Photovoltaics/Amorphous/ Solar Mines040512

SolarMine - An energy saving project pumping U.S. oil
by Shirley Georgi
This aerial photo shows the SolarMine Project at the ChevronTexaco’s Midway Sunset Oil Field in California, which delivers clean energy for drilling oil. The 500 kWp SolarMine project in Fellows, California is currently operated by ChevronTexaco. The power plant consists of UNI-SOLARR’s SSR-128 modules with Xantrex 300 kiloWatt and Xantrex  225 kiloWatt inverters.  Installed in 2002, the modules have produced an energy yield of 1700 kWh/kWp (Ed. note: Probably the number of kWh produced annually divided by the peak power delivered).  One year after installation the measured peak power was 528 kWac. (Photo is courtesy of Chevron Texaco with special  thanks to Gregory Hardy and Hermann Ng.)+
It was a beautiful, sunny, 950 F day in mid-March when BD editors ventured into the vast sand-laden  desert to visit the photovoltaic SolarMine Project in the ChevronTexaco oil fields outside of the small town of Fellows near Bakersfield, California. We arrived early and our tour guide Hermann Ng, engineer for the project, had not yet arrived.  Although we could see the solar panels, the area looked deserted.  Were the solar panels operating?  Why wasn’t there more activity at the site?

Hermann arrived shortly, and we soon learned that not only were the solar panels working, they were functioning above expectation and providing constant daytime electricity to the oil fields, equivalent electricity to power 200 to 250 homes.   What we were seeing were 4800 UNI-SOLAR lightweight and rugged 128 Watt south-facing modules located on 62  sturdy ground mounts on a six acre site adjacent to the Chevron/Texaco Pipeline Delivery Station 31.  The panels were fully operational, creating power from the sun’s energy with no pollution in noise and without adding contaminants to the air, land or water.

Project  Inception

In the late 1990s, it was Frank Ingraselli, President of Texaco Technology Ventures, and his team who envisioned  using a clean energy source to pump U.S. oil.  As Frank noted, there were several reasons to get involved.  Texaco was a strategic investor in ECD (Energy Conversion Devices).  “We owned 20 % of ECD.  We had heard a lot of very good comments on the products being produced from Uni-Solar, and while we were not a direct investor in Uni-Solar, we believed that they had the best product out there which we could use in a test of the (photovoltaics) technology.  It was also brought to our attention that the State of California was offering some fiscal subsidies.   Armed with these initial facts, my team at Texaco contacted the U.S. Producing Department in Texaco and  worked with the production engineers in Bakersfield; as a result, we came up with this (SolarMine)  project.  We put together an investment proposal; and according to our analysis, this (the SolarMine Project) would provide a positive return on the investment that would be made.  We approved the investment and started carrying out the work.”  

Adobe Photoshop ImageHermann Ng, ChevronTexaco field engineer, and Shirley Georgi, BD editor, discuss the Solarmine Project under the back side (shade) of the solar panels which angle to a height of  ten feet . The simplicity of the panel interconnects is seen in the wiring above Shirley’s head.   +

Frank added that he felt the project also had another enhanced  benefit.  “I viewed the Project as a responsible investment to show our customers, and the investing public, that we were serious about clean energy!”

Frank retired while SolarMine was being completed.  But, he has kept track of its progress and feels very positive about the results.  In  reflecting on the Project that he approved, he commented,   “I understand that the ‘post-investment’ analysis, in fact, showed that is was a good investment.”     

Work Begins

In 2001, United Solar Systems, a joint venture between Energy Conversion Devices (ECD) and N.V. Bekaert S.A., and Texaco signed the agreement to design and install a photovoltaic system for Texaco in California.  The installation was to be completed in a period of 18 months and the first phase was to provide a photovoltaic (PV) system capable of generating 400 kiloWatts of power to be used by Texaco in their oil fields. Since that date, Texaco and Chevron have merged to form ChevronTexaco, but the project continued as scheduled. (ChevronTexaco continues to own 20% of ECD stock.)

Adobe Photoshop ImageThe first  of the 4,800 flexible solar panels, about 1.3 feet wide by 18 feet long, is shown being  mounted on simple metal frames that resemble car ports.   The amorphous-silicon technology based panels can withstand direct impact and puncture without compromising their ability to generate power. (Photo is courtesy of ChevronTexaco  with special thanks to Gregory Hardy and Hermann Ng.) +

Dr. Dick Blieden,  Director at Uni-Solar Ovonic,  recalled how the project’s first scheduled meeting on September 12th, 2001 was darkened by the events of  September 11th.  Since all aircraft was grounded , the meeting could  not take place.  But, those involved were determined thatSolarMine would get underway, and all those involved rescheduled, booked airline flights  and met on September 19th to launch the project.  

The cost of the project, excluding the land, was $4.86 million.  With a California Energy Commission (CEC) Emerging Renewable Buydown Program offering a rebate of  $2.43 million, the cost to ChevronTexaco was cut by 50 percent.  

Adobe Photoshop ImageWhen the solar panels were installed, special consideration was given to the environmental protection of the land.  Thus, a holding pond for water was constructed.  (Photo is courtesy of ChevronTexaco Corporation.  Special thanks to Gregory Hardy and Hermann Ng.) +

Celebrating Success

On December 18, 2002, the system was completed and checked out;  the power was turned on.  As Dick Bleiden recalls, it was a week with very high winds, but the panels had been well constructed, and weather conditions did not affect performance in any way.  

Adobe Photoshop ImageThe solar-powered system is made up of 4800 Uni-Solar PVL-128 photovoltaic modules installed on south facing racks.  (Photo is courtesy of ChevronTexaco Corporation.  Special thanks to Gregory Hardy and Hermann Ng.) +

The first-of-its kind installation is producing baseload energy to operate oil well pumping units in an environmentally friendly way.  At the time of the completion, Jim Davis, president of Chevron Energy Solutions which provided technical assistance and training for the project, said the project would give “valuable experience in the design and development of photovoltaic systems for the businesses and  institutions  we serve.”  Stanford Ovshinsky, chairman and CEO of United Solar and President and CEO of ECD had positive remarks, too.  “The completion of this project is an important milestone in the development of thin-film solar energy solutions.”  

Adobe Photoshop ImageThere are 4800 individuals modules with 12 modules per string wired in series.  The 400  strings are wired in parallel. (Photo is courtesy of ChevronTexaco Corporation.  Special thanks to Gregory Hardy and Hermann Ng.)  +

Highlighting Benefits of Solarmine
Costs - To date, energy savings, by not having to use the grid full time, have been $83,000/yr. @ $0.063/kWh.

Emissions - With solar energy production being totallyenvironmentally friendly, 850 tons/yr. of carbon dioxide and 1950 lb./yr of NOx are avoided.

The schematic shows how strings of PV panels are combined in series to provide 396 Volts dc which is then converted to 600 Volt ac in the inverter. Isolation transformers first step up the ac to 480 Volts which, in a second transformer, is stepped up to the 12 kV grid distribution line  Voltage. Doubly redundant disconnects isolate the PV field from the grid. (Photo is courtesy of ChevronTexaco Corporation.  Special thanks to Gregory Hardy and Hermann Ng.) +

Maintenance -  In reviewing system performance to this point,  operations have been very smooth.  Hermann Ng said that he has totally turned the daily operations over to maintenance because there is no need for any engineering troubleshooting.  He also commented that the panels did not even need to be cleaned since the rainfall has been sufficient to wash off  dust or dirt.

Performance - The output of the solar panels have responded as initially defined.  As sunlight begins to appear, the panels begin their output at 80 kW, but by 12:15 PM, they reach their peak at about 500kW.  About 2 PM when the BD editors were visiting,  the display continually changed as the number of Watts of electricity were being recorded.  Glancing at the screen, the display registered 420 kiloWatts but a few seconds later the number jumped to 430 kiloWatts.  The automated tracking data base provides a base for  a real time   data collection for those evaluating the performance of SolarMine.  

The technology

History -Thirty years ago researchers realized that amorphous silicon could be used in PV devices by properly controlling conditions under which it is deposited and by carefully modifying its composition.

Amorphous silicon absorbs solar radiation 40 times more efficiently when compared to single-crystal silicone, so a film only about 1 millionth of a meter thick can absorb 90% of the usable light energy.    

Adobe Photoshop ImageThis block structure contains all of the conversion equipment needed for dc power to be converted to ac power.  Here, power is  also stepped up to feed the oil field distribution system. Since there is no battery backup or storage, connect from the grid at sundown and disconnect from the grid during sunrise is also seemlessly done via automation in this building.  (Photo is courtesy of ChevronTexaco Corporation. Special thanks to Gregory Hardy and Hermann Ng.) +

The amorphous silicon (a-Si) cells - Using proprietary- thin-film, vapor-deposited a-Si alloy materials, Uni-Solar Ovonic has developed proprietary technology to reduce the materials cost in a solar cell.  Because a-Si absorbs light more efficiently than its crystalline counterpart, the a-Si solar cell thickness can be 100 times less, thereby reducing materials cost.  with ECD pioneering and developing the process.  With this unique approach, amorphous cells with different light absorption properties can be deposited continuously, one on top of another, to capture the broad solar spectrum more effectively.  Using an automated solar manufacturing machine, a roll of flexible stainless steel, 1/2 mile long and 14 inches wide, sequentially deposits nine thin-film layers of a-Si alloy in a high yield, making a continuous, stacked three-cell structure .

Believing in the technology, N.V. Berkaert S.A., in its joint venture with ECD (United Solar Systems Corp.)  built a new manufacturing facility in Auburn Hills, Michigan in 2002.  Bekaert, which has since exited from the venture in May 2003,  spent $96 million building the thin-film factory. A new  $55 million thin-film solar cell manufacturing machine and related assembly equipment were also installed.  Energy Conversion Devices designed and built the new machine which is capable  of producing nine miles of solar cells in three days’ time. The  factory has a capacity to produce enough film to generate 30 megaWatts of power per year.  In an interview with Johnathan Fahley of Forbes, published 11/24/03, Mr. Ovshinsky declared that the technology ready for commercialization in 1978...will be profitable by 2005.  

Adobe Photoshop ImageInside the conversion building, BD Editor Shirley Georgi is told by Hermann Ng, guide and on-site facilities engineer,  that the dc power from the modules is converted to ac power and stepped up to 12,000 Volts for feeding the oilfield power distribution system.  All power is delivered to the grid.  There is no battery backup since all PV power is used immediately on the grid.  +

Commercializing photovoltaics - still an uphill climb

According to the Solar Energy Industries Association’s  (SEIA) Executive Director, Glenn Hamer, solar electric production in the U.S. dipped last year (2003).  In testimony submitted to the U.S. House Appropriations Committee Energy and Water Subcommittee in early April 2004, he said that SEIA is requesting  $100 million for the solar electric (photovoltaics) program.  He said funding has helped to bring down manufacturing costs, but more needs to be done.  Mr. Hamer noted the track record of solar manufacturing in the past 10 years  and said the prices have dropped by half.   In reviewing the U.S. Department of Energy’s (DOE) goal of generating solar electric for $.06/kWh by 2020, he noted that research funding must increase to accomplish the goal.

Adobe Photoshop ImagePerformance data is continually being monitored. Average monthly data in 2003 averaged over 500 kilowatts, peak. (Photo is courtesy of ChevronTexaco with special thanks to Gregory Hardy and Hermann Ng.) +Microsoft Excel Chart

Other countries in Europe and Japan are gaining in solar production; Mr. Hamer stated that production abroad was up 50% in just one year. He stated, “As Americans face growing concern over the outsourcing of their jobs, a booming solar industry is increasing and developing aboard.  The opportunity to participate in world-class research programs is one of the principal considerations for companies when deciding where to locate manufacturing.  Congress should invest in a strong solar R&D budget to promote America as a home for this growth industry.”   

Adobe Photoshop ImageThe first of two levels of automatic disconnect resides in the panels in the left side of the array.  The relatively large amount of electrical equipment required for consolidation, conversion and safety makes up a significant part of the PV system. Whether amorphous, crystalline, or any other distributed source, the electrical equipment is necessary.+  

State support is important, too.  In California, a state which has supported solar/PV energy systems, the amount of funding  has been scaled down for the California Renewable Program  Rebates. Effective January 1, 2004, the rates are $3.20 per Watt for photovoltaic systems less than 30 kiloWatts. (The initial incentive was $4.00 per Watt for PV.)  As of January 2004, The California Energy Commission stated that  the pilot performance-based program for PV systems 30 kW or greater was not being proposed.  The Energy Commission expects to develop this program at a later date. A total of $10 million is being reserved for this purpose.     

Residing quietly at the bAdobe Photoshop Imagease of the center pole is the second level of safety disconnect for the PV field. Each day until the operating parameters are sufficient to send PV power to the grid, the PV field remains disconnected. In case of PV filed faults, the disconnects separate the PV field from the grid, and if the grid goes down, the PV power is cutoff to keep dangerous Voltage from the grid line (anti-islanding) so that accidental shock cannot be delivered to either service people or the general public. +

Celebrating successes

At Uni-Solar Ovonic - The company continues its efforts to provide new sites with its thin-film amorphous silicon based PV generation.       During the first quarter of 2004, the company received two orders from Germany.  

Germany is a good area to market PV.  The German Solar Industry Association (BSi) expects a growth rate well above 50% for this year.  As Dick Bleiden emphasized, the German government is supporting solar.  The trigger for the surge in demand in the German photovoltaic market is the new feed-in-regulation, which provides high payback rates for solar energy.  “We are expecting photovoltaic sales of more than 1 Billion Euros and new capacities over 200 MWp for 2004,” said Gerhard Stryi-Hipp, Managing Director of the BSi.  

The order from Germany  received in March by Uni-Solar Ovonic is for a large system.  The initial order is for  1.25 MW of photovoltaic panels from  Sunset Energietechnik GmbH.  Sunset has also signed a letter of intention to purchase 5 MW of UNI-SOLARR products over the next 12 months. The UNI-SOLARR products will be used for on-grid systems on large roofs.  

Also, in March, Uni-Solar Ovonic was awarded a contract by Lockheed Martin to develop and deliver solar cells on polymer substrates. These solar cells will be used by Lockheed Martin inPhase 2 of the High Altitude Airship program, awarded by the Missile Defense Agency.  The airship, 150 feet in diameter by 500 feel in length, will be controlled by four electrically powered, vectored propulsion pods and powered by a solar regenerative battery-based power system with thin-film photovoltaics on the hull surface.

At ChevronTexaco - It is not known if the company will be installing more photovoltaic panels at SolarMine.  But, they are tracking the Project’s data.  An extensive data monitoring system, utilizing a wireless ethernet system, is capturing load information  and is evaluating the system’s performance.  This system is providing daily monitoring and troubleshooting for local operating personnel as well as longer term data monitoring and analysis from remote locations.  To date, as Hermann Ng mentioned several times, “...the system is operating without any hitches.”  Such positive remarks are truly a celebration for PV, especially for thin-film, amorphous silicon.       
BD Note: The question may arise from some readers as to why we would cover a story which made its debut in December 2002.  The editors feel that there is often too much emphasis  in the press on “ribbon-cutting” events  and valuable projects such as Solarmine are too soon forgotten.  It is important to note that such environmentally friendly projects  are operating   successfully.  Hopefully, such stories, as  ours, will be an impetus for photovoltaics to grow in strength for it truly is one of the only answers which can  create the power that we need  with no trade-offs in polluted air. Also, the lessons to be learned form long term use of amorphous PV will continue to play out in the following years at Solarmine. As this technology progresses, the energy independence of the country and the enhanced cleanliness of the environment will be among the biggest improvements in quality of life. We also extend a special thanks to Frank Ingraselli of Global Venture Investments LLC for initiating interest in the SolarMine Project and providing BD with contacts.         


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