help needed with bringing free solar electricity to Playa!

[vibrantnomad]

Friends,

This will be my first Burning Man and I want to showcase a new technology. I want to build a solar power generator to provide clean electricity for free at the festival.

The generator will be a relatively simple steam generator powered by SolarFlowers, which are easy-to-make parabolic solar collectors constructed using scrap materials (see http://solarflower.blogspot.com for details). The system incorporates proven technologies.

The situation is, I am out of the country until August 3. I need to find US-based people, preferably in the Western states, who can help me build the SolarFlower power generator.

I can provide schematics, instructions, money for materials, and a perhaps even a small stipend (though this is all coming out of my pocket, so goodwill time donations would be ideal).

Completed machines are needed by August 15, or the appropriate amount of time that allows me to drive the trailer to Burning Man. Could you or anyone you know possibly help me out?

Skills needed for steam generator: general metalworking, fitting, brazing

Tools/facilities needed: a home metalshop with hand tools (don’t need a lathe or milling machine), hacksaw, blowtorch, angle grinder, drill, gas brazing set

Number of people needed: 1-3 in the same geographic area

Time needed: 3 weeks – 1 month

One person could do the job in a month, or a few people working together in a few weeks (for example, one person doing the steam part, one person doing the boiler, and one doing the electric).

Even if you can’t help with building, you can help by asking around, spreading the word about SolarFlower, or contributing financially to the project (I’m going to start a Kickstarter campaign in the coming week).

I'd greatly appreciate any ideas, advice, connections, spreading the word, etc. Reply to this thread or send me a private message.

Help bring clean energy and an awesome DIY solar project to Burning Man!

Cheers,
Tim

[Snow]

At first glance this looks pretty interesting. I'll check it out in more detail later, I gotta get to bed. I'm a metalworker, but already have a project going on. Feel free to PM me and we'll chat.

[vibrantnomad]

SolarFlower:



Video of it automatically tracking the sun without electronics:

http://youtu.be/V0r5LP_kKVA

Rundown of how it works:

http://youtu.be/WrMltEp-dcw[/youtube

Amateur schematic to give a better idea of generator:



explanatory generator notes PDF downloadable here: http://forum.opensourceecology.org//dis ... -generator

[vibrantnomad]

Corrected link to video on how SolarFlower works: http://youtu.be/WrMltEp-dcw

[Dustdevil]

This seems like a lot of work to produce 550 watts during daylight hours only.

[knowmad]

This seems like a lot of work to produce 550 watts during daylight hours only.

Storage batteries, and Inverters, 550 is nothing to sneer at seeing how it will not be burning gas or noise.

Yeah! Thanks.

hey PM me I'm 3d year burner in the North west, I have an Electronics degree, most of those tools, time in August and a mobile Shop/studio/mad scientist lab.

l

[kvon]

[gyre]

This seems like a lot of work to produce 550 watts during daylight hours only.

Scalable?

[BBadger]

You've demonstrated that it can self-position itself towards the sun, but do you have any examples of these solar flowers even producing enough steam to spin a turbine? I'm not convinced that these things have enough juice even with 5 big ones. They also look very fragile, and playa dust is not going to help with reflectivity.

[Dustdevil]

Looking at the drawings and rereading your original post, I suggest you change the plans to include a base with a much larger footprint. You stated you have never been to the Playa. The wind is going to grab a hold of your device and it will fall over.

What is the approx cost to construct a single unit?

[ygmir]

yeah, Dustdevil has a good point!!
better plan for 60+ mph gusts, and from any direction.

[Elorrum]

Oh Kvon!!! How are you, Sweetie?!

[Dustdevil]

What pressure does the boiler operate at?

Naturally your steam turbines would be more than welcome at the Event, in fact I am quite certain they would draw a lot of attention. One thing you must remind your builders/operators to do is bring the current certification for the pressure relief valve and certification for the pressure vessel.

Devices such as yours are regulated by the Fire Art Safety Team. They will be more than happy to laminate you, as long as the inspector can verify those two items are current.

I for one would like to see it run.

[capjbadger]

yeah, Dustdevil has a good point!!
better plan for 60+ mph gusts, and from any direction.

Yes, a solid short wall to deflect the wind may be needed. That looks like it is made in large part from corrugated plastic. The normal winds out there will rip that to shreds. You'll most likely want some sort of wall around them anyway just to keep people from screwing with them.

-Badger

[capjbadger]

It may be too late in the game for this at this point, but have you thought about getting rid of the steam system completely and the related issues (pressure, all the water, etc) and replacing it with a sterling heat engine instead?
It would cut out a lot of the setup shown here. Less to build, less to break, less to haul.

-Badger

[Dustdevil]

I wanted to know the estimate cost so a comparison could be made to five 100watt solar panels. Fewer moving parts means less problems.

[capjbadger]

I wanted to know the estimate cost so a comparison could be made to five 100watt solar panels. Fewer moving parts means less problems.

I suspect his setup will be far cheaper since it's made mostly out of "waste" or free materials.

-Badger

[Dustdevil]

It seems it would be cheaper, but the time to build it has a value. As does the time to maintain it. It would also be helpful to know what the water consumption would be. Alternators are cheap, you can subtract the battery and invertor as they would be used for solar as well as steam.

I do suspect that the wind and dust would wreak havoc with the system.

I would still like to see it running.

[BBadger]

Vibrant really needs to build a prototype to even test whether these systems can even generate electricity at all. Most heat-based generators have separate heat exchanger fluids to prevent phase changes for efficiency purposes. Then a head exchanger is used to boil water in a separate, pressurized water chamber which actually does the mechanical electricity generation.

The only thing I've seen these Solar Flowers do in these videos is track the sun. None of the flowers are connected to anything. I think it'd be a waste of time to build them if they're not even proven to work even on a small scale.

[vibrantnomad]

Hey guys,

Thanks for all the input and support… I really appreciate it. I have no idea what I am getting into with this because a) it's my first Burning Man and b) I know next to nothing about engineering at this point, having just learned to build the SolarFlower last month here in New Zealand. However, this whole process of dreaming and brainstorming possibilities is helping me learn rapidly about both.

Dustdevil, the cost is roughly $50 for one SolarFlower of one square meter in size. It all depends on how much you can scavenge. The 550W is a rough estimate, could be more (much more if we go with evacuated tubes) or less depending. That estimate was based on the design provided, both of which were made by Alan, professional mechanical engineer and father of Daniel who invented the SolarFlower.

I'm not set on any particular design for the generator; that's just the only one I have right now. The boiler pressure depends on which one the builders choose - I don't think there is one specified in the explanatory generator PDF I linked to above. Thanks for the certification reminder and team information.

BBadger, we have 2 working prototypes, but unfortunately they haven't been hooked up to anything yet. We are in dire need of alpha testing on that front, you are right. I have asked Alan and Daniel to provide in-depth replies to your other points and am waiting for their responses.

capjbadger, sterling engine was the original intention and preference, but we had trouble finding an efficient one that is affordable. The only affordable ones were like 3-5% efficient, which just doesn't cut it.

I share everyone's concerns about durability, especially in the Playa environs. The walls seem like a good solution for wind, and perhaps also to ameliorate dust. The second prototype is much more durable than the first one which is shown in the videos; with a little wood and metalworking we could make new models as beefy as we wanted. I would bring extra aluminum sheeting (source-able dirt cheap from newspaper printers) to replace panels that could be marred by sand.

looking forward to continuing the dialogue and assessing the possible...!

[capjbadger]

It's not sand out there. It's dust. you won't have to replace scratched panels, just knock the dust off of it.

-Badger

[BBadger]

Let us know when you have a working power-generation prototype.

[solarflower]

Hi, this is Daniel, I prototyped the solar tracker and my father Alan designed the steam system pictured.

> do you have any examples of these solar flowers even producing enough steam to spin a turbine?

I've had it boiling water in the collector tube, which works as well as you'd hope.
You're right that nothing works until it's seen to work, but the physics of this kind of system are fairly well understood. Knowing the reflectance of the mirror (80-95%) and the efficiency of the collector (up to 90% with an evacuated tube), and that the tracker is accurate enough not to lose the sun, it's safe to say the only real variables are energy in (1 kW per square meter sunlight) and water mass (whatever gives the best results).

> I'm not convinced that these things have enough juice even with 5 big ones.

10 kilowatts input aint nothing...
It comes down to the efficiency of the steam engine, alternator, etc. My father has mapped out the numbers pretty well.
And if you want twice as much power, just build twice as many collectors. They're cheap enough and don't take long.

> playa dust is not going to help with reflectivity.

No doubt. For this type of environment I'd consider the reflective surfaces sacrificial, and take in extra in case they need replacing. Easy enough. Tho the point about it being dust, not sand, is a salient one. Not sure what akalie does to aluminium... but the surfaces at least only really need to last two weeks, and it's the Playa, not Mars.

> The wind is going to grab a hold of your device and it will fall over.

I was at BM in 04, and yeah, wind is potentially the main issue. A low windbreak will help a lot and shouldn't shade the collectors. I've had these things out in some pretty intense wind and rain and they didn't so much as shift. And this was with the earlier version which was significantly more damageable than the current.

> What is the approx cost to construct a single unit?

The verison I built in Australia was about AU$60, the New Zealand one about 50% more, but I only had three days to gather all the materials, so bought several components you wouldn't usually need to. Also a lot of that cost is things like high temp spray paint, which will do you dozens of the things.

> What pressure does the boiler operate at?

Comes down to how it's built. My father might have given a range for this, I can find out if necessary.

> bring the current certification for the pressure relief valve and certification for the pressure vessel.

Yeah good call.

> replacing it with a sterling heat engine instead?

We did look at that, and yeah it would be a bit simpler, but what you can currently buy in terms of off-the-shelf and kitset engines favours steam pistons in terms of efficiency, power range and cost. Stirling's aren't far off, and will hopefully get better over the next couple years, but as it stands steam's a bit more viable.

> the time to build it has a value.

From the construction workshop we did in NZ, I'd say three people could make a device start to finish in about half a week at five or so hours a day, not including getting the materials. If you were doing a bunch at once you might be looking at four a week.

> As does the time to maintain it.

Playa environment aside, the maintanence should be pretty low. It only has a couple of moving parts, and they're generally made from things like bikes, which are meant to survive much of anything.

> It would also be helpful to know what the water consumption would be.

I think we're looking at a closed system, providing an adequate condensor, so it shouldn't require extra water. The original idea was a combined power and water purification scheme, but this gave design problems with residues in the steam system.

> needs to build a prototype to even test whether these systems can even generate electricity at all.

The solarflower is an open source project aimed at providing universla energy autonomy, and electrical production was always a big part of that. Currently there's not really a good, home makeable solution for producing electricity from concentrated solar, and there very much needs to be. This project for Burning Man is an attempt to solve this, and whatever gets made here can then be shared with the world.
</rant>

> a head exchanger is used to boil water in a separate, pressurized water chamber

Good point and we looked at that, but for ease of construction water tube boilers in the collectors themselves are easier and function in the same sort of range.

> I think it'd be a waste of time to build them if they're not even proven to work even on a small scale.

I guess we're looking for people who want to be part of creating something.

[BBadger]

needs to build a prototype to even test whether these systems can even generate electricity at all.

The solarflower is an open source project aimed at providing universla energy autonomy, and electrical production was always a big part of that. Currently there's not really a good, home makeable solution for producing electricity from concentrated solar, and there very much needs to be. This project for Burning Man is an attempt to solve this, and whatever gets made here can then be shared with the world.
</rant>

Yeah, I got that. But a lofty mission statement doesn't answer the question: where is the working prototype generating electricity? Until you have that absolute minimum, there's no point in building, transporting, and relying on these contraptions for anything more than decoration.