Energy Storage May Already Make Sense for Many Commercial Customers

Seth Mullendore 
May 12, 2015  |  

In the wake of Tesla’s recently announced entrance into the stationary energy storage market, there has been a wave of analysis of what this might mean for residential and commercial utility customers. The bulk of the headlines have centered on the sleek residential Powerwall, but far fewer have investigated the implications of Tesla’s commercial-scale product, the Powerpack. In a new report, titled US Solar & Alternative Energy: The Real Battery Storage Opportunity, the global financial research company UBS sees commercial and industrial (C&I) customers as the market opportunity for Tesla and other energy storage companies.

According to the report, the reason why residential systems may not offer as many economic benefits at this time, while C&I systems have the potential to net a positive return, has to do with how each customer segment is billed for its respective electricity use. Residential utility customers are billed based solely on the volume of electricity consumed, measured in kilowatt-hours (kWh). Commercial customers are also billed on a volumetric basis, but in addition, they pay a demand charge, a fixed charge calculated on the highest magnitude of electricity used each billing period, measured in kilowatts (kW). Demand charges can be significant, accounting for 35-40 percent of a C&I customer’s electricity bill in some parts of the country.

This maximum level of electricity demand is known as peak demand. By selectively discharging when a customer’s level of demand reaches a certain kilowatt threshold, energy storage can act to effectively cap peak demand — a process called peak shaving. The process is all managed through intelligent control system software, which can learn a building’s energy use trends over time to optimize energy storage performance accordingly. Reduced peak demand translates into fewer demand charges and lower customer utility bills.

So, residential customers do not pay demand charges, while commercial and industrial customers do. And it is in those demand charge markets where commercial battery storage will likely make the first foray — because reducing those charges is a straight economic play with a good rate of return. In fact, UBS estimates that energy storage as a way to reduce these demand charges is already economical in several U.S. markets, including parts of California and New York City.

The UBS report models the 20-year internal rate of return (IRR) for an energy storage system costing $400 per kWh, a price point UBS predicts will be reached by 2018. Tesla’s Powerpack is already approaching this target at about $50,000 installed cost for a 100 kWh system, or $500 per kWh. The report finds that energy storage systems begin to show a positive IRR at a demand charge of around $10 per kW. At a demand charges of $16 per kW, the IRR comes in at about 7 percent. A $20 per kW demand charge produces a return of about 12 percent. Demand charges in certain California and New York markets are already in the $30-$40 per kW range, meaning the economics are likely to be favorable even at today’s energy storage prices.

UBS goes on to note that additional value propositions, such as payments for participation in ancillary services and demand response programs, can further improve the economic argument in favor of energy storage.

One component that UBS fails to quantify, or even mention for C&I customers, is that energy storage systems can be set up to island, or disconnect from the grid, in the case of a grid outage. When islanded, energy storage can provide backup power for customers, allowing them to continue operations when the grid is down. While energy storage systems designed for demand charge reduction or ancillary services may not be able to power all of a facility’s systems throughout a power outage, they can certainly take on a reduced or critical load, augmenting the capabilities of existing backup generators and extending the lifetime of onsite fuel supplies during extended outages. When combined with solar power, a storage system could theoretically supply resilient power to critical loads for an unlimited duration.

In comparison to C&I customers, the UBS report finds that residential customers will have less financial incentive to purchase energy storage systems. UBS specifically examines the case of batteries for backup power as compared to fossil-fueled generators. Though the numbers for residential storage look less favorable as an alternative to natural gas generators, UBS fails to look beyond economics alone. The fact is, lithium-ion batteries offer a lot to like as opposed to generators. Generators can be ugly, noisy, and polluting, they are limited by available fuel supplies; and they emit carbon monoxide, a dangerous gas that can be fatal if not properly vented.

Lithium-ion batteries have no emissions, are quiet, and while looks aren’t everything…have you seen the new Tesla battery yet?

Lead image: Light bulbs. Credit: Shutterstock.

Solar Ready Vets: Preparing Our Veterans to Join the Growing Solar Workforce

The transition from military service into the civilian workforce can be a vulnerable moment.

Many veterans indicate that finding a job is one of the greatest challenges they face in their return to civilian life, and one aspect of that challenge is translating military skills and experience in a marketable way for civilian employers.

At the Department of Energy, we like to say we’re solutions people. And there is a great opportunity here to help by connecting our talented veterans with a dynamic sector in our economy that needs them. Solar electricity generation doubled last year alone, and the solar industry is adding jobs 10 times faster than the rest of the economy. That’s why the Department of Energy and the Department of Defense joined forces to create the Solar Ready Vets program, which provides training to help military personnel translate and build on their skill sets and transition to careers in this thriving renewable energy field.

http://energy.gov/articles/solar-ready-vets-preparing-our-veterans-join-growing-solar-workforce-0

HOW DO WIND TURBINES WORK?

#DidYouKnow a #wind turbine works like the opposite of a fan? Instead of using electricity to make wind, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity to power homes and businesses. Learn more about how wind turbines work ⇢

http://www.energy.gov/eere/wind/how-do-wind-turbines-



U.S. Department of Energy

Amazing New Solar Panels Are Completely Transparent

Just so we’re totally clear, this is a huge deal. (Get it?)

posted on Aug. 27, 2014, at 3:51 p.m.

Kasia Galazka

BuzzFeed Staff

http://www.buzzfeed.com/kasiagalazka/transparent-solar-panels#.ou6byrdMk

Wind Vision Report from the U.S. Dept. of Energy

With utility-scale turbines installed in nearly every state, wind is already a major source of clean, domestic power for the nation. But what if wind supplied 35 percent of the country's electricity by 2050? That's one of the scenarios highlighted in our new ‪#‎WindVision‬ report, a detailed roadmap for America's wind energy future. Learn more: http://go.usa.gov/3aHGF

Find Financing for Energy Efficient Upgrades

http://www.energy.gov/eere/buildings/find-financing-energy-efficiency-upgrades

New programs from Focus on Energy!!

Contact us to reduce your energy costs today!



https://focusonenergy.com/business/businessprogramupdates

Rural Energy for America Program - Renewable Energy System and Energy Efficiency Improvement Guaranteed Loan and Grant Program

The Rural Energy for America Program (REAP) provides financial assistance to agricultural producers and rural small businesses in rural America to purchase, install, and construct renewable energy systems; make energy efficiency improvements to non-residential buildings and facilities; use renewable technologies that reduce energy consumption; and participate in energy audits, renewable energy development assistance, and feasibility studies.

http://www.rurdev.usda.gov/BCP_ReapResEei.html

IEA Report Predicts Solar Power Domination by 2050

Two reports released simultaneously last week by the International Energy Agency (IEA) say that by the year 2050, solar power could eclipse fossil fuels, hydro, wind and nuclear as the world’s most widely used source of electricity generation.

Vince Font, Contributing Editor 
October 08, 2014  |  

Utah, USA -- According to the IEA, solar PV could conceivably be used to generate as much as 16 percent of the world’s electricity needs by mid-century, with solar thermal electricity generated by concentrating solar plants (CSP) accounting for another 11 percent.

The reports state that when combined, PV and CSP could cut annual carbon dioxide emissions by more than 6 billion tonnes – effectively equaling the current output of worldwide transportation emissions and exceeding all CO2 emissions produced in the U.S. today.

According to Technology Roadmap: Solar Photovoltaic Energy, a decrease in the emission of 4 billion tonnes of CO2 per year could occur with worldwide installation of 4,600 GW of PV capacity by 2050. In order for this to occur, total PV capacity will have to reach an average of 124 GW per year, rising to 200 GW per year between 2025 and 2040.

Scott Sklar, chair of the Steering Committee of the Sustainable Energy Coalition and president of The Stella Group, says these targets in PV capacity are entirely within the realm of possibility. “I do think PV can hit these growth levels,” Sklar said, adding that a combination of “reduced loads and storage” – in addition to the use of other renewable energy sources like biomass – will have to be factored into the overall equation to achieve round-the-clock power generation.

By the beginning of 2014, total worldwide PV capacity had surpassed 150 GW and the IEA reports an estimated 100 GW of capacity being installed on a daily basis throughout 2014. “Massive cost reductions” were cited for the exponential growth, which saw more PV capacity installed in the last four years than in the last 40 years combined. The IEA believes the cost of PV will continue to drop, eventually hitting a cost decrease of 65 percent by 2050.

Sklar is also confident PV cost will plunge, if not quite by the margins predicted by the IEA. “Just by the aggregation of purchasing of materials, and scale-up of both module manufacturing and delivery chain, we can reduce costs at least by 50 percent by 2050,” Sklar said. “Possibly more.”

The second report, Technology Roadmap: Solar Thermal Electricity, stresses the inherent abilities of concentrating solar plants (CSP) to store thermal energy and provide necessary backup power on during peak times, on cloudy days, and overnight. Currently, the sum total of global solar thermal deployment is 4 GW – but the report projects with the installation of 1,000 GW of CSP capacity by 2050, 2.1 billion tonnes of CO2 emissions could be eliminated every year.

Additional deployment is expected to occur as a result of developing markets throughout Africa, Australia, China, India, the Middle East, and North and South America.

Frequently looked on as two competing technologies, the IEA sees PV and solar thermal energy ultimately achieving a complementary relationship that will serve to make up for the shortcomings of PV on overcast days and through non-daylight hours.

80' Wind Turbine Install

We are pleased to announce that we are in the process of installing a Bergey Wind Power Turbine that will stand 80' tall at a farm in McHenry County.

Below are some Interesting facts about Wind Energy from the Wind Energy Foundation www.windenergyfoundation.org

Interesting Wind Energy Facts

#1. The United States currently has 61,110 MW of installed wind project capacity, comprising 5.7% of total U.S. installed electric generating capacity.

#2. Wind mills have been in use since 2000 B.C. and were first developed in China and Persia.

#3. Wind power is currently the fastest-growing source of electricity production in the world.

#4. Iowa and South Dakota generated more than 25% of their energy from wind during 2013.

#5. A single wind turbine can power 500 homes.

#6. In 2012, the Shepherds Flat wind project became the largest online wind project in the United States (845 megawatts), breaking the record previously held by the Roscoe Wind Farm (781.5 megawatts).

#7. In 2013, the roughly 168 million megawatt-hours generated by wind energy avoided 95.6 million metric tons of carbon dioxide (CO₂) — the equivalent of reducing power-sector CO₂ emissions by 4.4% or removing 16.9 million cars from the roads.

#8. There’s enough on-shore wind in America to power the country 10 times over.

#9. In 2013, 12 states accounted for 80% of U.S. wind-generated electricity: Texas, Iowa, California, Oklahoma, Illinois, Kansas, Minnesota, Oregon, Colorado, Washington, North Dakota, and Wyoming. Source: U.S. Energy Information Administration March Electric Power Monthly report.

#10. Most wind turbines (95%) are installed on private land.

#11. Modern wind turbines produce 15 times more electricity than the typical turbine did in 1990.

#12. At times, wind energy produces as much as 25% of the electricity on the Texas power grid.

#13. American wind power is a $10 billion a year industry.

#14. Unlike nearly every other form of energy, wind power uses virtually no water.

#15. By 2030, U.S. wind power will save nearly 30 trillion bottles of water.

#16. At times, wind power produces as much as 45% of the electricity in Spain.

#17. Wind energy became the number-one source of new U.S. electricity-generating capacity for the first time in 2012, providing some 42% of all new generating capacity. In fact, 2012 was a strong year for all renewables, as together they accounted for more than 55% of all new U.S. generating capacity.

#18. During 2013, California led the nation in new wind installations (with 269 megawatts), followed by Kansas, Michigan, Texas, and New York.

#19. 70% of all U.S. Congressional Districts are home to an operating wind project, a wind-related manufacturing facility, or both.

#20. As of May 2014, the United States is home to 46,000 operating wind turbines.

#21. Right now, 559 wind-related manufacturing facilities produce a product for the U.S. wind energy industry across 44 states.

#22. Both Nevada and Puerto Rico added their first utility-scale projects during 2012.

#23. In 2000, more than 60% of U.S. wind power capacity was installed in California, with 17 states hosting utility-scale wind turbines. Today, 39 states and Puerto Rico share 60 gigawatts of utility-scale wind project development.

#24. Wind is a credible source of new electricity generation in the United States. Wind power comprised 43% of all new U.S. electric capacity additions in 2012 and represented $25 billion in new investment. Wind power currently contributes more than 12% of total electricity generation in nine states (with three of these states above 20%), and provides more than 4% of total U.S. electricity supply. Source: 2012 Wind Technologies Market Report (PDF 3.4 MB)

#25. Wind energy prices have dropped since 2009 and now rival previous lows. Lower wind turbine prices and installed project costs, along with improved capacity factors, are enabling aggressive wind power pricing. After topping out at nearly $70/megawatt-hour in 2009, the average levelized long-term price from wind power sales agreements signed in 2011/2012 – many of which were for projects built in 2012 – fell to around $40/megawatt-hour nationwide.

NET ZERO HOMES

NIST test house exceeds goal; ends year with energy to spare The net-zero energy test house at the National Institute of Standards and Technology (NIST) in suburban Washington, D.C., not only absorbed winter's best shot, it came out on top, reaching its one-year anniversary on July 1 with enough surplus energy to power an electric car for about 1,440 miles. Despite five months of below-average temperatures and twice the normal amount of snowfall, NIST's Net-Zero Energy Residential Test Facility (NZERTF) ended its one-year test run with 491 kilowatt hours of extra energy. Instead of paying almost $4,400 for electricity-the estimated average annual bill for a comparable modern home in Maryland-the virtual family of four residing in the all-electric test house actually earned a credit by exporting the surplus energy to the local utility. A net-zero energy house produces at least as much energy as it consumes over the course of a year. A number of states are taking steps toward encouraging or even requiring construction of net-zero energy homes in the future. For example, California will require that, as of 2020, all newly constructed homes must be net-zero energy ready. Both a laboratory and a house, the two-story, four-bedroom, three-bath NZERTF would blend in nicely in a new suburban subdivision. But it was designed and built to be about 60 percent more energy efficient than houses built to meet the requirements of the 2012 version of the International Energy Conservation Code, which Maryland has adopted. The 2,700 square-foot  test house is built to U.S. Green Building Council LEED Platinum standards-the highest standard for sustainable structures. Its features include energy-efficient construction and appliances, as well as energy-generating technologies, such as solar water heating and a solar photovoltaic system. Despite 38 days when the test house's solar panels were covered with snow or ice, the NZERTF's sun-powered generation system produced 13,577 kilowatt hours of energy. That's 491 kilowatt hours more than used by the house and its occupants, a computer-simulated family of two working parents and two children, ages 8 and 14. First year energy use totaled 13,086 kilowatt hours, which was about 3,000 kilowatt hours more than projected usage in a year with typical weather. In a normal year, a comparable home built to meet Maryland's residential energy standard would consume almost 27,000 kilowatt hours of energy. In terms of energy consumed per unit of living space-a measure of energy-use intensity-the NIST test house is calculated to be almost 70 percent more efficient than the average house in Washington, D.C., and nearby states. From July through October, the facility registered monthly surpluses. In November, when space-heating demands increased and the declining angle of the sun reduced the energy output of its 32 solar panels, the NZERTF began running monthly deficits. Through March 31, when the house's net energy deficit plummeted to 1,800 kilowatt hours-roughly equivalent to the combined amount of energy a refrigerator and clothes dryer would use in a year-temperatures consistently averaged below normal. Starting in April, the energy tide began to turn as the house began to export electric power to the grid on most days. In terms of cost, the NZERTF's virtual residents saved $4,373 in electricity payments, or $364 a month. However, front-end costs for solar panels, added insulation, triple-paned windows, and other technologies and upgrades aimed at achieving net-zero energy performance are sizable. In all, estimates that incorporating all of the NZERTF's energy-related technologies and efficiency-enhancing construction improvements would add about $162,700 to the price of a similar house built to comply with Maryland's state building code. Planned measurement-related research at the NZERTF will yield knowledge and tools to help trim this cost difference. Results also will be helpful in identifying affordable measures that will be most effective in reducing energy consumption. And research will further the development of tests and standards that are reliable benchmarks of energy efficiency and environmental performance overall, providing information useful to builders, home buyers, regulators and others.

WE MAY SOON(NOT REALLY) BE DRIVING ON SOLAR PANELS

In theory, the idea could work: replace all of the nation’s asphalt with solar panels, and we’d generate more than three times the electricity the US uses. Great idea and it would road and highway problems. Solar roads design would also filter storm water, replace above-ground power cables, prevent icy roads by melting snow, and light up to warn drivers if a deer wanders onto the road.

Unfortunately, the list of obstacles is long. The main problem is cost. There are roughly 29,000 square miles of road surface to cover. We need roughly 5.6 billion panels to cover that area. That’s a price tag of $56 trillion.

 The researchers have been unable to secure any large piece of the more than $2 billion a year spent on solar research and development around the world. Probably because there are too many more-practical, more-promising investments to be made to seriously consider this pipe dream.

This brings up a good point. Rooftop panels and solar arrays are already established as a viable power source, but adoption is still low. It’s hard to imagine a city ripping up asphalt and installing a largely unproven technology when it could achieve the same level of power generation by planting panels along the road.

Most of the technological challenges seem solvable. Those include things like how to keep the roads clean, how to increase the efficiency of the panels in the road, how to store the solar power, how to get electricity from more remote roads to the grid, and whether the glass is durable enough. Whether they’re solvable for a reasonable price tag is another question.

The first thing that one has to understand before beginning to look at numbers is this: an apples to apples comparison between asphalt or concrete roads and solar roads is not possible. 

An asphalt/concrete road is simply a hard surface to drive a vehicle on. A solar is a modern modular system with a multitude of uses and features.

 For an accurate cost comparison between current systems and the solar road system, you'd have to combine the costs of current roads (including snow removal, line repainting, pothole repair, etc.), power plants (and the coal or nuclear material to run them), and power and data delivery systems (power poles and relay stations) to be comparable with the solar road system, which provides all three.

This will be interesting to watch.

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GOOD SOLAR NEWS

Kyocera Solar reduces cost and increases efficiency with new 1000-volt modules

Kyocera Solar Inc. is now offering new 1000-volt solar photovoltaic (PV) modules designed to significantly reduce labor and materials costs while simultaneously increasing overall system efficiency.

The US electrical code was only recently amended to allow 1000-volt solar modules, following a similar development in Europe that enables wider use of high-efficiency 1000-volt inverters.

By specifying a 1000V system instead of the previous 600V standard, installers can reduce total system costs by a substantial amount — up to 20%, according to Kyocera engineers, depending on the individual project.

The cost reduction is achieved in several ways:

• Because 1000V PV systems incorporate more modules per string, materials and labor costs are minimized by reducing the total number of strings and combiners the system requires. 
• String cable used for 1000V modules is thinner and uses less copper, making it less expensive to purchase and install. 
• 1000V inverters are likewise smaller and less expensive to install than their 600V counterparts.

A more long-term advantage of the 1000V system is its ability to minimize resistive losses, also known as “voltage drop” — which is typically about 0.75% lower in a 1000V system than in a comparable system of 600V. This increase in efficiency results in significant energy retention over the 20+ year lifespan of a system.

INTERESTING INFORMATION

Wind farms can tame hurricanes: scientists

Huge offshore wind farms can protect vulnerable coastal cities against devastating cyclones like Katrina and Sandy by tempering winds and ocean surges before they reach land. researchers said.

Had such installations existed at the time, Hurricane Katrina which ravaged New Orleans in 2005, and Sandy, which smashed the coastlines of New York and New Jersey in 2012, would have been reduced to strong but not devastating winds.

The study, published in the journal Nature Climate Change, is the first to demonstrate that wind farms, deployed on a grand scale, can buffer violent hurricanes, the researchers said.

The team simulated the impact from farms of tens of thousands of turbines, placed miles offshore and along the coast of cyclone-vulnerable cities.

They found that turbine blades extracting energy from the wind on a very large scale can have a marked effect on the internal dynamics of a cyclone.  When wind turbines are present, they slow down the outer rotation winds of a hurricane.

This feeds back to decrease wave height, which reduces movement of air toward the centre of the hurricane, increasing the central pressure -- which in turn slows the winds of the entire hurricane and dissipates it faster.

In the case of Hurricane Katrina, sustained peak wind speed would have been reduced by as much as 98 miles per hour. Katrina's storm surge -- waves whipped up by the exceptional winds -- would have abated by up to 79 percent, said the study.

In the case of Tropical Storm Sandy, the model projected a drop of up to 87 mph in sustained peak wind speed and a 34-percent decrease in storm surge. When Sandy, at an earlier stage, was rated as a powerful Category 3 hurricane, it packed gusts of up to 115 mph.

According to the study, the turbines should not be damaged and would continue to produce power during these events. By taming the leading edge of the storm, they would also dissipate the buildup of the winds that followed.

As a result, the wind speed would not exceed the turbines' designed cutout speed -- a threshold that prompts the device to go into lockdown and feather its blades to prevent damage.

But, according to the study, these mega-farms would pay for themselves by generating electricity in addition to providing storm protection.

A 20-mile installation off the New York coast would cost about $210 billion  to build.

By way of comparison, Tropical Storm Sandy inflicted about $80 billion  in damage when it hit three states in 2012. The disaster spawned plans to build higher sea walls to shield New York from rising storm surges expected from climate change -- a project that carries estimated costs of between $10-29 billion but produces no revenue.

SOLAR TECHNOLOGY

Low-priced plastic photovoltaics

Solar cells and panels, which tap the power of the sun and convert it to electricity, offer a green - and potentially unlimited - alternative to fossil fuel use. So why haven't solar technologies been more widely adopted?

Quite simply, they're too expensive, Researchers have come up with a technology that might help bring the prices down.

To collect a lot of sunlight you need to cover a large area in solar panels, which is very expensive for traditional inorganic - usually silicon - photovoltaics. The high costs arise because traditional panels must be made from high purity crystals that require high temperatures and vacuum conditions to manufacture energy potential.

A cheaper solution is to construct the photovoltaic devices out of organic compounds - building what are essentially plastic solar cells. Organic semiconducting materials, and especially polymers, can be dissolved to make an ink and then simply "printed" in a very thin layer, some 100 billionths of a meter thick, over a large area.

Covering a large area in plastic is much cheaper than covering it in silicon, and as a result the cost per Watt of electricity-generating capacity has the potential to be much lower.

One major difficulty with doing this, however, is controlling the arrangement of polymer molecules within the thin layer. Scientists have developed an advanced structural probe technique to determine the molecular packing of two different polymers when they are mixed together. By manipulating how the molecules of the two different polymers pack together, they have created ordered pathways - or "nanowires" - along which electrical charges can more easily travel. This enables the solar cell to produce more electrical current.

This work highlights the importance of the precise arrangement of polymer molecules in a polymer solar cell for it to work efficiently. Researchers and scientists expect polymer solar cells to reach the commercial market within 5 to 10 years.

SOME ( A REAL LOT OF) ASSEMBLY REQUIRED

IKEA rolls out consumer solar panel systems in British stores

I'll take the Billy bookcase, the Karlstad sofa, and a pack of solar panels in black.

Don't laugh it may be true some day.

IKEA stores in Britain this week began selling rooftop solar panel systems, giving the industry a boost after rounds of feed-in tariff cuts and freezes.

The Swedish retail giant confirmed Monday it would roll out the systems to 17 of its stores in Britain in coming months in partnership with Chinese panel-maker Hanergy Solar U.K. after conducting trial run this summer at an outlet in Southampton, England.

Believed to be the first time photovoltaic energy systems have been made available through a mass-market retailer, IKEA's move comes a year after feed-in tariffs paid to British panel owners were slashed from 69 cents per kilowatt to their current 23 cents.

IKEA announced the consumer roll-out after using solar panels extensively to help power its own facilities. Under its corporate sustainability program, the retailer has installed more than 250,000 panels across its stores worldwide and is aiming to produce as much energy as it consumes by 2020.

The price of a standard 3.36-kilowatt PV system for a semi-detached home would run about $10,800, including value-added tax, with 15-percent discounts available under IKEA's Family loyalty program.

Steve Howard, IKEA's sustainability chief, told The Wall Street Journal despite likely low profit margins, the retailer wants to build PV systems into "a real business."

They're becoming easier to sell thanks to the volatility of energy prices, he said, adding, "You don't have to care about the environment and climate change, you can just care about the finances."

After a surge of PV panel-buying when Britain first introduced its feed-in tariff scheme, the number of homes installing rooftop systems has dropped as the FIT has gone down. The British Solar Trade Association says the solar market is currently installing about 100,000 solar systems per year -- far below the projected 300,000.

It will be interesting to see which model prevails. Either way, IKEA's move represents a big bet on solar panels' potential to shake their reputation as boondoggles and become the latest sleek status symbols for the modern home. The company has already begun the work of recasting their aesthetic image, suggesting that its solar panels resemble "flat-screen televisions."

SOLAR CELL IMPROVEMENTS

New Connection between Stacked Solar Cells Can Save on Wasted Energy

Researchers have come up with a new technique for improving the connections between stacked solar cells, which should improve the overall efficiency of solar energy devices and reduce the cost of solar energy production. 

The new connections can allow these cells to operate at solar concentrations of 70,000 suns worth of energy without losing much voltage as "wasted energy" or heat.

Stacked solar cells consist of several solar cells that are stacked on top of one another. Stacked cells are currently the most efficient cells on the market, converting up to 45 percent of the solar energy they absorb into electricity.

But to be effective, solar cell designers need to ensure the connecting junctions between these stacked cells do not absorb any of the solar energy and do not siphon off the voltage the cells produce - effectively wasting that energy as heat.

Researchers discovered that by inserting a very thin film of gallium arsenide into the connecting junction of stacked cells we can virtually eliminate voltage loss without blocking any of the solar energy.

This work is important because photovoltaic energy companies are interested in using lenses to concentrate solar energy, from one sun (no lens) to 4,000 suns or more. But if the solar energy is significantly intensified - to 700 suns or more - the connecting junctions used in existing stacked cells begin losing voltage. And the more intense the solar energy, the more voltage those junctions lose - thereby reducing the conversion efficiency.

We have created a connecting junction that loses almost no voltage, even when the stacked solar cell is exposed to 70,000 suns of solar energy. And that is more than sufficient for practical purposes, since concentrating lenses are unlikely to create more than 4,000 or 5,000 suns worth of energy. This discovery means that solar cell manufacturers can now create stacked cells that can handle these high-intensity solar energies without losing voltage at the connecting junctions, thus potentially improving conversion efficiency.

This should reduce overall costs for the energy industry because, rather than creating large, expensive solar cells, you can use much smaller cells that produce just as much electricity by absorbing intensified solar energy from concentrating lenses. And concentrating lenses are relatively inexpensive.

RECYCLING STUDY

Landfill nation: What makes consumers less likely to recycle?

Consumers are more likely to toss a dented can or a chopped-up piece of paper into the trash than to recycle it, according to a new study in research that examines recycling habits.

Although products that have changed shape are still recyclable, the likelihood of a consumer recycling a product or throwing it in the trash can be determined by the extent to which it has been distorted during the consumption process.

The study looked at how consumers treat products that have gone through physical changes during and after consumption that "distort" the product (but do not affect its recyclability). For example, a piece of paper might get crumpled up or torn into smaller pieces, or an aluminum can might get crushed or dented. And when that happens, people are less likely to recycle.

In one study, participants were asked to evaluate a pair of scissors. Some were asked to cut either one or two sheets of paper into smaller pieces, while other consumers were given a sheet of paper and asked to evaluate the scissors without cutting the paper.

Everyone was then asked to dispose of the paper on the way out (next to the exit were two identical bins, one for trash and one for recycling). Consumers recycled the whole sheet of paper more often than the smaller pieces (regardless of the total amount of paper).

Around the world, more than two billion tons of trash is generated each year, with the United States throwing away more than any other country. Understanding why consumers throw recyclable products into the garbage instead of recycling them could help companies and public policy makers find novel ways to encourage consumers to step up their recycling efforts.

These findings point to important outcomes of the post-consumption process that have been largely ignored and provide initial insight into the psychological processes influencing recycling behavior, the study concluded.

TO CLEAN OR NOT TO CLEAN...THAT IS THE QUESTION

Cleaning Solar Panels Often Not Worth the Cost

Don't hire someone to wash your dirty solar panels. That's the conclusion of a study recently conducted.

Researchers found panels that hadn't been cleaned, or rained on, for 145 days during a summer drought in California, lost only 7.4 percent of their efficiency. 

Overall, for a typical residential solar system of 5 kilowatts, washing panels halfway through the summer would translate into a mere $20 gain in electricity production. For larger commercial rooftop systems, the financial losses are bigger but still rarely enough to warrant the cost of washing the panels. On average, panels lost a little less than 0.05 percent of their overall efficiency per day. The study is focused on smaller systems, for very large installations, economies of scale may mean that washing panels is worth it.

Dust on PV panels does make a difference but it's not a big enough factor in Wisconsin to warrant cleaning. Researchers believe that this is the largest study quantifying losses of electricity output due to dirty solar panels conducted so far. Typically, particulate matter from air pollution, agriculture, construction and traffic accumulates on the panels, as well as pollen and sea salt.

Researchers also found that solar panels mounted at an angle of less than five degrees caused bigger losses in efficiency. That's because dirt slips off panels that are installed at a steeper angle. Here in SE Wisconsin we angle solar arrays at slightly less than 45 degrees.

But solar panels heavily soiled with bird droppings should be cleaned. That's because the droppings essentially block all sunlight and will not be washed away when it rains. Engineers also found that photovoltaic panels were dirty enough to warrant cleaning due to very specific and localized circumstances. For example, being directly next to and downwind of a highway, factory or agricultural field may generate enough dirt to warrant cleaning.

Next steps in the study would be looking more closely at the sites that did warrant cleaning and determine what caused the panels to get so dirty. Finally, researchers could add collectors at specific sites to determine what kind of dirt accumulates on the solar panels; whether special materials could keep dirt from accumulating; and whether special, less costly washing systems would do a better job at removing dirt from the panels.

WIND TURBINE NEWS

New certified small wind turbine announced for US market

The United States has incredible wind power resources, and Government reports predict that 20 percent of electricity will be wind produced by 2030.

There's great community support for developing small wind power, and the latest small wind turbine to pass the Small Wind Certification Council (SWCC), and achieve American Wind Energy Association (AWEA) approval for State incentives is the Kestrel e400nb.

With wind prevalent in most States and an average speed of 4.1 meters per second, wind energy is a great way to become eco-friendly, self-sufficient, less reliant on fossil fuels and reduce your electricity bill. And, depending on your State's scheme, you can even earn money when you send energy back into the grid.

The leading small wind turbine from Kestrel can produce 3,930 kWh annually, and is ideal for the US due to its size and affordability. Teamed with its durability it can withstand high wind speeds (156mph) and has proved itself already in the US with a number of successful installations.

DID YOU KNOW .....?

Top 10 windiest US cities (based on average annual wind speed)

1. Boston, Massachusetts 12.3mph

2. Oklahoma City, Oklahoma 12.2mph

3. Buffalo, New York 11.8mph

4. Milwaukee, Wisconsin 11.5mph

5. Dallas, Texas 10.7mph

6. Kansas City, Missouri 10.6mph 

    San Francisco, California 10.6mph

7. Cleveland, Ohio 10.5mph 

    Minneapolis, Minnesota 10.5mph 

    Virginia Beach, Virginia 10.5mph

8. Providence, Rhode Island 10.4mph

9. Chicago, Illinois 10.3mph

10. Detroit, Michigan 10.2mph

A quick science lesson

Electricity produced by the turbine is processed by an electronic inverter and fed into the grid. The property is then preferentially supplied by wind power, and any shortfall during peak demand is supplied by the grid. The result is that your energy bill is reduced by the amount of wind energy that is harvested.