October's/November's Question of the Month Due to time constraints there was no November/October QOM
August's/September's Question of the Month Subject: Game Boy Question:
I only like game boy. What is this solar anyways?
Answer:
Check out the new Nintendo's Game Boy Advance cartrigde
"Boktai: The Sun is in
Your Hands" from Konami. Its the first game to incorporate sunlight in the game plan.
with a solar sensor in the cartridge.Sunlight also plays a part in the game itself. The bad guys are stronger with less light, the good guys are stronger with more light.
Boktai's creator says he wanted to combine the natural world and the video game world.
Release date is September 16th/17th. And don't forget you can recharge your
batteries with solar power too.
July's Question of the Month Subject: Safe Water Question:
I’m worried about some of the news I see on tv. Can I use solar to help me get safe drinking water in an emergency?
Answer:
Yes, solar purification is a viable option.
http://www.sodis.ch/ Describes a solar water disinfection process that improves the
microbiological quality of water. That means it’s good against bacteria, virus, and various parasites but it WON’T eliminate various chemicals or radiation that may or may not be present. (They do describe a similar process to remove arsenic though)
http://solarcooking.org/solarwat.htm “Summary of Water Pasteurization Techniques”
Describes not only water pasteurization techniques, but also how to build a water pasteurization indicator.
http://www.itdg.org/html/technical_enquiries/docs/solar_distillation.pdf is an excellencent document in pdf format that describes solar water distillation. This method
is effective against bacteria, virus, and various parasites, chemicals(except those with a lower vapour point than water) and can even remove or reduce radiation from fallout
by removing the irradiated particles. Also if there is no avaible water of any quality, a limited amount can be extraxted from plant material if you use a solar pit still.
June's Question of the Month Subject: Alternate power source Question:
I am interested in setting up an Alternate power source for my home. I live in the Tropics and since tropical region have an abundant sunshine, I have decided to use the Solar Energy as an Alternative source of Energy.
This is where I need your expertise in this subject.
Kindly advice as to:-
1) How big a Solar Panel would I need to generate .......watt of electricity daily?
2) What kind of Battery would I need to store the Electricity generated by the Solar Panels?
3) What all Materials would I need to build a Solar Panel at home?
4) How do I go about Building the Solar Panel?
5) Once finished how do I link it to my House's electric lines/terminal?
As you can see, I require to have all the information from Scratch to Finish.
I would be greatly indebted to you if you could help me out by giving me your valuable expertise in this matter.
Thank you for your time and consideration, awaiting your positive and speedy reply in this regard.
Yours Sincerely
Vinod Kumar Menon
From
The Republic of India.
Answer:
The first thing you will need to do is a load analysis
to determine how much electricity you anticipate needing.
Are you expecting to run just a few efficient lights and
a radio or small tv. Or are you planning to run a washing
machine or heating/cooling systems and cooking equipment.
If you are connected to the grid now, your electric company
will have records of your previous usage. If you plan no
change of lifestyle or habit, you can use this figure
(It will most likely be in kilowatt-hours).
If this is not available, you can calculate it yourself
Write down the wattage of the devices and the
approximate amount of time you plan on using them a day.
Example Load Analysis
watts
hours a day
watt-hours a day
Compact fluorescent light(120ac)
18
0.5
9
LED light (3voltdc)
0.1
5
0.5
Radio (1.5voltdc)
0.5
2
1
Total watt-hours a day = 10.5
The storage capacity of a battery is rated in ampere-hours
To figure out how big of a battery (or battery bank) you need first convert watt-hours to ampere-hours using the following formula
Current expressed in amps = Power expressed as watts / Voltage
Don't use the voltage of the appliances here but rather the voltage of your battery. Assuming a 12volt 30 ampere-hour car battery for this example we have
10.5 watts / 12volts = .875 amps
which is well within the safety margins for example battery so that we don't draw out too much power and cause sulfation or draw it out to fast and warp the plates. In addition if there are days in which power can not be generated(i.e. cloudy weather) it is best to have
a reserve of power to allow for this. In actual fact our example battery could be scaled down considerably and still have an ample safety margin on all points.
Deep cycle lead acid batteries ("marine style" or better) are the preferred battery. However for most applications standard ("car style") lead-acid batteries are fine. Whichever type you get they need to be properly maintained for maximum usable life.
Larger systems require the use of a charge controller & low voltage disconnect to protect the batteries.
I am uncertain as to whether you want to a) join cells together to make a panel or b) create the solar cells from scratch.
In the case of a) Besides the physical & electrical joining of the cells, don't forget they have to be properly located and properly mounted (so they don't fall off or create water leaks).
In the case of b) I know of no way to build an efficient silicon solar cell. The copper oxide solar cells that can be made at home are so inefficient that one would need a large roof's worth to operate a small LED light. (If you are curious about them see http://www.scitoys.com/scitoys/scitoys/echem/echem2.html or
http://www.angelfire.com/ak/egel/solcell.html)
It is much more practical to use a home built windmill or waterwheel where conditions allow, or where they do not, to use concentrated sunlight (via lens or mirrors) to drive a
Stirling engine.
Either way, if you plan on using standard household ac appliances, instead of dc appliances made for for car or marine use, you will need to convert the dc power your system produces and stores into ac power using an inverter.
This should be your first step. There's much more including
selecting the correct size and type of wire to limit voltage drops. However, I am reluctant to go any further until I more clearly understand your present situation and your ultimate goals for this project so I may assist you better.
PS If you are on grid power linking into your house mains
can be very dangerous if you aren't very careful and understand fully what you are doing. You will also need a "auto disconnect switch" which will disconnect from the grid if the grid power fails. This is so that line workers are protected and so that the inverter does not attempt to provide power to the immediate neighborhood.
I have no knowledge of any laws or regulations in your area, but be advised in some places special permits are required for any electrical work.]
May's Question of the Month Subject: Off Grid distant power Question:
I am building a micro hydro system. I want to run power to a cabin that is about 1200 feet from the source. I would like to end up with at least 120V at the cabin.
What is the most cost effective way to cover the distance?
I will be using an ES&D turbine which can generate 12, 24 or 48V DC. I plan to install a battery bank (Trojan)not far from the turbine. Then invert to 220V or 440V with a Trace inverter.
Power consumption would be small since it is a "weekender" kind of cabin.
Most Trace 60hrz inverters have a 220 or 120 output. If I use 220 I'd loose a lot in the line without buying lots of copper. Can you make any suggestions?
There is no closer site to build the cabin on from the most efficent "run" onn the creek.
Answer:
More data would be helpful, but let's start with what you have and go from
there. First, the higher the voltage, the lower the current for a given power
level. In other words, if you ran 120 volts from the turbine and required 1200
watts at the cabin, you would be sending 10 amps through the cable. If the
turbine produced 240 volts, you could achieve the same power level (1200 watts)
by sending only 5 amps. And with a three wire cable, the 240 volts could be
split at the cabin into two 120 volt utilities (but balancing the load is
important!). At 1200 ft, this will definitely impact your cost.
Although there are advantages to both underground and aerial, I will assume
that you will be running your cable underground. In which case, you can get
away with UF (underground feeder) type cable. This will be less expense than
running 1200 ft of conduit or placing 60 poles. If you are going aerial, let
me know as it will impact (slightly) the calculations.
Now lets look at the size wire needed. Regardless of the voltage involved
(to a degree anyway), the size of the wire will be determined by the length of
the run and the amount of current passing through it. For example, allowing
for a 2% drop in voltage at 10 amps (120 volts), you will need at least 1/0
wire (personally, I would go with 2/0). At 5 amps (240 volts) a #2 would work.
By the way, when doing this project, it is very important to have breakers on
both ends of the 1200 ft run. I don't usually agree with the electrical code,
but this is important.
If your anticipated load is not 1200 watts the following formula may be used to calculate the diameter of the wire needed.
Circular mils = (D * I * 22) / VD
Where :
Circular mils = the diameter of the wire
D = distance in feet (one way)
I = current in amperes
22 = a constant for use with copper wire (using aluminum wire [please don't], use 36 instead)
VD = the acceptable voltage drop in volts
By the way, I'm using the term watts as volt-amperes. This assumes that your
power factor will be 100% (resistive loads like heating devices, incandescent
lights, etc.). If the power factor is lower, it will change the formulas. But
this will give you a "worst case" scenario.
Also electrical code varies from country to country, and within the US, it varies, to some extent from state to state so be sure to get whatever permits and approvals you need before hand!
I hope this has helped you somewhat.
April's Question of the Month Subject: solar radiation Question:
Can you tell me how much solar radiation falls on illinois in one year in terms of kilowatts. any part of illinois is fine.
Answer: You looking for this state of Illinois site.
The solar resources are expressed in watt-hours per square meter per day (Wh/m2/day).
Actually they include two maps one for Flat-Plate Collectors and one for Solar Concentrators so you can find the one that suits you best.
Unless this is a homework question, in which case you want the flat plate map and be sure to convert watt-hours into kilowatts like you wanted ;-)
March's Question of the Month Subject: tank heaters Question: In this part of the country (nebraska) we use electric or propane heaters to keep our cattle watering tanks de-iced. Temperatures often are as low as 10 degrees F. or lower.
Has anyone devised a heater for this purpose? An electric 1500 watt heater does an adequate job on a 250 gallon tank. It has crossed my mind to convert the power from a solar panel to 120 volts and plug in the heater. I think smaller wattage heaters are made, which would necessitate a smaller tank of course.
Opinion/advice please, thank you very much.
Answer: I'm afraid I'm totally unfamiliar with cattle raising and had to research your question a bit. Also I am unsure of the size of your herd and budget for this project so please excuse me if some of these solutions seem better suited to a smaller or larger cattle operation than yours.
Buytack.com sells a solar powered watering trough for horses and cattle that they guarantee to 50F degrees below zero. You can fill with a garden hose or have a direct line attached with auto fill and shut-off float to keep full. It's $639.
Cleardomesolar sells an affordable water trough/pond water heating pad, although I'm not certain it's well suited to your area.
The October, 2000, Farm & Food Report from Saskatchewa tells of a Large-Volume Water Trough that holds 6,400 gallons. The total cost is about $1,700. It doesn't use solar, it apparently use the thermal mass of the water itself to keep it from freezing.
As far as using solar generated electricity a 1500watt heater is consuming about 13amps at 120volts. In converting 12volt dc solar panels through an inverter to supply this much power would require quite a lot. Consider the cost of the panels(with a likely best possibly price of around$3 per watt), charge controller, batteries, and inverter. Even on sale this could be a long "pay back".
Also, have you considered the option of burying the tank? Even in Nebraska there's a depth at which water will not freeze.
The passive water heating systems I'm most familiar with are homemade systems that recirculate water through a grid of black pipes on a heat retentive surface (bed of black gravel ect.) Something like this may be your most economical solution if you like to "homebrew". At least it should greatly reduce the amount of energy required.
See this example from Homepower.
January's/February's Question of the Month Due to time constraints there was no January/February QOM
All "Question's of the Month" are subject to editing for space and general readablility.
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