the P2 cards. I prefer the reliability of the P2 cards and the fact that I don’t have to keep another piece of equipment powered up all the time.

P2 cards are definitely not cheap. But sometimes cost is less of a factor than durability and/or reliability. And 8-gig cards have dropped in price.

You might also want to look at the P2 Store, which has the ability to hold up to 7 8-gig cards. Two P2 Stores is roughly the price of a single Firestore.

And a single battery will literally power a P2 Store all day long — it’s a real miser when it comes to energy consumption. And I’ve transferred cards into it while walking around — never lost a single frame of video. Porta Brace makes a custom case for it which makes it very weather resistant.

Just my 3 cents… 🙂

Dean Sensui — Imagination Media Hawaii

[Tony Cope]

Thanks so much for the time and energy of your response… very valuable info. I’ve talked with the woman at the base camp – and I can use their portable gas powered generator — waiting on it’s specs, but I’m guessing it’ll be a decent one. Also, I like the idea of the p2 cards – I’ll have 8 of them with me, so that should get me through a day.

I’ll be taking 2 HVX cameras, but I’m now the only camera guy going on this trip – so I think I’ll have the Firestores there, just in case – and use them for timelaspes, and possibly longer form interviews.

Thanks again,
T

[Dean Sensui]

Overall, it sounds like an interesting and challenging assignment.

Good luck with it all!

Dean Sensui — Imagination Media Hawaii