admin answers:

Simple answer, you need a multi-input grid-tie inverter.
My dad has one on his DC solar array. It can accept between 50 and 270 volts DC which is good for solar because he can wire them in series to add the voltage rather than parallel adding amperage which requires larger wires… Etc.
There are permanent magnet alternators you can order online that will produce pure A/C with no voltage limitation so you can control the output voltage via rpm governance. You could set things up to produce 120v A/C and tie directly in. You still need a grid tie device to protect your equipment and the grid.

Now the issue you will come into with an alternator generator is no control mechanism to compensate for load. Electrical generation is directly proportional to torque. If you put a heavy load on the system, it will become harder to turn which could slow down your rpms and in turn lower your voltage.

For this reason, alternators are typically used to charge battery banks which connect to an inverter.
You could wire a lot of batteries in series to get a higher voltage capacity and just rectify the A/C before it hits the batteries. Then you get a buffer allowing your alternators to have a range of output voltage which will give leeway for rpm fluctuation. And since the batteries will be a predictable load you really should have no trouble maintaining a steady speed.

Now I am guessing that you must have your driving force figured out. Generally speaking there is a direct conversion of horsepower to watts. 1 hp of torque will produce about 750 watts of power at top efficiency.
Steady water flow in a well designed system can easily exceed 40 hp in a single turbine which could drive several alternators. Steam is another good alternate fuel source. Solar concentration is often used to produce heavy steam generation. The trick is tuning the focus to achieve about 550 degrees or so, to get saturated steam. The down side is you only produce when the sun is out. I have an idea for combining these two concepts together. Use heavy solar concentration to turn the lower water pool into steam to lift it back to the top, while also condensing it through a turbine at the top. It’s a question of, how much sunlight will it take to move enough water that you have a nightlong supply running back down?
Seems like a major undertaking. It’s quite difficult to direct sunlight from a large array at a low position. Much easier to target the top of a tower.
Anyways, finely polished metal is the best way to reflect the most energy. I’m interested in building a smaller closes loop system for potentially scaling up. I’m wondering how high I can get the water via steam, and how many turbine stages it can fall through… In theory I can heat that steam continuously for hundreds and even thousands of feet of rise. Rocky Mountains are a good place to try that…
This kind of system could be ideal for property where there is ground water available but no naturally flowing surface water. You could even incorporate a distillery and fish pond, irrigation, etc.

I can’t divulge my ultimate experiment that this ties to. I think I figured out a way to store energy even better than batteries and raised water tanks.

admin answers:

It makes a big difference where you are located, what resources are available, if you are working with new construction or renovating old existing work.

In general, any path to energy independence is going to start with conservation. With heating and hot water this may mean point of use heaters, insulation, heating surfaces instead of the air (radiant heating costs less in operation) ventilation instead of air conditioning, earth tubes etc. Start to satisfy your existing 100% of current energy demands you may be able to achieve 20 to 30% with conservation techniques.

We feel warmer if surfaces are warmed than if only the air is warmed. It is more efficient as the surface temps can be 10 deg lower than we would normally heat the air. Radiant heating in floors and sometimes walls works well with both solar thermal panels and geothermal as a heat source.

In new construction a masonry stove (not cast iron) can be a very efficient use of wood. It may be lit once per day to a very high heat. The balance of the day and night the massive masonry structure radiates heat to the dwelling.

Geothermal, ground source heat pump applications are a kind of alternative form of heating conservation. It saves heating costs but still requires some energy. It does not yet supply more than it requires.

Solar thermal is 60 to 80% efficient vs photovoltaic which is only about 8 to 22% for the homeowner. There is some speculation that solar thermal plus a stirling generator may be several times cheaper than photovoltaic panels for producing electricity. ($1/ watt vs photovoltaic $5/watt.) Heat is also easier to store than electricity. So store heat to make electricity. Solar thermal comes in several designs for residences. In new designs it is in passive solar heating. For both new designs and retrofits a solar sun room may provide additional heat. Solar thermal systems can active or passive. Active systems have pumps. Solar thermal panels can be flat plate or vacuum tube collectors water based collectors or air collectors that have no liquids in them. Solar thermal energy can be used for heat, hot water, air conditioning and to generate electricity with a mid temp range stirling engine/generator.

It also would be possible in more rural settings to generate your own natural gas with a bio digester. It would however require massive amounts of bio fuel. However if the supply exists it is certainly a possibility.

While wind turbines are a possibility for electrical energy there is the duel problem of having power when you need it. First the wind must be blowing with sufficient strength and secondly there needs to be some type of energy strorage capacity. This storage shoud have deep cycle capacity. Heating water or a phase change material may be one option. Chemical storage may be another (hydrogen) Pumped hydro may be practical in some locations. There is some discussion of using compressed air for storage. This might give a byproduct of heat that could be used to some benefit. Otherwise we are left with batteries.

admin answers:

Geothermal As A Green Energy Source
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Geothermal energy is energy obtained by tapping heat from the earth itself. This comes from magma and the radioactive decay of uranium, thorium, and potassium.

The downside to geothermal energy is the fact that it is expensive to build. On the other hand, because the earth’s crust continuously decays replenishing the heat, it is still a renewable source of energy.

There are three types of geothermal plants around. These are namely dry steam, flash, and binary.

Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine that spins a generator.

Flash plants take on water at temperatures over 200 °C, out of the ground, and allows it to boil as it rises to the surface then separates the steam phase in steam/water separators which runs the steam through a turbine to generate electricity.

Last, you have binary plants. Here, hot water flows through heat exchangers and that boiling organic fluid is what spins the turbine.

Once power is generated, the condensed steam and remaining geothermal fluid from all three types of plants are injected back into the hot rock to pick up more heat.

Geothermal plants are used operational in different parts of the globe. These are usually located in geologically unstable parts of the planet. You can see some in Chile, Iceland, New Zealand, United States, the Philippines and Italy. At home, two most prominent areas for this are in the Yellowstone basin and in northern California.

If you were to compare the amount of energy collected from geothermal to solar, you still get more from the sun. Despite that, people should still use it since solar energy cannot be harnessed when the clouds block the sun’s rays from reaching the solar panels.

Geothermal energy is a green energy source just like wind, hydropower and biofuel because it is a renewable. By maximizing its potential, we don’t have to worry about the price of oil in the world market when it hit more than $110 a barrel and is now under $40 in the world market.

But that is not the only thing we should be concerned about. We should also do our best to protect the environment given that coal fired and nuclear power plants produce harmful gases and radioactive waste that may cause to people and the surrounding areas.

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Why Is Hydropower A Green Energy Source?

Why is hydropower a green energy source? It is because we are able to harness electrical power by converting water into electricity.

The use of hydroelectric power or even hydroelectricity dates back to Ancient Greece and China when they installed waterwheels in rapidly flowing rivers to turn millstones and other equipment. Years later, this was used in the New World which is now known as North America to power saws and other equipment.

But the hydroelectric plants of today still use the same basic principles as the historical waterwheel with some variations. The difference is that we use the force of the power to push the turbine which in turn powers a generator thus generating electricity.

To make sure that there is a steady flow of power being produced, a dam has to be built to retain the water. If there is a need for more power, the gates of the dam are opened so water can be released. During non-peak, the gates are closed. To ensure there is water at all times, some dams have a recovery and pumping systems to the water released can be used again.

There are issues with the use of hydroelectricity. Some claim that it poses a problem for fish and aquatic plants on both sides of the dam. Because the flow of water has been altered, the nutrient rich silt which helps crops grow could be affected which is exactly what happened when the Aswan Dam was completed in Egypt.

Lastly, you have ocean thermal energy. Here, you get power based on the different temperatures in the water. For this to work, you need at least 38 degrees Fahrenheit difference between the warmer surface water and the colder deep ocean water. Still in the trial stage, it is used Japan and Hawaii.

Hydropower is a green energy source. It is safe to use and what is even better is that it is renewable.

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My answer is : Hydro and Geothermal

admin answers:

Hey Sanusi, always good to hear someone is interested in this. We have a home that is completely powered by the wind and sun. It’s been 10 years now since we started, and we have made plenty of mistakes. My suggestion is you start small, something on the order of a hobby sized system, and learn from it first. You really only need a few things. First is the solar panel of course. A good starter size is something in the 50 to 75 watt range. That way it is large enough to take advantage of the critical size for the best price to power ratio, but not so large it has to be delivered on a truck. That size panel in the US should cost about 200 to 400 dollars. Next is a battery. The best bang for your money is in a pair of golf cart batteries. You need two because they are 6 volts each, and the panel and most DC appliances are 12 volt. If you manage to buy a panel with diodes built into the back, then all you need after that is a wire to connect the panel to the battery. A diode is an electrical check valve, it allows power to flow in one direction, but not in the other. This is necessary so the panel can feed into the battery in the daytime, but the battery will not feed back into the panel at night.

Many solar systems use a charge controller, but here is a good rule of thumb. If the maximum amp rating on the panel is less than 2% of the amp hour rating on the batteries, then you don’t need a charge controller, the panel will never overcharge the battery. Golf cart batteries are typically 220 amp hour, and a 75 watt panel will only have an amp rating of 4 amps. The most important thing is you connect the panel to the battery correctly, positive to positive, and so on, then you can leave it hooked up all the time. We have a similar arrangement at our place we put in first, and it is still working today 10 years later. In fact, it was featured in an article in Home Power Magazine once, you can look them up online and use their search engine to find, “Starting Small.”

I would suggest doing a little reading, then shopping for parts and trying your hand at growing your own electrons, it’s fun and rewarding, and when you are done, you will have a small backup 12 volt power source. Good luck, and take care, Rudydooo

admin answers:

They are portable road ‘matrix’ signs with self contained power packs – usually solar panels & battery -or for more long term use , a diesel generator. They have a radio link to the area police traffic office so they can be updated as necessary to inform of delays or diversions ahead

admin answers:

As far as the person who said that solar lights are only good for accent lights, I am assuming they have never bothered to buy quality fixtures. With solar, you get what you pay for.

Solar shed lights would be great, or solar panels that you could use to charge radios, etc. Solar sheds lights are easy to install and use and they are bright, last for 3-4 hours continuously on one charge. You mount the solar panels on the roof or a sunny side of the barn. Then, you drill holes to connect the solar panels to the solar lights inside. Good shed lights come with materials that seal the area where the cord connects through the wall or roof. See below for a few options that are well worth the money.

There are also portable solar lamps that you can move indoors after they charge. And yes, we sell them but we also use them quite efficiently. Feel free to call us and we’ll try to work out a deal for you. Rechargeable lights are also good, but you would have to bring them with you each time you hang out.

admin answers:

Hey Chris, Homer is correct in that the device you speak of does not extract free energy from thin air. It has been called the Tesla Coil, Tesla Generator, and lately the Tesla Unlimited Energy Device. The device is a receiver. What Tesla was trying to get at was that energy can be pumped into both the earth and the atmosphere, transmitted over long distances and picked back up at the receiver to be used for whatever purposes were desired. This free energy has to be produced and put into the atmosphere first, purportedly by a power company. It isn’t free, but the problem is it can be pirated at any location with the use of another Tesla Coil, which means less of it is now available for the receiving coil that may have been originally built to receive the energy in the first place. It’s like a bank using a high power cannon to blast dollar bills into the air that are carried on the wind until someone on a tall hill reaches up and grabs them as they drift by. It isn’t free money, it’s the banks, and they’re going to want someone to pay for it. The dollar bills do not occur naturally as a result of atmospheric movement, they have to be put there first, same as Teslas free energy.

Well in the end, we do transmit energy over long distances, with the use of a wire, and then anyone willing to pay for some of it can hook their wire to the long wire with a meter to keep track of how much they are using so the electric company can pay their bills too. You don’t have to get your power from them however, we don’t. Our home generates its power from the wind and sun, now that is free energy. While solar photovoltiac panels have only been around 50 years or so, wind power dates back to the 3rd century, even before Tesla showed up with his building sized lightning producing hairbrush. You don’t have to be a physicist to make a wind turbine or a solar panel work either, we put ours in ourselves 10 years ago and it still works fine today.

UFOTV.com has an interesting video on this Tesla Unlimited Free Energy, how anyone can build a receivier and extract energy from the atmosphere for free. They are also publishers of videos and MP3 downloads on such proven scientific endeavors as, “Inside the Alien Mind,” and, “Unknown UFO’s today.” If that’s the source of your research, check and see if you can finish their latest MP3 download before the next ship lands in the desert. I found it interesting that this Tesla device can be built with common substances and ordinary tools by anyone handy, while at the same time claiming the notes on its construction were somehow mysteriously absconded with. If we don’t have the notes, how do we know what the thing is made out of?

If you want to learn more about Tesla energy transmission, check out Wikipedia, or physicsforums.com, they have a pretty good discussion on the system and how it actually works. If you want free energy instead, check out solar and wind at some of the sources below, we did years ago, it’s how we got to where we are today. Good luck Chris, and take care, Rudydoo

admin answers:

Hey Cat, Gatorbait has a good resource listed there, AWEA, or American Wind Energy Association. To cut to the chase, most modern turbines today never make it past 25% efficiency, regardless of how hard the wind is blowing or what their design speed is.

First, the highest efficiency that can be attained by any wind conversion technology was discovered by Albert Betz, it is called the Betz Limit, which is 59%. Once you begin extracting this level of energy out of the wind, the direction of the wind is altered nearly 90 degrees and moved outward, which destroys its ability to push the blade around on the next pass. You can read about it at the link below, there is a fair amount a calculus involved. A really well designed blade operating at its ideal wind and rpm speed today might reach the upper 30’s, or maybe low 40’s, but this says nothing for the efficiency of the generator or gearbox. There is also the fact that a small amount of power is used operating the controls of the machine, like unfeathering blades, turning the unit into the wind (this is done with a motor on the large utility sized machines instead of a tail), and the fact that some of these controls operate when the wind is not blowing, waiting for the moment it does.

To boil it down, on a good day, you might see 25% from a good turbine overall. That might not sound like much, but consider some of our mainstay techology efficiencies today: Incadescent light bulb 4%, gasoline car, 24%, solar electric, or photovoltiac, panels, 13%. There is plenty of energy in a passing column of air to make electricity from one large turbine to run an entire village, and once you build and install one of these devices, you never have to feed it again. This is why all the power companies are busy putting them up, they make so much more sense than coal or natural gas once you get just a few years down the road. The fact that they operate cleaner is exciting, but is really a side note to why companies are spending so much money on them today. I’ll list some sources and links below for you to check out.

One word of caution, in the 11 or so years we’ve been powering our home with the wind and sun and teaching renewable energy seminars at the local schools, I’ve found that there are 3 things in vast supply in the area, sun, wind, and missinformation. It is amazing to me how many people will weigh in on a topic like this never having laid a hand on a turbine our a panel. Stick with the sources below, and rely on your own research and intuition instead of asking hacks like us online for advice on renewable energy, you’ll be better informed in the end. Take care Cat Man, Rudydoo

From a Wikipedia Article:
The aerodynamics of a horizontal-axis wind turbine are not straightforward. The air flow at the blades is not the same as the airflow far away from the turbine. The very nature of the way in which energy is extracted from the air also causes air to be deflected by the turbine. In addition the aerodynamics of a wind turbine at the rotor surface exhibit phenomena that are rarely seen in other aerodynamic fields.

In 1919 the physicist Albert Betz showed that for a hypothetical ideal wind-energy extraction machine, the fundamental laws of conservation of mass and energy allowed no more than 16/27 (59.3%) of the kinetic energy of the wind to be captured. This Betz’ law limit can be approached by modern turbine designs which may reach 70 to 80% of this theoretical limit.

admin answers:

The most reasonable solution is to ration oil via price. Eliminate the cartels like OPEC which are manipulating the price of oil for their own profit plans. Let oil go to those who want to buy it and let the price determine who wants it the most. Let the capitalist market determine its allocation… This is a new concept since the oil market is currently controlled. Anyway, alternatives will become more available and appealing.

Second, eliminate government energy plans and laws. Much of the lack of innovation in the energy creation and distribution markets is because government has insisted on preconceived ideas of what is acceptable and what is not. This has stifled much need innovation and options. These energy laws are known to have a material impact on the forms of energy distribution. LG

admin answers:

The answer is non-trivial. The cell will convert photons beyond its band-gap into electric current but it will not convert all the energy of the photon. Indeed the shorter the wavelength, the less of the energy will be converted and the lower the efficiency at that wavelength. And then you have to keep in mind that shorter wavelengths can not penetrate the material as well as long wavelengths and there is a loss of quantum efficiency in the blue.

admin answers:

Plain and simple way.

First calculate a moderate use of electricity, add 20% and rig the house with a solar system.
As a backup (for when solar panels get too old or other issues) have a 1930’s style diesel generator back up and battery backup. Using a pulsed charging system can make batteries last for longer than the standard 10 years rating.

For fuel, make bio-diesel for your generator and for a diesel vehicle. This merely requires oil, lye, water and the processing equipment. You should buy good quality lye, but if you can’t, there’s always the opportunity to make your own (wood ash lye was used in pioneer days to make soap)

Water sources can be a well, rain catch system and purifiers for use with tanks. If your thinking long term I’d suggest a water tower.

You obviously would have to have some supportive equipment for this process. Like enough land to grow food or at least produce that you can extract oil from. A machine for extracting that vegetable oil for making diesel (some suggest a bio reactor and grow algae) and load up on alot of small equipment that is manual (like spice grinders, flour / grain griders, meat griders to minimize your need for electricity, therefore reducing the size of your solar power system.

admin answers:

Well you can figure it out yourself pretty closely if you wish to do a little math. Im pretty drunk, but basically add up your wattage of all your appliances. 1000w= 1kw. The meters read in kw/ hours. 24 hours in a day, and get your average. My families house is quite large and wasteful, which I can comment on positively at all, since I am “green” and definitely have my own thoughts on the enviroment. A good “safe” guess would be 3000 watt of constant use.

Have you thought of windpower? Much better if you can have it in your area. Lasts longer, and runs 24 hours a day. I would guess you need 6000 watts of solar panels, or a 3kw wind generator. Althought numbers look blurry at this point haha.

GO GREEN! Help out all the wasteful and polluting people!

admin answers:

A simple way to generate electricity is to take a permanent magnet hobby motor and spin its shaft. A motor consumes electric energy to produce mechanical energy, while a generator consumes mechanical energy and produces electrical energy. Basically the only difference between a motor and generator is the direction of power flow. Mechanical => Electrical or Electrical => Mechanical

Not all motors are capable of creating electricity by just spinning the shaft. As you correctly pointed out not all motors have permanent magnets and require power to establish magnetic fields.

The hobby motor available from Radio Shack is a DC motor and will produce pulsating DC. DC motors (and Generators) use a commustator to switch the output polarity of the power being generated as the generated power is starting to change direction. All generators produce AC in their windings, it is the Conversion of AC to DC by rectification or commutator switching that creates DC power.

Alternators use slip rings and maintain the same polarity of electrical connections to the windings (no switching ocurrs). This allows the AC created in the winding to flow directly to the output connections as AC.
In a car alternator a series of diodes are used in a full wave rectifier configuration to convert the AC into DC.

A stepper motor can be used to easily generate AC as it doesn’t have a commutator.

Beaware that the frequency of any AC you generate will be dependant upon the speed that the shaft is turned and the number of poles inside the motor/generator. You can minimize power line transmission losses by using AC just like the power companies do and then convert the AC to DC to charge batteries. Then use an inverter to convert the battery DC into usable AC power.

For a small semi practical homebrew windmill consider the ability to charge a few small rechargable AA batteries an accomplishment.

Beaware that you will need to use a diode when charging batteries to prevent battery current from backflowing into the generator and motorizing it. You want your generator to porduce power and not consume it. Using rectifiers in an AC generator would provide this blocking capability but using DC motors or solar cells will require the addition of at least one diode to prevent current backflow when the generator isn’t producing enough power. (no wind for windmill or no sun for solar cell)

admin answers:

Because they are too expensive to stand up in the open market, because of manufacturing costs and they are unreliable and unpredictable.

Solar electric is about $0.36/KWH to produce electricity, and if batteries are added to have lights at night, solar costs upward ot $0.50/KWH (not including transmission costs)

Wind turbines are about $2.40/KWH (not including transmission costs)

Coal generation is about $0.02/KWH and natural gas is about $0.03/KWH (not including transmission costs)

Corn for methanol needs about 8 units of energy to produce 10 units of energy. Switch grass would only need about 4 or 5 units of energy to produce 10 units of energy, but switch grass can not be taxed or regulated for hidden taxes and revenue to politicians and those that are subsidized by using corn as a source for making methanol.

Wind and solar generation has not been cost effective since they were first tried, and will not be cost effective. They are an option in remote areas where no transmission lines are available. Most remote areas that need moderate amounts of electricity generally use diesel engines to power generators, or natural gas to run gasoline type engines to generate electricity.

Bottom line, subsidies are only for laundering tax dollars and/or to buy votes. I would expect more alternative energy companies will go belly up in the near future.

Electric and hybred vehicles are also not cost effective. Electric vehicles were tried in the early 1900’s and failed for the same reason they failed today and will fail in the future. To get any amount of distance, a large truck or tractor trailer is needed to haul all the batteries needed to get a hundred miles or more distance before needing to recharge, and it would take two or more days to recharge all those batteries, or a charging station way too expensive to be practical.

Conventional generating plants need to be on low efficient standby to power up in a moments notice for when there are random clouds or gusting winds, which actually emits more CO2 than if they were on full power operation, so there is actually more CO2 emitted by using wind and solar than simply using the coal or gas powered plants. This is a dirty little secret few know about. In Scotland, Germany, and other countries, wind farms are being paid to shut down from time to time because they are so sporadic, which punches gaping holes in the whole “Free electricity” theory.

Cheap labor is only a small factor for the US not being as competitive globally. It is the taxes and the regulations that companies have to meet that costs so much and causes the US to not be as competitive globally. The excuse for being cheap labor is a distraction for us to know that the over regulation and compliance to safeguard against the trial lawyers is what costs the most for businesses.

admin answers:

Solar: Pro – some sunlight every day, can be mounted discretely
Con – not much sun in the UK, panels get dirty

Wind: Pro – massive subsidies
Con – the wind is unpredictable, doesn’t work when it’s calm or stormy, massive turbines spoil the landscape, turbine noise can upset neighbours, chops up bats and birds, need massive concrete bases, need backup power stations, CO2 used in construction and transport, towers can fall down and blades can fly off. The UK wind farm subsidy scheme was developed by Ed Milliband, followed by Chris Huhne!

Tidal/Wave: Pro – Predictable, low profile, lots of potential (water being much denser than air)
Cons – high capital costs, needs more research

admin answers:

To some extent all of our houses are dependent upon grid electricity for heating because even oil or gas units have electrical components.

If your home has electric heat it is probably located in an area where this was an reasonable installation choice. This is probably because the electricity is relatively cheap in your area due to a nearby hydroelectric power station. Many of the areas well served by hydro power are not as good for solar power and the opposite is also true.

The amount of solar radiation received is known as the insolation value. An example of a “sunny” area with high insolation values would be like this one: http://www.nrel.gov/csp/pdfs/csp_sw.pdf

Solar panels may be a viable option for several reasons. A “sunny” area may not be as important a criteria as the availability of grants and tax credits in your area. Technology is always improving and this may be something to watch. But all of this only goes to the economic question of how long before the system “pays for itself.” Perhaps you are more concerned with the environment and are less concerned about the economics. This is also a valid consideration.

There are two broad distinctions in “solar panels.” One branch is photovoltaic that produce DC electricity that must be converted to “AC” with an inverter. In some locations you can have a meter that runs both ways and then you can sell your unused electricity to the power company through “the grid.”

Solar thermal is the other type of panels. They are a more mature technology and generally are more cost effective systems. You should slice up your energy usage differently. Your hot water may take up 30% of your total energy usage. Perhaps you are using an electric hot water heater at this time. It could be converted to a solar hot water system using solar thermal panels. Your air conditioning usage can also be a heavy energy demand. There are AC systems that run from solar thermal panels like a gas refrigerator.

Last there are two other solar thermal options that might be useful in your house. Both are different kinds of additions. One is a solar room that when you install plants would be called a greenhouse. The other is to install a Trombe wall by glazing the exterior of a masonry wall. Both of these systems would provide additional warm air to your home.

By reducing the demand for grid electricity you are doing the same thing as having solar photovoltaic panels that will supply part of your usage but with a cheaper technology.