Feature
A Spark for Solar Power
CPS Energy has teamed with a San Antonio company to install a roof full of solar panels capable of generating 200 kilowatts of electricity


San Antonio’s city-owned power provider has the sun in its eyes.  Looking into the future, CPS Energy has teamed with a San Antonio company to install a roof full of solar panels at a 67,000-square-foot former warehouse being rebuilt at the shuttered Pearl Brewery on the northern edge of downtown. The panels are capable of generating 200 kilowatts of electricity—equal to about one-fourth of the building’s total energy needs. It is the largest such project in the state.

With an operating life of more than 40 years, the project eventually will have a positive cash flow, according to Andrew McCalla, president of Meridian Energy systems. But while payback is important, this kind of project is not just about that, he said. It is about using advanced technology that also benefits the environment because its operation does not pollute the air or water.

The solar power unit is not cheap, but it will have many benefits, CPS Energy officials say. For one thing, it will be a valuable test bed and learning laboratory for solar power. For another, it will help educate architects, engineers and CPS Energy’s own municipal re- searchers as well as the general public about this emerging technology. And it just might provide the needed spark to get other businesses and public utilities to give solar energy a try, too.

The solar project is part of an ambitious effort by Silver Ventures, a San Antonio real-estate investment firm, to redevelop the 22-acre Pearl Brewery site into a multipurpose urban village on the San Antonio River. The company has been reworking historic structures at the old brewery and adding new construction to create an urban center that includes residential, commercial, retail, educational and entertainment facilities.            

Because Silver Ventures is emphasizing environmental stewardship in the redevelopment, solar energy and energy and water conservation are an important part of the effort.

“We think that the Pearl Brewery redevelopment is great for San Antonio, and we are excited to be a part of it,” said Valerie von Schramm, CPS Energy’s senior research manager for renewables, distributed energy and environment. “By participating in the solar project, CPS Energy is stepping out front in a big way for solar energy in the community while helping [the utility] to diversify our energy sources.”

CPS Energy will monitor the solar project closely, using state-of-the-art metering equipment to test its viability in a real-world setting. The utility also will share what it learns to assist public and private organizations that may be interested in installing their own solar electric systems, von Schramm said.

A public display will allow visitors to the Pearl site to see for themselves how the solar unit is operating, she said.

“We believe the project will be a useful educational tool for students and the public as well as a model for future commercial uses of solar energy,” von Schramm added. “We have received many inquiries about the solar project and expect the high level of interest to continue.”

The solar electric panels were installed in June, and tenants are scheduled to move into the building in August. It is known as the Full Goods Building, where beer once was temporarily stored before being shipped out. The building has been converted from a warehouse into a combination residential, office and retail facility. Besides the solar panels, the building has one of the most energy-efficient air-conditioning systems available. It also has a system to capture, store and recycle rainwater for landscape irrigation. 

Silver Ventures and CPS Energy have committed $1.35 million for the solar project: $950,000 from Silver Ventures and $400,000 from CPS Energy. CPS Energy is the nation’s largest municipally owned energy operator, providing electricity and natural gas service in and around the country’s seventh-largest city. It serves about 680,000 electric customers and 320,000 natural gas customers.

The Pearl Brewery operated from 1883 until 2001. Silver Ventures bought the property in 2002 and began converting buildings in the brewery complex to residential, office, meeting and training spaces. Silver Ventures and CPS Energy announced the joint solar project in June 2007.

Hooking up with CPS Energy for the solar project made sense because both organizations saw the potential benefits and both were willing to invest in it, said Darryl Byrd, development director for Silver Ventures.

“It has been a good partnership and a very positive thing for the community,” Byrd said.

The project uses solar cells, or photovoltaic cells, that convert sunlight directly into electricity. Solar cells have been around for decades and are used in everything from pocket calculators to orbiting satellites. They are not cheap, but costs have come down considerably as the technology has continued to improve. Also, increased demand has reduced production costs.

Solar cells have no moving parts. They are made of special materials that can generate a small amount of electrical current when sunlight strikes their surface. A large number of cells can be packaged to form a panel. An installation of a large number of panels is called a photovoltaic array.

The Pearl project is the largest solar-cell array in Texas, said Andrew McCalla, president of Meridian Energy Systems, an Austin-based firm that designed and installed the equipment.

“We are elated to be a part of this important project,” McCalla said. “We have projects around the state and nation, but this one is our shining star.”

With an operating life of more than 40 years, the project eventually will have a positive cash flow, according to McCalla. But while payback is important, this kind of project is not just about that, he said. It is about using advanced technology that also benefits the environment because its operation does not pollute the air or water.

Bill Sinkin, founder of a nonprofit solar advocacy group called Solar San Antonio, agrees.

Solar energy brings many benefits that are not always easy to calculate, according to Sinkin, whose group has been credited with helping Silver Ventures and CPS Energy get together on the project.

“We love that solar project,” Sinkin said. “The new Pearl Brewery owner [Silver Ventures] is a good environmentalist and is setting the tone here in San Antonio for building with the environment in mind. And, thanks to the owner and CPS Energy, we believe this solar project is also setting the tone that will encourage and promote the future use of solar energy.”


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Bill McCann is a retired communications manager and journalist who takes on freelance writing and editing assignments when the fish aren’t biting.

Shedding Light on Solar

By Kaye Northcott
and Kevin Hargis

Practically speaking, solar-generated electricity is still but a glimmer in our future, but new technologies hold great promise for sunny Texas. Our electric cooperative members use photovoltaic arrays primarily to pump water for remote stock tanks or to heat swimming pools and household water tanks. Many cooperatives have rules and procedures for members who wish to supplement their grid power with home arrays. Contact your cooperative to see if it has solar programs.


Cost Challenges

The primary drawbacks to solar are the necessity to back up this source of electricity with a conventional energy source that works on cloudy days and at night, and the current high cost of solar technology. The good news is that the solar industry anticipates solar technology will get cheaper. Current costs are about 25 to 50 cents per kilowatt-hour (kWh) for solar-generated electricity compared to 13 cents per kWh for electricity from coal or natural gas.

Austin Energy, a leader in Texas municipal utilities, gives a generous $4.50-per-watt rebate for customers who install solar energy. The city estimates that this pays between 45 percent and 75 percent of the cost of installing a system. But a 1,000-watt (1 kilowatt) photovoltaic system, which is considered the smallest practical residential array, would still cost between $6,000 and $10,000. Even with this rebate, less than 1 percent of the city’s residential and commercial customers have installed solar systems.


Texas Shines Light on Solar

The Texas State Energy Conservation Office, or SECO, has several programs designed to promote increased use of solar energy, both photovoltaic and passive. The agency has sponsored or is in partnership on several demonstration projects, ranging from lighting systems for city parks to a parking garage installation at the University of Texas-Houston Health Sciences Center.

The Texas Parks and Wildlife Department is working with the Alternative Energy Institute at West Texas A&M University in Canyon, which focuses mainly on wind power research, to monitor photovoltaic output at a demonstration project at Sheldon Lake Environmental Center.

For Texas electric cooperatives, SECO offers the Stand-Alone Photovoltaic program, which aims to educate co-op workers and leaders about stand-alone systems without grid ties. They are usually photovoltaic panels used for water pumping, electric fences and other small-scale uses in areas away from power lines.

One of the agency’s biggest solar projects is Texas Solar for Schools. Under the program, which began in 2001, SECO has supplied 1- to 3-kilowatt solar systems to school districts across the state. The systems allow schools to save money on their electric bills while giving students the opportunity for hands-on learning. The Lower Colorado River Authority (LCRA) has partnered with SECO over the past three years in the program.

 
Incentives for Solar

The state of Texas provides some incentives for solar power installation for consumers, mainly in the form of a property tax exemption for certain solar systems. For businesses engaged strictly in solar energy sales, installation or manufacturing, there is a franchise tax exemption. In addition, Texas corporations can deduct the cost of a solar energy device they own and use from their franchise taxes. SECO provides a guide to federal tax credits for solar installation on its website, www.seco.cpa.state.tx.us.

 
Into the Future

Photovoltaic arrays, roof-mounted silicon solar panels, are the most common technology for solar electricity and could soon be replaced by flexible solar film that is relatively inexpensive to produce.

• Many companies offer thin film that requires glass to hold it in place.

• Even better, perhaps, are the new thin-film solar cells being developed by HelioVolt and Ascent Solar Technologies. HelioVolt has announced plans for a manufacturing facility in Austin. Ascent plans to be selling rolls of solar cells by 2010.

• Farther down the road may be quantum dot solar cells as small as a nanometer (a billionth of a meter). The theoretic efficiency of normal solar cells is about 43 percent, according to the EnergyPulse newsletter. Quantum dots could increase that efficiency to as much as 60 percent.

 
Even Smarter Buildings and Windows

What if your windows and walls could automatically reflect light when it is hot outside and let light in when it is cold, helping to keep inside temperatures relatively stable? Such windows and walls are expected to be available this year from RavenBrick of Denver (www.ravenbrick.com). Its thermo-reflective filters are transparent at low temperatures and highly reflective at high temperatures.

 
Large-Scale Solar Collectors

Just as there are huge wind farms now providing backup power for conventional electricity generation, central solar power towers will likely do the same in the future. The facilities generate electric power from sunlight by focusing concentrated solar radiation on a tower-mounted receiver. Hundreds of thousands of small sun-tracking mirrors called heliostats or large, flat sun-tracking mirrors reflect sunlight to the receiver. In some technologies, liquid salt is pumped and heated through the receiver and then stored until power is needed from the plant. The molten salt is then pumped into a steam-generating system that turns a conventional electric generator.

In November, an Australian company signed a $500 million agreement with Pacific Gas and Electric to produce 177 megawatts at a solar-thermal plant in California’s Central Valley. The project should be on line in 2010.

The experimental Solar Two plant in California’s Mojave Desert, financed in part by the Boeing Company and Bechtel Corp., is being followed by Solar Tres, a commercial solar collector in Spain. Meanwhile, Torresol Energy, an international consortium, recently announced it will design, build and operate three central tower receivers in Spain. Beyond Spain, the company has its sights set on developing other commercial solar generating plants in sunbelt areas around the world, including the United States.

 


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