Inverters Lower Solar Costs

Inverter technology drives lower solar costs Leesa Lee, Enphase Energy, Petaluma, CA USA Info Provided by:Scott's Contracting GREEN BUILDER, St Louis "Renewable Energy" Missouri.http://www.stlouisrenewableenergy.com, contact scotty@stlouisrenewableenergy.com for additional information Distributed architecture is a leap forward for inverter technology with continued advances expected to drive lower installation and maintenance costs. Solar power is poised to go mainstream in North America. In the U.S.—the world’s leading energy consumer—the solar market is especially ripe. As with any new technology, though, how fast it happens depends largely on economics. Installation costs Solar system installation costs include three main components: solar module, 50%; balance-of-system (BOS) and labor, 40%; inverter, 10%. Solar module prices, while still accounting for the majority of overall system costs, have come down significantly—as much as 50% compared to 2008. Modules are becoming increasingly commoditized, and as their prices drop, BOS, labor, and inverters become more important as they become a larger proportion of the total cost of an installation [1]. Therefore, the BOS and inverter segments have seen increased interest over the past few years. One reason why inverters have received so much attention is changes in inverter technology, which impact not only inverter costs, but also BOS and labor costs. Improved inverter technology can also help with other challenges that PV must overcome to gain widespread acceptance in the marketplace. New inverter technologies Inverter R&D has focused on two areas. The first is incremental changes in the existing string/central inverter, and most of these changes are geared toward higher efficiency and larger capacity. These changes have led to bigger, more centralized inverters, for example, SMA’s new 500kW 500U PV inverter. The second recent inverter development is a move toward decentralized architectures, including partial solutions such as DC-to-DC optimizers, consisting of add-on electronics designed to augment a central inverter, and complete inverter solutions such as microinverters. System cost Inverter prices have not decreased significantly in the past few years, and with module prices falling, inverters represent a greater portion of the total cost of a solar installation. As mentioned, inverter technology can also have a significant impact on BOS and labor costs. For example, higher-capacity central inverters reduce the number of inverters that need to be installed in very large systems, thereby reducing labor costs. This is offset to some extent by the wider distribution of DC wiring and the need for bulky and expensive DC combiners and DC circuit overcurrent protection. New AC-based inverter systems can incorporate AC BOS equipment rather than DC junction boxes, DC combiner boxes, connectors, and fuses. Generic AC equipment is much cheaper than specialized DC BOS, and so total installation expenditures can be reduced significantly. Similarly, new inverter technologies, e.g., microinverters, avoid the need for a large central inverter, further reducing installation costs. This is particularly true for larger systems, where the large inverter can require installing a concrete pad, an air-conditioned hut, fencing, and a crane to lift the inverter into place. New inverter technologies also have the potential to reduce solar array operating costs. Microinverter technologies make the array less prone to performance degradation from dust and debris, meaning less frequent washing. Normal soiling of modules can easily reduce power output by 5 or 6%. Also, inverters based on a distributed architecture allow for delayed maintenance. In this type of highly redundant system, if one module or inverter fails, the outage is limited to that module. The rest of the array will continue to operate normally. System owners and operators can have a plan of scheduled maintenance rather than emergency maintenance. Furthermore, maintenance costs are lower because microinverters can be swapped out quickly and easily, and by less-skilled staff—compared to large central inverters, which require expert diagnosis, repair, removal, and replacement. Finally, systems that include inverter communication and per module monitoring dramatically reduce the time required to troubleshoot the PV array. Energy harvest Inverter technology has always had a significant impact on energy harvest. The serial nature of module installation results in the “Christmas light effect,” i.e., any impact (dust, debris, shade) on module performance will also affect the other modules in the string. Distributed inverter architectures mitigate this effect as each module becomes an independent power producer. Per-module MPPT enables increased energy harvest. SunEdison recently installed their first microinverter-based system, resulting in energy harvest numbers 20% greater than the figures estimated during the design process [2]. Reliability Every installer knows about inverter reliability problems. The biggest headache is sending a tech to a site repeatedly to troubleshoot a system failure, and then return to install a replacement inverter. Microinverter technology introduces both improved unit reliability as well as better system reliability. Unit reliability is improved largely due to the change in architecture to a distributed inverter system where each unit is only converting a small portion of the power of the array. Microinverters typically have a small thermal footprint and low nominal operating voltages, both of which reduce stress on components, thereby increasing reliability. For example, the Enphase Microinverter processes less than 215WAC at 95.5% efficiency and has a nominal operating voltage of 30 – 50V. System availability is high because even if one inverter fails, it represents only a tiny fraction of the array. Finally, new distributed inverter technologies include per-module monitoring, allowing the installer to identify malfunctioning modules quickly and easily, and then simply swap-out the problem inverter utilizing the lowest possible labor skill level. Safety Increasing PV safety means minimizing the risk of fire and DC arc faults. PV fire safety has two aspects: prevention and suppression. AC-based inverter technologies can help reduce fire risk because an arc in an AC system self-extinguishes 120 times per second (on a 60Hz power system), whereas a DC arc is continuous. An AC system has no distribution of dangerous high voltage DC. AC-based systems are also safer for firefighters. An AC-voltage distribution system can be shut off prior to fighting the fire, while the widely distributed high-DC voltage of a DC system remains energized whenever the sun is shining. Enabling technologies Microinverters are not a new technology, with several early models gaining popularity in the 1990s. These pioneering models were gradually phased out, primarily due to their inability to break through the 90% efficiency barrier. The new generation of microinverters has efficiencies that are comparable or higher than popular central inverters, and reliability rates that are far superior to central inverters. There are many advances that have made this new generation of microinverters possible. These include advances in semiconductor technology, the availability of silicon carbide diodes to enable higher efficiency, and ASIC technology that has played a large role in shrinking the size of the unit and improving reliability. In addition, potting compounds are now available that enable the unit to withstand colder temperatures, and MOSFET’s that have far lower resistance than those available ten years ago. Finally, new magnetic materials and electrolytic capacitors are particularly well-suited for high-reliability and long-life applications when implemented in the low-voltage design of microinverters. Future trends The next logical step for inverter technology is integration of the inverter into the PV module, to create an AC module. This evolution will benefit all members of the solar value chain significantly. Module manufacturers like the concept as a way to “decommoditize” their offerings, thereby enhancing revenues and profits. It removes an entire step in the installation process and streamlines ordering and procurement, and of course system owners get the benefits of an integrated solution. Distributed architecture is a significant leap forward for inverter technology. With the market share inroads that microinverters have made, we can expect to see additional models introduced. And as these advances continue to drive lower installation and maintenance costs, the industry will inevitably reach a price point where mass adoption becomes inevitable. Conclusion Microinverters were popularized in the 1990s but didn’t gain widespread adoption due to efficiency limitations. With PV module prices decreasing significantly, more attention is being paid to BOS, labor, and inverters, leading to resurgence in distributed inverter technologies. References http://www.deloitte.com/view/en_US/us/Insights/Browse-by-Content-Type/deloitte-review/article/cd308136aaea2210VgnVCM200000bb42f00aRCRD.htm http://findarticles.com/p/articles/mi_pwwi/is_200911/ai_n42129009/ Leesa Lee is the director of product marketing at Enphase Energy, 201 1st Street, Suite 300, Petaluma, CA 94952 USA; ph.: 877-797-4743; email llee@enphaseenergy.com. Analay Solar Andalay AC Solar Power System TM Delivers Maximum Performance With Enphase micro-inverters built right into each panel, Andalay delivers powerful performance over its 25 year lifetime. Unlike ordinary panels where their power production varies from hour to hour, each Andalay panel consistently operates at its maximum power potential. Additionally, these revolutionary panels continue to operate at maximum power even if one panel goes down compared to ordinary panels where the malfunction of one panel from shading or other failures takes down all of the panels. As a result, these revolutionary panels can perform 5% to 25% higher than ordinary panels.

Window Selection Guide

Optimizing Windows
Here’s how window design, placement, and performance can make a greater impact on efficiency and comfort without busting the budget.

By:Rich Binsacca http://www.ecohomemagazine.com/green-products/optimizing-windows.aspx?page=2

Scott's Contracting GREEN BUILDER, St Louis "Renewable Energy" Missouri.http://www.stlouisrenewableenergy.com, contact scotty@stlouisrenewableenergy.com for additional information

Rules of Thumb for Selecting Windows
Though windows are only one target among several products and practices toward a top-notch thermal envelope, there are still rules of thumb to follow to optimize their impact.

Southern Exposure: An all-day exposure, per the sun’s path. In heating (i.e., cold) climates, leverage it with a better U-factor (ideally 0.20 or less) but less-efficient SHGC (perhaps 0.50 or higher) to boost heat gain in the winter and offset heating energy; use overhangs or other shading devices to cut down gain in the summer, when the sun is higher in the sky. In cooling (i.e., hot) climates, spec windows with U-factors and SHGC ratings of 0.30 or better and use shading tactics. “If I have to choose between blocking the summer sun and some solar gain in the winter, I’ll elect to block it,” says Texas custom builder Don Ferrier.

Western Exposure: Solar gain mostly in the late afternoon. Bob Saxler, architectural marketing manager at Andersen Windows, advises builders to focus on this elevation first, as it is the most difficult to control. If possible, orient the house and floor plan away from this exposure, such as situating utility areas, bathrooms, and, ideally, the garage on that side, and specify small and fewer operable (ideally casement) windows with efficient U-factors and SHGC ratings to mitigate solar gain and provide some measure of passive ventilation. If you have a view to the west, he says, boost the SHGC even more and look for multiple shading opportunities inside and out.

Northern Exposure: In this hemisphere, the least opportunity for solar gain. A dual-pane window with a standard low-E coating on the inner face of the outside pane (cold climate) or the outer face of the inside pane (hot climate), is sufficient. “We always recommend a low-E window for north-facing windows for its insulating value alone,” says Val Brushaber, director of product management, certification, and architectural development for Hurd Windows & Doors. The number and size of windows can be dictated by views, exterior aesthetics, and floor plan as much as thermal efficiency, though fewer windows is always better in that regard. North is also notorious for prevailing winds, so think about air infiltration and passive ventilation through casement windows (instead of hung units) or fixed windows to lessen leakage.

Eastern Exposure: Rich in daylight, but far cooler than its opposite exposure. You can dial up the SHGC rating to 0.40 or more, especially in heating or mixed climates, while a U-factor of 0.30 is plenty to retard thermal transfer through the window.

AN INTEGRATED APPROACH

The breakfast room scenario, and even more dramatic examples of homes that use windows of varying U-factor and SHGC values to take advantage of passive solar heating, cut down on heat gain from a western elevation, or save costs on a northern exposure, underscores the merits of a building science (or integrated) approach to energy efficiency and thermal comfort.

“In reality, everything is related [to thermal performance and comfort],” says Saxler. “You need a total home evaluation if you want to fine-tune your windows.” An energy audit by a local rater certified by the Residential Energy Services Network (www.natresnet.org) is a good place to start, while most window manufacturers and/or their dealers employ software programs to determine ideal specifications based on other, whole-house factors, such as wall insulation values.

Gaiser is even more blunt about the role of windows in lowering a home’s energy demand. “If you want to save energy, put in fewer windows,” he says. Upgraded insulation costs far less than high-performance windows, he says, and results in a better thermal envelope and a faster return on investment. “Windows rarely pay back as well as other energy-efficiency measures. Put them in for light and views, but not for energy efficiency.”

Which takes us back to the original question of whether specifying window performance for each orientation is worth the effort, at least in terms of thermal value. For builders, the decision may come down to marketability. “It’s an opportunity to stay one step ahead of the competition, to offer a house that’s more comfortable and efficient than the next guy,” says Saxler. “If you do the building science, you’re in the top 10% of all builders.”

Contact Scotty@stlouisrenewableenergy.com for your next Window Order


RESOURCES:
The Efficient Windows Collaborative:
http://www.efficientwindows.org/

Energy Star (Qualified Windows):
www.energystar.gov/windows

Lawrence Berkeley Laboratory, Windows & Daylighting Division:
http://windows.lbl.gov/

National Fenestration Rating Council:
http://www.nfrc.org/

Residential Windows, A Guide to New Technologies
and Energy Performance
by John Carmody, et. al., available at http://www.wwnorton.com/

Recycle Cigarette Butts

scientists find use for cigarette butts

Scott's Contracting GREEN BUILDER, St Louis "Renewable Energy" Missouri.http://www.stlouisrenewableenergy.com, contact scotty@stlouisrenewableenergy.com for additional information


China scientists find use for cigarette butts


Thu May 13, 3:21 am ET

HONG KONG (Reuters) – Chemical extracts from cigarette butts -- so toxic they kill fish -- can be used to protect steel pipes from rusting, a study in China has found.

In a paper published in the American Chemical Society's bi-weekly journal Industrial & Engineering Chemistry Research, the scientists in China said they identified nine chemicals after immersing cigarette butts in water.

They applied the extracts to N80, a type of steel used in oil pipes, and found that they protected the steel from rusting.

"The metal surface can be protected and the iron atom's further dissolution can be prevented," they wrote.

The chemicals, including nicotine, appear to be responsible for this anti-corrosion effect, they added.

The research was led by Jun Zhao at Xi'an Jiaotong University's School of Energy and Power Engineering and funded by China's state oil firm China National Petroleum Corporation.

Corrosion of steel pipes used by the oil industry costs oil producers millions of dollars annually to repair or replace.

According to the paper, 4.5 trillion cigarette butts find their way into the environment each year. Apart from being an eyesore, they contain toxins that can kill fish.

"Recycling could solve those problems, but finding practical uses for cigarette butts has been difficult," the researchers wrote.

China, which has 300 million smokers, is the world's largest smoking nation and it consumes a third of the world's cigarettes. Nearly 60 percent of men in China smoke, puffing an average of 15 cigarettes per day.

(Reporting by Tan Ee Lyn; Editing by Miral Fahmy)

10 Things Home-Security Firms Won't Tell You

Scott's Contracting GREEN BUILDER, St Louis "Renewable Energy" Missouri.http://stlouisrenewableenergy.blogspot.com,


10 Things Home-Security Firms Won't Tell You

Jonathan Dahl, SmartMoney.com

May 12th, 2010


10 Things Home-Security Firms Won't Tell You
1. "A little home security goes a long way."

It's official: We live in a society increasingly obsessed with the technology of safety. According to Security Sales & Integration magazine, Americans spent $28.2 billion on electronic security systems in 2009, up from $25.9 billion in 2006. Yet crime in general, and burglaries in particular, have been steadily decreasing. As comforting as it may be to have an elaborate alarm system - the average home-security package costs about $1,400 for installation and equipment, and about $23 a month to monitor - the reality is that you can deter most break-ins much more cheaply.

There are lots of proactive - and inexpensive - ways you can protect your home from a break-in, says Frank Santamorena, founder of Security Experts, a security services company in New York. Lighting works wonders. Merely keeping the boundaries of your house ("perimeters" in security lingo) well lit- perhaps with motion-sensor lights, which cost less than $100-will discourage most burglars. But since the majority of home break-ins occur during the day, when people are away at work, experts suggest a few additional precautions. Keep hedges trimmed low to minimize hiding space around the house, and make sure there's a good, strong lock installed on every door. And many homeowners make the mistake of putting their name on their mailbox. A burglar can get your phone number and find out if you're not home immediately, "without even having to knock on the door," says Santamorena.
2. "The cops can't hear your alarm."

Think your alarm will ring right in your local police station? Forget about it. The majority of today's home security alarms ring in a so-called central station, where monitors will phone your house, ask for a code word, and notify the police if you don't respond. That central station can be anything from a boiler room downtown to a concrete bunker in another state, and it may or may not be manned by your security company, but rather a third-party subcontractor.

Not thrilled with the idea of having your alarm ringing 1,000 miles away at a company you've never heard of? You should be. For one thing, a feel for local conditions might come in handy when your life is at stake. "You're better off being with a local alarm company with a central station than you are with a national company," says Santamorena. And more than that, he says, you want a "UL-listed" system. That means the product is certified by Underwriters Laboratories and is mandated to meet certain standards that, for instance, ensure there's backup power in case of a power failure, he says.
3. "This system is more trouble than it's worth."

Sales of systems might be up, but once they're installed, not all folks actually use them. It could be that they're worried about false alarms or that they only set the alarm when they're away for an extended period. "It could be that the way the system is laid out and designed doesn't work well with their particular lifestyle," says Scott Goldfine, editor of Security Sales & Integration. They might have small children or cleaning staff who tend to set it off, or house guests who don't the code.

"Any system that you have installed, it's important you get the proper training on how to use it. And you want to use it every day," says Michael Miller, president of the Electronic Security Association (ESA), an industry group.
4. "The local police hate us."

If you have an alarm system installed in your home, one thing is almost certain: You will trigger false alarms. This is, of course, a nuisance in itself. But the real problem is that police departments know it. Nationwide, the majority of alarm calls are false, rendering alarms' overall reliability quite thin. In some locales, the police have responded by fining homeowners for repeat false alarms.

Phoenix, for one, allows residents three - after the third, it's $75 a pop. A third false alarm in Santa Monica, Calif., costs homeowners $136.70; after that you'll get hit with a $180 fine. In Montgomery County, Md., officers may not respond at all to homes that have had multiple previous false alarms. "If it's the fourth one today and there's nothing unusual about the alarm, or the alarm company advises it's a malfunction or error, the supervisor has discretionary authority to cancel the call," says Corporal Dan Friz, a spokesman for the department.

But there's a concerted effort by the security-alarm industry and local authorities to reduce false alarms. Working with the Security Industry Alarm Coalition, an umbrella trade group, several states have implemented ordinances that require homeowners to register their alarm systems with the local police. The regulation also mandates new equipment standards and two-call verification, so an alarm monitoring station will attempt to confirm an alarm by contacting the homeowner at two different phone numbers before requesting a response.
5. "We'll try to sell you expensive gadgets you don't really need."

Security experts and police generally agree that an effective home-security system contains both perimeter and interior sensing devices. Each system can each include some impressive-sounding gear. Perimeter alarms might have magnetic or plunger contacts; foiling, vibration, or shock detectors; and window screens that hold concealed alarm wire for perimeter alarms. And interior alarms might involve pressure mats, photoelectric beams that cast infrared light, heat sensors, and motion detectors. But just because all these gizmos are available doesn't mean you need every one to have a sound security system.

Before making any purchases, homeowners should do an assessment of their home to determine what exactly they're trying to protect. Not all alarms and gadgets are right for all homes, and this mostly depends on the individual characteristics of your property. Consider how large your home is and how many potentially vulnerable entrances there are.

"You don't need an alarm on every window, but motion detectors need to be placed in key points," says Jim McGuffey, a security consultant in Philadelphia. Once the doors have been protected and motion sensors installed in key areas like staircases and hallways leading to bedrooms, a house should be pretty well set.
6. "Our rent-a-cops are very low-rent."

Many home-security firms offer some kind of guard service along with alarm monitoring. Some drive company-owned "patrol" cars, and some even carry weapons. Yet in spite of the high level of responsibility for these jobs, the standards for training are uneven. While most states require that security guards be licensed, California-- which does run background checks - you need only be 18 years old, have $102 for the application fee and submit to 40 hours of training.

McGuffey recommends homeowners who hire private guards to ask if the company conducts criminal background checks on their personnel. "I would also ask: What kind of training do you give your guard force," he says.

The security-system industry is actually pushing Congress to mandate criminal background checks for employees of companies that install burglar alarm, fire alarm and other types of security systems. Now, individual states decide whether background checks are required. These companies send installers and technicians into homes, business and schools, and "we want to make sure they don't have criminal backgrounds, especially if an employee is coming from another state," says ESA's Miller.
7. "Getting past our alarms is tough-unless you have a pair of scissors."

Last year, nearly a dozen homes in Lewisville, outside Dallas, were burglarized. In an attempt to disable the alarm systems, the criminals cut power and telephone lines before forcing their way inside the homes, according to a local news report. In one case, the burglars got away with a flat-screen TV, a Wii game system and a digital camera.

The standard home alarm is transmitted over a telephone line, and getting around it requires little more than the ability to figure out where the line is and the skill to handle a good pair of wire cutters. Most alarm companies now offer some sort of backup protection, which typically consists of a radio or cellular device that notifies the central station your line has been cut. But these backup systems can cost a lot more-around several hundred dollars extra in addition to monthly charges.

There are ways around this if that expense is out of your budget. If your home's cables come from the ground up, Santamorena suggests paying someone to dig a foot or so down, through foundation of the house, and snake the wire through there, so they're hidden from sight. "The key is to make sure the phone lines aren't coming up on the side of the house," he says.
8. "We may use unethical sales tactics."

These days, homeowners need to beware of salespeople who come knocking. The Better Business Bureau received nearly 3,000 complaints about burglar-alarm companies in 2009, up from 2,087 in 2008. Many complainants allege that the salesperson used high-pressure tactics and made claims that were not included in the final contract, according to the BBB.

Last month, the Electronic Security Association announced a new code of ethics for door-to-door sales in an effort to cut down on deceptive pitches. "Rogue salespeople," as the ESA called them in a statement, have been making headlines with lawsuits filed by major security-alarm companies against door-to-door salespeople for misleading customers. Just last month, ADT Security Services filed a suit against three employees of another company, alleging that during a sales call one salesperson coerced a 95-year-old Tennessee woman into switching out her ADT system and signing a contract with another firm.

For now, the ESA is relying on companies to self-enforce its new ethics code, which requires sales representatives to carry photo ID and bars them from making false statements about competing organizations. The BBB advises consumers to deal only with reputable firms and to check out the offer and compare bids from several installers.
9. "You're stuck with us."

One common complaint from alarm system customers is that their alarm contracts renew automatically. Unless there is a specific request that you want to cancel your service, your contract will be renewed - anywhere from one to five years, depending on the company. Many homeowners don't mark their calendars with their home-security system contract's expiration date. If you're in a three-year contract, and don't make a point of sending a letter of cancellation before it expires, you could be hooked into another three-year term.

Ken Kirschenbaum, an attorney who represents home security companies, says auto renewal is not unique to the alarm industry, and provides an important service for the consumer. "Without an auto renewal provision, those services would terminate at the end of a contract," he says, leaving the subscriber without this "essential protection."

Some states, such as Utah, require written notice to the consumer before a contract can automatically renew (for consumer contracts in general, not just security firms). Either way, homeowners should read their contracts - including the fine print - carefully for "automatic renewal" language. Contracts should indicate a time frame in which customers can give written notice that they want to disconnect the service.
10. "If you have a pet, we might be less effective."

Some alarms say they are "pet-immune," allowing your furry friends to move freely around the house. Others say they can reliably distinguish between human bodies and pets weighing up to 80 pounds. But as recently as 2009, 27% of false alarms were attributed to pets, according to Security Sales & Integration. One potential culprit: the feline of the house. "Cats can get anywhere and they move in crazy ways," says Goldfine.

It also matters how furniture is situated. If the pattern of detection includes, say, a book case, a cat can potentially climb up on that and get in the alarm's line of detection. "If you're getting them installed in your house and you have pets, I would have that discussion with the installing company to find out how well they really work," says Goldfine.
Updated and adapted from the book "1,001 Things They Won't Tell You: An Insider's Guide to Spending, Saving, and Living Wisely," by Jonathan Dahl and the editors of SmartMoney. Article Found at:http://realestate.yahoo.com/promo/10-things-home-security-firms-wont-tell-you