Archive for Global

4 Factors Driving the Marriage of Solar and Energy Storage

A solar-powered microgrid demonstrates the potential of coupling big batteries with commercial solar. What if you could finance the energy storage equipment, much the way solar panels are financed, and the batteries provided a revenue stream? Modern grid-scale battery systems are only put in place to save money or provide services to the grid. An example is one installation that includes 402 kilowatts’ worth of solar canopies in the parking lot and, in a twist that differentiates it from most commercial solar projects, a shipping-container-sized battery from startup Solar Grid Storage. Here in Knoxville we have a battery enhanced solar powered car-charging station located at the EPRI location off Dutchtown Road. On a daily basis, though, the battery will deliver frequency regulation services to the local wholesale grid. By providing quick bursts of power to keep a steady balance between supply and demand, battery owner Solar Grid Storage will earn money that is normally paid to natural gas power plant operators.

Here are the factors that are driving the combination of commercial solar and energy storage.

1. The technology is there. Better batteries are in development that will lower cost.

2. The economics can make sense. AES Energy Storage, for instance, provides frequency regulation services at a wind farm in West Virginia, buffered by a 32-megawatt lithium-ion battery bank. Revenue comes from reducing demand charges by using stored energy during peak hours. Most of its customers are in California, which has subsidies for distributed energy storage. By contrast, the desire to have emergency power has become a priority in East Coast states hit hard by Hurricane Sandy and other severe storms.

3. Solar installers want storage — if it pencils out. Military bases and island locations that rely on diesel generators are obvious candidates. A battery can smooth out the flow of power that panels provide to the local grid and address issues, such as the drops in voltage that come when clouds pass over. Batteries could also enable solar installations in places, such as farms, which would have required costly upgrades to the grid infrastructure. The contracts to finance a combined solar and storage system are complex and need to become more standardized, as power purchase agreements are, said president Scott Wiater of Standard Solar. Financing these types of systems is still relatively new and developers need to find customers willing to try not only solar, but also relatively new energy storage technology.

4. NRG Energy Inc. and Exelon Corp.’s Constellation unit say interest in combining solar power with battery storage has soared in the year since Hurricane Sandy knocked out power to millions of homes and businesses on the East Coast. They are among more than a dozen solar providers that have introduced or enhanced in the past year systems that combine rooftop solar panels that generate power and batteries that retain electricity to use later.
People with solar-powered homes and businesses were frustrated to discover that losing power from local utilities also knocked out the inverters that connect rooftop panels to the grid, leaving them unable to tap the electricity they were producing. Adding battery storage solves that problem, said Tom Doyle, chief executive officer of NRG’s solar unit.

It’s also a growing threat to utilities.
“When Sandy came along we really didn’t have a product to keep solar power flowing during blackouts,” Doyle said in an interview yesterday at the Solar Power International conference in Chicago. “Now we can install systems that continue operating when the grid fails, and the costs are coming down.”
Battery storage can add more than 20 percent to the cost of a typical 10-kilowatt solar system for a four-bedroom home, Brendon Quinlivan, director of solar development at Constellation, said in an interview.

original article can be found at: http://www.greentechmedia.com/articles/read/three-factors-driving-the-marriage-of-solar-and-energy-storage and http://www.bloomberg.com/news/2013-10-23/nrg-and-exelon-see-batteries-spurring-demand-for-solar.html

Japan Next-Generation Farmers Cultivate Crops and Solar Energy

Farmers in Japan can now generate solar electricity while growing crops on the same farmland. This co-existence or double-generation is known as “Solar Sharing” in Japan. The concept was originally developed by Akira Nagashima in 2004, who was a retired agricultural machinery engineer who later studied biology and learned the “light saturation point.” The rate of photosynthesis increases as the irradiance level is increased; however at one point, any further increase in the amount of light that strikes the plant does not cause any increase to the rate of photosynthesis.

By knowing that too much sun won’t help further growth of plants, Nagashima came up with the idea to combine PV systems and farming. He devised and originally patented special structure, which is much like a pergola in a garden. He created a couple of testing fields with different shading rates and different crops. The structures he created are made of pipes and rows of PV panels, which are arranged with certain intervals to allow enough sunlight to hit the ground for photosynthesis.

Based on the tests conducted at his solar testing sites in Chiba Prefecture, he recommends about 32% shading rate for a farmland space to reach adequate growth of crops. In other words, there is twice as much empty space for each PV module installed. Takazawa installed 348 PV panels on a small 750 square-meter of farmland. PV panels are installed on pipes, which are 3-meter high from the ground. Rows of PV panels are installed every 5 meters. Under the PV system, Takasawa’s father has been cultivating peanuts, yams, eggplants, cucumbers, tomatoes, and taros and will cultivate cabbages during the winter. These vegetables are sold at a nearby street and consumed by his neighbors.

Many have questioned stability and durability of the PV structure for solar shared family. Nagashima stated that his systems, which are made of thin pipes without concrete footings, even withstood strong winds and earthquakes during the Fukushima Tsunami disasters in 2011. These systems are extremely lightweight and installation of PV panels are spaced out, allowing air to flow through between the panels. This will eliminate concern that the panels will receive wind load and be blown away, therefore, reducing the need for complicated and expensive mounting hardware.

Leading Utilities Recognize the Need for Solar Energy as Older Nuclear Plants Pass Their Economic Viability

CEOs from opposite sides of the country also spent much time discussing the increasing role of renewable energy and distributed generation.

California is known for having the nation’s most ambitious renewable energy mandate while North Carolina, where Duke is based, also has a growing solar energy presence.
Edison CEO Ted Craver said electric utilities would be mistaken to dismiss distributed generation as merely a “fringe” business in the future. The Edison chief said his company initially started in the field by supplying big solar arrays for “big box” stores.

“A lot of this is really experimental,” Craver said. Utility subsidiary Southern California Edison (SCE) used to rely on industrial customers for one-third of its load but that is now probably closer to 10 percent, Craver said.

While some argue that California policy has been inhospitable to heavy industry, it’s important to realize that manufacturers are looking to generate more of their own power, Craver said.
The utility, SCE, is also investing more in the transmission side of its business to accommodate the growing role of distributed generation in California.

Duke is developing a variety of resources in its service territories — including new combined-cycle and peaking units in Florida — to help compensate for retirement of the Crystal River nuclear plant and potential coal units retirements as well. California is known for having the nation’s most ambitious renewable energy mandate while North Carolina, where Duke is based, also has a growing solar energy presence.

Photovoltaic System Pricing Updated 2013

The following is an extract from a recent study by Lawrence Berkeley National Labs and National Renewable Energy Laboratory. The report is a high-level overview of historical, recent, and projected near-term PV system pricing trends in the United States, drawing on several ongoing research activities at LBNL and NREL. Prices are subject to the location, suppliers, pricing, as well as local economic factors. According to the report near future analysts expect system prices to continue to fall, but for module prices to stabilize (Module ASP projected to be between $0.50/W – $0.75/W by 2014 ).

Modeled overnight capital cost for systems quoted in Q4 2012 (expected to be installed in 2013):

Residential (5.1 kW) was $3.69/W, a reduction of 13% from Q4 2011

Commercial (222.5 kW) was $2.61/W, a reduction of 19% from Q4 2011

Utility-scale (192.8 MW) was $1.92/W, a reduction of 23% from Q4 2011.

The report can be downloaded here

DOW Solar Powerhouse Shingle

On November 2nd, TSEA will hold the 4th annual Solar Tour. One of the stops on the tour will be with Twin Willows Development off of Hardin Valley Rd, near Buttermilk Dr. The first house, installed with DOW’s solar shingles, will be explained by subdivision developer Adam Hutsell, and his installer, Jim Laborde. This will be a first for TVA, in which a developer will be installing solar as part of the overall construction of the homes at no extra cost. In addition to the solar, the energy saving features of the construction and choice of appliances tend to save energy, reducing the cost of monthly expenses. The tour will begin with an introductory talk at 8:30, at the Public Meeting room at Knoxville Transit Center on Church St(across the street to the Civic Center). We have limited seating, so arrive as soon as possible to ensure a place on our bus!

Solar Panels Growing Hazard for Firefighters – Why the Need for Integrated Converter with each panel

Firefighters battling the massive 11-alarm blaze at the Dietz & Watson distribution center in South Jersey faced an unlikely foe during the fight — solar panels.
A solar array with more than 7,000 photovoltaic panels lined the roof of the nearly 300,000 square-foot refrigeration facility which served as a temporary storage center for the company’s deli meats and cheeses. But the panels, while environmentally sustainable and cost-saving, may have led to the complete destruction of the warehouse.
Fighting the fire under bright blue skies Sunday, Delanco Fire Chief Ron Holt was forced to keep firefighters from attacking the blaze from the roof because of electrocution concerns.
“With all that power and energy up there, I can’t jeopardize a guy’s life for that,” said Holt. Those electrocution fears combined with concerns of a collapse forced firefighters to simply spray the building with water and foam from afar.
Ken Willette from the National Fire Protection Association, a nonprofit that develops standards for firefighting, says electrocution is one of the hazards firefighters are increasingly facing fighting blazes at structures where solar panels are deployed.
“Those panels, as long as there’s any kind of light present, whether it’s daylight or it’s electronic lamp light, will generate electricity,” he said.
A 2011 study from the Underwriters Laboratory found solar panels, being individual energy producers, could not be easily de-energized from a single point like other electric sources. Researchers recommended throwing a tarp over the panels to block light, but only if crews could safely get to the area.

original article

SLevy: The issue is the series connection of many panels result in high voltages being developed which could be lethal if improperly handled. There are several answers but the one that makes the most sense to me is to modify the junction box in the back of each panel with an intelligent converter (either a DC-DC converter or a DC-AC inverter) that can disconnect itself from the string either from an internal sensor detecting a fault condition, like heat, or by the main disconnect for the solar system being activated so that all panels are isolated from each other. Then the danger is controlled and fire-persons can do their job and not worry about high voltage danger. A wireless remote monitor will verify the safe condition allowing firefighters to do their job in safety. The other benefit to the solar array owner is the same detection system will warn of panels being stolen. The cost of the intelligent converter should be 10% or less than the cost of the basic panel. Present fire safety regulations do not address this problem.

FERC Chair Jon Wellinghoff: Solar ‘Is Going to Overtake Everything’

If anybody doubts that federal energy regulators are aware of the rapidly changing electricity landscape, they should talk to Jon Wellinghoff, chairman of the Federal Energy Regulatory Commission (FERC).

“Solar is growing so fast it is going to overtake everything,” Wellinghoff told GTM last week in a sideline conversation at the National Clean Energy Summit in Las Vegas.

If a single drop of water on the pitcher’s mound at Dodger Stadium is doubled every minute, Wellinghoff said, a person chained to the highest seat would be in danger of drowning in an hour.

“That’s what is happening in solar. It could double every two years,” he said.

Geothermal, wind, and other resources will supplement solar, Wellinghoff said. “But at its present growth rate, solar will overtake wind in about ten years. It is going to be the dominant player. Everybody’s roof is out there.” Advanced storage technologies also promise lower costs, he said. “Once it is more cost-effective to build solar with storage than to build a combustion turbine or wind for power at night, that is ‘game over.’ At that point, it will be all about consumer-driven markets.”

If FERC does not ensure the grid is ready to integrate the growing marketplace demand for distributed solar and other distributed resources, Wellinghoff said, “We are going to have problems with grid reliability and overall grid costs.”

Transmission infrastructure will be able to keep up with solar growth. The big changes will be at the distribution level where FERC has less influence, he explained. But the commission has been examining the costs and benefits of distributed generation (DG) in wholesale markets.

“Rate structures need to be formulated in ways that fully recognize the costs and benefits of distributed resources,” Wellinghoff said. “In many utility retail rates, a disproportionate amount of the fixed costs are recovered through a variable rate. That is problematic when a lot of people go to distributed generation.”

The net metering controversy this has caused at utilities like Xcel and Arizona Public Service, he said, can only be resolved by “the fully allocated, fully analyzed cost and benefit study of distributed resources.”

Tea Party Joins with the Sierra Club to Promote Solar in Georgia

As Debbie Dooley co-founder of the Atlanta Tea Party explains, “I’m a grandmother, and I want to be able to look my grandson in the eyes and tell him I’m looking out for his future. Conservation is conservative, and protecting our children and our natural resources is a conservative value.” Those who believe in the free market need to reexamine the way our country produces energy. Giant utility monopolies deserve at least some competition, and consumers should have a choice. It’s just that simple, and it’s consistent with the free-market principles that have been a core value of the Tea Party since we began in 2009.

“In Georgia, we have one company controlling all of the electricity production, which means consumers have no say in what kind of power they must buy. A solar company could not start up and offer clean power to customers because of restrictions in state law. Our Constitution does not say that government should pick winners and losers, but that is what government is doing when it protects the interests of older technologies over clean energy that’s now available at competitive prices. I say, let the market decide” says Debbie.

She goes on to explain, “Georgians are currently and unjustly denied this opportunity, and will continue to be unless a law is passed to change the system. That is why the Atlanta Tea Party supported Senate Bill 401 in the past legislative session. Georgia Power opposed it and it never made it out of committee. We will try again when the Georgia legislature reconvenes in January 2014. All states should allow their citizens the opportunity to generate and sell their own solar power.”

So I ask our elected state and federal officeholders, “Why hesitate in voting for extending the Master Limited Partnership to renewables?” Level the energy playing field. Here in Tennessee, our citizens have the same demands as our neighbors in Georgia. TVA board serves the people in the valley, why not listen to their demands for cleaner energy?

Postscript: Americans for Prosperity, which like the Tea Party have been nurtured and sponsored by the Koch brothers oil billionaires, is dismissing the Georgia faction as an aberration, or even more damming, as a “green Tea Party.” It has sought to turn the issue of rights on its head by arguing that rooftop solar will “infringe upon the territorial rights to the distribution grids” of the network operators.

TSEA August Newsletter Editorial

TSEA Editorial

Disputes over the use of small-scale solar power are flaring across the nation. At issue in an Iowa lawsuit is whether solar-system marketers can sell electricity in territories where local utilities have exclusive rights to customers.

In TVA territory distributors are forbidden from generating electricity and that extends down to small installations on residential homes. The overall concept of an individual providing some of its own power and selling the rest to the utility company is called net metering.

Net metering or net energy metering (NEM) allows electricity customers who wish to supply their own electricity from on-site generation to pay only for the net energy they obtain from the utility. NEM is primarily used for solar photovoltaic (PV) systems at homes and businesses (other distributed generation (DG) customers may have access as well). Since the output of a PV system may not perfectly match the on-site demand for electricity, a home or business with a PV system will export excess power to the electric grid at some times and import power from the grid at other times. The utilities bill customers only for the net electricity used during each billing period. Alternately, if a customer has produced more electricity than they have consumed, the credit for that net excess generation will be treated according to the NEM policy of the state or utility.

Benefits of distributed solar include:

• PV systems generate the most electricity during the middle of the day when demand is the highest.
• Net metered PV systems reduce the need to expand transmission grid capacity
• Net metering allows for the development of a solar energy market and the jobs that come with it

Currently 44 states plus D.C. have implemented net metering policies. The following map shows the six states that forbid net metering.


Utilities “are proponents of renewable energy,” said Barry Shear, president of Iowa’s Eagle Point Solar LLC, but only “if they own the energy assets and the electrons flow through their grid and they can bill you.”
“The electric utility industry’s preservation of revenues and investor capital will be determined by its success in aligning with the following five consumer mega-trends reshaping the U.S. economy” says Bill Roth President of NCCT, a nationally recognized business coach, economist, ranked as a top-five writer on sustainability and business best practices. To paraphrase his proposed trends as:
1. Consumers are in active pursuit of lower bills,
2. The electric utility industry’s revenues are at risk with a generation that views the industry as missing in action,
3. Today moms manage the household budget. They expect the companies they do business with, including their utility, to provide products and services that align with their values,
4. Electric utilities need to mimic CEOs of major corporations who are adopting sustainability to reduce their operating costs, increase customer alignment and mitigate risks, and
5. Consumer acceptance of cost reducing disruptive technologies that challenge existing utility economic models.

The issue being brought up in this Iowa dispute is the question as to who supplies electric power to residential customers. The dispute can be resolved with changing the economic model of how solar can be integrated into the existing business models of TVA and independently owned utilities. Nobody has to lose. The existing model in our state can be preserved allowing TVA to generate all the electricity selling the power through their distributors who connect the electricity to the residential commercial customers.
The issue now is not who owns the power sources, but how we raise the funds for solar farms and distributed solar needs. The answer maybe to apply the economic model of micro-investments.
The model published in the July/August issue of Solar Today, addresses the existing barriers through the following channels.
• The income will be generated by residential customers who are interested in improving their environment as well as income generation.
• TVA will manage all future solar installations in cooperation with their distributors.
• Income from the sale of solar power will be channeled from TVA and it’s distributors to the residential investor.
• TVA and its distributors will be responsible for the operation and maintenance of all solar generation where the cost for the O&M will come from the profits of solar sales.
• Home owners and businesses that sign up for the program will agree to compensate the distributors for the cost of maintaining and upgrading the distribution system.
• For distributed generation TVA will compensate the owner of the property for renting their roof.

The essence of the model is discussed in the Solar Today article which can be retrieved at the American Solar Energy Society (ASES) website

Arizona leads states in per-capita solar energy

The report notes that it is not availability of sunlight that makes states solar leaders, but the degree to which state and local governments have enacted effective public policy for the development of the solar industry.


Arizona leads the nation in per-capita solar energy, according to a report released Thursday.

Following Arizona, in descending order, are: Nevada, Hawaii, New Jersey, New Mexico, California, Delaware, Colorado, Vermont, Massachusetts, North Carolina and Maryland.

The details are in a report titled “Lighting the Way: What We Can Learn from America’s Top 12 Solar States,” released by the Environment America Research & Policy Center. The organization — online: www.EnvironmentAmerica.org — is a public interest group that advocates for strong environmental policy.

“The sky’s the limit on solar energy,” Rob Sargent, energy program director with Environment America, said in a news release. “The progress of these states should give us the confidence that we can do much more. Being a leader in pollution-free solar energy means setting big goals and backing them up with good policies.”

The report emphasizes that it is not availability of sunlight that makes states solar leaders, but the degree to which state and local governments have enacted effective public policy for the development of the solar industry.

Reference: http://www.thetowntalk.com/article/20130725/BUSINESS/130725020/Arizona-leads-states-per-capita-solar-energy-report-says