Big Solar

At Lincoln Financial Field in Philadelphia, there are several alternative energy installations. One of them is this huge solar array that hangs on the south side of the stadium.


Not sure how much electricity that generates, but it’s certainly quite large. You can barely see the vertical windmills on the top left corner of the array. Might have to check into this and see how much juice they get. It would be interesting to know.


Old Town, New Power

Madrid is an ancient city, no doubt about it. Still, you’ll find forward thinking people, including those operating this hotel near the Plaza Mayor. Look carefully at the roof.

It looks like they have an evacuated tube system for heating water and some photovoltaic panels to make electricity. Good idea. There’s plenty of sunshine in Madrid, might as well use the energy.  I would have liked to talk to someone at the hotel to see how much energy they were saving. Alas, not enough time.

Published in: on October 9, 2010 at 10:46 am  Leave a Comment  
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Hot Water, Aruba

Many homes in Aruba do not have running hot water. Some use small, point of use units to heat water used in the shower. These are typically electrically powered and draw quite a bit of current. However, the other day I spotted this solar hot water unit.

solarhotwater1This unit is actually quite sophisticated. It has a flat collector plate that captures the sun’s rays, transferring the heat to water piped through the collector area. Then the hot water is stored in an insulated tank you see at the top left of the unit. This way, even after the sun goes down, you have hot water on demand. Here in Aruba, where the sun is very strong, this unit can deliver enough hot water for a typical family of four. The best part is, after the initial investment of purchasing and installing it, there are no additional costs. This one is mounted at ground level for easy maintenance but they can also be mounted on top of the roof.

If you’re considering a home in Aruba, I strongly suggest a system like the one pictured above. It will save you money in the long run and thereby make your island home that much more affordable.

Bon dia from Aruba.

Island Power, Inverters

The DC/AC inverter is the heart of any off-grid power system with electricity produced by solar and wind. Most small wind turbines and solar panels produce direct current (DC) electricity. However, the electricity you use in your home is alternating current (AC). We won’t bog down here with the details of that. Suffice it to say that you need to convert the DC to AC. The device that does this is called an inverter. The inverter draws power from the wind turbine and solar panels as well as from the batteries in the system. It then delivers it to the system in clean, regulated, AC form. Here’s a look a stack of four inverters as part of a system built by Outback Power.

Those four magic block boxes, one on top of each other, are the inverters. Each one of those takes 48 volt DC current and converts it to 120 volt AC current. The output of each one is combined in the adjacent boxes so that you can have both 120 and 240 volts. This system, with its four inverters produces a maximum of 10,000 watts of steady power. It can handle a surge load for a brief period of up to 14,000 watts.

10,000 watts is enough to power my entire house in Aruba, including those two power-hungry air conditioners. I rarely run them at the same time. Nonetheless, I’ve over-sized the system to handle the demand. Over-sizing is the key to happiness with off-grid systems (and pick-up trucks). It is always cheaper to build a larger system at the beginning than to upgrade later.

Lately, these systems have been growing in popularity. Companies like Outback have made them easier to set up, more efficient, and less maintenance intensive. Similarly, contractors have used them in “plug and play” systems that are easy for homeowners to understand. I can’t wait to have mine working and putting the money back into my own pocket instead of paying a utility company.

Published in: on August 31, 2008 at 10:45 am  Leave a Comment  
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