Friday, April 27, 2007

How To Build A Solar Energy Generator For Less Then 500 dollars


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When you first heard about solar energy, you were probably interested in it because it was clean and low in cost. But you were probably discouraged when you were told that placing solar panels on your home would cost well over $20,000. However, what these companies aren't telling you is that you can build your own solar energy generator for less then $500.

Source Silent Winds.com


It is an unfortunate fact that many large companies make money off the ignorance of their customers. This is especially true when it comes to solar energy. When you first heard about solar energy, you were probably interested in it because it was clean and low in cost. But you were probably discouraged when you were told that placing solar panels on your home would cost well over $20,000. However, what these companies aren't telling you is that you can build your own solar energy generator for less then $500. As you can see, knowledge is both power and value.

The parts for your solar energy generator can be purchased from regional stores. It is excellent for use in a power outage, and you can plug your computer, television, and other products into it. In addition to your home, it can be used while you travel. The first thing you will want to do is buy a solar panel. You should be able to get a solar panel which produces 12 to 16 volts of electricity for only $100. Solar panels can be found at RV stores. The next thing you will need to buy is a battery. It should be a 12 volt deep cycle battery, and it will need to be made from either gel, acid, or lead. A deep cyle battery can be used many times over. You should be able to get this for no more than $60.

The next thing you will need is a battery box. This will cover up the terminals, and is good if you are going to place it in your home or transportation. A battery box should cost no more than ten dollars. The third product you will want to buy is a DC meter which is 12 volts. It can be purchased from electronics stores for about $25. After this you will want to purchase what is called a DC input. They can be found at automobile parts stores, and should cost no more than $10. You will need it to power your DC products. For your AC products, you will need to buy an inverter.

The inverter can transform DC current from the battery into AC current. You will want to get an inverter which is 115 volts and 140 watts. It can be purchased at an automobile supply store for about $50. If you are looking for inverters which are even more powerful, they may need to be purchased online. Before you begin purchasing these products, you will need to know the number of watts your products use. For example, if your computer uses 20 watts and your microwave uses 40 watts, your solar power generator will need to be able to produce at least 60 watts. You will want it to give you as many watts as possible.

You will need to drill the meter and DC input to the top of the battery box. You will next want to attach the meter to the wingnut terminals of the batter with a insulated wire. The negative poles should be connected first. Connect only one wire at a time. You will then want to attach the DC inlet to the battery in the same manner. After this has been done, attach the solar panel to the batter using the same method. Now you will want to close the lid. Take the solar panel and put it in a place where the sunlight will strike it directly. It will take a maximum of 8 hours to charge a battery that is dead.

It can run fans and lights all night. You can also use larger panels, inverters and batteries to make it even more powerful. If you use larger panels, batteries, and inverters, you should be able to run televisions, computers, and video game consoles.

The Solar House, Part Two and Three


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In fact, because we now generate more solar energy than we can use, we welcome friends who own electric vehicles over to charge their car batteries for free.



Solar, Part 2 (Aug 2004)

This month we reinstalled the 4-kW solar array over our main roof and put in place the 2-kW, triangle-shaped array of 14 panels over our garage. Our now 6-kW solar system includes a 4-kW inverter to convert the DC electricity coming from the solar panels into AC to power our appliances. Most homes wouldn't require a 6-kW system; we added the extra 2-kW solely to power up the 24 nickel metal hydride batteries in our Toyota RAV4 all-electric vehicle (seen in main image). In fact, because we now generate more solar energy than we can use, we welcome friends who own electric vehicles over to charge their car batteries for free. Cost: included in costs noted in "Solar, Part 1"

Battery Backup (Sep 2004)

To be prepared in case of blackouts, we installed an 8-kW battery reserve system. This includes an inverter and charge controller that regulate energy flow to and from the batteries. If the utility grid goes down and we have a string of very overcast days, our batteries will give us about three days worth of conservative electric use. If the sun is shining, we have unlimited energy, of course. Cost: included in costs noted in "Solar, Part 1"

Solar, Part 3 (Oct 2004)

This month we replaced our natural gas-fired water heater with an active, closed-loop solar hot water system (see the two gray solar panels visible on the left side of the roof) and a new 220-volt electric hot-water heater. Cost: $2,500

New Heating/Cooling (Jan 2005)

The final step in making our house comfortable involved replacing the old, five-ton heating, ventilation, and air conditioning (HVAC) system with a split-ductless heat pump/HVAC system. This is a three-zone system, with small units in the den, dining room, and upstairs master bedroom. The system has an outside central operating unit and a compressor-heat exchanger that is about half the size of a typical air conditioner. Cost: $4,200

Costs & Benefits

After $18,500 in rebates and tax incentives, the total cost for all our energy-efficient improvements and our solar system, including labor, came to $43,000. We calculated that, if we had not made the retrofit, our energy bills for 2004, including fuel and oil for a gas-powered car, would have come to $6,000. With the upgrades, we have no energy costs (except for $5 a month for the one therm of natural gas we use, mostly for cooking). Thus, our entire energy makeover will pay for itself in just over seven years ($43,000/$6,000 = 7.2). And because our loan for these improvements is based on home equity, the interest payments are tax-deductible.

Since we remain connected to the utility grid, Southern California Edison's time-of-use billing program measures our overall electricity consumption and production. Rates vary depending on season and peak versus off-peak hours. With normal sunshine, we can actually see our meter "feeding the grid." Our electricity production earns us "use-it-or-lose-it" credit from the utility. In summer peak hours (10 a.m. to 6 p.m.), we can earn over 40 cents per kilowatt-hour; even during off-peak summer hours and in winter, we can earn credit. Each year, our credit amounts to between $200 and $300.

It's true that we live in warm, sunny California, which has some of the best rebates and tax incentives for going solar in the nation. But wherever you live, you can benefit from energy-efficiency and renewable-energy upgrades to your existing home and become part of the solution to global warming. See Resources for more general information. For more specifics on the Williamsons' retrofit, see this article published in Solar Today Magazine, from which our feature was drawn.


*Note: "Zero-energy" here refers to energy purchased, not energy used.

Tuesday, April 24, 2007

This Solar House, Part One


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In this two part feature, Norma and Alan Williamson explain in detail how they went about a zero-energy retrofit of their home, which saves money, energy, and the global climate.



Solar House, Part 1 (Dec )
We moved into our 2,300-square-foot house around Thanksgiving 2003. Within a month, in order to make use of state rebates that would decrease after the first of the year, we purchased a 6-kilowatt photovoltaic (PV) system. Installation occurred in two phases. First, in December, we installed the 4-kW array of 35 sapphire-blue PV panels that you can see on the south-facing side of our main roof; eight months later we added the 2-kW set over the garage (see "Solar, Part 2" below). This 6-kW PV system supplies all our energy needs, from our home's heating and air conditioning to the "fuel" for our electric car. (To learn how PV panels work, see Inside a Solar Cell.) Cost: $36,000 (6-kW system; after rebates and tax incentives totaling $17,500, our out-of-pocket expenditures came to $18,500)

Insulation (Jan–Feb)
As part of our goal to make our home net-zero-energy—that is, generating more energy than is consumed—we set about improving our home's insulation. In January, we contracted a company to inject cellulose (recycled paper) insulation into the walls, bringing them up to an R15 level. (The R-value indicates the resistance of a material to the passage of heat and cold.) The following month, we replaced our leaky, single-glaze aluminum windows with dual-pane thermal windows. These are so-called "low-emissivity" windows, which keep winter heat in and summer heat out. We left our front picture window (behind car in main image and at left) intentionally non-low-emissivity, so the winter sun could warm our living room—a passive solar technique. Cost: $1,300 (insulation), $10,000 (dual-pane windows)

Roof (Mar–Jul)
To further increase thermal resistance, we decided to replace the roof and upgrade our attic insulation. In March, we removed the 4-kW solar array as well as the existing, substandard roof tiles. The following month, we brought the attic insulation up to an R30 level. Then, in June, we installed aluminized solar sheathing on the roof. This is a thermal reflective plywood that keeps external heat out and reflects interior heat back in. We also installed roof jacks (to hold up the solar array) and then a new composite shingle roof. Finally, in July, we put in a whole-house cooling fan and whole-house heat-recirculating system (as well as two skylights, one seen in the center of the roof). The fan cools the attic and ceilings when outside temperatures are high, while the heat fan shuttles warm air from the attic to the ground floor when outside temperatures are low. Cost: $300 (attic insulation), $23 per 4' x 8' board (solar sheathing), $4,000 (new roof), $600 (whole-house fan), $570 (whole-house heater), $1,450 (two skylights)



Monday, April 23, 2007

Building-integrated photovoltaic solar power


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"Utility rates are only heading one way -- up," says Brad Dougherty, a mechanical engineer working with BIPV solar cells at the National Institute of Standards and Technology.

Solar power systems cost about 90 percent less than they did in the 1970s, and prices have been dropping about 5 to 7 percent each year, according to the Solar Energy Industry Association. Solar power is a hedge against rising energy prices.


Story by Denise Trowbridge
April 16, 2007
BizRate.com

If you want free electricity from the sun but don't want rows of pool-table-sized solar panels destroying the lines of your roof, there's now an easier, more attractive solar option.

Building-integrated photovoltaic solar power, or BIPV, has taken the ugly and awkward out of residential solar power systems.

Simply put, BIPV is the mixing of solar power cells into materials you'd normally see on a building, such as roof shingles or the UV coating on a window or skylight.

It's most popular application is the solar shingle, where solar cells are glued or mounted to the surface of a common roofing material, such as slate, cement or asphalt. The shingles are then installed just like a traditional roof. The solar panels are no longer on the roof, they are the roof.

The technology has been around for about five years, but it's become more popular recently, thanks to declining prices, federal tax credits and state incentives for homeowners installing alternative energy systems.

Homeowners qualify for a tax credit of 30 percent of the cost of a solar power system, up to $2,000. The credit, which reduces the tax owed dollar-for-dollar, was set to expire in 2007 but has been extended through 2008. Most states offer additional incentives, including grants, low-interest loans and state tax deductions.

When combined, incentives can lower the upfront costs of installing a solar power system by 60 to 70 percent, says Noah Kaye, director of public affairs with the Solar Energy Industries Association.

The typical American household uses about 10,656 kilowatt-hours of electricity each year, or about 888 kwh per month, which means a 6 kw solar power system would be needed to cover all of that home's electricity needs.

A one-kilowatt BIPV solar roof system costs about $14,000 before incentives, says Art Rivera, marketing representative for Sunslates, a solar roof tile manufacturer in Sacramento, Calif. At that cost, the typical American family would have to spend $84,000 to generate all the electricity it uses.

That price tag is out of reach for many Americans, which is why most homeowners opt for a partial solar electricity system. Most install 2 to 3 kw systems, Rivera says, which can reduce electricity bills by 25 percent or more. Homeowners on a budget also have the option to increase the capacity of their system over time, as they can afford it. Most solar electricity systems are modular, so more solar panels or shingles can be added to the current system after it's installed.

Each 1 kw shingle system requires about 100 square feet of roof space and produces between 1,600 and 2,000 kilowatt-hours of electricity each year, depending on where you live. If electricity costs 10 cents per kilowatt-hour, each 1 kw of solar power would reduce your electricity bill by $160 to $225 each year for the life of the system. Solar shingles typically last 20 to 25 years, and are designed to withstand hail and tropical-storm force winds.

Lower utility bills for the future are a big part of the appeal.

"Utility rates are only heading one way -- up," says Brad Dougherty, a mechanical engineer working with BIPV solar cells at the National Institute of Standards and Technology.

Solar power is a hedge against rising energy prices.

"It's like buying a car that has 25 years of gas in the tank," Kaye says. "The fuel is free, so the upfront cost is the only cost."

Add in the environmental benefits, which include reduction of greenhouse gases linked to global warming, and it's a win for consumers.

It doesn't hurt that solar power systems can also boost the resale value of real estate.

"Homes with solar (power) sell for more," says Brad Collins, executive director of the American Solar Energy Society. "The resale value solar adds to a house is often more than the cost of the system."

That's music to homeowners' ears in a rocky housing market. It's also become a selling point for homebuilders.

Developments where BIPV solar roofs are standard issue are popping up all over California. About 30 neighborhoods there are using SunTiles, a BIPV roofing material, on all or most of the new homes built in those developments, including a 650-plot Lennar Homes project in Roseville, Calif., that claims to be the world's largest all solar-powered community.

But solar power isn't just for the Sunbelt. It can make just as much sense in Boston as in Albuquerque, N.M. "Photovoltaics produce 25 percent more power in Albuquerque, N.M., but Boston's electricity rates are much higher, so the savings are about the same," Kaye says.

Figuring out if it makes sense for your home can be complicated. The time it takes to recoup your investment in solar power varies by region, but some basic rules apply everywhere.

For instance, solar power does best on a south-facing roof. Electricity production falls about 15 percent if the roof is facing east or west. And the more you pay for electricity, the less time it will take to recoup your investment. There are online calculators to help you crunch the numbers for your neighborhood.

It may seem like common sense, but working solar into your home-improvement schedule can save money, too. If you need a new roof anyway, or if you're building an addition onto your home, installing BIPV instead of traditional roofing can be a good option, Dougherty says. The price tag is comparable.

"But if your existing roof is in good shape, it doesn't make sense to replace it," he says. If your roof has a few more years of life left, traditional rack-mounted solar panels might be a better choice.

Net-metering standards also come into play. Most solar roofs are net metered, meaning they are tied to the traditional electricity grid. Net metering allows homeowners to buy traditional electricity from the power company when their solar system isn't producing enough. When it's generating more than the homeowners need, they sell electricity back to the power company. Not all states allow net metering.

Installation costs vary as well, due to local labor costs. BIPV isn't quite a do-it-yourself project yet, but installation is simple. The pieces can be installed by just about any qualified roofer, and are then tied into the utility grid by an electrician.

If you're on the fence about solar power, it could pay to wait a year or two. In the near future, solar options might make more economic sense to more people. Solar power systems cost about 90 percent less than they did in the 1970s, and prices have been dropping about 5 to 7 percent each year, according to the Solar Energy Industry Association.