Mobile Recording Studio Completely Solar Powered - General Questions

[ErikHoppy]

Hi all,

I'm a musician/recording engineer/voice over artist planning to build an off-grid solar powered studio in an RV or box truck. I'll drive around the country recording bands and myself while sleeping in the vehicle. Basically, a bedroom and studio on wheels.

Before I spend any more time planning this, I need a realistic estimate on if it's even possible and how much it would cost to create a solar/battery array.


Power Consumption:
LED Lighting: 100w
Computer/Screen: 200w
Studio Monitors: 300w
Amp/Keyboard/Misc: 100w

TOTAL: 700w needing to run MAX of 10 hours/day, if I have a full day session booked. This is the max, average would be half that or less, since I'd use headphones and laptop for personal use, thus only using 200-300w of equipment on an average day. But, I need to be sure that my system could potentially book out a full week at 10 hours/day at 700w and recharge daily. 700w x 10hours = 7,000WH per day MAX

Planned Solar/Battery System:
4x 400AH 6v batteries = 800AH @ 12v = 9600WH
4x 220w 12v panels
1000w 12v inverter
Hardware, Charge Controller, etc.

Total Cost: $3,000 or so

-Will 9600WH give me enough juice without completely draining the batteries? I read on this forum that up to 80% drain is acceptable and 80% of 9,600WH is 7,680WH, thus giving me enough juice for 700w for 10 hours, yes?

-Will 880watts of solar panels recharge the batteries daily, in summer sun?

I have never worked with solar before and sure could use some help in planning the proper setup. Am I way off?

I truly appreciate any help and I am very eager to learn!

[Sunking]

10 hours/day at 700w.

Planned Solar/Battery System:
700w x 10hours = 7,000WH per day MAX
4x 400AH 6v batteries = 800AH @ 12v = 9600WH
4x 220w 12v panels

Well you will not like what you learn here. Not even in your wildest fantasy can this be done with solar.

To generate 7000 wh of usable power with solar on a RV with 0 Degree tilt and a whopping 4 Sun Hour which is not even remotely possible you are looking at:

Panel Wattage = 2600 watts. No way is your RV large enough to hold that many panels.
12 Volt Battery Capacity = 3000 AH or about 1600 pounds worth of batteries. You have no spce for that much battery, nor can your RV handle the weight.
MPPT CHARGE CONTROLLERS. 3 units of 80 amp capacity. Another $2100 down the drain.

Just panel, battery, and controller cost will run you around $12,000. Want an inverter wiring and material to make it work add another $4000.

Only way you can do this is buy you a good auxiliary Power Unit like a generator and run all your equipment from that directly. You RV alternator is not even capable of doing that. No way in he!! is solar going to do it. What is above will not even work because there is no way you could possible get 4 Sun Hours on a RV using 0 degree tilt with NO SHADE from SUN Up to Sun Down. Just not going to happen.

[ErikHoppy]

Holy crap, I knew I was off, but not by that much!

This completely ruins the idea of a mobile studio off grid. How was I so wrong? I see plenty of RVers living off of 1-2 panels and a battery. Are their power consumption needs really that much less than mine, even with lighting, fridge, cook top, AC, etc?

What if I dropped the high wattage items and went absolute minimal...

MacBook Air: 15w
LED Lighting: 60w

Total: 75w @ 10hr/day = about 1/10th my original consumption, thus needing 260w panel wattage (better go with 3x 100w panels to be safe) and a minimum 300AH battery.

No way I'd be recording bands, but at least I could continue my own music and voice overs to pay the bills.

Is this correct now?

[Sunking]

Holy crap, I knew I was off, but not by that much!

This completely ruins the idea of a mobile studio off grid. How was I so wrong? I see plenty of RVers living off of 1-2 panels and a battery. Are their power consumption needs really that much less than mine, even with lighting, fridge, cook top, AC, etc?

You have a few things wrong about RVer's

Cooktop and fridge run off LPG, not electric.
They use the vehicle alternator with a battery isolator to do most of the charging while driving and have a Generator to make up the shortages when parked. Solar is just there to look cool and save some generator gas. Otherwise they pull into a RV park and use Shore Power hook up.

[ErikHoppy]

You have a few things wrong about RVer's

Cooktop and fridge run off LPG, not electric.
They use the vehicle alternator with a battery isolator to do most of the charging while driving and have a Generator to make up the shortages when parked. Solar is just there to look cool and save some generator gas. Otherwise they pull into a RV park and use Shore Power hook up.

I see, damn my naive, creative mind! Thanks for your quick replies. Would a 300w solar kit and a 400AH battery cut it for just basic lighting, laptop and cell phone charging? AKA, van living like a vagrant.

[Sunking]

I see, damn my naive creative mind! Thanks for your quick replies. Would a 300w solar kit and a 400AH battery cut it for just basic lighting, laptop and cell phone charging? AKA, van living like a vagrant.

Yeah but a bit lop sided on ratios. In a RV with 0 Degree Tilt about all you are going to get is 3 to 4 Sun Hours per Day. Using a 12 volt battery using a MPPT controller for each Amp Hour of Battery requires:

Panel Wattage = 1 watt
MPPT Current = .09 amps.

So if you have a 100 AH battery you would need a 100 watt panel and a 10 amp MPPT Controller. That would yield you on average around 250 to 275 Watt Hours per day of usable power. Depends on location and time of year. Stay far away from kits. What I would reccomend is you get:

200 watt Grid Tied Panel, not a battery panel.
15 amp MorningStar Sun Saver MPPT controller.
A Pair of Trojan T-105 Golf Cart Batteries, or a pair of 6 volt AGM 230 AH battery. Both are 6 volt Golf Cart Batteries. The Trojan are Flooded and AGM is sealed.

Will cost you around $550 to $600 and give you a solid 500 Wh or .5 Kwh/day. Also buy a electronic Battery Isolator. You will use that to charge the battery anytime th evehilce is running and they are cheap around $70. You alternator can do more in 30 minutes than a 200 watt panel can do for 2 days.

[outofbounders]

Sunking is right on, our entire house runs at a max 3-400watts and we barely keep afloat with 1020ah and 1500watt pv.
What you are not used to living on grid is keeping tabs on this balance. I would start with a kill-a-watt meter and you'll surprise yourself -

I helped set up a food truck with a 170w panel and 400ah and that is just a glorified charging station w/ lights a small fan, ipod dock...

Don't get too hung up on the details though, just go for it and learn along the way. I believe in small systems, we have one just for our chicken coop!

[JoonWolfsberg]

Hi Guys, I build a 100% solar powered mobile "off grid" recording studio. I'm a Composer for soundtracks and songs.

Studio inside of my bus >>> SolarPoweredRecordingStudio.jpg






That's my bus (from 1969) from outside >>> TourbusJOON_WOLFSBERG_aussen.jpg





These are the solar panels >>> 13866809_1075263592519284_990480539_n.jpg





Energy Management >>>

13652434_1075263562519287_1653535461_n.jpg

Solar Charger >>>

13664492_1075263589185951_1467387108_n.jpg

Batteries >>>

13867141_1075263565852620_1922014441_n.jpg


TECHNICAL INFOS:

4x 220Ah Solar Batteries (2x 24V / 440Ah)
5x 150Wp /24V Solar Panels
1x Victron Multiplus 70/3000
1x Solar Charger

Energy-Consumption of my mobile Studio is about 150Watt.

Even on days with a mix of clouds and sun, we get about 200Watt from the sun.
Without any sunshine, the 4 batteries last about 5 days (8h a day working time) for recording/producing music off grid.

[organic farmer]

... I read on this forum that up to 80% drain is acceptable and 80% of 9,600WH is 7,680WH, thus giving me enough juice for 700w for 10 hours, yes?

To fully charge a battery at 100% State-Of-Charge [SOC] and then to drain it down to 80% SOC, is not going to hurt the battery.

Dipping down to 60% SOC [or lower] is a 'deep cycle'. There is a lot of discussion about how deep you can deep cycle, and about how many times you can deep cycle any battery.



Starting at 100% SOC and draining 80% of the power means that you have gone to a 20% SOC.