Sandra asks…

Advice on setting up a solar system for an NGO in Kenya?

I run a charity based in Canada. We are looking to provide our partner NGO in Kenya with a laptop, printer and solar power system (as they are outside any grid) that will allow them to reduce their costs.
The solar panel and battery would have to suffice to charge six cell phones a day plus use of the laptop for at least an hour (and ideally two hours) daily plus occasional use of the printer.
1. I have heard that there are laptops made specifically for use in the developing world with solar energy, and so are more energy efficient and are not as expensive. Is this so and where might I inquire about it?
2. Barring that, what are some things to look for when choosing which laptop/printer to purchase when relying on solar power and a limited budget?
3. What solar panel, battery and inverter combination do you recommend for these conditions? Is there a way of saving on the inverter/controller?
Thanks,
Santiago Perez

Sam Deane answers:

You might look for machines which will run directly on the DC power of the solar system and battery (maybe 12 or 24V DC). Even if you do find something that runs on the *nominal* voltage, you may wish to examine the specifications carefully to see that they will accept the range of voltages (maybe 10-14V) coming from the battery. It might be a little more efficient (no energy lost as heat in transformers and inverters) and reliable (no transformers or inverters to fail and stop the whole system).

Joseph asks…

Should we send energy down to Earth in the form of microwaves?

I read about satellites with solar panels popular mechanics. The idea was to have these solar panel satellites orbit the Earth and send the energy generated down in the form of microwaves. I’m no genius but it seems like a bad idea to me. I thought microwaves were responsible for heating the water molecules in our food to a boiling temperate. What are clouds made up of?

Sam Deane answers:

Well, on the face of it, I’d have to say no we shouldn’t send energy down to Earth in the form of microwaves.

However, solar energy panels on our roofs are a great way to harness the sun’s heat and store the energy in a battery.

Mary asks…

How much Oil do you consume per year?

For me, I change the oil on my van and car every six months.
24 QTS per year
I don’t use oil for heating because its 85 degrees all year around where I live.
I have solar panels and wind generator so I only pay an average of $25.00 a month for electricity.
I believe that the price of oil and gas is fine and don’t care if it goes up to $25.00 a gallon.
What is all the whining about when we have it made as Americans?

McCain 2008
dadvice1 : Grow my own food,Only eat fish and chicken. Dont Fly,Dont receive mail. E-mail only. Not concerned about old people just me.

Sam Deane answers:

You eat food. Food requires oil for farming and delivery of products. Do you get mail? Fly on an airplane?

Do you care about elderly or poor who don’t have the same opportunity to avoid gas and oil like you?

Linda asks…

What should i do in this situation?

I just got slapped in the face with my grade for my science fair. My teacher gave me an 83.5 on my science fair. basically what my science fair was about was if a regular person could construct an EMP device (disables and destroys electronics) and how can someone protect their electronics against EMPs (of any kind) and also solar flares. Though it may sound simple, to complete this experiment I had to learn how to solder electronics and I spent $100s on this experiment and 30 plus hours building the device (I tried something off the internet 3 times before I made up my own circuit). I’m in 9th grade and a teacher who was helping me on the project (not the one who gave me the grade) asked me if we were sure if i wanted to do this topic because it was a higher level project and “it would be a feat in itself if you could pull it off”. So i was able to complete this experiment, wrote the research paper and had a college professor (not just any proffessor as in he has been the president of 2 different colleges in the past) and he said it was an extremely well written paper. I go into class to present my project and everyone is commenting on how good the back board was and i go to present and everybody loved my presentation except my teacher. She said i didn’t do too well on the presentation (figures, i have speech impediment) and my research was 1. insignificant and 2. nothing new was discovered. First of all it was significant because I was able to pull it off and secondly I tested something I have never heard of anyone testing (I tried to see if an anti-static bag would provide protection from the EMP, which it didn’t). Now this teacher was being a total hypocrite in saying that it was insignificant and nothing new was found. Other projects that got better grades than me and went to the school fair included “Do candle scents effect blood pressure?” (which was a middle school level project has been done before (anyone ever hear of aroma therapy?) and was poorly executed) and “Does the placement of a softball pitcher’s feet effect the speed of the pitch?” (this one was an average project, poorly executed and consisted of the pitch standing on the left, middle and right of the mound (which is a flat piece of rubber that the pitcher can’t step off of or its an illegal pitch) and the girl did horrible on the presentation) and one that went to the county science fair: “what charges a ipod the fastest: kinetic energy, 1 solar panel, or 2 solar panels?” (I don’t even have to tell you why that’s an extremely simple project and 3 people i know of in the school did similar projects). I’m really offended by my grade on this and I want to know what I need to do.
@nixie: I might try to revamp this project for next year so if you could, can you tell me more about your experiments? like is there any way i could have access to your work including the procedure on how to make these things? I probably wouldn’t do anything with explosives but i have a good idea of what to do in coming years to expand my project and of course you would get any credit you deserve

Sam Deane answers:

Your teacher is being unfair about your work and possibly biased in his/her judgment. EMP/EMI is a pretty complex topic, if you managed to to even make and EMP device and test for EMP effectively, you have done the work and deserve a good grade. Talk to your parents of principal. This sounds really unfair.

I have an interest in EM effects, designs and development, its really complex stuff, and requires considerable research I would feel really upset too if my teachers dismissed by efforts like that.

Anti static bag, hmmm, didn’t think of that.
Kudos to your for thinking outside the box.

For my project:
I used a Faraday cage. Some dude invented that like 100 years ago. Used in microwaves (the thing in every kitchen) today.
For the EM device I tested two. A homemade and crudely assembled HERF gun, a device that sends out powerful microwave frequency EM energy. Plugs right into a wall, can mess up a CRT monitor pretty badly at 30 feet.
The other I found years earlier and its a dangerous device the soviets researched and devolved in the 60s/70s. Their idea was to create an EMP pulse by putting a powerful electromagnetic field around some high explosives, they’d time it perfectly so that when the field is at its strongest the explosives go off, instantly forcing the field to expand. Rumors has it that the US military has many similar devices for testing somewhere in the Mojave desert (California & Nevada). For the soviet ones the approx specs are: 3 million volts at 50,000 amps peak, 15 kilograms SEMTEX high explosive. Can fry a car at 300 meter’s range. Determined not to be practical, project was abandoned.
I used a couple ounces of nitrocellulose (not illegal) and a 63kJ capacitor bank (2,150 volts at 200,000 amps peak). My EMP device did work, using a large inductor loop (32 feet in diameter (16 feet from bomb) of 32 gauge copper magnet wire, I recorded two jumps of EMP at time of detonation, first one was weak, when the magnetic field was fully developed, second was when the field was forced to expand. My timer systems were fully mechanical, I’m not so good with digital circuits and IC’s. I borrowed a digital oscilloscope to measure the EM energy.

It was a cool project but is not practical.
CMEs/Solar flares are currently the most potent of EMP events. The other is a Neutron bomb, the USA has 4 of them and the soviet union has 3. They somehow managed to “misplace” 2 of them. A neutron bomb is a nuclear weapon without all the devastation and fallout. A burst of neutrons snuffs out all life and like any nuclear detonation, an EMP is produced.

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Sandra asks…

Advice on setting up a solar system for an NGO in Kenya?

I run a charity based in Canada. We are looking to provide our partner NGO in Kenya with a laptop, printer and solar power system (as they are outside any grid) that will allow them to reduce their costs.
The solar panel and battery would have to suffice to charge six cell phones a day plus use of the laptop for at least an hour (and ideally two hours) daily plus occasional use of the printer.
1. I have heard that there are laptops made specifically for use in the developing world with solar energy, and so are more energy efficient and are not as expensive. Is this so and where might I inquire about it?
2. Barring that, what are some things to look for when choosing which laptop/printer to purchase when relying on solar power and a limited budget?
3. What solar panel, battery and inverter combination do you recommend for these conditions? Is there a way of saving on the inverter/controller?
Thanks,
Santiago Perez

Sam Deane answers:

You might look for machines which will run directly on the DC power of the solar system and battery (maybe 12 or 24V DC). Even if you do find something that runs on the *nominal* voltage, you may wish to examine the specifications carefully to see that they will accept the range of voltages (maybe 10-14V) coming from the battery. It might be a little more efficient (no energy lost as heat in transformers and inverters) and reliable (no transformers or inverters to fail and stop the whole system).