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.