Solar Electric for the Beginner
from Home Power online March 05

Perhaps what the home-scale renewable energy (RE) world needs most are ways to introduce people to RE technologies and the gizmos that make it possible. After all, even the best ideas aren't embraced until they are explained in simple terms. So whether you are the rookie who wants to understand how solar-electric systems work, or that better describes your spouse, friend, or prospective customer, this article explains the guts and bolts of the three most common options in solarelectric systems: grid-intertied, grid-intertied with battery backup, and off-grid (stand-alone). Understanding the basic components of an RE system and how they function is not an overwhelming task. Here are some brief descriptions of the common equipment used in grid-intertied and off-grid solar-electric systems. Systems vary - not all equipment is necessary for every system type. In the diagrams, the numbers in red correspond to the components needed.

Also known as on-grid, grid-tied, or utilityinteractive (UI), grid-intertied solar-electric systems generate solar electricity and route it to the electric utility grid, offsetting a home's or business's electrical consumption and, in some instances, even turning the electric meter backwards. Living with a grid-connected solar-electric system is no different than living with grid power, except that some or all of the electricity you use comes from the sun. In many states, the utility credits a homeowner's account for excess solar electricity produced. This amount can then be applied to other months when the system produces less or in months when electrical consumption is greater. This arrangement is called net metering or net billing. The specific terms of net metering laws and regulations vary from state to state and utility to utility. Consult your local electricity provider or state regulatory agency for their guidelines.

PV panels are a solar-electric system's defining component, where sunlight is used to make direct current (DC) electricity. Behind a PV panel's shimmering facade, wafers of semiconductor material work their magic, using light (photons) to generate electricity - what's known as the photovoltaic effect. Other components in your system enable the electricity from your solar-electric panels to safely power your electric loads like lights, computers, and refrigerators. PV panels are assigned a rating in watts based on the maximum power they can produce under ideal sun and temperature conditions. You can use the rated output to help determine how many panels you'll need to meet your electrical needs. Multiple modules combined together are called an array. Although rigid panels are the most common form of solar electricity collector, PV technology also has been integrated into roofing shingles and tiles, and even peeland-stick laminates (for metal standing-seam roofs). PV modules are very durable and longlasting - most carry 25-year warranties. They can withstand severe weather, including extreme heat, cold, and hail stones.

2 Array Mounting Rack AKA: mounts, racks Mounting racks provide a secure platform on which to anchor your PV panels, keeping them fixed in place and oriented correctly. Panels can be mounted using one of three approaches: 1) on a rooftop; 2) atop a steel pole set in concrete; or 3) at ground level. The specific pieces, parts, and materials of your mounting device will vary considerably depending on which mounting method you choose. Usually, arrays in urban or suburban areas are mounted on a home's south-facing roof, parallel to the roof's slope. This approach is sometimes considered most aesthetically pleasing, and may be required by local regulators or homeowner's associations. In areas with a lot of space, pole- or ground-mounted arrays are another choice. Mounting racks may incorporate other features, such as seasonal adjustability. The sun is higher in the sky during the summer and lower in the winter. Adjustable mounting racks enable you to set the angle of your PV panels seasonally, keeping them aimed more directly at the sun. Adjusting the tilt angle increases the system's annual energy production by a few percent. The tilt of roofmounted arrays is rarely changed - adjusting the angle is inconvenient and sometimes dangerous, due to the array's location. Changing the tilt angle of pole- or ground-mounted arrays can be done quickly and safely. Pole-mounted PV arrays also can incorporate tracking devices that allow the array to automatically follow the sun across the sky from east to west each day. Tracked PV arrays can increase the system's daily energy output by 25 to 40 percent.

The DC disconnect is used to safely interrupt the flow of electricity from the PV array. It's an essential component when system maintenance or troubleshooting is required. The disconnect enclosure houses an electrical switch rated for use in DC circuits. It also may integrate either circuit breakers or fuses, if needed. A charge controller's primary function is to protect your battery bank from overcharging. It does this by monitoring the battery bank - when the bank is fully charged, the controller interrupts the flow of electricity from the PV panels. Batteries are expensive and pretty particular about how they like to be treated. To maximize their life span, you'll definitely want to avoid overcharging or undercharging them. Most modern charge controllers incorporate maximum power point tracking (MPPT), which optimizes the PV array's output, increasing the energy it produces. Some batterybased charge controllers also include a low-voltage disconnect that prevents over discharging, which can perma nently damage the battery bank.

Without a battery bank or generator backup for your gridintertied system, when a blackout occurs, your household will be in the dark, too. To keep some or all of your electric needs (or "loads") like lights, a refrigerator, a well pump, or computer running even when utility power outages occur, many homeowners choose to install a grid-intertied system with battery backup. Incorporating batteries into the system requires more components, is more expensive, and lowers the system's overall efficiency. But for many homeowners who regularly experience utility outages or have critical electrical loads, having a backup energy source is priceless.

Your PV panels will produce electricity whenever the sun shines on them. If your system is off-grid, you'll need a battery bank&emdash;a group of batteries wired together to store energy so you can have electricity at night or on cloudy days. For off-grid systems, battery banks are typically sized to keep household electricity running for one to three cloudy days. Gridintertied systems also can include battery banks to provide emergency backup power during blackouts - perfect for keeping critical electric loads operating until grid power is restored. Although similar to ordinary car batteries, the batteries used in solar-electric systems are specialized for the type of charging and discharging they'll need to endure. Lead-acid batteries are the most common battery used in solar-electric systems. Flooded leadacid batteries are usually the least expensive, but require adding distilled water occasionally to replenish water lost during the normal charging process. Sealed absorbent glass mat (AGM) batteries are maintenance free and designed for grid-tied systems where the batteries are typically kept at a full state of charge. Gel-cell batteries can be a good choice to use in unheated spaces due to their freeze-resistant qualities.

System meters measure and display several different aspects of your solar-electric system's performance and status, tracking how full your battery bank is; how much electricity your solar panels are producing or have produced; and how much electricity is in use. Operating your solar-electric system without metering is like running your car without any gauges - although possible to do, it's always better to know how much fuel is in the tank.

In battery-based systems, a disconnect between the batteries and inverter is required. This disconnect is typically a large, DC-rated breaker mounted in a sheetmetal enclosure. This breaker allows the inverter to be quickly disconnected from the batteries for service, and protects the inverter-to-battery wiring against electrical fires.

Inverters transform the DC electricity produced by your PV modules into the alternating current (AC) electricity commonly used in most homes for powering lights, appliances, and other gadgets. Grid-tied inverters synchronize the electricity they produce with the grid's "utilitygrade" AC electricity, allowing the system to feed solar-made electricity to the utility grid. Most grid-tie inverters are designed to operate without batteries, but battery-based models also are available. Battery-based inverters for off-grid or grid-tie use often include a battery charger, which is capable of charging a battery bank from either the grid or a backup generator during cloudy weather. Most grid-intertie inverters can be installed outdoors (ideally, in the shade). Most off-grid inverters are not weatherproof and should be mounted indoors, close to the battery bank.

Although they are most common in remote locations without utility grid service, off-grid solar-electric systems can work anywhere. These systems operate independently from the grid to provide all of a household's electricity. That means no electric bills and no blackouts - at least none caused by grid failures. People choose to live off-grid for a variety of reasons, including the prohibitive cost of bringing utility lines to remote homesites, the appeal of an independent lifestyle, or the general reliability a solar-electric system provides. Those who choose to live off-grid often need to make adjustments to when and how they use electricity, so they can live within the limitations of the system's design. This doesn't necessarily imply doing without, but rather is a shift to a more conscientious use of electricity.

The AC breaker panel is the point at which all of a home's electrical wiring meets with the "provider" of the electricity, whether that's the grid or a solar-electric system. This wall-mounted panel or box is usually installed in a utility room, basement, garage, or on the exterior of the building. It contains a number of labeled circuit breakers that route electricity to the various rooms throughout a house. These breakers allow electricity to be disconnected for servicing, and also protect the building's wiring against electrical fires. Just like the electrical circuits in your home or office, an inverter's electrical output needs to be routed through an AC circuit breaker. This breaker is usually mounted inside the building's mains panel, which enables the inverter to be disconnected from either the grid or from electrical loads if servicing is necessary, and also safeguards the circuit's electrical wiring. Additionally, utilities usually require an AC disconnect between the inverter and the grid that is for their use. These are usually located near the utility KWH meter.

Most homes with a grid-tied solarelectric system will have AC electricity both coming from and going to the electric utility grid. A bidirectional KWH meter can simultaneously keep track of how much electricity flows in each of the two directions&emdash;just the information you need to monitor how much electricity you're using and how much your solar-electric system is producing. The utility company often provides intertie-capable meters at no cost.

Off-grid solar-electric systems can be sized to provide electricity during cloudy periods when the sun doesn't shine. But sizing a system to cover a worst-case scenario, like several cloudy weeks during the winter, can result in a very large, expensive system that will rarely get used to its capacity. To spare your pocketbook, size the system moderately, but include a backup generator to get through those occasional sunless stretches. Engine generators can be fueled with biodiesel, petroleum diesel, gasoline, or propane, depending on the design. These generators produce AC electricity that a battery charger (either standalone or incorporated into an inverter) converts to DC energy, which is stored in batteries. Like most internal combustion engines, generators tend to be loud and stinky, but a welldesigned solar-electric system will require running them only 50 to 200 hours a year.

As you can see, the anatomy of a photovoltaic system isn't that complicated. All of the parts have a purpose, and once you understand the individual tasks that each part performs, the whole thing makes a bit more sense. Now you're ready to look at the system articles and schematics in Home Power without your eyes glazing over, and you'll have a clearer understanding of what is going on in the articles. To solidify your understanding, your next task should be to examine a solar-electric system in person. The National Tour of Solar Homes each fall is one way to see a variety of systems. Also, many renewable energy fairs and workshops feature tours of solar homes. Check the listings for your area in the Happenings calendar in each Home Power issue to find out where you can learn more about RE systems and meet the people who are using renewable energy in your area.

Green Swamp rescuers call out. A long distance
phone service helps activists raise money
to defend the sensitive wetlands.

By Robert Sargent
Orlando Sentinel Staff Writer
February 19, 2005

GROVELAND(Fl) -- Activists desperate to protect Central Florida's Green Swamp from dense development are hoping to ring up support through a novel fund-raising method.

 The creation of a long-distance phone service is part of a growing trend since the 1996 federal deregulation of the telecommunications industry. The services sell low-cost long-distance access and other telephonic options akin to MCI, Sprint and AT&T.

 The difference with Green Swamp Phone LLC -- which backers hope will help with the fight to limit development in the 850-square-mile swamp southwest of Orlando -- and similar companies across the country is that they give a portion of callers' monthly bills to environmental and political causes.

 "We talked about doing the typical dinners, community garage sales or selling T-shirts and hats -- the big picture is that those don't provide what we need," said Rob Kelly, president of the Citizens Coalition of Lake County.

Green Swamp Phone works as an agent selling services for Telrite Corp., one of the country's biggest but lesser-known wholesale long-distance providers regulated in the state by the Florida Public Service Commission. Experts say the idea of fund raising with phone bills is becoming more common nine years after federal officials overhauled laws that once restricted certain competition in the telephone business.

"It's a cottage industry that has sprung up around deregulation," PSC spokesman Kevin Bloom said. Tampa-based GOP Communications, for example, contributes 5 percent of customers' monthly phone bills to the Republican Party of Florida."It's one of the many fund-raising tools we have at our disposal," party spokesman Joseph Agostini said.

Working Assets has used services including long distance, wireless and credit cards to raise a reported $46 million for activist groups such as Greenpeace and Human Rights Watch. Others, such as OneChristianVoice and MightyWorks, contribute to faith-based organizations. 

"People want to feel good about where their money goes," said Liz Karan, director of the Sacramento, Calif.-based Earth Tones, which contributes to several environmental organizations.

In Groveland, the 100-plus members of the Citizens Coalition of Lake County lobbied for a Nov. 2 ballot initiative to protect what is considered one of Florida's most vital environmental assets next to the Everglades.

 The Green Swamp covers portions of Lake, Polk, Sumter, Hernando and Pasco counties. Its wetlands feed five river systems and help to recharge underground water supplies used for drinking throughout most of Florida.

 The coalition reacted last year after the Groveland City Council gave preliminary approval for more than 600 homes in part of the massive swamp, sparking fears that even the most sensitive of Florida's environmental areas could not escape Central Florida's speedy development sprawl.

 Members launched what would become a costly campaign to fight Groveland's growth plans. They gathered petitions for a referendum and later filed a lawsuit to force the city to put the ballot item before voters.

 The coalition had to go back to court when developers tried unsuccessfully to block the Green Swamp vote. About 72 percent of Groveland voters then supported the measure to significantly limit development in the city's portion of the swamp to one house for every five acres.

 The community support was a big success for the coalition. But the developers are still fighting -- Banyan Construction and Lanor Land Trust are in Lake circuit court to block the city from enacting the ballot initiative.

 Coalition members have paid for many of the ongoing legal bills to battle the developers. Other financial support has come from donations and environmental groups such as the Sierra Club and the Audubon Society.

 The coalition's Kelly, who also runs several online Web sites selling prepaid phone service, said Green Swamp Phone is a commercial business set up independently from the nonprofit citizens group.

 "When a developer wants to fight to get into the Green Swamp, their strategy is to run people out of money [in court]," Kelly said. "So what we decided to do is put together a company that would be dedicated full time to generating revenue to protect the swamp."

 The company signs up callers for long distance and other phone services through a toll-free number and its Web site, www.greenswampphone.com. Ten percent of all its customers' monthly phone bills are then donated to the coalition to help pay for legal expenses and to provide public information about the swamp.

 If 4,000 customers have an average long-distance bill of $15 each month, the annual contribution to protect the swamp will be about $72,000, according to the company's Web site.

 After the court battle ends, Kelly said he hopes the new phone business will continue to attract customers with low-priced long-distance service while funding educational programs about the Green Swamp.

 "There's really no limit to how many people we can reach," he said.

By Maggie Fox, Health and Science Correspondent

Reuters Online

WASHINGTON (Reuters) - A parcel of studies looking at the oceans and melting Arctic ice leave no room for doubt that it is getting warmer, people are to blame, and the weather is going to suffer, climate experts said on Thursday.

 New computer models that look at ocean temperatures instead of the atmosphere show the clearest signal yet that global warming is well underway, said Tim Barnett of the Scripps Institution of Oceanography.

 Speaking at an annual meeting of the American Association for the Advancement of Science, Barnett said climate models based on air temperatures are weak because most of the evidence for global warming is not even there.

"The real place to look is in the ocean," Barnett told a news conference.

 His team used millions of temperature readings made by the U.S. National Oceanic and Atmospheric Administration to calculate steady ocean warming.

 "The debate over whether or not there is a global warming signal is now over, at least for rational people," he said.

 The report was published one day after the United Nations Kyoto Protocol took effect, a 141-nation environmental pact the United States government has spurned for several reasons, including stated doubts about whether global warming is occurring and is caused by people.

 Barnett urged U.S. officials to reconsider.

 "Could a climate system simply do this on its own? The answer is clearly no," Barnett said.

 His team used U.S. government models of solar warming and volcanic warming, just to see if they could account for the measurements they made. "Not a chance," he said.

 And the effects will be felt far and wide. "Anywhere that the major water source is fed by snow ... or glacial melt," he said. "The debate is what are we going to do about it."

 COLD WINTERS, HOMELESS POLAR BEARS

 Other researchers found clear effects on climate and animals.

 Ruth Curry of the Woods Hole Oceanographic Institution found that melting ice was changing the water cycle, which in turn affects ocean currents and, ultimately, climate.

 "As the Earth warms, its water cycle is changing, being pushed out of kilter," she said. "Ice is in decline everywhere on the planet."

 A circulation system called the Ocean Conveyer Belt is in danger of shutting down, she said. The last time that happened, northern Europe suffered extremely cold winters.

 She said the changes were already causing droughts in the U.S. West.

 Greenland's ice cap, which contains enough ice to raise sea levels globally by 23 feet, is starting to melt and could collapse suddenly, Curry said. Already freshwater is percolating down, lubricating the base and making it more unstable.

 Sharon Smith of the University of Miami found melting Arctic ice was taking with it algae that formed an important base of the food supply for a range of animals.

 And the disappearing ice shelves meant big animals such as walruses, polar bears and seals were losing their homes.

 "In 1997 there was a mass die-off of a bird called the short-tailed shearwater in the Bering Sea," Smith told the news conference.

 The birds, which migrate from Australia, starved to death for several years running when warmer waters caused a plankton called a coccolithophore to bloom in huge numbers, turning the water an opaque turquoise color.

 "The short-tailed shearwater couldn't see its prey," Smith said.

 Oregon Approves Non-Flush Urinals For Gov't Facilities

The Wholesaler
February 2005

Salem, Ore---Oregon officials have voted to approve an interpretive ruling to permit the installation of waterfree urinals in city, county, state, and federal government facilities in the State of Oregon. The approval promotes and enables unique and effective water conservation throughout the state.

The ruling was prompted by calls for alternate technologies to address the growing shortage of fresh water throughout the region. Interest in waterfree urinal systems has grown across the nation as civic leaders adopt a greater sense of urgency about finding solutions for a future where fresh water may be less available and more costly.

According to Tim Wood, director of the Oregon Parks and Recreation Department, testing of waterfree urinals began in Oregon during 2001 at 13 locations to quantify water savings, effluents and potential odors. The summary report to the Oregon State Plumbing Board concluded that the waterfree urinals in the pilot program are safe and fall well within acceptable limits established by the Department of Environmental Quality.

Jay Troger, president of Falcon Waterfree Technologies, commented, "Waterfree urinals are designed to meet one of the most critical issues we face today-- the need to cost-effectively conserve our rapidly diminishing supply of fresh water. Because each Falcon Waterfree urinal saves an average 40,000 gallons of fresh water per year, this amount of water does not need to be transported to the urinal or away from it. In addition to conserving water, this also means significantly reduced water and sewer expenses. And with an estimated 50 million flush urinals installed globally, it's easy to see why a proven waterfree alternative is gaining favor."

The Falcoln Waterfree urinal system includes a specially designed vitreous china urinal and a unique, patented cartridge. Urine enters the cartridge and passes through a biodegradable sealant fluid before entering the drain line. The cartridge and sealant are proven to be more effective than a standard P-trap as a barrier between drain line odors and the open air. The waterfree urinal's simplicity of design also eliminates costly maintenance required by the valve systems in conventional flush-style urinals.

Troger noted, " The Falcoln Waterfree urinal offers additional advantages because it not only saves water, it also promotes a healthier environment. These urinals are touch-free so there is little chance of bacteria transfer possible as is the case with manual flush systems. Because there si no water used there is no breeding ground for bacteria, as shown in extensive scientific studies. And as an added benefit, Falcoln urinals create more pleasant restrooms because they eliminate the ammonia odor caused when urine reacts with water to cause ammonia oxide. No water means no reaction. It's a win-win situation for everyone- facility managers and occupants.

Two leading brands of waterfree urinals are Falcoln Waterfree Technologies and Sloan Waterfree Urinals. Falcoln and Sloan waterfree urinals are in use in thousand of facilities including the Rose Bowl, University of North Carolina, San Diego Zoo, schools, universities, airports, parks, and public facilities around the world. These units reduce water demands and sewage treatment by billions of gallons per year.