How to Make a Solar Power

Generator for Less than $300

Frequently Asked

Questions about the Solar

Power Generator

How to Make a Wind

Turbine out of a Hank-

Crank Flashlight

by Phil Heiple 2010 SolarWind Press

How to Make a Solar Power Generator

for Less than $300

by Phil Heiple

Using parts easily available from the internet (see helpful

links) and your local stores, you can make a small solar

power generator for $250 to $300. Great for power

failures and life outside the power grid. Power your

computer, modem, vcr, tv, cameras, lights, or DC

appliances anywhere you go. Use in cabins, boats, tents,

archaeological digs, or while travelling throughout the

third world. Have one in the office store room in case of

power failures in your highrise. I keep mine in my

bedroom where it powers my music, lights, dvd player,

laptop, and (ahem) a back massager. I run a line out the

window to an 8" x 24" panel on the roof. This is the

smallest simplist set-up practical for daily use. It saves

me about five dollars a month off my electric bill.

1. Buy (or make) yourself a small solar panel. For

about $100 you should be able to get one rated at 12

volts or better (look for 16 volts) at an RV or marine

supplies store

2. Buy yourself a battery. We

recommend rechargeable

batteries from green companies.

Get any size deep cycle 12 volt

lead/acid or gel battery. You

need the deep cycle battery for

continuous use. The kind in your

car is a cranking battery--just for

starting an engine. Look for

bargains, the cheapest ones

should cost about $50-60.

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3. Get a battery box to

put it in for $10. (This is

good for covering up the

exposed terminals in case

there are children about If

you going to install the

system in a pump shed,

cabin, or boat, skip this.)

3. Buy a 12 volt DC meter. Radio Shack has them for about

$25.

4. Buy a DC input. I like the triple inlet model which you can

find at a car parts store in the cigarette lighter parts section for

about $10. This is enough to power DC appliances, and there

are many commercially available, like fans, one-pint water

boilers, lights, hair dryers, baby bottle warmers, and vacuum

cleaners. Many cassette players, answering machines, and

other electrical appliances are DC already and with the right

cable will run straight off the box.

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5. But if you want to run AC appliances, you will have to invest

in an inverter. This will convert the stored DC power in the

battery into AC power for most of your household appliances. I

bought a 115 volt 140 watt inverter made by Power-to-Go at Pep

Boys for $50. Count up the number of watts you'll be using (e.g.,

a small color television(=60 watts) with a VCR(=22 watts),

you'll need 82 watts.

Inverter

6. Use a drill to attach the meter and DC input to

the top of the box.

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7. Use insulated wire to attach the meter to the wingnut

terminals on the battery. Connect the negative (-) pole first.

Only handle one wire at a time. Connect the DC inlet to the

battery in the same way. Connect the solar panel to the

battery in the same way.

8. Close the lid (I use a bungee cord to keep it tight). Put the

solar panel in the sun. It takes 5-8 hours to charge a dead

battery; 1-3 hours to top off a weak one. It will run radios,

fans, and small wattage lights all night, or give you about 5

hours of continuous use at 115 volt AC, or less than an hour

boiling water. This system may be added on to with larger

panels, inverters, and batteries.

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Options: A pop-up circuit breaker may be added between the

positive terminal and the volt meter. Some of you will want an

ampmeter as well. The panels I recommend have built-in

bypass diodes, but I recommend charge controllers for people

who have panels without diodes. Another option is a voltage

regulator, which is not necessary for a system this small, but a

larger system would require one.

Basic Solar Power Generator

8" x 27" MBC-131

Uni-Solar soft panel

Rated power (Watts, peak): 5.50

Typ. 12 Volt Charging (Amp. Hrs/Wk) 13.00

Voltage, Typ. Max Power (Volts) 15.60

Current, Typ. Max Power (Amps) .35

Weight (pounds) 1.5

10 feet cable with battery ring,

terminals, fuse, and convenient

2 pin plug

Technical specs for this little solar box.

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Copyright Boa Boy Productions 19196, 2008, 2009, 2010, Phil Heiple all rights reserved.

Frequently Asked Questions 1. How many appliances can I run off your system? "How many" refers to the total number of watts required.

Different appliances use different amonts of watts. You don't need to know what a watt is; you only need to count up how many total watts your appliances require. Your television, your laptop, even your hair dryer will have a little nameplate somewhere listing how many watts, volts, and amps it takes. Sometimes it only lists the volts and amps. To figure out the wattage, multiply the volts times the amps.

Here's the formula: Volts X Amps = Watts.

That will give you the watt hour load. For example, add up all the wattage on all the light bulbs you will be running off it. Two sixty watt light bulbs means 120 watts. Add an inkjet printer (35 watts), computer (55 watts), 17" LCD flatscreen monitor (45 watts), and a cellphone (5 watts) and your office is fully running at 260 watts. Get an inverter of at least 300 watts.

You will quickly learn how inefficient many of our everyday items are. For example:

Microwave 900-1500 Coffemaker 1200 Toaster 1200 Food dehyrater 600 Dishwasher 1450 Hairdryer 1500 Electric iron 1200

A sun oven could replace all of them for free. (Well, maybe not the hairdryer--I don't recommend sticking your head in a sun oven.)

Other equipment:

10" table saw 1800 1/2" Hand drill 600 Vacuum cleaner 900 Laser printer 900

So the best thing to do is figure out your minimum needs, and then buy an inverter that at least covers that, or better still, buy the biggest inverter you can afford. Then you can add on to it.

2. How long can I run them? "How long" refers to the total number of amps required.

Again, you do not need to know what an amp is other than it is the unit for measuring how long your set up can help you out. An amp hour (AH) is how many amps required to run it for an hour. A kilowatt hour (KWH) is how many kilowatts are needed in an hour. How many Watt-Hours in a battery?: Watts are pretty simple - it is just battery voltage times amp-hours. A 12 volt 105 AH battery can supply (under perfect conditions and to 100% discharge) 12 x 105, or 1260 Watt-hours (1.26KWH).

Here's the formula: Amps = Watts/Volts

The amps listed on your appliance are probably listed in milliamps (mA) or thousanths of an amp. An alarm

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clock takes about one. A refrigerator will need a few amps. A toaster will take more amps than a refrigerator, but runs for only a few minutes.

BUT, deep-cycle batteries can only be discharged to about 50% of their capacity without damage. In other words, you can expect a 100 amp-hour battery to supply around 50 amp-hours of power between charge cycles without suffering damaging. THEREFORE: get a battery with twice the amps you think you'll need. Then test your battery with a meter.It should always be in the 80-90% range. If you use a charger, then you need to take a reading ONE HOUR after any charging cycle. It is important to wait this hour because all batteries hold a surface charge that will give you a false reading after charging. All deep cycle batteries are rated in amp-hours. An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps x hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) x .333 (hours), or 6.67 AH. The accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured.

3. Can I run my refrigerator off your system? (No.) Your refrigerator is too inefficient. As much as 20% of an average home's energy usage is for the frige. Even small dorm-sized models draw too much for a practical solar system.

But you can invest in a 12-volt DC powered refrigerator. The best ones use zero maintenance, brushless, thermostatically controlled DC compressors. They cost about half as much as propane refrigerators, with a small one starting at about a thousand dollars. You will also need a bigger panel; a 75-100 watt solar panel would do it for most. Unless you live in the very cold northern latitudes having short days and low sun angles, most parts of the United States will average 4 to 4.5 hours of direct sun per day during the winter months and 5 to 6 hours per day during the summer months. Of course, some milder geographic locations may also have lots of rainfall and cloud cover, which reduce these average hourly values. As an example, if you select a refrigerator or freezer that requires 40 amp-hours per day to operate, this means you will need a solar array that can provide at least 10 amps output (40 amp-hour/4 hours) during the winter, and 6.6 amps output (40 amp-hour/6 hours) during the summer. If your solar system will be used year-round, then you may want to use the smaller sun-hour value. Since the ambient air temperatures are cooler in the winter than summer, all refrigerators and freezers will require less energy to operate during colder months, so a more accurate winter calculation would use the amp-hour load given for lower ambient temperatures.

Nova Kool and Sundanzer both make 12- and 24-volt DC powered refrigerators. Some are AC/DC. You can order them from Solar Sphere.

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Some Nova Kool and Sundanzer both make refrigerators are AC/DC. (That would

be perfect for rolling blackout areas--most of the Third World. They live on AC

and then automatically switch over to the DC battery when the power goes out.)

But let me break down what else you will need.

A small 1.8 cubic foot capacity model REFRIGERATOR will require a 45 watt

solar panel, a 60AH battery, and a 15 amp charge controller.

A FREEZER is also 1.8 cubic ft. but requires a 110 watt solar panal, a 150 AH

battery, and a 15 amp charge controller.

A 8.1 cubic ft. capacity freezer gives you over four times the capacity at less than

twice the price but will require a 215 watt solar panel, a 300 AH battery, and a 15

amp charge contoller.

4. "Does it matter how thick my wires are? I put my solar panel on the roof and it

doesn't deliver as much power to my battery as before, when it got less sunlight.

Um...what's an ohm?"

These are all the same question. Electricity flowing through a wire must overcome

resistance to get from one end to the other. A thicker wire has LESS resistance than

a thinner one. A wire twice as thick has half the resistance. A longer wire has more

resistance than a shorter one. The amount of resistance is measured in ohms. When

one volt causes one ampere of current flow, the resistance is one ohm. You can buy

an ohmmeter to measure your ohms, but electricians mainly use them to find

defective connections.

DC electricity is more vulnerable to resistance than AC. That's why the battery in

your car has short, thick cables.

So, use wires as thick as practical. The wires from the panel to the battery should

be as short as possible. Carry the battery up to the roof if you have to. Then a short

connection to the inverter. And then a long line can go from the inverter to you

(because it is AC).

A digital multimeter will test ohms as well as voltage, current and other useful

stuff:

5. "In your instructions you say to buy a DC meter. What's it for?"

The DC meter lets you know how much of a charge you have in the battery.

Remember, you don't want it to discharge more than 50%. And you don't want to

damage it by overcharging. The DC meter (one of the settings on a multimeter)

will allow you to monitor the state of your battery.

6. "Can your system pasteurize water and milk?" (Yes)The original question was "Can your system boil water long enough to make it safeto drink?"Yes, it can. But it is a myth that drinking water has to be boiled for ten minutes.Pasteurization is achieved at a lower temperature for a shorter period. For bothwater and milk (or anything) all the necessary germs (including E. Coli,Rotaviruses, Giardia, the Hepatitis A virus, and Colera) are dead after having beenraised to a temperature of 160 degrees F (72 degrees C) for one minute.Therefore do not waste the precious stored energy of the battery by bringing thetemperature up higher than you need to. Heating water is probably the mostinefficient use of this system. A sun oven would do the job more efficiently withthe sun rays--assuming it was in the daytime, sunny, and safe to go outdoors. They work really good and are a lot of fun. But they cost about $240 each. Theyreach 300 degrees F and higher. BUT, if all you want to do is pasteurize, ahomemade sun oven made out of cardboard and tin foil should be able to get you inthe right temperature range. Use a thermometer to be sure. Health care providerswill want to test their results. One way this can be done is with a nifty little devicecalled a "pasteurization indicator." You can get one for about nine bucks from myfriends at Solar Sphere."So with a few thousand cardboard boxes, a few hundred rolls of aluminum foil,and the proper guidance the Cholera epidemic in Haiti could have been preventedand 1,751 lives (as of Nov. 30, 2010) could have been saved?"Yes. This is no joke.BUT, if all you have is the solar power generator pasteurize with, here is thesmartest way to do it: First of all, don't use an inverter to power a microwave orelectric range. This will suck your battery dry very quickly. Instead, use directconnections with the battery. There are a variety of devices that plug directly intocigarette lighter ports. These range from little dip-in infusers to 20-oz. coffee pots.And still the best way would be to monitor what you are doing and only raise thetemperature for as high as you have to for as long as you have to. These littlebeasts take about 20 amps each. I have to warn you that these immersion heatersare dangerous (the dip-in model can brand you) and the other two will permanentlyself-destruct if you keep them plugged in without any liquid in them just once.

Copyright 2010. SolarLight Productions.

How to Make a Wind Turbine

out of a Hank-Crank

Flashlight

by Phil Heiple

SolarWind Press

2010

Using parts from a hand-crank flashlight and a few household items, you can make a

small wind turbine that generates electricity. You can even rig it up to recharge your

batteries. This is an easy to make demonstration device of self-sustaining non-

polluting renewable electricity...

You will need:

One hand-crank flashlight

a very small phillips screwdriver

three nails

a wooden ruler

one rubber band

one pencil top eraser

one sheet of cardstock

a one-inch piece of dowel

some really good glue

A piece of cardboard for the rudder

A pole to mount it on

1. Get yourself a hand-crank flashlight.

2. Remove the tiny screws and open it up. one side has the crank and a nifty set of

gears. The other side has a circuit board with the generator on one end, battery, on/off

button, and LED lights on the other end. Lift out the circuit board.

3. The generator has a little gear on its back. I found it too short to attach a

propeller to, so I glued a short one-inch piece of dowel to it (I used Gorilla Glue).

Let it dry overnight.

4. Cut the generator off the circuit board, being careful not to break the wires going

from it. (I used wire cutters to snip through the plastic.) Turn it vertical and attach

it to the end of the wooden ruler with two small nails through the holes the screws

were in. Attach the rest of the circuit board flat to the ruler with a rubber band.

5. Stick the rubber eraser over the dowel.

6. Now the propeller. I made a simple pinwheel out of a page of cardstock that I

cut into a 8 1/2 by 8 1/2 square. Instead of a pin in the middle, I stapled the flaps in

at about a inch from the center. Then I cut a small square in the exact center,

slightly smaller than the eraser. Then I gently pushed the pinwheel over the eraser

and it locked in place.

7. Blow at the pinwheel. It should spin freely. You are in business.

8. Make a rudder for the other end of the ruler. I used a scrap piece of foamcore

about ten inches by seven inches and just cut a slot in it and slipped it over the

ruler, which had a useful groove down the middle. The rudder fitted nicely without

any glue.

9. Find the center of balance by balancing it on your finger. Drill a small hole at

the balance point. Get a pole and attach your wind turbine to the post with a flat

head nail smaller than the hole. Be careful to only hammer the nail in so far. Wind

turbine should rotate freely.

10. Take your wind turbine outside. A gentle breeze is all it takes to get it spinning.

The battery was as dead as a doornail when I started. After 30 minutes of spinning,

I pushed the on/off button. Viola! The LED lights lit up!

How to Recharge Your Batteries

How to Recharge Your Batteries: recharge your batteries by taping them to the

ruler and then running wires from their poles to the leads going to the 3.6 volt

battery. Connect positive to positive; negative to negative. Line your batteries up

positive to negative. Two AA or AAA batteries (1.5 volts each) can be recharged at

a time. Unlike a charger plugged into the wall, recharging this way doesn't use

electricity generated by coal, other fossil fuels, or nuclear power.

Strong, gusty winds will tear this apart. So will rain. So try making the pinwheel and

rudder out of tin or plastic. And cover up the exposed circuits with a styrofoam cup

cut in two or a plastic bag.

Putting washers above and below the ruler on the nail will help it rotate around the

pole.

You can glue the propeller and rudder on. Make a better propeller.

Attach it to your bike and recharge your batteries as you pedal.

By Phil Heiple copyright 2010 SolarWind Press