Island Solar Power, Aruba

The photo below shows the roof of the Dutch Marine Base located in Savaneta, Aruba. A few years ago, they installed these solar panels in order to power their motor pool facilities. I have not been able to go inside to check them out up close, but I’m told the system works very well.

This is a large installation of panels. About 10 times what I will put up for my own house. Still, it shows what can be done. Furthermore, since the system activated, the price of electricity on the island has increased significantly. Thus, the payback time has decreased, making it a better investment than originally anticipated.

At this time, there is a flurry of activity in alternative energy in Aruba. The local power company has a monopoly on electricity generation and distribution. They are not pleased with the clamor for private systems that are grid connected. No monopoly likes to have it’s authority and revenue questioned. There is talk of 500 permits being issued for grid-connected systems. This is a smoke and mirror approach that will only lead to special fees and taxes designed to limit the private sector and make private ownership of power generation too costly. Nonetheless, private individuals are installing systems that are OFF-GRID. It won’t be long before the flood gates are open. The cost of electricity in Aruba is blindingly high and the incentive to have individual systems is extremely rewarding. Thus, the private sector will not only reduce pollution but also give those people who put forth the effort a great return on their investment. Go for it.

Published in: on August 17, 2008 at 10:59 am  Leave a Comment  
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Island Energy Production

So in the last post, I said I needed to DELIVER 7,000 watts of power to keep my airco system working here in Aruba. The next logical question is how am I going to produce electricity in the first place. Well, here in Aruba we have copious supplies of both wind and sun. The trade winds blow across this island day and night, month after month, we few exceptions. My own observations show that the average wind speed on my property is in excess of 24 mph. As for the sun, it blazes at least 8 hours a day. Cloudy and rainy days do occur but not very often and rarely several in a row.

So, how do we get the wind to make electricity? With one of these:

To the left is a Southwest Wind Power, Whisper 200, wind turbine. More commonly referred to as a “windmill.” The unit produces a maximum of 1,000 watts of power when a steady breeze of 27 mph is passing through its blades. But wait a minute, I said my average speed is only 24 mph. That’s right and at 24 mph this unit produces 800 watts. To keep it simple, this wind turbine could (theoretically) power an electrical device requiring 800 watts of power given  the conditions I described.

In the real world, things are a bit different. Here’s where we all have to concentrate. Let’s say that at my house the wind blows at 24mph for 10 hours each day. That means the windmill would produce 800 watts times 10 hours for a total of 8,000 watts. What can 8,000 watts do? It could run that big airco of mine for a little more than 2 hours. Now, my on-site observations show that the wind blows MORE than 24 mph for approximately 20 hours per day (yes, it is that windy in Aruba). So, I can reasonably expect this unit to deliver 16,000 watts per day to the system.

I did mention something about the sun. The example is much the same with different equipment. A solar panel like the one on the left does the job. Yeah, it’s one of those sort of shiny blue things that typically goes on the roof. My system will use 200 watt panels. Each one will produce 200 watts if operating at its maximum. I’m going to string 5 of them together to have the potential for 1,000 watts. Again, I’m going to de-rate the output to 800 watts and I’m going to say that it will produce that much 7 hours per day for a total of 5,600 watts per day.

Now it is time to combine these two sources. Together, I’m expecting them to produce a total of 21,500 watts per day. Let’s round DOWN again, to 21,000. Finally we get to the fun part. What can I do with the 21,000 watts and those airco units? Just divide the production by the demand. I could run them both for 3 hours since they require 7,000 watts together. I could run the larger one for about 6.5 hours, or the smaller one 7 hours, or some combination of both. Since I rounded demand UP and production DOWN, I should have some room to maneuver here.

Either way, I’m satisfied that this method of production will give me what I want, which is to run those air conditioners long enough to keep my cat, my wife, and myself comfortable here in Aruba. Next time I’ll talk about combining this power into a manageable form. In between, we’ll have some more fun on the island, writing books, and taking photos.

Published in: on August 6, 2008 at 3:32 pm  Comments (1)  
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Island Energy (Demand) Calculations

We’ve been having fun, traipsing around Aruba, looking at beaches, checking out the sights, dining at all kinds of restaurants. However, having a house here is like having a house most anywhere else in the sense that utilities are a serious issue. The cost of electricity in Aruba is quite high because they burn oil to make it. (I’m not going to get into the politics of this just now. Suffice it to say that I believe in private solutions.)

My original goal for the house was to power the air conditioning system off the grid. Thus, the question, “How much power do I need to produce to get those airco’s off the grid?” The answer follows:

Last year, I installed two brand new split-type air-conditioners. The larger one uses 14.4 amps of power at 220 volts which means approximately 3168 watts. The smaller one uses 12.6 amps at 220 volts, consuming 2772 watts. Add those two together and you end up with at least 5,940 watts. When it comes to power use, I like to round UP. Therefore, at a minimum, I need to produce 6,000 watts of electricity to run both air conditioners at the same time. But wait a minute! When you first turn the airco on, it draws a bit more power to get started. So, let’s set the minimum at 7,000 watts. To correct myself slightly, I need to DELIVER that many watts to keep these unit cranking.

Okay, how am I going to do this? Production will come from a wind turbine and solar panels (photovoltaic). This power will have to be converted from direct current (DC) to alternating current (AC). How is that going to be done? With an INVERTER. What if the wind isn’t blowing and the sun isn’t shining? Electricity will be stored in a BATTERY BANK. How is the battery bank going to be charged? Through the inverter and a CHARGE CONTROLLER.

Are you still with me? I hope so. None of this is as complicated as it sounds and there are some details that aren’t discussed here. (Please, if i made any mistakes, let me know so I can correct them.) You can purchase entire systems that are basically “plug and play.” A qualified electrician can have you up and running in no time.

Now, the next post is going to look at ENERGY PRODUCTION for this system. There will be pictures, too. Remember one thing: Once the system is operating, you get a return on your investment and protection against future price increases. Every time the price of energy goes up, it’s as if you’re saving more. And you are because you have a fixed cost for your system and a little extra for the maintenance.

Enough for now. Stay tuned. And don’t forget that you can control your energy consumption AND production. Don’t let anyone tell you differently. You have to be willing to change a little or a lot depending on your goals. However, you do not have to live in a cave, eating berries.

Published in: on August 6, 2008 at 12:01 pm  Leave a Comment  
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Island Wind Power, Part 1

I am optimistically titling this post Island Wind Power, Part 1, because I hope to post numerous more times on this subject. Here in Aruba, the trade winds blow just short of constantly. They range from a breeze of about 5 knots to a steady cracking of 30 at times. Nonetheless, the island currently relies on an oil fired electricity plant. Part of this plant has boilers and turbines, the other part is giant reciprocating units (think big diesel engines). To me, this is outrageously foolish. (There is a plan to investigate a wind farm here but it’s moving slower than backwards.)

Anyway, some people have put up small wind mills to generate electricity for their domestic needs. The unit shown below doesn’t look like much, but it is probably in the 500 watt class.

 I’ve seen a bunch of these go up in the last six months. With the price of fuel, it’s no wonder there aren’t more. So, just how much power can this unit provide? Given that the wind in Aruba is steady and strong, the unit probably runs at 90% of it’s output about 80% of the time. Thus, we’re talking about 72% of 500 watts or 360 watts at any given time. Doesn’t sound like much, does it? Well, consider that this is 24 hours a day. (I know it’s an assumption so don’t remind me how this may be inaccurate. We’re making an example to illustrate the point for discussion. Okay?) Then, 360 watts times 24 hours equals 8,640 watts per day. What will that do for your electric bill? Here in Aruba, it will do a lot. That is enough power to run one of my air conditioners about four hours a day which is all I run it in the first place. Given that air conditioning is the single biggest user of power in my house here, it would reduce my electric bill by a significant amount thereby giving me a handsome return on the investment for the wind turbine, and protection against future price increases.

If your eyes haven’t glazed over yet, let me say I’m cutting the cable now so as not to bore you to tears. These posts will take a look at how a system can be put together, one piece at a time, and supply virtually all of a home’s electricity needs off the grid. In Aruba, there is foolish talk that if you put up a windmill the electric company will cut you off the grid. Not true. The electric company does not want your system CONNECTED to the grid and at present this is a good thing. In the first place it is a safety issue to protect the linesmen who must work on the transmission cables. Secondly, every Tom, Dick, and Harry, dumping power into the grid without a standard is bad for the grid. Therefore, as long as your system is COMPLETELY INDEPENDENT of the grid, you’re okay. They will send you a nasty letter, and after your lawyer sends a nasty one back with verification that you’re not connected the story ends there.

But our energy alternatives will continue here, hopefully, because I love the idea of making a reasonable investment, getting a great return, and protecting the environment in the mean time. Power on!

Published in: on July 24, 2008 at 11:01 am  Leave a Comment  
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