301 Moved Permanently

---

nginx

U.S. Looks To Germany On Solar Grid Integration

Despite its success in managing variable-generation power sources such as wind and solar, Germany’s electricity distribution system is beginning to show signs of saturation. And while German officials work to resolve grid-related challenges, U.S. solar advocates - who view Germany as a bellwether - are closely monitoring developments.

“The aggressive pro-solar policies in Germany created the demand that brought affordable solar to the U.S.,” says Bob Gibson, spokesperson at the Washington, D.C.-based Solar Electric Power Association (SEPA). “The U.S. market will continue to benefit from the solar experience in Germany if that country leads the way to efficiently managing a high penetration of solar on the grid.”

With about 5% of its gross electricity production supplied by solar generation, Germany is one of the world’s leading solar photovoltaic markets. In May 2012, Germany’s solar PV systems delivered an astounding 30% of country-wide peak delivery demand. However, while celebrating the country’s solar capacity, officials discovered an uncomfortable issue with variable generation: Germany has “a 50.2 Hz problem.”

In 2008, around the time the country was rapidly integrating large amounts of solar on the grid, Germany’s existing low-voltage interconnection standards stipulated that distributed generation be automatically disconnected if system frequency exceeded 50.2 Hz.

“During a light load condition, if system frequency rose above 50.2 Hz, more than 3 GW of PV generation could be lost,” says Charlie Smith, executive director at the Virginia-based Utility Variable Generation Integration Group (UVIG). “This was greater than the largest single contingency for which the European interconnected system was designed to withstand. Detailed system simulations showed that the system could become unstable and result in a system collapse under such conditions.”

In 2012, Germany rectified the problem by implementing a new low-voltage interconnection standard. Additionally, Germany instituted a field retrofitting effort that involved changing the pre-programmed over-frequency trip settings in PV inverters. About 315,000 PV systems sized 10 kW or larger are scheduled to have their inverters either retrofitted or replaced within four years.

German solar officials contend that the retrofitted inverters will be less sensitive for increased ride-through and staged in their timing to minimize their switching impact.

“It is a very expensive and time-consuming process,” Smith says, citing estimates that the German government will spend as much as $500 million to rectify the problem. And it all could have been avoided with some foresight before the solar boom took place, he adds.

Last year, the San Diego-based Western Electric Industry Leaders (WEIL) group urged regulators to require the installation of “smart inverters” on all new solar generators in the region to ensure their smooth integration into the electric grid. Specifically citing the
example of Germany, WEIL says quick action would protect the grid from power fluctuations caused by the integration of increasing amounts of variable-generation solar capacity.

SEPA’s Gibson says the recent tumult in Germany’s renewable energy market is a cause for concern. SEPA is planning a fact-finding trip to Germany this September.

“There is a fear that all these changes will bring calamity to the energy market and the economy,” he says. “Or, do the Germans manage it effectively and transition to a stable renewable energy future?”

- Mark Del Franco

 

NREL Explores
State PV Policies

Grid interconnection policies and net-energy metering are the two pillars upon which a state is most likely to build a thriving distributed generation solar sector. This is one of the conclusions of a new study conducted by the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL).

Another key finding is that the order in which a state implements solar policies has a major impact on the overall success. Examining the dynamics of “policy stacking” was a key goal of the study.

“Which policies can a state implement - in what order that doesn’t break the bank?” says Elizabeth Doris, a senior project leader at NREL and a co-author of the report, which builds on her earlier research on strategic sequencing of state solar policies.

One of the problems legislators tasked with developing solar policies face is the tendency of advocates and opponents of particular measures to argue by anecdote.

“Anecdotes are great, but it doesn’t mean it would work elsewhere,” Doris says. “Every state has its unique context.”

Of course, some lessons do travel. The trick is identifying which ones and where else they might be applicable.

The NREL study is as interesting for the way it examines the solar marketplace in the U.S. as it is for the conclusions it reaches. Doris and her colleagues organized states into broad categories based on the similarities of their non-policy solar market factors. Ideally, the effectiveness of solar policies of a given state could be compared to those of another state in the same category on an apples-to-apples basis.

The study also considers a “suite of policies” condition, where a state has some combination of the above policies. The study specifically excludes monetary incentives, such as state-sponsored tax breaks and rebate programs, because the purpose was to provide a prescription for implementing solar policies without laying out significant amounts of cash.

The yardsticks by which states were grouped was relatively straightforward, with four basic measures considered: household median income as collected by the 2010 U.S. Census; the technical potential for solar on rooftops as determined by previous NREL studies; cost of competing grid electricity represented by a three-year average residential electricity price as collected by the DOE in 2013; and the general community interest in energy conservation and renewable energy as scored by the American Council for an Energy Efficient Economy.

The grouping and analysis of states provides a means for making useful comparisons of policy effectiveness. The report also features four in-depth case studies of individual states that are representative of the groups.

The result of the analysis is a guide for those who advise elected officials and their staffs on the formulation of state-appropriate policies for promoting distributed solar power.

“We look at the legislative side and also the regulatory rulemaking side of solar policies,” Doris says.

The new study is the first in a series of three that will explore additional factors in solar policy effectiveness in the U.S. that will roll out annually. - Michael Puttré

 

Interior Approves
550 MW Of Solar

The U.S. Department of the Interior (DOI) has approved two solar projects, one in California and the other in Nevada.

The DOI says that the 300 MW Stateline Solar Farm Project will be built in San Bernardino County, Calif., on approximately 1,685 acres of public land located two miles south of the California-Nevada border. The facility will connect to the grid via a 2.7-mile, 220 kV transmission line.

The 250 MW Silver State South Solar Project, the DOI adds, will be located near Primm, Nev., on approximately 2,400 acres of public land.

Both projects are proposed by First Solar and have commitments from Southern California Edison to purchase the output for 20 years, the DOI notes.

According to the DOI, First Solar has agreed to undertake significant project design changes and mitigation measures to minimize impacts to wildlife and to water, historical, cultural and other resources.

 

MassCEC Adds Hot Water To Solar Program

The Massachusetts Clean Energy Center (MassCEC) has increased the rebate amounts available for individual projects completed under the Commonwealth Solar Hot Water program.

Under the new guidelines, homeowners and business owners will be eligible for rebates of up to 40% of total system costs, up to $4,500 for residential systems or up to $50,000 for commercial-scale sys-
tems.

Nonprofit organizations and municipalities - which are not eligible for state and federal tax incentives - will be eligible for larger rebates. Additional funding will be available for projects that are installed alongside solar electricity systems.

Launched first as a pilot program in 2011, the Commonwealth Solar Hot Water Program offers rebates for qualifying solar hot water projects at residential, multifamily, commercial-scale, municipal and nonprofit buildings. R