Small-scale Wind Energy

Many areas of Nicaragua are blessed with enough wind to make wind power practical. Two areas mentioned in various studies are the west side of Lake Nicaragua and near Estelí. There are likely many more. Use the wind energy section of this map to look at the feasibility for your area.

here is a very useful and comprehensive pdf from Canada about domestic scale wind power.

One wind issue is availability. That is, wind doesn't always blow. In some areas it comes close to always. In addition, wind combined with solar is generally practical as you typically have wind during a storm when there is little solar available. The setup cost per kilowatt hour for wind generation is significantly less than photovoltaic and economies of scale apply. Solar panels get a bit cheaper with size but the cost per unit area doesn't change dramatically. Wind power depends on the swept area of the blades so doubling the rotor diameter quadruples power output. If the wind map for your area looks good try to generate most of your electricity with wind rather than photovoltaic.

In any event you will need some way of storing spare energy (see the energy page for storage battery details)

Another alternative is wind with potential enegy storage. That is, you either pump water into an elevated storage area with wind directly or with an electric pump run from the wind generator. You then use the stored energy to run a water turbine. An alternative is to use wind power to compress air which drives a generator as needed. Unfortunately efficiency losses are introduced at every part of the chain.

Wind Electric

Here a windmill of some type directly produces electricity that is then stored in batteries. Electrical needs of much of Nicaragua's rural populace will be very small so a small-scale system with minimal storage (batteries) becomes very practical. If water pumping is desired, an elevated storage tank and electric pump that operates when there is power to spare decreases the needed battery capacities.

An interesting link on low-technology wind is Other Power. This web page offers some "experiments" that have produced usable wind turbines. On the power experiments page you can find some interesting projects.

The projects include building the props and alternators. Their typical alternator is build from automobile disk brake drums and surplus computer disk drive magnets. The projects are labor-intensive but not high tech. For example, the alternator coils are hand-wound using a plywood jig and magnets are glued in place with epoxy.

While wind plants could be bought, the idea of building complete systems (including towers--clearly it is not hard to find someone here who knows how to weld) in Nicaragua and installing them to bring electricity to rural areas just "feels right".

For those more constructionally challenged (or less inclined to loose the odd appendage due to the magic effects of niobium magnets) here is a priced list of good quality Chinese horizontal and vertical axis machines, towers and controllers.

Siting

Your wind generator needs to be as high as possible. This costs money. Think carefully about output voltage and siting because carrying low voltage DC current any substantial distance is expensive. Do you want to generate 110 or 220V AC? Where will your storage batteries be? Do you want a DC line to your house for LED lamps, DC motors etc?

Wind Speed

Generators vary considerably as to the wind speed at which they begin to generate useful amounts of power (startup speed). Obviously compare the wind power available with your requirements, then go for the next largest size you can afford.

Few horizontal axis machines will survive winds of 100 mph. You will need to be able to drop the tower if winds of this speed are likely or it will likely drop itself, probably on you, your car or house.

No wind generator will survive a lightning strike. Ground everything well unless you are prepared to do a Tom and Jerry imitation. Use a lightning conductor at the top of the tower (these do not intercept and ground a lightning strike; rather they generate a stream of ions to neutralise the charged cloud lurking above).

Noise

With a horizontal axis wind generator (the commonest 'propellor' type) there are several sources of noise. Small generators produce a tiresome aerodynamic whine or buzz. Larger generators (if they use a gearbox to speed up the rpm to drive an off-the-shelf alternator) may well produce a gearbox whine. Without a gearbox there is the characteristic 'whump' each time a blade passes the tower.

Vertical axis generators (Savonius rotor type) are much quieter, survive much higher wind speeds and cost more. They tend to have a lower startup speed.

For what it's worth I will be installing a 5Kw vertical axis 220V generator for 16K USD including tower and controller.

A 5Kw solar panel array from the same source would cost 26K USD.