The Transmission Imperative for Renewables

It's an interesting time to be involved with electricity. The power industry is on the verge of the biggest changes since the days of Thomas Edison and George Westinghouse. Recent breakthroughs around the world in power transmission systems have made it imperative for the U.S. to develop a more intelligent, flexible, long-haul transmission network that can carry renewable energy from remote locations to major population centers.

RPS Driving Build Out 

Today in the U.S., 33 out of 50 states have some kind of renewable standard. These renewable portfolio standards (RPS), and their corresponding deadlines for compliance, have significantly impacted generation spending.

Proposed goals for a national renewable portfolio standard vary from 12 to 25 percent. If the government enacts a national standard, experts estimate that incremental capacity additions of more than 300 GW will be needed. Transmission capacity for this new and mostly remote generation, however, does not exist. With an average construction schedule of 60 months to 72 months for a 500 MW, 345 kV transmission line, it could take well beyond 2025 to build the needed transmission lines.

The North American Electric Reliability Corp.’s (NERC’s) October 2009 publication, “2009 Long Term Reliability Assessment 2009 – 2018,” notes that although existing reserve margins are adequate across the U.S. for the next few years, the first priority must be to expand the grid and increase transmission capacity to handle expected renewable generation growth.

The report concludes by saying: “More than 11,000 miles (or 35 percent) of transmission above 200 kV proposed and projected in this report must be developed on time to ensure reliability over the next five years.” NERC strongly believes that construction siting is the most urgent issue for the electric power industry, now and well into the future. 

Bulk Transmission Capacity: A Prerequisite

If utilities are to harvest the vast renewable power potential in remote locations in the U.S., or anywhere in the world, they must be able to move it efficiently from its production point to cities and load centers where people live and work.

Bulk transmission capacity is a prerequisite for large-scale renewable generation. While many renewable power sources’ intermittent nature creates challenges for grid reliability, proven, readily-available and cost-effective transmission technologies exist to mitigate their impact. They are available now and include high voltage direct current (HVDC) and flexible AC transmission systems (FACTS).

Several key transmission projects in the U.S. focus on transmitting renewable generation:

• Southern California Edison continues to add transmission to support wind generation in the Tehachapi region.
• FPL’s NextEra Energy has completed much of its merchant transmission associated with its Horse Hollow Wind Energy Center project in Texas.
• LS Power’s Southwest Intertie will move renewable power from Wyoming and Montana to substations near Las Vegas, using AC and possibly high voltage DC transmission.
• Another LS Power project, Overland Transmission, will apply either high voltage AC or DC circuits across 560 miles to move renewables-fueled generation between eastern Wyoming and southern Idaho.
• San Diego Gas & Electric’s Sunrise PowerLink will play a major role in bringing renewable generation from the Imperial Valley into southern California, even though it was built primarily to ensure system reliability and support load growth. According to the Renewable Energy Transmission Initiative, the Imperial Valley region has potential for 6,870 MW of solar, 3,495 MW of wind and 2,000 MW of geothermal power generation.

Although multiple major transmission projects are underway or nearing construction in the U.S., they are not enough to support RPS requirements. The two key renewable power transmission capacity expansion impediments are:

• The fragmented and time consuming regulatory approval process, and
• The absence of an integrated renewable generation and transmission strategy.

A look at a couple of examples of recent transmission successes in Europe and China provide an idea of what U.S. transmission could look like.

Europe: Visionary Governments Prepare for Offshore Wind

In the North Sea, 81 miles off Germany’s coast, the world’s largest offshore wind farm is connected to the grid using advanced HVDC technology. With HVDC cables lying both underwater and underground, the project’s environmental impact is minimized and the regulatory and siting procedures have been swift. The project connects wind generators and transmits power to a new substation on Germany’s coast. The power is then connected to the existing transmission grid.

The BORWIN 1 offshore wind farm demonstrates how HVDC can effectively accumulate power generated in remote locations and transmit it to load centers. Through the use of HVDC and wind generation, Transpower, the transmission grid operator, expects to avoid 1.5 million tons of CO2 emissions per year by replacing fossil fuel generation.

This summer, an even larger project was launched off Europe’s coast. ABB is working with Transpower to supply an 800 MW power link. This project will use HVDC Light technology to transmit power from the 400 MW Borkum West II wind farm (see Figure 1) and other wind farms to be developed nearby. The wind farms will be connected to an offshore HVDC converter station that will transmit electricity to the onshore HVDC station at Dörpen, on Germany’s northwest coast, via 165 kilometers of underwater and underground DC cables. The Dörpen/West converter station will in turn feed AC power to the mainland grid. At 320 kV, this will be the highest voltage level of extruded cable ever used for HVDC. State-of-the-art transmission technologies like these are integrating renewable energy sources efficiently, ensuring grid reliability and stability and lowering environmental impact.

 China: Transmission Link Up and Running

China continues to set the example and lead the way in developing advanced transmission technologies that tap the power of renewable energies without many of the state or national obstacles faced in the U.S. or Europe. For example, ABB recently worked with the State Grid Corp. of China (SGCC) to create the world’s first ultrahigh-voltage direct current (UHVDC) transmission link for commercial operation. ABB believes this project represents the world’s longest and most powerful transmission link (see Figure 2).

The ±800 kV Xiangjiaba to Shanghai UHVDC link can transmit up to 7,200 MW of power from the Xiangjiaba hydropower plant in southwest China to Shanghai, the country’s leading industrial and commercial center, which is about 2,000 kilometers away in eastern China. The new link can meet the electricity needs of about 24 million people and sets a new benchmark in terms of voltage levels and transmission capacity, superseding the 600 kV Itaipu transmission line in Brazil, which was also developed by ABB.

The high-capacity power link comprises a single overhead line and occupies less space than the existing system. Moreover, transmission losses on the new line are less than 7 percent; considerably less than the existing 500 kV system. The electricity saved is equivalent to the power needs of around one million people in China.

UHVDC transmission is a new and expanded development of HVDC. It is particularly suitable for vast countries like China and India, where consumption centers are often located far from power sources, including renewables.

Overcoming U.S. Obstacles

While in other parts of the world, governments, regulators, utilities and industries are working toward common goals, many transmission projects in the U.S. have not yet overcome regulatory hurdles.

The good news is there is proof that things can be done differently. In Texas, utilities, multiple regulatory agencies, generation companies and reliability councils are working together to execute a Public Utility Commission (PUC) order effectively, timely and fairly. Hallmark to this activity is the PUC-driven coordination between transmission and generation stakeholders. When completed by the end of 2013, this Texas CREZ (Competitive Renewable Energy Zones) initiative should result in incremental addition of more than 5,000 miles of high voltage AC transmission, allowing 18 GW of renewable generation to be reliably moved from west Texas into Dallas, San Antonio and Austin.

ERCOT consulted other regional transmission organizations, independent organizations, independent system operators and utilities while studying and developing multiple scenarios. The Texas Department of Wildlife provided impact analysis. Based on ERCOT recommendations, the PUC chose one of four CREZ scenarios and ordered its development.

The PUC provided stakeholders with guidelines and protocols, assuring them that neither generation nor transmission investment will be “stranded.” This was done to provide generation stakeholders the assurance they need before building new wind generation.

To comply, wind generators have been busy. Nearly 11 GW of wind power are installed, 450 MW of new wind power are under construction and nearly 13 GW of wind are in development.

The bottom line in Texas is that these projects got off the ground in a matter of years, not decades.

Swift regulatory and siting procedures, fair cost allocation and political courage to execute are needed to resolve key obstacles delaying renewable energy and related transmission build out across the U.S. and other nations grappling with this issue.

A progressive PUC, like the Texas PUC, and cooperation between the various regulatory agencies that have agreed on common goals and executed the reviews and permits needed to keep schedules on track, can lead to success.

Idaho Gov. C.L. Otter recently said, “The recent economic recession has slowed the growth in demand for electricity, but we cannot squander this opportunity to address future needs. It is clear that coordination among states, the federal government, all segments of the industry and non-governmental organizations is essential for the region to meet its clean energy needs.”

The Texas CREZ is an excellent example of how things can get done in the U.S. A visionary PUC with political support, a coordinated regulatory process, and the courage by everyone involved combines for a favorable environment for sustainable renewable power growth. This model can, and hopefully soon will be, applied across the U.S. as it is elsewhere.

Solar Takes Wind in Test

Blustery gusts keep a wind turbine spinning at Inland Power and Light's corporate headquarters on the West Plains, but solar panels are the real powerhouse at the utility's alternative energy pilot project.

The solar panels have produced about five times as much electricity as the wind turbine over the past 14 months. The sun’s ability to generate more electricity than the wind – even during short winter days – has surprised the utility’s engineers.

“Solar,” said Richard Damiano, the utility’s chief engineer, “is trouncing wind.”

Inland Power set up the experiment to help the utility customers compare alternative-energy options for their homes. Each year, the utility fields from 50 to 60 calls from people interested in producing some of their own electricity. Initially, most think they want a wind turbine, Damiano said.

To help customers with the analysis, Inland Power officials decided to collect their own data.

The utility bought a 35-foot wind turbine and a bank of solar panels. The systems are representative of technology scaled to individual homeowner use, Damiano said. Each cost from $22,000 to $24,000 to install.

Conventional thinking suggested that wind turbines would outperform solar panels, particularly on gray winter days.

“It’s the West Plains, so there’s a perception that the wind is always blowing,” Damiano said.

But wind is more erratic than people realize, he said. The wind dies down, for instance, during hot weather and cold spells. Inland Power’s turbine is similar to the larger ones installed in the Columbia River Gorge. It needs a stiff breeze of around 12 miles per hour to start producing electricity.

Solar panels, on the other hand, generate a certain amount of electricity even on cloudy days.

During the first 13 days of January, Inland Power’s solar panels produced 35 kilowatt-hours of electricity, compared with 10 kilowatt-hours from wind generation.

The results don’t surprise Linda Finney, who sold the wind turbine to Inland Power. She and her husband initially installed it on a grassy hill above their home on the Palouse Highway, about 12 miles south of Spokane. After two years, they took the turbine down because it wasn’t generating the results they hoped for, and they replaced it with 16 solar panels.

At certain times of the year, “our meter runs backwards,” said Finney, executive director of Leadership Spokane. “We’re banking energy during the summer months.”

Damiano said some customers do the research and still end up with wind turbines. In areas heavily shaded by trees, for instance, wind turbines can outperform solar panels.

In the Inland Power pilot project, the solar panels produced about 15 percent of a typical household’s electric needs over the course of a year. The wind turbine produced less than 3 percent.

From a cost-benefit standpoint, erecting a wind turbine or putting in solar panels is still a reach for most homeowners, Damiano said. Those who take the plunge are making a lifestyle choice to reduce their carbon footprint, he said. Recovering the installation costs for turbines or solar panels can take years, even with the 30 percent tax subsidy available to homeowners.

“It will take you a chunk of time,” Finney acknowledged. But she encourages people to think about the long-term benefits.

“Some people spend $25,000 on a new car,” she said. “We decided this is how we wanted to live and how we wanted to spend our money.”

ReneSola Improves Cell Efficiency with New ‘Virtus Wafer’

ReneSola has recently announced that it has developed a new multicrystalline wafer, the Virtus Wafer, which improves solar cell efficiency. 

The Virtus Wafer, which has been endorsed by several leading global solar cell manufacturers, achieves an average cell conversion efficiency rate of 17.5%, more than 1% higher than the industry-standard cell conversion efficiency rate for cells using multicrystalline wafers. ReneSola intends to commence pilot production of the Virtus Wafer in the first half of 2011.

Mr. Xianshou Li, ReneSola’s chief executive officer, commented, “We are excited about our new Virtus Wafer, which is the direct result of our team’s technological innovation and hard work. The Virtus Wafer is remarkable in that it’s able to produce a conversion efficiency rate close to that of a monocrystalline wafer while maintaining the relatively low production cost of a multicrystalline wafer. We will continue to engage in R&D initiatives to stay at the forefront of solar technology and deliver high-quality, cost-effective solar wafers to leading energy companies across the globe.”

The City of Huntington Beach and SunEdison Announce Agreement to Deploy over 2 MW of Solar Capacity

Construction expected to begin spring 2011

SunEdison, a leading worldwide solar energy services provider and subsidiary of MEMC Electronic Materials, Inc. (NYSE: WFR), and the City of Huntington Beach, California, announced today that they have signed agreements pursuant to which SunEdison will deploy over 2 megawatts (MW) of solar capacity at three Huntington Beach city properties without upfront costs from the City.

Through solar Power Purchase Agreements (PPAs) between the City of Huntington Beach and SunEdison, SunEdison will finance, construct, monitor and maintain three carport canopy photovoltaic power plants at the Huntington Beach Civic Center, Central Library and City Yard. In return, the City will buy the energy produced from these solar systems to offset their demand from the grid at predictable energy rates for 20 years.

Commenting on the agreement, Mayor Cathy Green said, "Huntington Beach’s solar project is a tangible commitment to the environment and our programs in Huntington Beach." Aaron Klemm, Energy Project Manager for Huntington Beach, added, "We evaluated a number of ways to meet our municipal solar capacity goal. The Power Purchase Agreement model made the most sense for us as there are no upfront capital or maintenance requirements from the city, and we receive very competitive power prices."

"SunEdison makes solar a reality for public sector clients like the City of Huntington Beach," said Brian Jacolick, General Manager, Americas for SunEdison. "With smart solar programs, proven experience and strong financing capabilities, SunEdison is the clear choice for government solar solutions."

The U.S. Department of Energy and the Energy Efficiency and Conservation Block Grant (EECBG) Program provided the funding for the initial research and consultation for the three solar carport canopy systems.

Once completed, the three deployments are expected to produce more than 63 million kilowatt hours (kWh) of clean solar energy over 20 years, enough energy to power over 5,900 average U.S. homes for one year. SunEdison is expected to start construction in the spring of 2011.

Duke Energy and SunEdison Announce Completion of 17.2MW Solar Farm

– Solar farm will produce enough energy to power more than 2,600 homes annually
– Second largest active solar photovoltaic deployment on the east coast

Duke Energy and Sun Edison LLC, a leading worldwide solar energy services provider and subsidiary of MEMC Electronic Materials (NYSE: WFR), have recently announced the activation of the final phases of a 17.2 megawatt (MW) solar farm in Davidson County, N.C.

Constructed in five phases and covering over 200 acres of land, the project is comprised of more than 63,000 photovoltaic solar panels and is expected to generate an estimated 28 million kilowatt-hours annually–enough energy to power more than 2,600 homes a year.

"Solar energy continues to increase in its importance to North Carolina customers," said Brett Carter, President, Duke Energy North Carolina. "Partnerships, like the one with SunEdison, have allowed Duke Energy to comply with North Carolina’s solar requirements in a cost effective way."

The solar farm was made possible through a solar energy service agreement between SunEdison and Duke Energy where SunEdison designed and deployed the project and will be responsible for the ongoing operations and maintenance of the facility. Financing was made possible through lease financing provided by MetLife and Bank of America Merrill Lynch. The project is rated at 17.2MW as measured in direct current, or 15.5MW as measured in alternating current.

"We are pleased to have provided financing to help complete this signature project while helping provide renewably sourced electricity to Duke Energy customers – many of whom are Bank of America customers, as well," said Todd Karas, President of Banc of America Public Capital Corp. "This project adds to the list of financing we’ve provided as part of Bank of America’s 10-year, $20 billion business initiative focused on addressing climate change."

"SunEdison is proud to be working with Duke Energy in meeting its solar energy goals," stated Robert Reichenberger, U.S. Vice President of Utilities for SunEdison. "By bringing together the right people, technologies and financing solutions, SunEdison is able to make large-scale solar a reality for utilities and their customers across the globe."

About Duke Energy

Duke Energy Carolinas owns nuclear, coal-fired, natural gas and hydroelectric generation. That diverse fuel mix provides approximately 19,000 megawatts of electricity capacity to approximately 2.4 million customers in a 22,000-square-mile service area of North Carolina and South Carolina.

Headquartered in Charlotte, N.C., Duke Energy is a Fortune 500 company traded on the New York Stock Exchange under the symbol DUK. More information about the company is available on the Internet at: www.duke-energy.com. To learn more and contribute to the discussion about the energy issues of today and the possibilities of tomorrow seewww.sheddingalight.org.