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July 14, 2008

Home Solar Power Systems: How Many Kilowatts (kws) are Created?

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Daniel Stouffer asked:


The first thing you might ask - what is solar radiation and how does it related to solar generated electricity? That is a good question and a topic discussed in our next article in our series dedicated to home solar power. This article, on the other hand, explains how kilowatts are calculated based upon the energy output of your solar array. We will also highlight the difference between solar cells connected in parallel versus in series. The average American home uses about 25 kWh of electricity per day. The following example illustrates how to calculate the power produced by a residential solar energy system. Looking over a solar radiation grid, we can determine that a residence gets five daylight hours of solar radiation in one day which is then averaged out over the entire year. Solar radiation maps are highlighted on may websites throughout the Internet. You can do a quick search for "solar radiation" to find one. In any area across the entire United States, they detail out the amount of sunshine hitting a given location based upon the time of year and its address. Calculating the power from a solar energy system Divide the average kWh per day by the average sun hours per day. For this example, we take 25 kWh divided by 5 hours of sun per day = 5 kW system This 5 kW system will generate 25 kWhs under optimal conditions in direct sunlight for 5 hours, or 25 kWh on an average day with some at peak production and most of the sunlight at less than optimal angles. Future articles related to solar energy will continue to explain the effects of sun angle, reflection, and refraction on the design, output, and installation of solar panels. Energy as it Pertains to Solar Modules Individual solar modules that are measured in watts have a particular voltage (around 40 volts) and a particular amperage (around 5 amps). A solar module with 40 volts and 5 amps is called a 200-watt module, which means that it has the potential to produce 200 watts of electricity when in direct sunlight, away from trees or shading, and clear of snow or debris. Since most electrical components around your house are only rated for 600 volts DC, it is rare to see a solar array with a string larger the 15 solar modules. On the other hand, since inverters need a minimum voltage or pressure to turn them on, you will seldom have a solar array with a string solar modules with a size smaller then 6. Electrical components, like solar cells, panel modules or batteries, can be connected in either series or parallel. This makes a big difference in the total quantities of energy produced from the solar energy system, as well as the stability of the technology over time. Each solar module or component has a positive and a negative pole. In essence, this is the same way batteries have their negative and positive poles arranged. Take a look at how you but batteries in a flashlight. Same idea here. The manner in which these poles are connected makes a big difference. Connect Solar Panels in Series When you connect residential solar energy systems in series, you connect the positive (+) pole on one component to the negative (-) pole on the next. When modules are connected in series, the voltages are added. Adding voltage together in this fashion creates a long chain of solar modules all working together, depending upon each other, and creating a flow of current that increases along the length of the system. These modules in series are called Strings. The average string is 8-12 modules so the voltage would be 320 - 480. Unfortunately, we encounter some negative aspects of of this type of construction. Connecting Solar Panels in Parallel When you connect solar panels or components in parallel, you connect the panels so current can travel to your inverter and to your house via multiple paths. Unlike adding solar modules in series which increases the volume of current as it goes, the solar panels connected in parallel has the effective of leaving the current or volume of electricity passing through the system the same. Solar panels or strings of solar arrays tied together in parallel are called parallel systems. Their amps are combined together but the total voltage remains the same. Adding amps is like increasing the volume, the pressure stays the same but the volume goes up. Inverters can only handle so much volume so you will seldom see more than 1 to 3 strings in parallel; positive ends to positive ends with negative ends to negative ends. One of the advantages of parallel connection is that electricity continues to flow, even though one of the components (or strings) is damaged. If a system is entirely in series, one damaged component stops the entire system. You may remember the ever-frustrating Christmas lights that were connected in series. Often difficult to trouble shoot, strings of lights connected in series are hard to fix when one bulb blew out. Now, the modern Christmas lights are connected in parallel. You are able to determine this easily. There are usually two different wires coming in and out of each bulb. You can feel this via their less frustrating maintenance and operation. Options for Residential Solar Energy Systems In this article, we explained in some detail how solar modules calculate the power they produce as well as how connecting solar arrays in series or parallel can have an large impact on energy output as well as complexity of design. Our next article will cover how sun angle affects solar energy systems and how to quantify the solar power produced from the sun. New solar energy system rentals allow you to upgrade your home to solar generated electricity with no large system to purchase. You can rent the solar energy equipment needed to generate up to 100 percent of your electricity needs. Exciting aspects related to clean, green solar energy are emerging all around us.

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Ultimate Biodiesel Guide


October 9, 2006

Biodiesel production ranges from factory output to home brew


Many consumers are looking into new ways to power their lives these days and get off the big oil treadmill. They are looking for cleaner and less environmentally impactful fules to run their machinery, cars and trucks on each day. One of the emerging fules that has many folks changing over is biodiesel.

Biodiesel is gaining large amount of corporate attention each year but there are many who are goin their own route to make and fule their cars. One actress who is big into green issues has converted her old gas guzzler into a biodiesel fuled machine. She gets her supply from a local former military facility close to her house. [I won't name drop here as she likes her privacy]

I ran across this today about a home brew operation that is fueling a fleet of buses in Sothern California.

"Maurice Vanegas doesn't use banana peels and trash to make fuel like Michael J. Fox did in "Back to the Future," but his recipe isn't far off.

The operator of a fleet of buses uses a mixture of soybean and vegetable oil to make biodiesel, which can be used to power diesel vehicles but does not contain petroleum.

"Every gallon I can make is one less gallon that we have to get from unfriendly countries," said Vanegas, 37, owner of Transit Systems Unlimited.

By manufacturing the transparent, lemon-color fluid himself, Vanegas has tapped into a blossoming industry.

Biodiesel is the nation's fastest-growing alternative fuel in the country, according to the National Biodiesel Board, a trade association based in Missouri. "

There are some down sides to making it yourself. The process does create some by products that are useful for others in manufacturing cosmetics and candles but you have to find a buyer and you have to store the glycerin compounds. Safety is paramount too as the elements of the mixture can be dangerous inf not handled properly.

Read more about this biodiesel home brew solution

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October 4, 2007

When Do We Say Something is Energy Efficient?


Something is energy efficient if it uses energy efficiently. It can be used to refer to energy conversion efficiency which refers to the proportion between the amount of input of energy used in the system compared to the useful output. Useful output can mean either heat, mechanical power, or electrical power



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December 4, 2007

Is Your PC Hotter Than a Jumbo?


The IT sector in the UK has a carbon footprint as big as the airline industry. IT equipment represents the highest consumption of power for most businesses and yet the power used is rarely measured, let alone managed. Once you start to measure your output, you'll see just how much you could be wasting.



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December 5, 2006

Hydrogen Fuel Cell Driven Generator For Indoor Use


November 29, 2006 Livermore, California – Power Air Corporation , today announced unit cell performance and cost improvements due to advances in the materials and design of its patented fuel cell technology.

“We are very pleased with the increase in both power and lifetime achieved to date by our Engineering team” states Mr. Remy Kozak, President and CEO of Power Air. “The new design and materials will form the basis of the ZAFC Indoor Generator Prototype we will demonstrate at the Fuel Cell Expo 2007 in Tokyo, Japan in early February”.

PWAC FUEL CELL

Unit cells are assembled together to form a stack which delivers the electrical power from the Zinc Air Fuel Cell (ZAFC). The higher single cell voltage output versus current demand means more power output and higher efficiency for the fuel cell stack.

PWAC GENERATION 6 PLUS TEAM “Our new unit cell design delivers about 5% more power output from a smaller footprint” continued Mr. Andy Turnbull, Director of Engineering at Power Air. “As well as improved performance, the new design lends itself to faster assembly, and therefore reduced cost, of the fuel cell stack.”

Power Air has announced previously its intent to unveil its Indoor Generator Prototype at four separate Fuel Cell Shows early in 2007, including the Hannover Messe in Germany in Mid April, Alternative energy 2007 in Chicago, USA, and the hydrogen & Fuel Cell 2007 International Conference and Trade Show in Vancouver, Canada in late April.

The ZAFC based generator to be demonstrated at the tradeshows will be similar in appearance to traditional generators – showing how readily Power Air’s fuel cell stack can be incorporated into commercial applications. In function, however, the Power Air generator will deliver added value, including the ability to provide reliable back-up or occasional use power safely indoors with zero emissions.

Power Air Corp www.poweraircorp.com

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