Displaying items by tag: solar energy

Citizens call on TVA to stop passing gas

KNOXVILLE — The Tennessee Valley Authority in coming years plans to add both natural gas and solar plants to its portfolio to meet what it says are rising energy demands.

TVA’s Board of Directors laid out the federal utility’s plan in a meeting at Norris Middle School in May. Environmentalists at a previous hearing criticized the utility’s focus on natural gas rather than renewables or other measures. Other people, largely tied to local power providers, argued that a switch to renewable energy would be unreliable.

TVA showed a map in a press release following the meeting, showing four proposed natural gas plants and two proposed solar plants. Two of those natural gas plants would be in Tennessee while the other two are planned for Alabama and Kentucky. It stated these new plants will total 3,800 megawatts. It also spoke of its System Operations Center, set to open in fall 2024 in Georgetown to manage the utility’s grid. TVA also stated a desire to research nuclear technologies.

“Our region is experiencing growth at six times the national average, which means we must invest in our current power system and build new generation so we can continue meeting our region’s demand,” said TVA president and CEO Jeff Lyash.

Several citizens criticized TVA’s focus on natural gas plants and new pipelines at the listening session May 9. Among them was Clinton resident and activist John Todd Waterman.

MEMPHIS — Area residents were invited to a film screening of “Keep the Lights On” and a panel discussion at the Memphis Rox climbing gym with community members, local advocates and policy experts. The event, which ran from 10 a.m. to 4 p.m. Saturday, Aug. 20, coincided with Global Climbing Day, and professional rock climbers Nina Williams, Manoah Ainuu (who recently summited Everest), Olympic Silver Medalist Nathaniel Coleman, and Fred Campbell hosted and participated in community and climbing-oriented events prior to the film screening and conversation. 

The film follows Memphis Rox staff member and leader Jarmond Johnson, recounting his experiences with intermittent energy access growing up in South Memphis, his growth into a gang activist and mentorship role at Rox, and, ultimately, working with professional rock climber and environmental activist Alex Honnold (best known for the academy award-winning film, Free Solo) to bring solar energy to the gym. Following the screening, Jarmond and a panel of experts discussed takeaways from the film, and how equitable access to solar energy could help all Memphians keep their lights on. 

— Southern Alliance for Clean Energy

As Hellbender Press reported in April, the Tennessee Valley Authority plans to phase out its use of coal. And as we mentioned in an action alert, TVA is conducting a scoping process pertaining to the preparation of an Environmental Impact Statement (EIS) for retirement and replacement of the Kingston Fossil Plant. TVA is preparing similar EIS for its other remaining coal-fired power plants as well.

Although TVA lists "construction and operation of solar and storage facilities" in these scoping documents as an alternative for replacement of coal as the power source, it has made no secret of its belief that construction of gas-powered combustion turbines (CT) and natural gas pipelines to feed them will be the best solution to replace the outdated generation capacity.

Unlike other power utilities, TVA has been making it more difficult, financially unattractive or impossible for distributed renewable energy, storage and even efficiency projects to get realized, according to proponents of renewables and some of TVA’s local power distribution partners. TVA also reneged on its agreement with other utilities to make large amounts of wind power available to the Southeastern United States through the Plains & Eastern Clean Line high-voltage direct-current power line project.

PV Magazine & BO Klima: Berlin macht Solardächer zur Pflicht

The rooftop solar law, passed on June 16, says every new building and substantial renewal of an existing building’s roof must be equipped with solar panels covering at least 30 percent of the roof surface.

The German capital — which is on the same latitude as Labrador City — intends to become more climate friendly. It wants to act as a role model for other municipalities and states in how to accelerate the energy transition. It aims for solar to cover 25% of its electricity consumption.

The city contends, the solar potential of its roofs has gotten inadequate consideration and expects the new law will create many future-proof jobs in planning and trades.

Building owners may opt to use solar facade panels or contract with third parties to build and operate equivalent solar capacity that fulfills the mandate elsewhere in the city. But critics of the law say it does not address how to optimize its implementation with present practices, regulations, and tariffs. They predict, this law will be inefficient and costlier than other methods to stimulate renewable energy generation.

Bavaria, for example, launched an incentive program that awards combined new solar and battery storage installations. Applications for that program have multiplied quickly and now are deemed likely to surpass the 100,000 installations mark by the end of its third year.

Germany, whose entire southern border is farther north than Quebec City or Duluth, has a long history of technology and policy leadership in renewable energies. In 1991 the German Electricity Feed-in Act was the first in the world that mandated grid operators to connect all renewable power generators, pay them a guaranteed feed-in tariff for 20 years and prioritize these sources.

The rainbow colors show the diffraction of sunlight by a mirror with a nanostructured grating, which was applied to the back of the silicon subcell. The sun’s spectrum is thus captured even better in the silicon bottom cell.  © Fraunhofer ISE / Photo: Michael Schachtner

Fraunhofer Institute for Solar Energy Systems: Tandem Photovoltaics Enables New Heights in Solar Cell Efficiencies – 35.9 % for III-V//Silicon Solar Cell

The photovoltaic (PV) solar panels most commonly used for commercial applications today have an efficiency in the range of 16 to 22 percent. On the lower side of this range, one finds less-expensive panels, mostly made with poly-crystalline solar cells, while monocrystalline cells dominate the upper side.

The highest-efficiency panel presently on the market is SunPower’s A-Series residential panel, with a claimed 22.8 percent efficiency in converting photons to electrons under standard conditions. That's up just slightly by 0.73 percent from five years ago. Although many other manufacturers have caught up to offer panels rated at more than 21 percent, development progress of silicon-based monocrystalline PV toward the theoretical limit of around 30 percent has slowed to a crawl.

Over the same period, newer technologies for multijunction PV cells with thin subcell layers of gallium-arsenide and similar semiconductors, grown on top of silicon or perovskite crystalline materials, has been progressing rapidly and may be capable of exceeding 50 percent efficiency in the future. Lab results still require years of research and manufacturing development before panels come to market. Initially their high price will limit them to market niches where low-weight and small-surface per Watt will justify the cost, such as for aerospace applications or covering electric vehicle surfaces. The following links provide a good overview of such technologies and discuss their longer-term outlook.

DOE Energy Efficiency & Renewable Energy: Multijunction III-V Photovoltaics Research

Frauenhofer ISE: Tandem Photovoltaics – The Road to Higher Conversion Efficiencies