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March 1, 2012 | Leave A Comment

Our New Portland Home

Recently, my wife and I bought our first home in North Portland. There were many reasons that we fell in love with the home but, being a solar installer, I was most excited about the South facing roof (prime real estate for my solar panels), and the TED home energy detective that came with the house.

My new friend TED

I had heard about these neat devices before, but I must say since moving in I have become addicted to monitoring our home energy usage. Our home is already quite energy efficient but it has been a revelation seeing exactly how much power we use when the heat pump outside kicks on.Our first few days in the house we were using about 20kwh per day. After readjusting the thermostat from 72 to 68 inside and to 66 at night our usage went down to 10kwh/day.

Knowledge is Power

Knowledge is power and if you have no way to monitor what you use how are you supposed to be thrifty about energy efficiency? Imagine you were grocery shopping and you didn’t get the bill for the entire month and you had no idea what each item cost you. That is how we consume our energy today.

 

Check out this great video below to learn more about TED.


Posted in Energy Efficiency, Solar Technology | Tags: , ,

December 19, 2011 | Leave A Comment

Unique solar energy designs

Design is the adaptation of means to a pre-conceived end. The end can be purely for aesthetic purposes or to improve efficiency, functionality or a combination of all three. It has been said that the genius of Steve Jobs of Apple fame was his ability  to combine technology and design.  The seemingly benign and ubiquitous vacuum cleaner was revolutionized by Sir James Dyson, who after over 5,000 failed attempts
designed the “cyclonic” cleaner for a more beautiful and powerful product.
When considering the “design” of a solar energy system, whether for residential or commercial purposes, it is hard to envision anything other than a linear concept, that is, straight lines of solar panels arranged next to each other. However, recently several experimenters thought outside the box and came up with solar system designs that are anything but linear.

Seventh grader discovers more efficient solar design

First, Aidan, a 13 year old seventh grader from New York entered a contest sponsored by the American Museum of Natural History in an attempt to win the “Young Naturalist Award.” On a winter hiking trip in the Catskill Mountains of New York, he noticed that contrary to his belief that tree branches were nothing more than a tangled mess, he saw a pattern in the way tree branches grew. His research project studied the complex design of trees and how they “are more efficient than humans in collecting solar energy.” The more that young Aiden learned and experimented, the more he thought about creating a new way to arrange solar panels. In trying to understand the spiral nature of branches on different types of trees (i.e. oak vs. maple) Aiden concluded that the pattern of the branches followed the “Fibonacci” sequence as did many other forms of nature. He states: “I designed and built my own test model, copying the Fibonacci pattern of an oak tree……In place of leaves, I used PV solar cells hooked up in a series that produced up to 1/2 volt, so the peak output of the model was 5 volts. The entire design copied the pattern of an oak tree as closely as possible.” Aiden placed his solar Fibonacci tree model and a linear array in his backyard for two months. He found that the Fibonacci tree array captured 20% more electricity and collected 2 1/2 times more hours of sunlight during the day. Here is a more detailed review of the project. You can read more about Aidan’s project here as well. However, this claim of young Aiden has not been without controversy as it flies in the face, as some people believe, of common sense. For a review of the controversy surrounding Aiden’s project see this link.

Solar Origami

Jeffrey Grossman is an MIT power engineering professor. He states that standard flat solar panels are only “optimized to capture sunlight at one point of the sun’s trajectory-otherwise they need automated tracking systems to follow the sun.” In his attempt to increase the efficiency of the design itself of a solar array he turned to the ancient art of origami. He found that folded solar cell systems could produce constant power throughout the day and didn’t need tracking. He claims that his new designs are “up to 2 1/2 times more efficient per comparative length and width than traditional flat arrays.” ” Like young Aiden, Grossman was inspired by the way that trees spread their leaves in all directions to maximize their exposure to the sun. He worked with MIT graduate student Marco Bernardi to create a computer program that mimics the process of evolution. The computer program would randomize patterns of exposed surfaces and then choose the most efficient one to start the next generation — how Darwinian.
What resulted were gorgeous sun-capturing shapes that resemble origami. In some structures the surfaces also reflect upon each other, intensifying the sunlight and increasing energy gain. Grossman noticed that the larger the shapes, the more effective the arrays were — sometimes they reached 120 KWh per day when a traditional array would generate 50 KWh. He is continuing his research to find the most effective folding patterns and has teamed up with Professors Vladimir Bulović and David Perreault of EECS to create a prototype system.”
I don’t think that we’ll be seeing these designs in the backyards of urban areas as traditional flat panel arrays seem more appropriate. However, I can envision some of these designs springing up in our future cities, where Fibonacci Solar Trees or Origami Solar Constructs represent a bold message that the 21st century will be the age of renewable power.


Posted in solar design, solar panels, Solar Technology | Tags: , , , , ,

August 2, 2011 | 2 comments so far

Enphase Energy, the popular micro inverter manufacturer recently released the next generation M215 micro inverter. There were several key improvements that make this new release a major breakthrough for the solar energy market.

1. Higher Output:

The new micro inverter has a higher AC watt output that is more in line with the current 250 watt solar modules.

2. Greater efficiency:

The inverters have now achieved 96% efficiency which in turn means greater overall production.

3. 25 year warranty:

Here’s the game- changer. Most string inverters come with a standard 10-15 year warranty which means you will have to replace your inverter at some point while owning your solar system. Since the modules will remain productive for at least 25 years, a string inverter would need to be replaced once, possibly twice, over the useful life of the system. Now, the Enphase M215 micro inverters carry the same 25 year warranty as the solar modules.

4. Free life time monitoring:

The Enphase monitoring platform is what really separates their product from other inverter manufacturers. That monitoring used to come at a cost; $2 per inverter per year. Now that extra cost has been removed.

So, how much do micro inverters cost compared to a string inverter?

Let’s take a look at a 3kW system comprised of 12 Solarworld 250W solar modules.

String Inverter: PV Powered 3000W inverter                  Cost before mark-up: $1860

Micro Inverter: 12 Enphase M215 plus Envoy                  Cost before mark-up: $2561

There is definitely a premium for installing the Enphase micro inverters but considering the warranty alone it makes sense to go with the micro inverter option.

 


Posted in Residential Solar, Solar Technology | Tags: , , ,

March 29, 2011 | 3 comments so far

Enphase Microinverter Install

One of the best technology breakthroughs in the solar energy world in the last few years was the invention of the micro inverter. Solar panels produce DC electricity. The inverter is the main electrical component that converts the DC electricity to AC electricity that our homes can use. The micro inverter by Enphase is attached to each solar panel and converts the DC solar energy to AC right at the source. There are several advantages to this.

1. Better overall production. Having each panel paired with its own inverter mitigates the effect of shade on your array.

2. No single point of failure. If one inverter fails it only slightly affects the overall production of the solar array.

3. Per module monitoring. On of the most exciting aspects of Enphase is that it allows the system owner to track the production of each solar panel in the array. If one panel or inverter fails or is under performing you will receive an alert from Enphase. Below is a snapshot of the powerful monitoring software.

enphase snapshot


Posted in Solar Technology | Tags: , , ,