Hi, I’m doing a school project. We are required to design a classroom which exists in a "storage" container, with the idea that this classroom could host 25 learners and be self-sufficient so that it would be able to be used in rural settlements.
What is the easiest and cheapest method of using solar energy? The energy would only need to be used in winter for lighting and maybe a heater/radiator of some sort.
Ideas????
Windows. They will give plenty of light and are much cheaper than trying to make electricity with solar panels and changing it back into light again.
I have designed solar systems for rural schools. It is easy to provide enough electricity for lights, as long as you use lights that don’t use a lot of electricity. CFL or LED lights make a good amount of light, but don’t use a lot of power. Heating the room can be a little more complicated, but it is still possible. You would use different types of solar panels for heat than you would for electricity.
Lights: let’s say four 13W CFL lights (equal to 75W each with incandescent lights) for 5 hours.
4 x 13W x 5 hours = 260 watt hours a day. I don’t know where this project is, but let’s say in the winter you get 3 sun hours. 260 wh / 3 sun hours / .67 inefficiency = 129 watts of solar panels needed to make enough electricity for 1 day of lights. You can get a 135W solar panel for around $400, http://www.altestore.com/store/Solar-Panels/Kyocera-KD135SX-UPU-135W-12V-Solar-Panel-with-J-Box/p7945/
Then you need to store that electricity in a battery. I’m not going to get into the math, but you need about 70ah battery for every day you want to store the power. That’s another $150 http://www.altestore.com/store/Deep-Cycle-Batteries/Batteries-Sealed-Agm/Universal-Ub12750-12V-75Ah-20Hr-Sealed-Agm-Batt/p2002/
Now compare that with making heat. A typical space heater is about 1500W. 1500W x 5 hours = 7500 watt hours. Yikes! You’d need almost 4000W of solar panels to power that! A better way is to use solar thermal collectors, they are designed to capture the heat of the sun, even in winter, and heat the room. A solar air heater like this one for $1600 can heat up to 750 square feet http://www.altestore.com/store/Solar-Air-Heating/Your-Solar-Home-Solarsheat-Products/Your-Solar-Home-1500G-Glazed-Solar-Air-Heater/p2282/ . It will only heat on sunny days, so you would need something else that can store heat, but on sunny days, this heater works great!
A more complicated solar thermal system heats water, and stores the hot water in a tank. Then that hot water can be used day and night, even on cloudy days, to heat the room, either through a wall heater or radiant floors (tubes running hot water under the floor). These systems will cost a bit more, but much less than trying to make enough electricity to run an electric heater. You can see a description of the system heating my house at http://www.altestore.com/gallery/Amy-Beaudet-gallery/v/9358727169/amys_water/
Solar Cell(also known as photovoltaic i wont recmmd. solar heater as it is unreliable). Cheap or Expensive depends on the efficiency. Higher efficiency = higher cost 🙂
-efficiency(%) in terms of ability to absorb the UV or solar energy
things you need to know in a Photovoltaic system(a fully integrated circuit)
1)absorbs solar or light(specifically UV light) energy and converts it to electrical energy
2)able to store excess electrical energy for later use(in the night where there isn’t any sunlight)
3)many applications for solar power
4)main adv. sunlight is free, doesn’t pollute the environment
main disadv.: you need the capital(cash) to build and patch up a photovoltaic system
cheers
I already have seen Solar Lighting being put in our new schools where I live and I really think it will save on the cost for heat; electrcity. I`m not really sure if you can buy a piece of solar panels from a store that carries it or maybe you could ask a Salesperson if they have any scraps that you could use for your project. It wouldn`t hurt to ask. Good Luck!
It is possible but very expensive to build a solar system that will make a room the size of a classroom "Self Sufficient" in winter period. May even be practically impossible if located where a lot of cloudy days are experienced.
At least the projects design and cost calculations may open your students eyes to the fact that Solar power is not easy and cheap like the news media likes to make us believe.
I have studied solar power for years. My first guess is you would spend over $100,000 and still not have a system that could support the goal of "Self Sufficient" unless class is willing to spend many days bundled up in freezing temperatures. May be possible in an area like Arizona or the Sahara desert.