Fitting a solar rig in a rural school in Cambodia - Need advice!

[Fede123]

Hi guys and gals,

My name is Fede, and I'm currently in Cambodia with my wife.
After visiting the school in a very remote floating village in the province of Siem Reap, we decided with my wife we needed to do something to help them.
The school is just 4 walls and a roof, made of tin, incredibly hot, with no running water, or electricity. Just a blackboard and chairs. We just bought them over 600 books, plus notepads, pens and so on. Can't fix the running water problem, but we can give them electricity if we can install a full solar rig in the school. The thing is... I have no clue what to buy, how many panels, what consumption they could have, etc. This is a very DYI project, as there are, obviously, no solar energy consultants, and the people at the solar panel shop barely spoke English, and in any case they were just salesmen with very little knowledge on the subject and did not know how to calculate what we needed. The electrician wouldn't go all the way to the village to make an assessment, either. So I'm wondering if you can help us out.

The school has 5 rooms, each one of them is 45m2 (485 square foot). I want to install DC LED lights, a couple of fans, and an AC outlet for a computer and printer (one for the whole school, not per classroom).

Questions:
1- Not really sure how many DC LED lamps I need per room. I assume about 8.
2- No idea how much a DC roof mounted fan consume.
3- Same for the computer.
4- How many gel batteries do we need?
5- what else am I missing?

Guys, as you can see... I know nothing about the subject, but I really would like to help the school and try to make this happen. Any suggestion will be greatly appreciated.

Thanks,
Fede and Yana.

[solarix]

Check into something called a "GravityLight". Designed for rural 3rd world areas. Uses a gear mechanism to turn a slowly falling weight into electricity to power a light. Just reset the weight by hand every hour or so to get "free power". The problem with gifting solar systems into remote areas is the difficulty of providing service. When something (the batteries) go bad, they have no way to repair it.

[Mike90250]

Ditto on the battery problem. Batteries will be abused, river water added to them will ruin them, Being run flat, leaves covering the solar panels, and the fuel for the generator. Couple cloudy days with low batteries, and they are ruined, unless the generator is run to charge them.
While a solar power plant is a very generous gift, without a Plant Engineer there to maintain it, it is really good money wasted.

Having said all that, there are several stickies in the off-grid section covering design of power systems. The very first step is to accurately determine the daily watt-hours required, then the battery size is chosen, and finally the solar PV array is sized to charge the battery bank. And it becomes very expensive to make a mistake, and end up with either an over built $$$$ system, or one that is too small, and cannot support the loads. Like a 2 seat car is fine for a newly married couple, but, when children come along, you need a larger car, you can't just add an extra seat .

[malachiuri]

Fede123, Please contact me at malachiuri@gmail.com.

I was in Siem Reap in October and was touched by the poverty, but also by the tremendous people we met. I would like to help you fund your work with the school.

M

[dennis461]

I work for a wordwide company in the energy sector.

A word of caution, do not put anything on the roof without an engineering study.

You will be liable if the roof caves in.