Friday, May 29, 2009

Solar Air Heaters

A little idea I was playing around with is making a solar air heater for next winter. Usually they force air through a box that is essentially a solar oven. But a lot of heat is lost on the glass and even through the walls of these devices. So, they end up using special glazing or double walled glass to add insulation value. Also, they can actually add insulation to the walls as well.

But what if you used air itself as the insulator.

I'm not a huge fan of solar photovoltaic due to its price. Although I have 3 of them, each 120 watts. They can be made cheaper by building them yourself though. But using the sun's heat is usually cheap and efficient. A typical PV panel is about 15% efficient, but solar hot water or air heater is about 50% to 70%.

Basically it is just plywood walls and that transparent sheeting (2 feet by 8 feet). There is a 8 foot length of flat black stove pipe run through the middle. And the walls are covered in shiny mylar or aluminum foil. Each pipe would get sun on every square inch and the pipe is super insulated by the hot air surrounding it. Assuming this is at least 50% efficient, then this would be about 1,000 watts of power or about 3,400 btu per hour. You can string these together and get more power. You would want to use a squirrel cage fan that has some power to push the air if you have more than 2 or 3 of these though.
Notice too, that the glazing is at a 45 degree angle. If you put it on a roof that has a 45 degree angle, then the glazing will be at 90 degrees. This would be great for the low winter sun. Most houses have a more shallow angle, like maybe 30 degrees. Still, that would be 75 degrees, great for the low winter sun.

Also, if you put it on the ground and have a higher exit and low input, you would have a thermosiphon system. The colder air at floor level would "fall" outside and into the solar heater bank. Then as it heats up it rises into the house through another pipe connection. You would need flaps on it at night so it shuts down air flow at night, otherwise it would become a cooler instead of a heater.

I'd like to test this sometime, we'll see.


Wednesday, May 27, 2009

windmill ebook cover testing

I am tired of my Wind Power and Battery Systems book cover so I decided to experiment and come up with a new one. Here is the old one.And here is the new one. The background in the picture below was taken a couple of blocks from my home.

Also, I started working on my Grid Tie experiments today. Just getting the stuff together to start. I have a large wooden pulley and a DC motor and an AC induction motor and a rubber belt. I'll be using my kill-a-watt meter for testing. I have a pwm 12volt motor controller for changing the speed during the testing.


Tuesday, May 26, 2009

Hooking up the other stuff

Today, I will briefly touch on how to hook up a battery bank, fuses, load dump controller, and inverter. The following example in the picture isn't the only way to do it, but it is a good "poor man's" alternative. You could just hook up the battery straight to the windmill with just a diode in line. Then the battery could have a inverter hooked to it and no dump load controller or charge controller of any kind. In that case you would have to watch and make sure the batteries don't overcharge and you might have to turn on some more lights, tv, etc. to put a load on the inverter.

Another extreme entails all expensive equipment from the charge controller all the way to $6,000 inverter banks. I have chosen for my example a more simplistic and cheaper alternative.

In the above picture there is wire going from the windmill to the battery bank. The thickness of that wire depends on the length of wire and how many amps it is to take. This gauge number can be calculated by the "DC Motor Analyzer" software.

The shunt is a piece of stainless steel. This is described in my book Poor Man's Guide
to Homemade Amp Meters and also shown in the Shunt Designer software. By flipping the toggle switch to the right, the meter reads the battery voltage. If you set the meter to milivolts and flip the toggle switch to the left, then every milivolt is equal to 1 amp. For example, 5.4 milivolts would be 5.4 amps.

The breaker is there to protect the generator if furling doesn't happen at the right time. It should be rated at about 3 to 4 times the amp rating for the generator. The inverter has to be connected with very thick cable and never longer than 10 feet. I use 10 feet at double 0 gauge. The fuses for the inverter and the dump load controller should be mounted as close to the battery as possible. The size of the fuse just depends on how many amps you expect to draw. For example, if I had a 1500 watt inverter and I expected up to 2400 watt surge when starting a motor, then 2400 watts divided by 12 volt battery would be 200 amps. If it were a 24 volt battery, then that would mean 100 amps.

The dump load controller can be found here.


Friday, May 22, 2009


This list is taken directly from

Useful Energy Conservation Tips

For Consumers:

In the winter, turn your thermostats down to 68 degrees or below. Reduce the setting to 55 degrees before going to sleep or when leaving for the day. (For each 1 degree you turn down the thermostat in the winter, you’ll save up to 5% on your heating costs.)
Turn off and un-plug non-essential lights and appliances. The electricity generated by fossil fuels for a single home puts more carbon dioxide into the air than two average cars!
Avoid running large appliances such as washers, dryers, and electric ovens during peak energy demand hours from 5:00 a.m. to 9:00 a.m. and 4:00 p.m. to 7:00 p.m.
Close shades and blinds at night to reduce the amount of heat lost through windows. This also applies during the day for warm climates.
Buy Energy Star appliances, products and lights.

For Business:

In the winter, turn your thermostat down to 68 degrees or below. Reduce the setting to 55 degrees at the end of the day. (For each 1 degree you turn down the thermostat in the winter, you’ll save up to 5% on your heating costs.)
Turn off all unnecessary lights, especially in unused offices and conference rooms and turn down remaining lighting levels where possible.
Set computers, monitors, printers, copiers and other business equipment to their energy saving feature and turn them off at the end of the day.
Minimize energy usage during peak demand hours from 5:00 a.m. to 9:00 a.m. and 4:00 p.m. to 7:00 p.m.
Buy Energy Star appliances, products, and lights.
Consider placing outdoor signs on a timer so they only run until 1:00 am,saving electricity during non-peak hours.

Tips for Kids and Teachers:

Choose an energy monitor for your classroom every week who will make sure that energy is being used properly.
At home, hold a ribbon up to the edges of windows and doors. If it blows, you’ve found a leak. Tell your parents.
When you leave the room, turn off the light.
Here are some more detailed tips to help you conserve energy.

Heating and Cooling Tips

Set your thermostat as low as is comfortable in the winter and as high as is comfortable in the summer.
Clean or replace filters on furnaces once a month or as needed.
Clean warm-air registers, baseboard heaters, and radiators as needed; make sure they’re not blocked by furniture, carpeting, or drapes.
Bleed trapped air from hot-water radiators once or twice a season; if in doubt about how to perform this task, call a professional.
Place heat-resistant radiator reflectors between exterior walls and the radiators.
Use kitchen, bath, and other ventilating fans wisely; in just 1 hour, these fans can pull out a houseful of warmed or cooled air. Turn fans off as soon as they have done the job.
During the heating season, keep the draperies and shades on your south-facing windows open during the day to allow sunlight to enter your home and closed at night to reduce the chill you may feel from cold windows. During the cooling season, keep the window coverings closed during the day to prevent solar gain.
During the heating season, close an unoccupied room that is isolated from the rest of the house, and turn down the thermostat or turn off the heating for that room or zone. However, do not turn the heating off if it adversely affects the rest of your system. For example, if you heat your house with a heat pump, do not close the vents-closing the vents could harm the heat pump.
Select energy-efficient equipment when you buy new heating and cooling equipment. Your contractor should be able to give you energy fact sheets for different types, models, and designs to help you compare energy usage. Look for high Annual Fuel Utilization Efficiency (AFUE) ratings and the Seasonal Energy Efficiency Ratio (SEER). The national minimums are 78% AFUE and 10 SEER.
Look for the ENERGY STAR® labels. ENERGY STAR® is a program of the U.S. Department of Energy (DOE) and the Environmental Protection Agency (EPA) designed to help consumers identify energy-efficient appliances and products.

Duct Tips

Check your ducts for air leaks. First look for sections that should be joined but have separated and then look for obvious holes.
If you use duct tape to repair and seal your ducts, look for tape with the Underwriters Laboratories (UL) logo to avoid tape that degrades, cracks, and loses its bond with age.
Remember that insulating ducts in the basement will make the basement colder. If both the ducts and the basement walls are uninsulated, consider insulating both.
If your basement has been converted to a living area, install both supply and return registers in the basement rooms.
Be sure a well-sealed vapor barrier exists on the outside of the insulation on cooling ducts to prevent moisture buildup.
Get a professional to help you insulate and repair all ducts

Heat Pump Tips

Do not set back the heat pump’s thermostat manually if it causes the electric resistance heating to come on. This type of heating, which is often used as a backup to the heat pump, is more expensive.
Clean or change filters once a month or as needed, and maintain the system according to manufacturer’s instructions.

Solar Tips

Keep all south-facing glass clean.
Make sure that objects do not block the sunlight shining on concrete slab floors or heat-absorbing walls.
Consider using insulating curtains to reduce excessive heat loss from large windows at night.

Fireplace Tips

If you never use your fireplace, plug and seal the chimney flue.
Keep your fireplace damper closed unless a fire is going. Keeping the damper open is like keeping a 48-inch window wide open during the winter; it allows warm air to go right up the chimney.
When you use the fireplace, reduce heat loss by opening dampers in the bottom of the firebox (if provided) or open the nearest window slightly-approximately 1 inch-and close doors leading into the room. Lower the thermostat setting to between 50 and 55 degrees F.
Install tempered glass doors and a heat-air exchange system that blows warmed air back into the room.
Check the seal on the flue damper and make it as snug as possible.
Add caulking around the fireplace hearth.
Use grates made of C-shaped metal tubes to draw cool room air into the fireplace and circulate warm air back into the house.

Cooling Tips

Whole-house fans help cool your home by pulling cool air through the house and exhausting warm air through the attic. They are effective when operated at night and when the outside air is cooler than the inside air.
Set your thermostat as high as comfortably possible in the summer. The less difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.
Don’t set your thermostat at a colder setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and unnecessary expense.
Consider using an interior fan in conjunction with your window air conditioner to spread the cooled air more effectively through your home without greatly increasing your power use.
Don’t place lamps or TV sets near your air-conditioning thermostat. The thermostat senses heat from these appliances, which can cause the air conditioner to run longer than necessary.
Plant trees or shrubs to shade air-conditioning units but not to block the airflow. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.

Insulation Tips

Consider factors such as your climate, building design, and budget when selecting insulation for your home.
Use higher density insulation, such as rigid foam boards, in cathedral ceilings and on exterior walls.
Ventilation plays a large role in providing moisture control and reducing summer cooling bills. Attic vents can be installed along the entire ceiling cavity to help ensure proper airflow from the soffit to the attic, helping to make your home more comfortable and energy efficient.
Recessed light fixtures can be a major source of heat loss, but you need to be careful how close you place insulation next to a fixture unless it is marked. “I.C.”-designed for direct insulation contact. Check your local building codes for recommendations.
When installing insulation, follow the product instructions on installation and wear the proper protective gear.

Weatherization Tips

First, test your home for air tightness. On a windy day, hold a lit incense stick next to your windows, doors, electrical boxes, plumbing fixtures, electrical outlets, ceiling fixtures, attic hatches, and other locations where there is a possible air path to the outside. If the smoke stream travels horizontally, you have located an air leak that may need caulking, sealing, or weatherstripping.
Caulk and weatherstrip doors and windows that leak air.
Caulk and seal air leaks where plumbing, ducting, or electrical wiring penetrates through exterior walls, floors, ceilings, and soffits over cabinets.
Install rubber gaskets behind outlet and switch plates on exterior walls.
Look for dirty spots in your insulation, which often indicate holes where air leaks into and out of your house. You can seal the holes by stapling sheets of plastic over the holes and caulking the edges of the plastic.
Install storm windows over single-pane windows or replace them with double-pane windows. Storm windows as much as double the R-value of single-pane windows and they can help reduce drafts, water condensation, and frost formation. As a less costly and less permanent alternative, you can use a heavy-duty, clear plastic sheet on a frame or tape clear plastic film to the inside of your window frames during the cold winter months. Remember, the plastic must be sealed tightly to the frame to help reduce infiltration.
When the fireplace is not in use, keep the flue damper tightly closed. A chimney is designed specifically for smoke to escape, so until you close it, warm air escapes-24 hours a day!
For new construction, reduce exterior wall leaks by either installing house wrap, taping the joints of exterior sheathing.

Water Heating Tips

Repair leaky faucets promptly; a leaky faucet wastes gallons of water in a short period.
Insulate your electric hot-water storage tank and pipes, but be careful not to cover the thermostat.
Insulate your gas or oil hot-water storage tank and pipes, but be careful not to cover the water heater’s top, bottom, thermostat, or burner compartment; when in doubt, get professional help.
Install nonaerating low-flow faucets and showerheads.
Buy a new water heater. While it may cost more initially than a standard water heater, the energy savings will continue during the lifetime of the appliance.
Although most water heaters last 10 to 15 years, it’s best to start shopping for a new one if yours is more than 7 years old. Doing some research before your heater fails will enable you to select one that most appropriately meets your needs.
Lower the thermostat on your water heater; water heaters sometimes come from the factory with high temperature settings, but a setting of 115 degrees F provides comfortably hot water for most uses.
Drain a quart of water from your water tank every 3 months to remove the sediment that impedes heat transfer and lowers the efficiency of your heater. The type of water tank you have determines the steps to take, so follow the manufacturer’s advice.
If you heat with electricity and live in a warm and sunny climate, consider installing a solar water heater. The solar units are environmentally friendly and can now be installed on your roof to blend with the architecture of your house.
Take more showers than baths. Bathing uses the most hot water in the average household. You use 15 to 25 gallons of hot water for a bath, but less than 10 gallons during a 5-minute shower.
Water heating is the third largest energy expense in your home, typically accounting for about 14% of your utility bill. Shorter showers, more efficient showerheads and lowering the thermostat on your water heater can help to decrease this expense.
Consider the installation of a drain water waste heat recovery system.

Cold-Climate Window Tips

Install exterior or interior storm windows; storm windows can reduce heat loss through your windows by 25% to 50%. Storm windows should have weatherstripping at all moveable joints; be made of strong, durable materials; and have interlocking or overlapping joints. Low-e storm windows save even more energy.
Repair and weatherize your current storm windows, if necessary.
You can save 10% or more on your energy bill just by reducing the air leaks in your home.
Install tight-fitting, insulating window shades on windows that feel drafty after weatherizing.
Close your curtains and shades at night; open them during the day.
Keep windows on the south side of your house clean to maximize solar gain.

Warm-Climate Window Tips

Install white window shades, drapes, or blinds to reflect heat away from the house.
Close curtains on south- and west-facing windows during the day.
Install awnings on south- and west-facing windows.
Apply sun-control or other reflective films on south-facing windows.

Tips when shopping for windows

When you’re shopping for new windows, look for the National Fenestration Rating Council (NFRC) label; it means that the windows are performance certified.
Remember, the lower the U-value, the better the insulation. In colder climates, a U-value of 0.35 or below is recommended. These windows have at least double glazing and low-e coating.
In warm climates, where summertime heat gain is the main concern, look for windows with double glazing and spectrally selective coatings that reduce heat gain.
Select windows with air leakage ratings of 0.3 cubic feet per minute or less.
In temperate climates with both heating and cooling seasons, select windows with both low U-values and low solar heat gain coefficiency (SHGC) to maximize energy benefits.
Look for the ENERGY STAR® and EnergyGuide labels.

Landscaping Tips (Dependent on Geographic Area)

Trees that lose their leaves in the fall (i.e., deciduous) are the most effective at reducing heating and cooling energy costs. When selectively placed around a house, they provide excellent protection from the summer sun but permit winter sunlight to reach and warm your house. The height, growth rate, branch spread, and shape are all factors to consider in choosing a tree.
Vines provide shading and cooling. Grown on trellises, vines can shade windows or the whole side of a house.
Deflect winter winds by planting evergreen trees and shrubs on the north and west sides of your house; deflect summer winds by planting on the south and west sides of your house.

Indoor Lighting Tips

Turn off the lights in any room you are not using and consider installing timers, photo cells, or occupancy sensors to reduce the amount of time your lights are on.
Use task lighting; instead of brightly lighting an entire room, focus the light where you need it. For example, use fluorescent under-cabinet lighting for kitchen sinks and countertops under cabinets.
Consider three-way lamps. They make it easier to keep lighting levels low when bright light is not necessary.
Use 4-foot fluorescent fixtures with reflective backing and electronic ballasts for your workroom, garage, and laundry areas.
Consider using 4-watt mini-fluorescent or electro-luminescent night lights. Both lights are much more efficient than their incandescent counterparts, and the luminescent lights are cool to the touch.
Compact Fluorescent Bulbs (CFL)

These compact fluorescent bulbs are four times more energy efficient than incandescent bulbs and provide the same lighting. Use CFLs in all the portable table and floor lamps in your home. Carefully consider the size and fit of these systems when you select them. Some home fixtures may not accommodate some of the larger CFLs.
When shopping for new light fixtures, consider buying dedicated compact fluorescent fixtures with built-in ballasts that use pin-based replacement bulbs.
For spot lighting, consider CFLs with reflectors. The lamps range in wattage from 13-watt to 32-watt and provide a very directed light using a reflector and lens system.
Take advantage of daylight by using light-colored, loose-weave curtains on your windows to allow daylight to penetrate the room while preserving privacy. Also, decorate with lighter colors that reflect daylight.
If you have torchiere fixtures with halogen lamps, consider replacing them with compact fluorescent torchieres. Compact fluorescent torchieres use 60% to 80% less energy and can produce more light (lumens) than the halogen torchieres.

Outdoor Lighting Tips

Use outdoor lights with a photocell unit or a timer so they will turn off during the day.
Turn off decorative outdoor gas lamps. Just eight gas lamps, burning year round, use as much natural gas as it takes to heat an average-size home during an entire winter.
Exterior lighting is one of the best places to use CFLs because of their long life. If you live in a cold climate, be sure to buy a lamp with a cold-weather ballast.

Dishwasher Tips

Check the manual that came with your dishwasher for the manufacturer’s recommendations on water temperature; many have internal heating elements that allow you to set the water heater to a lower temperature.
Scrape off, don’t rinse off, large food pieces and bones. Soaking or prewashing is generally only recommended in cases of burned-on or dried-on food.
Be sure your dishwasher is full, but not overloaded.
Don’t use the “rinse hold” function on your machine for just a few soiled dishes. It uses 3 to 7 gallons of hot water each time you use it.
Let your dishes air dry. If you don’t have an automatic air-dry switch, turn off the control knob after the final rinse and prop the door open a little so the dishes will dry faster.

Refrigerator / Freezer Energy Tips

Look for a refrigerator with automatic moisture control. Models with this feature have been engineered to prevent moisture accumulation on the cabinet exterior without the addition of a heater. This is not the same thing as an “anti-sweat” heater. Models with an anti-sweat heater will consume 5% to 10% more energy than models without this feature.
Don’t keep your refrigerator or freezer too cold. Recommended temperatures are 37 to 40 degrees F for the fresh food compartment of the refrigerator and 5 degrees F for the freezer section. If you have a separate freezer for long-term storage, it should be kept at 0 degrees F.
To check the refrigerator temperature, place an appliance thermometer in a glass of water in the center of the refrigerator. Read it after 24 hours. To check the freezer temperature, place a thermometer between frozen packages. Read it after 24 hours.
Regularly defrost manual-defrost refrigerators and freezers. Frost buildup increases the amount of energy needed to keep the motor running. Don’t allow frost to build up more than one-quarter of an inch.
Make sure your refrigerator door seals are airtight. Test them by closing the door over a piece of paper or a dollar bill so that the paper or bill is half in and half out of the refrigerator. If you can pull the paper or bill out easily, the latch may need adjustment or the seal may need replacing.
Cover liquids and wrap foods stored in the refrigerator. Uncovered foods release moisture and make the compressor work harder.
Move your refrigerator away from the wall and vacuum the condenser coils once a year unless you have a no-clean condenser model. Your refrigerator will run for shorter periods with clean coils.

Other Energy-Saving Kitchen Tips

Be sure to place the faucet lever on the kitchen sink in the cold position when using small amounts of water. Placing the lever in the hot position uses energy to heat the water even though it never reaches the faucet.
If you need to purchase a gas oven or range, look for one with an automatic, electric ignition system. An electric ignition saves gas because a pilot light is not burning continuously.
In gas appliances, look for blue flames. Yellow flames indicate the gas is burning inefficiently and an adjustment may be needed. Consult your manufacturer or your local utility.
Keep range-top burners and reflectors clean. They will reflect the heat better, and you will save energy.
Use a covered kettle or pan to boil water. It is faster and it uses less energy.
Match the size of the pan to the size of the heating element.
If you cook with electricity, turn the stovetop burners off several minutes before the allotted cooking time. The heating element will stay hot long enough to finish the cooking without using more electricity. The same principle applies to oven cooking.
Use small electric pans or toaster ovens for small meals rather than your large stove or oven. A toaster oven uses a third to half as much energy as a full-sized oven.
Use pressure cookers and microwave ovens whenever it is convenient to do so. They can save energy by significantly reducing cooking time.

Laundry Tips

Wash your clothes in cold water using cold-water detergents whenever possible.
Wash and dry full loads. If you are washing a small load, use the appropriate water-level setting.
Dry towels and heavier cottons in a separate load from lighter-weight clothes.
Don’t over-dry your clothes. If your machine has a moisture sensor, use it.
Clean the lint filter in the dryer after every load to improve air circulation.
Use the cool-down cycle to allow the clothes to finish drying with the residual heat in the dryer.
Periodically inspect your dryer vent to ensure it is not blocked. This will save energy and may prevent a fire. Manufacturers recommend using rigid venting material, not plastic vents that may collapse and cause blockages.
Look for the ENERGY STAR® and EnergyGuide labels

See you all on next week,

Wednesday, May 20, 2009

Solar Powered Spotlight

I'd like to discuss making a motion sensor spotlight that is solar powered. It will contain a battery that is charged during the day when the sun is out. This is great if you need light but don't want the expense or trouble of running power lines. It also means that the system is portable.The concept is simple. It consists of a 12 volt battery that is charged by a 2 - 5 watt solar panel. This battery is connected to a 75 watt inverter which, in turn, powers two compact flourescent spot lights (23 watts each). These spotlights are connected to a light and motion sensing base. The whole thing is in a wooden box to protect the battery and inverter from the weather and to make it more mobile.

Item Estimated Cost
75 Watt inverter $25
12 volt car battery FREE
spotlight motion sensor $15
2 CFL spotlights (23 watts) $15
2 watt 12 volt solar panel $20
plywood for enclosure $10
Total $85
The battery is just a 12 volt car battery you can pick up for free and desulfate (per my ebooks such as windmill or welding). With a solar panel less than 10 watts, you won't need a charge controller. You will have to place the inverter at the bottom of the box and make sure that the box is vented with small holes at the top. This is due to the corrosive gasses that come off the battery when charging or draining. Don't put big holes because birds will make it their home. You can also encase the inverter in it's own section with vent holes. All the vent holes should have a mesh or screen on the inside to keep bugs out as well. And make sure that rain can't get in. The handles are just pieces of rope put through holes and knots tied on the inside.


Tuesday, May 19, 2009

24 Volt Battery? But I have a 12 volt inverter.

I received an email from a customer with this question. He had a 1,000 watt 12 volt inverter but he had one 24 volt forklift battery. Here is my response to him.

There are a few ways to do it. One is to get a 24 volt to 12 volt converter. Most only handle up to about 200 to 500 watts. That's not enough for this situation and they cost about $200 for the 500 watt version.

Another is to use 2 inverters, so you would have to buy another 1000 watt inverter. But they cost about $50 on ebay plus some shipping.
In this case you would charge the 24 volt battery with the windmill but each inverter would connect to only half of the battery. You would have to try and balance your loads. Don't use too much power from one side and not the other.

Probably the best way is to split the battery into 2 sections, 12 volts each. You will make one cut shown below. Only cut after the battery has sat for at least 6 hours with no charging. Then run connections as shown below. This will parallel 2 sections of 12 volts each. This doubles the amp hours of the battery rating. So, if it is 700 amp hours at 24 volts, this would now be 1400 amp hours at 12 volts. But the two sections should be close to the same resting charge. If you charge and desulfate for a few days and let the battery sit for a day and each section is about 12.7 volts then you are good to go. If one section is 12.6 and the other is 12.2 then the low half needs to be desulfated before connecting the two together. The lower side will always drag the other side down and eventually ruin it as well.


Monday, May 18, 2009

Solar Panels and battery bank

Well, I finally got a chance to hook up my solar panels to the batteries. I'm using the garden shed as "Power Central". We rent here so we have to be careful what we do. The green box above is the battery box with 4 golf cart batteries in it. You can see below that the other box is for all the associated electronics. On the left is my 60 amp charge controller. The top right is the breaker box. And the bottom right is the 3000 watt modified sine wave inverter.

Below is the battery box. Notice the very thick cable (2/0 ). The yellow wire is a temperature compensation sensor. It goes to the charge controller. When the batteries are cold, it compensates by charging more than normal. I'm in the process of taking apart some forklift battery banks and making smaller 3 cell banks with a welded steel box. Each one would weigh about 250 lbs instead of 1100 lbs. Much easier to maneuver. Two of those would be 12 volts and I'll be putting those inside the shed.

Below are the 3 panels (120 watts each). When the sun was almost setting and the sunlight was not even hitting the panels directly, I was getting 8 amps to the battery. At high noon I get about 25 amps.

Friday, May 15, 2009

Tiny Little House

Talk about lowering your carbon footprint. This is a tiny house. I like the layout of it though. This was for sale on Craigslist in San Francisco. Supposedly a small family lived in here and they were expecting another baby so it became just too small. lol

Take a look at some of these pics. Notice the loft bed with rope ladder.

DIY solar panels

Here is a video from Green Power Science that talks about making cheap solar panels. It looks like you could make 2 panels at 120 watts each for about $200 to $225 after you buy the glass and resin for the sealing. That is about a 75% savings from buying them new. Amazing! It looks like they will make more videos on this in the future, but this is a good start. Also, there are lots of free info out there on making these.

Candle Heater

Actually, it is called the Kandel Heeter. It can be found here. It collects and concentrates the heat from a candle (that would normally escape straight up to the ceiling) and converts it to radiant heat. This guy is selling them for $29.95 each. I would love to make one, but for that price, I might as well buy one.

Remember, this would only heat a small well insulated space. But, still, a really cool idea.


Thursday, May 14, 2009

Updated Charger/Desulfator

With amp and volt readout
by Richard Lewis

Today, I'll be showing you how to make an updated model of my desulfator and charger that you see in my windmill book. This version is nice because it has a pluggin for a simple digital meter and with a flip of a switch you can read the current to the battery, or battery voltage. It also has another switch for a high or low charge current setting. In the below design I used a standard spring loaded speaker wire quick connect box. I used light switches for the on/off and the hi/lo switches. I used a spdt light switch for amps/volts switch. I used a GFCI socket inside instead of an isolation transformer for safety. I also show a pair of 80 MFD capacitors for my high section charging. Actually, it parallels those along with the 24, giving me 184 MFD. That would be about 7.6 amps of charging and about 1 amp at the low setting. You can use some more capacitors in parallel, but remember to make sure your switches, wires, fuse and rectifier can handle the current. The fuse should be just under what the rectifier can handle. If you hook the battery up backwards, this fuse will blow instantly. I used 25 amps for my fuse because I had a 30 amp full wave bridge rectifier.
Notice the 1/4 inch stainless steel bolt (about 2 inches long). It has to be stainless, not plated or galvanized. And the wire connections must be exactly 1 inch apart.
But it is important to have the current sensing wires connected on the inside, while the current carrying connections should be toward the outside. The sensing wires can be a small gauge but the current carrying wires should be a larger gauge, enough to carry the required amps.

This is your shunt and when you select amps on the switch above, you need to turn your meter to milivolts. A reading of 5 milivolts would indicate 5 amps for example. A reading or 8.9 mV would be 8.9 amps. When you switch back to volts, you will have to turn your meter back to the right range unless you have an autoranging one.

You can see in the picture above that I am set for volts and I'm reading the battery at 12.6 volts.
Here is the plugging on the side for plugging in your meter. It is meant for speaker wires but it works great for this application.


Let's fix some batteries!!

Wednesday, May 13, 2009

Homemade battery charger - desulfator

Here is my tried and true, although potentially lethal, desulfator.

Low Voltage Heating Element (4,000 Watts) for $10

by Richard Lewis

Some of you have read my ebook Homemade Amp Meters. In it I talk about using cheap metal such as zinc plated or stainless steel "all thread" or "ready rod" as a shunt for measuring amps. You can run the current through this all thread and take a cheap multimeter and connect the two leads at a very precise distance apart, then the milivolt reading would equal the amps. I include free software with the ebook that computes that distance among other things.

But, what I don't say in the book is that you can use stainless steel all thread as a heater element. For instance, if you were to put in the calculator "shunt calculator" 1/4 inch stainless steel and you have the 1 milivolt (mv) setting, then it would show 1.027 inches as the result. What that also means is that every 1.027 inches of 1/4 inch stainless steel all thread would be 0.001 ohms in resistance at room temperature.

If you take the equation Power = Voltage ^2 / Resistance, and took a 36 inch piece of all thread, then...

12 volts ^2 / (36/1.027) * 0.001 = 4,108 watts. After the stainless steel gets very hot, it increases the resistance and then puts out about 3,000 watts or so. If you were to put cooling fins of some sort that were painted with flat black high temp paint, you could keep it at 3,500 to 4,000 watts or so. Same is true if it were in water.

I know it sounds crazy, but people are spending lots of money on heating elements or some other load for their windmill (when the batteries are charged but the windmill is still spinning). I've seen $25 to $80 per 12 volt heating element and they are only 600 watts. You would have to buy 7 of these and spend $175 to $560 plus shipping just to get 4,000 watts of heating. And those heating elements will burn up if they aren't exposed to water. With the stainless steel, you can use it in the air for an air heater system or you can use it in water. Coolest part is, you can go to the local building supply store to pick it up. I found it at Home Depot. But, make sure it is stainless, not galvanized.

I've also seen the use of light bulbs. But remember, a 100 watt light bulb is meant for 120 volts. If you put 12 volts through it, then you will only be at 1 watt (NO, that isn't a typo, it is really only 1 watt). So, that wouldn't work. You could take car headlamps. They are about 2 to 3 amps. So, that would be 24 to 36 watts each. You would need more than a hundred of them (to equal the stainless steel option) at $5 each. Hmmm, still not a good solution.

You could try a 120 volt heater. But, at 12 volts you would be at 1/10th the voltage and therefore 1/100th the power. So, a 1500 watt space heater would put out 15 watts of heat at 12 volts.

Anyway, I hope you can see the merit of using a simple all thread stainless steel rod as a heating element.


homemade tachometer (rpm gauge)

Here are some instructions on making a homemade tach on

You just need a cheap $15 - $20 bicycle speedometer and set the wheel size to be 268 mm or 27 cm. The magnet is attached to the wheel or shaft you are measuring. Its diameter doesn't matter. Then the mph reading times 100 is the rpm. For example, 28.1 mph = 2,810 rpms

Plywood Pulley for a VAWT (Vertical Axis Wind Turbine)

For my new book I'm testing out different VAWT (Vertical Axis Wind Turbine) designs. One thing about a typical VAWT, especially savonious is that they spin with more torque but much lower rpms. So a pulley is required to step up the speed. The motor I was testing with is a 3200 rpm motor, 17 amps and 130 volts DC. And it has a 3 inch pulley on it. As you can see from my VAWT windmill calculator, it needed a 7 to 1 gearing. In this case that is a 21 inch pulley.

Well, good luck finding a 21 inch pulley that fits an "A" belt and attaches easily to the bottom wooden plate of a savonius windmill. Basically, the situation required a plywood pulley. You can make them almost any size. They are a lot easier than most people think to make and they work fantastic. Here is a pic of my 21 inch plywood pulley on the 48 inch diameter bottom plate.

Here is the jig for the router and the next picture is the VAWT bottom plate

If you go to this page then you will see a pulley calculator. It is good to play around with those numbers to estimate the load on the bearings due to belt tension. The bigger the pulley, the less belt tension you need.

Tuesday, May 12, 2009

Renewable Energy for the Poor Man

I've run the Poor Man's Guides website about 3 years now. When it started, I was focused on writing about making homemade DIY windmills or wind turbines. That was my first book, Poor Man's Guide to Wind Power & Battery Systems. And it has been a great seller since the summer of 2006. I started writing some articles, usually about once a month. I will post those here for people to see and I'll be taking them off the main site.

I think blogging about the things I'm working on will keep people "tuned in and turned on" so to speak. That is what we need now. We are beyond just thinking that renewable energy and systems is a "cute and good idea". We are now at the "Holy Crap, what the hell are we gonna do?" phase. I hope that I can get the message out to more people. We all don't have $40,000 to throw at a new solar system. What is the "poorman" (or poorwoman) going to do?

Well, that is what I will talk about. It will range from welding with car batteries to windmills to homemade solar ovens. And, yes, the true geek will slip out from time to time. I apologize in advance to the non-geeks. I will try to speak slowly for you guys...jk :)

All are welcome. I will start by posting one of my old articles for your enjoyment. It was written a few years ago. It is about Hydrogen Fuel Cells.

Fuel Cell or not Fuel Cell? That is the question.
by Richard Lewis

Everytime I see a news story either online or on the TV about hydrogen, they always seem to mention fuel cell technology. It's not that I hate fuel cell technology. It's just that there are so many problems as of current, that it isn't a suitable technology for the near future. Maybe in 10 years or so...who knows.

Cost Let's take the average sedan with 100 horsepower and do some simple math. If you have 100 hp, then that is equal to 74,600 watts. A good internal combustion engine (ICE) runs at about 35% efficiency (average car is about 25%). So, that would mean that the car used 213 kw in fuel just to get its useable power. The average cost for a fuel cell is about $4,500/kilowatt. That would mean that a fuel cell for that average sedan would cost (at 50% eff.) a whopping $475,000! By the end of the decade they hope to be down to $800/kw. Even that would make for an expensive fuel cell costing about $85,000. If they ever make it to $35/kw by 2015 or so, then that would be $3700 per fuel cell.

And platinum is getting more rare and more expensive. There simply isn't enough platinum on the planet to supply all 800 million cars with fuel cells. And platinum will skyrocket in price if fuel cells become more mainstream. Alkaline fuel cells could be used, but they don't work well when carbon monoxide is present. And as a transitional phase to a hydrogen economy, there will still be "regular" cars on the road producing plenty of carbon monoxide. Also, the alkaline fuel cell is far too bulky for cars.

Everyone will tell you that fuel cells are more efficient than internal combustion engines. The fuel cell is often just above 50% efficient. While a typical internal combustion engine (ICE) is about 25%. But here is the rub. If you take a typical ICE and convert it to run off of 100% hydrogen, then you will have to change the timing to about top dead center. Then the efficiency will go up to about 50%. Less power is wasted in heat and less is transfered to the walls of the cylinder. In fact, most will be transfered to the downstroke of the piston. In reality, this efficiency boost isn't always seen as pure horsepower but rather a boost in fuel efficiency.

How long do they last? Another problem is how long a fuel cell lasts. According to Perdue University, an ICE will last about 5,000 hours while a fuel cell will typically last about 1,000 hours. If you were to drive an hour to work and an hour home and a couple hours on the weekend, then that would be about 12 hours per week. That works out to just over a year and a half before your $100,000 fuel cell is dead. Yeah, that's a bargain. NOT

Pure Hydrogen To put it simply, the hydrogen going into your $100,000 fuel cell has to be extremely pure. Otherwise, you might damage it.
Alternatives? Meet the ICE engine

Let's face it, switching over to hydrogen is a huge step. We don't really have the infrastructure set up. At $250,000 per fuel cell car, it doesn't seem likely that a large portion of the 800 million cars on the planet will switch over. I don't even see a large portion of wealthy people switching over, especially knowing that a $100,000 fuel cell has to be replaced every couple of years.

But there are some shortcuts we can take. For example, we could use natural gas pipelines to transfer hydrogen across the country. And depleted oil wells could be used as a temporary storage of excess hydrogen.

We could setup hydrogen generators at home that will turn electricity and water into hydrogen. They could also be run with solar and/or windmills.

And since most vehicles on the road these days use internal combustion engines, we could do a cheap conversion on them so they could utilize hydrogen and/or gas. The IC engine will last about twice as long running off straight hydrogen and will need fewer oil changes and tuneups. Imagine 10,000 hours of driving. In the above example, that would be 16 years of nice driving and only changing the oil and spark plugs a few times.

And the upgrade is simple and fairly fast. It involves a carbon fiber tank for storage, a header injection system and a few controls and valves. Something any mechanic can perform. A rough estimate today would be about $1,000 in parts...maybe $1,500. That sure beats a $250,000 car and a $100,000 fuel cell replacement every few years. The government could even offer tax breaks for having a conversion done.

A car properly modified to run off of hydrogen can actually clean the air. The only exhausts from this type of vehicle will be water vapor and a very small amount of nitrous oxides. Although, the nitrous oxides would be about 500 times less than a normal car emits. So, a hydrogen car driving around the city would actually clean the air.

And since you can still run off of regular gasoline, there is no downside. You can even run in hydrogen boost mode. This is when you run off of normal gas and add about 7% or more hydrogen to the mix. This will boost your fuel economy about 30%.

"The Solar Hydrogen Civilization" by Roy McAlister