Low cost energy

I hear that low cost reliable access to energy is the "best" way to lift people out of abject poverty. I'm interested to know what you think the best energy sources and generation methods are. You can list any mechanism you want to allow energy access and I think we should grade them on the following scale:

Self reliance factor 1 = depends on somebody else, 10 = self reliant
Complexity scale 1 = very complex, 10 = very simple, almost neolithic
Pollution factor 1=lots of pollution
Cost factor 10 = basically free
Versatility factor 1=energy can only be used for 1 thing, 10= plug in almost anything

Add your own factors if you want.

Mine are
Passive heating and cooling: 10, 5, 8, 4, 2
Rocket stove/oven/heater: 9-10, 7, 7, 7, 4
Gasification: 7, 3, 6, 6, 9
Solar power: 7, 3, 6, 3, 9

One system that I'm looking at as a future project is heating with solar heaters that are made from recycled materials such as soda cans.

Self Reliance = Low maintenance
Complexity to build = Beginner
Cost = Low depending on how material is acquired.
Versatile = Not much use, other than heating during daytime, since sunlight is required.
Pollution factor = Low (no emissions, once built)

The only down side is location placement matters for this type of heater. Since it needs direct sunlight, you will need to place it on the side of the building/structure that receives the most sunlight at desired time of heating.

I built a soda can collector once upon a time.  I found a can opener that would remove the inner part of the can top. Where the opening is.  I then painted many cans with hi-temp black spray paint.  I built a 4 x 8 foot frame with plywood and foam board.  Used 2 x 6 framing for the sides and covered it in a sheet of plexiglas.  There were 2 x 6 baffles inside to help guide the air around in a maze of sorts to give it a good length of time in the collector.  there were inlet and outlet ports on the same side of the panel and it was all driven by a bathroom fan.  If I had to do it again I would use a computer fan, as the bathroom fan was overkill.

Nicolas Keeton wrote:One system that I'm looking at as a future project is heating with solar heaters that are made from recycled materials such as soda cans.

Ok so it generates some heat, maybe even a lot of heat depending on the scale. I like the low cost. What can you use these things for? The objective here is to lift people out of abject poverty, how would such a situated person use one of these?

I think you are under rating solar.  Here are 2 of mine.

house solar thermal

shop solar curtain.

A week ago we were at 40 below in northern Wyoming  The shop froze about 1/2" of ice on the radiator test tank with no heat yet this year.  We had a number of gray days leading into that cold snap.  Following it we have about a foot of snow on the ground.  With 3 days of good sun the shop was hitting 64 degrees late this afternoon with no heat this year.  The house I heated for 4 days thru the worst of the cold snap but quit a week ago.  With freezing temps out every night and still lots of snow on the ground between the passive and active solar of the house I hit 74.8 degrees in the house.  More importantly I am recharging the basement walls with heat at the same time to have heat during the next gray stretch.  Neither system is break the bank expensive.  Neither system is complicated.  Both are within the range of an average builder.  And both are reaching payback in just a couple of years.

C. Letellier wrote:I think you are under rating solar.

Aren't these passive heating and cooling techniques? I though I rated those as very good solutions for low cost energy. I put them slightly lower than the rocket heater approaches because I think they are more expensive, require more forethought to implement so more planning and possibly more engineering (although rocket stoves can be pretty complicated), and as far as I can tell only address one aspect of heat (room heating) while you can also cook, bake, boil water, dry clothes, etc. with a rocket stove. I think I hear you though, I'm open to entertaining different ratings for these.

But I do love solar, I have three kinds of solar ovens and cookers, and love using passive solar.

Well, my understanding was the original rocket stove was developed to reduce fuel use in developing countries and reduce indoor air pollution.
https://rippleafrica.org/project/fuel-efficient-cookstoves-in-malawi-africa/

https://en.m.wikipedia.org/wiki/Rocket_stove#:~:text=Larry%20Winiarski%2C%20Technical%20Director%20of,hypocaust%20heating%20and%20cooking%20systems.
So locally produced, of great social benefit helping with deforestation and time use in collecting wood and indoor air pollution.
Solar cookers could be put in that category as well.
I think small solar setups are popping up everywhere as they can compete with kerosene lamps. Neither is really easy to produce but both are deemed important enough that people are spending their limited funds on them... All great projects that are moving forwards

Thomas Tipton wrote:I built a soda can collector once upon a time.  I found a can opener that would remove the inner part of the can top. Where the opening is.  I then painted many cans with hi-temp black spray paint.  I built a 4 x 8 foot frame with plywood and foam board.  Used 2 x 6 framing for the sides and covered it in a sheet of plexiglas.  There were 2 x 6 baffles inside to help guide the air around in a maze of sorts to give it a good length of time in the collector.  there were inlet and outlet ports on the same side of the panel and it was all driven by a bathroom fan.  If I had to do it again I would use a computer fan, as the bathroom fan was overkill.

This is exactly how i'm building my current one, using leftover foam insulation and small electronic fans. Can open way is the fastest/easiest method I've used, since drilling with hole saw catches the can and crushes it.

Kyle Covington wrote:

Nicolas Keeton wrote:One system that I'm looking at as a future project is heating with solar heaters that are made from recycled materials such as soda cans.

Ok so it generates some heat, maybe even a lot of heat depending on the scale. I like the low cost. What can you use these things for? The objective here is to lift people out of abject poverty, how would such a situated person use one of these?

Heating motor homes, tents, rooms, buildings, etc. There's videos on youtube of people heating homes that have snow on the ground with these systems.

Take people living in the west as an example with no access to free firewood. In the winter time, they are paying to use gas/propane/firewood to heat during the daytime/night. One of these systems can help lower heating cost, during daytime which allows them to use their money for other things.

Use a six inch fastener bit extension for your drill motor if you have one and you can pop those cans into the plywood with one screw right in the convex section of the can on the bottom.  Works like a charm.

I live on a river now so I plan to use a hydro kinetic turbine to produce heated water. A more common application is to build something to make electricity, but that is not a huge cost for me. Domestic hot water is a different story though.

For those talking about pop can solar there are better answers.  So far the best I have seen is the fiberglass window screen collectors.  Here is one comparison but so far they have won every comparison I have seen.  The labor you spend in using the pop cans invested in earning enough to pay for the screen would still likely pay out.  First link is better science but no pop cans.  Second is pop cans vs screen collectors.

collector comparison.

pop can vs window screen

Now if you go dig a bit more yet you will find the foil lined boxes win against black boxes for the window screen as any light that passes thru the screen then has to make its way back out thru the screen too heating the screen from both sides and improving efficiency.  This adds another 3% to 5% typically to collector efficiency vs black box inside.