Sunday, March 20, 2011

Last post from Puerto Penasco

Tomorrow, Fraser and I are leaving our lovely little R&D center here just as this town starts to come alive again. It's spring break so in the past 2 weeks we've seen more tourists and revelers than we have in the past 4 months!  The days are longer, the air is warm and the mood PP, a very tourism reliant town, is on the rise. 

Last week we donated the Phaeton to the local Instituto Tecnol├│gico Superior de Puerto Pe├▒asco. They have an industrial design program and the professor in charge, Rodrigo, is very excited about the opportunity for students to apply their skills to a real world project with social and environmental benefits. The institute sent a truck and some guys to pick the machine up and then we set up the machine together and I ran a little workshop on how to care for the machine, establish a tight focal point, and make new mirror modules. We're going to be in touch and I'll act as a sort of advisor to any students who take an interest. A few already have. While we were setting up the array quite a few students passed by to gawk at the pot of boiling water and the flaming stick. We sure are glad to see the array going to a good cause!

While we'll be sorry to leave, we have a lot to look forward to. We're taking the scenic route home, and by that I mean we'll be driving up the West Coast to Vancouver where we'll spend a few days and then across Canada, visiting relatives along the way! I'll get to see the town where my grandad grew up, and I'll finally meet a lot of family that I haven't yet had the pleasure of getting to know. We're going to take around 3 weeks to drive back and then we're going to build another Phaeton, this one for demonstrations, and then start hitting up international aid, international development and various philanthropic orgs to mount a project.  

I'll update mid trip with pics of our journey! 

Saturday, March 5, 2011

Results! A convenient, inexpensive, high-power solar cooker

Now, I know some of you are saying "But Lorin, didn't you already have a convenient, inexpensive, high-power solar cooker?" And the answer is yes, but this is the convenientest, inexpensivest, high-poweredest yet! Well, not high poweredest, fine, but still. This is a really important development for solar cooking internationally.
This is what it’s all about right here: we’ve finished the core of our new solar cooking system.
I contend that this is one of the simplest, most convenient and most cost effective high power (2kwh) solar cooking solutions.
I’ll go into technical and performance details in a later post but for now just check out the ergonomics and consider the facility of use. Waist high cooking console with a lever to control the mirrors and a ‘rearview mirror’ to peek at the underside of the pot to ensure that the machine is properly oriented. The cooking console is far enough removed from the mirrors that putting up a shade or umbrella will not affect the system. All while harnessing 2kwh of solar thermal energy. Enough to boil 8L of water in 40 minutes.
It’s a simplified version of our old mainstay, the Helios array that we’re calling the Phaeton coupled with something we’ve managed to develop that we’re calling an upward reflector. Thin mirror strips reflect the light upwards and onto the bottom of a cooking vessel, enabling boiling or frying in a traditional manner.
There’s a reason we call these technologies Solar Fire. No new recipes required… the Phaeton will cook anything a fire cooked and more.
The convenience factor matched with the power of the machine and leveraged using the upward reflector means that this is a significant development which helps to overcome a persistent flaw in many solar cookers of this size. Observe the following pictures of larger solar cookers which are in more or less the same size league as ours.

The bigger they get, the less accessible the focal point becomes at certain times of day, or the more extreme the angle of incoming light which hinders some processes like frying. Waist high solar cookers like the Devos cooker at the very right have difficulty exceeding 2 square meters of collector area. Tinytech on the far left has an inexpensive, solid 3 square meter cooker, but the geometry does not favour frying, one cannot install a shade, accessing the pot means shading the reflector, and it cannot operate as early or late. The Phaeton can operate from an hour after sunup to an hour before sunset. In the clear skied tropics you get 8 good hours of solar cooking per day. I have yet to make a big test batch of rice but based on some rough figuring the Phaeton can prepare at least 50kg of rice per day. Instead of rice we’ve been making marmalade and dried pineapples :D
Oh, and it costs less than $500 to build.
Designed to be built onsite by local tradespeople the Helios array uses common materials that are off the shelf in nearly every country on the globe.
My grandfather and I want to engage in international aid projects wherever the need is greatest. Aid organizations running camps in Haiti could see these machines work 8hrs a day and pay themselves off in less than a year, reducing fuel budgets and improving health standards by sterilization and improved air quality. Sub-Saharan countries ravaged by deforestation and suffering under the weight of energy poverty can use this free technology to start generating wealth at all levels of society.
Seriously, we’re mounting a project, somewhere, somehow, and we’d love your help.

Sunday, February 27, 2011

Solar food dehydrator

If you recall the solar drier prototype from a few posts ago you'll recognize it here, though now paired with our new Helios array.
The Vesta was underpowered so we decided to hook it up with a 35 sq. ft Helios array. 
Fraser administers the 'smoke test' where we place a burning stick at the air intake and count out how long it takes for it to escape through the chimney, giving us a rough idea of airflow. We're running at about 45 cubic feet per minute at a max of 150F. This is OK performance but we've still got some tinkering around to optimize the system. 
This is a test batch of about 10lbs of nixtamalized corn, AKA hominy. Still 
a couple hours of drying time left to go but we're hoping to have a fully 
dried product in a single day of drying. 
By midweek we should be done building 'la piece de resistance', a waist height cooking console with multiple configurations for boiling, frying, baking and roasting! 

Monday, February 21, 2011

Working Hardly

Apparently when it comes to blogging I can take it or leave it. For a while, anyhow. It has been too long since my last post and so I am here to remind you all that we're still working and making good progress. It may not be the kind of progress we originally intended, but progress isn't progress without.. ... progress.

Orange marmalade abounds! We're eating our test batches at the rate of about a liter a week because the stuff is just so good! I'll post the recipe once I can coax it out of grandad. We've made more hibiscus flower jelly (in Mexico hibiscus flowers are called 'flor de Jamaica'. And we made an apple / hibiscus fusion that is very, very fine!

Surely we can't have been making jellies and marmalades all this time, so what have we been up to? Well I took a couple of weeks vacation, enjoying a visit by my friend Aysa from Toronto, I was bedridden for a week by my bad back which took an inexplicable turn for the agonizing, I took it easy for another week just working afternoons and we've taken a total tangent, getting away from the Vesta array and starting in on a new vision for the Helios array including finally solving the problem of the cursed upwards reflector!

So we shifted gears from product development back to where my heart dwells, in technological research and development. booya!

Next post will describe the new Helios, it's advantages as well as our quest to reflect. upwards.

Sunday, January 2, 2011

Product development

We've been wrestling with this solar drier for a couple of weeks now and thought it was time to switch things up a little bit. Yesterday being new years day, we weren't in the mood for anything too heavy so we decided to make some jelly.

Until now we had refrained for lack of suitable jars, but we found some decent glass jars that will serve us during the product development phase. I've also placed an order in Mexico's industrial heartland for 500 jars and hot seal tops which will serve us once we've got our recipes. It's a good thing I like toast!

First up: Tamarind jelly.

Here Fraser can be seen testing the jelly to see if it is ready to 'set'. We ended up with just over a liter of delicious, powerful jelly. We're going to try to get our jars into some local stores but regardless we're both going to start eating a lot of toast... :)

Sunday, December 19, 2010

Solar Drier Prototype

Fraser and I have just completed our Vesta powered food drier Mark I. In the past two weeks we have built an additional Vesta and we have done a considerable amount of tinsmithing, the results of which can be seen here:

The whole contraption pivots around the central post of the Vesta, which is more or less of the same design as the previous model. The drier sits atop a chassis which is joined to the central post by a hinged boom made of heavy angle iron. The two bicycle wheels are angled such that their axles point directly at the post.

Those bicycle wheels. At first we looked in the hardware stores for new wheels, but all the hard rubber wheels of the diameter that we wanted were built for huge loads and were more expensive than need be. Fraser quite rightly said that we could find a child's bike for cheap and have a smoother ride. I added 'small child's bike' to the list of things to keep my eyes open for as we ran our various errands.

Soon thereafter we came across a second hand store, the likes of which you'll see every few blocks in most lower income residential neighbourhoods here in Puerto Penasco. On the sidewalk (or what may pass for a sidewalk) in front of someone's house, there are racks of clothing, toys, kitchenware, exercise machines and a wide variety of bits and bobs. It's essentially a permanent garage sale. Neighbours get rid of their unwanted stuff conveniently and she who sells stuff waits for another neighbour to need the object in question.

In the slew of stuff for sale I spied a bike of the size we were looking for. In the right condition too. Not too old, but old enough to be cheap. We pull up, get out and I ask the woman how much for the bike.
"Oh, no, I couldn't sell it, it belongs to my son." she says.
Toying with the idea that this could be a gringo upsell tactic I reply "Really? That's a shame we've been looking all over for one that size... it's just right."
She considers. "Well, let's ask him. MANUEL!!" she calls out to the house. A little boy comes cruising out of the courtyard on a bigger, nicer bike with the chain rusted and hanging loose. "Want to sell your little bike?"
"No!" he shouts, dismounts his bigger bike, runs to the smaller one and zooms off. His mother and I look at eachother and smile. "How does 100 pesos sound?" An eyebrow raises. Too high. "About right" she replies.

Manuel comes zooming back and his mother tells him this bike is too small for him anyway and that with the money he can fix the chain on his big bike. "And have enough left over for candy" I chip in.
"500 pesos!" he exclaims, his eyes big, licking his lips. We laugh. His mom tells me to hand him the money (100 pesos!) and he immediately runs off to show his friends. Later that day I did this to his bike:

I'm working on a more thorough montage for the construction of this latest Vesta as well as some of the construction of the drier.

Over the course of this latest building phase we've vacillated between thinking of ourselves as very clever and utter fools. We're quite happy with the result so far but there is still doubt as to whether or not it will work as it did when grandad built it in his head. I'm of the opinion that it won't, and will need forced air to work properly. Grandad is coming around to this perspective in his way.
It has been cloudy for the past few days and so we've been working on a back up plan. Our idea of using steel screen as a heat exchanger at the focal point took Fraser's fancy and he thought that the same principle could be applied to the more conventional solar drier which looks something like this ----------------->

So we've built a test collector roughly the same shape as the glass portion of the collector to the right, only 1 foot deep with 14 layers of steel screen to absorb the sunlight.
While I am sure that it will perform better than a flat black sheet metal collector, I think that it is overkill. The central idea being porosity means more surface area which means more contact with air which means more effective transfer of heat. No doubt it will work better, but expense and difficulty of construction have drained my enthusiasm. Nevertheless, out curiosity is piqued and we will construct two other collectors of the same size: one of the flat black sheet metal and another, somewhere on the spectrum between sheet metal and screen.

I think that, while interesting, the experiments will come to nothing much of value because in my experience and research I've found that passive drying does not provide the level of control, heat or airflow that a more 'active' drier does and so cannot produce the same quality of product. We shall see.

Sunday, December 12, 2010

Busy little bees

Onward and upward! Fraser and I continue to plug away at our list of tasks... we're very nearly finished our fruit and veggie dehydrating unit and a second Vesta. Once finished they will allow us to really get into some serious gathering of data and experimentation, which we await with great anticipation.

We are going to nixtamalize corn and dry it, we'll dry bananas, onions, pineapple and mangos, we're going to make tamarind jelly, hibiscus jelly and orange marmalade and if we're feeling ambitious we'll roast peanuts with chili and garlic.