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Solar On Commercial Buildings | Earth Wise

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The United States installed 3.6 gigawatts of photovoltaic solar capacity in the first quarter of this year to reach a total installed capacity of 81.4 GW.  That is enough to power about 16 million American homes.  More than 2/3 of that capacity has been installed during the past five years.  

There has been a boom in solar installations in recent years and, until the Covid-19 pandemic stuck, 2020 was expected to be the biggest year yet.  Now the unprecedented health, social, and economic conditions in our country creates great uncertainty in such forecasts.

Nevertheless, the opportunities for growth in solar power continue to be substantial.  A new report from the energy research firm Wood Mackenzie looked at the prospects for using the roof space of commercial buildings for solar power.

Currently, just 3.5% of commercial buildings in the U.S. have solar panels on their roofs.  Another 1% of those buildings are attached to solar projects located off-site.  The report looked at how many buildings are potential targets for solar projects.

After accounting for buildings that are too small or that use too little electricity to make solar power a worthwhile investment, the report estimated that 70% of commercial buildings in the U.S. – amounting to some 600,000 sites – are candidates for solar installations.  Doing this would provide 145 GW of new solar capacity, which is nearly twice as much as currently exists in this country. 

Commercial solar installations have their own unique logistical and financial challenges.  While utility solar can scale to lower costs and residential solar has financing opportunities, commercial solar has neither.  But ultimately, it represents an important opportunity for our future energy system.

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U.S. Commercial Rooftops Hold 145 Gigawatts of Untapped Solar Potential

Photo, posted June 25, 2014, courtesy of Rob Baxter via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Are Slowly Taking Over | Earth Wise

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According to data released by the Federal Energy Regulatory Commission, wind, solar, and hydropower provided 100% of the 1.3 GW in new U.S. electrical generating capacity added in April 2020.  Furthermore, the FERC report revealed that renewable sources accounted for 56% of the 9 GW added during the first four months of the year.  Apart from renewables, the balance of new generation was almost entirely made up of new natural gas capacity.   There have been no new capacity additions by coal, oil, nuclear power, or geothermal energy since the beginning of the year.

Renewable energy sources now account for nearly 23% of the nation’s total available installed generating capacity and continue to increase their lead over coal, which now accounts for only 20% of the nation’s electricity generation.

FERC data also suggests that renewables’ share of generating capacity should increase significantly over the next three years.  So-called “high probability” generation capacity additions for wind, minus anticipated retirements, project a net increase of nearly 27 GW, while solar is projected to grow by 24 GW.  By comparison, net growth for natural gas is expected to be just over 20 GW. 

Hydropower, geothermal, and biomass are all expected to experience net growth while the generating capacity of coal and oil are expected to plummet.   Nuclear power is forecasted to remain essentially unchanged.

In total, over the next three years,  the mix of all renewables is predicted to add more than 50 times the net new generating capacity added by natural gas, coal, oil, and nuclear power combined.  Renewables are truly on the rise.

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Renewable Energy Provides All New US Generating Capacity in April – Forecast to Add Almost 50x More Than Coal, Oil, Gas & Nuclear Over Next Three Years

Photo, posted May 24, 2011, courtesy of Michael Mees via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Massachusetts And Energy Policy | Earth Wise

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The transition to a renewables-based energy future continues to accelerate, but there are still many forces that can slow it down.  Government policy has a major role to play.  At the moment, the federal government is trying to prop up the fossil fuel industry with financial incentives and rampant deregulation.  So more than ever, innovative policies at the state level are essential drivers for revolutionizing the energy system.

One state where policy is trying to make a big difference is Massachusetts, which has created the Clean Peak Energy Standard or CPS, finalized and approved in late March and now taking effect.   A clean peak standard is a regulatory tool to reduce the costs and environmental impact of periods when electricity demand is highest, and generation tends to be the most polluting.  The CPS requires electric retailers to procure a minimum percentage of their annual electricity sales from renewable generation or energy storage.  That minimum amount will increase each year.

The CPS is formulated to incentivize better utilization of clean energy technologies to supply power when energy demand is high.  The problem is that there are times when the sun is not shining and the wind isn’t blowing, but energy demand is at its highest.  The solution is to use energy storage technologies that can supply power when it is needed.  Furthermore, storage can be relied upon during times of extreme weather that cause power outages.

Massachusetts has already started using energy storage in its grid.  The small town of Sterling installed an energy storage system in 2016 that provides crucial backup power to the police station and emergency dispatch center, thereby keeping first responder operations running even during extended power outages.

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Massachusetts is setting the benchmark for nationwide clean energy transformation

Photo, posted March 30, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Could Take Over By 2035 | Earth Wise

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A study by UC Berkeley looked at the prospects for renewable energy sources to become the primary source of energy in the United States over the next 15 years.  Even though fossil fuels continue to fill that role at present, the plummeting costs of alternative energy sources – primarily solar and wind power – are making them increasingly attractive on the competitive market.

These cost reductions have occurred much faster than what was anticipated even just a few years ago.  According to the study, it is technically and economically feasible for renewable sources to provide 90% of our electricity by 2035.

The Berkeley researchers took the available data on renewable energy and created two scenarios for the next 15 years.  The first has energy policy remaining as it is now, without ambitious policy changes that encourage the growth of renewable energy.  In that scenario, they estimated that 55% of the US energy infrastructure would come from renewables.  That amount will not produce the change needed to meet Paris Climate Agreement goals but would simply come about because of the dramatically lower costs for renewable energy.

The second scenario includes state and federal governments leading the way to finance and facilitate the energy reform needed for a greener 2035.  It also relies on the large-scale use of grid-scale batteries to store the energy collected from solar and wind installations for when it is needed.

Which scenario is more realistic will depend on several major influential factors, notably the trajectory and consequences of the COVID-19 pandemic as well as the results of the November elections.   These things will have a huge impact on the future of our energy system.

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Report: By 2035, 90 Percent of the US Could Be Powered by Renewables

Photo, posted May 25, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Surpass Coal | Earth Wise

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In 2019, energy consumption in the U.S. from renewable sources exceeded consumption from coal for the first time since before 1885.  This has come about from a combination of the continued decline in the amount of coal used for electricity generation as well as the continued growth in renewable energy, mostly from wind and solar.

Until the mid-1800s, burning wood was the main source of energy in the U.S. and, in fact, it was the only commercial-scale renewable energy source until the first hydroelectric plants came online in the 1880s.  Coal was used as fuel for steamboats and trains and making steel but only started to be used to generate electricity in the 1880s.

In 2019, U.S. coal consumption decreased for the sixth consecutive year and fell to its lowest level in 42 years.  Natural gas has displaced much of the energy generation from retired coal plants.

At the same time, renewable energy consumption in the U.S. grew for the fourth year in a row to a record high level, almost entirely as a result of the growing use of wind and solar power.  In 2019, wind power surpassed hydroelectric power for the first time and is now the most-used source of renewable energy for electricity generation in the U.S.

Coal was once commonly used in the industrial, transportation, residential, and commercial sectors.  Today, in the U.S., it is mostly used to generate electricity, and that use is rapidly declining.

Electricity consumption for 2020 is likely to be anomalous in many ways as a result of the Covid-19 pandemic shutdowns.  From all indications, however, the role of renewable energy will only have been increased during the shutdown period.

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U.S. renewable energy consumption surpasses coal for the first time in over 130 years

Photo, posted July 26, 2013, courtesy of Don Graham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Building The World’s Largest Battery Energy Storage Plant | Earth Wise

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The Monterey County Planning Commission has unanimously approved a joint project between Tesla and Pacific Gas and Electric to turn the Moss Landing Power Plant in California into the world’s largest battery energy storage facility.

The Moss Landing Power Plant is a natural gas-powered electricity generation plant located at the midpoint of California’s Monterey Bay.  At one time, it was the largest power plant in the state of California with a generation capacity of 2560 MW but has been gradually shutting down over time.

The new facility will incorporate 1.2 GWh of storage capacity for energy generated by solar and wind systems.  The stored energy will be available for use during periods of high energy demand and lower output.  This is about ten times larger than Tesla’s Hornsdale energy storage project in Australia, which was three times bigger than any other batter storage facility when it was built a few years ago.  In 2018, the battery system at Hornsdale made back a third of its cost in just one year.  The systems make use of Tesla’s Megapack battery products which come in pre-assembled units that provide 3 MWh of energy storage capacity.

The project will make use of existing power lines to transmit energy around Monterey County and parts of Silicon Valley.  Tesla and PG&E hope to break ground in early spring with completion scheduled for the end of the year.  California has been adding massive amounts of wind and solar power to its electrical grid and incorporating energy storage is an important step towards creating a truly resilient power system.

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Humongous Tesla Battery Plant Approved In California Is 10× Bigger Than World’s Biggest Battery Plant

Photo, posted September 22, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar And Wind Power In China | Earth Wise

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Reducing greenhouse gas emissions is a global challenge and nowhere is that challenge greater than in China.  China accounts for 30% of the world’s emissions and much of that comes from coal power plants.  If the world is going to reach its climate targets, China is going to have to replace as much as possible of its current power mix with renewable energy.

As of 2018, China still made 69% of its electricity from fossil fuels.  Its vast coal reserves have driven its rapid industrialization and better standard of living.  But terrible air pollution problems along with climate issues have led to heavy investments and rapid expansion of both wind and solar power in China.

China is now a world leader in renewable energy, both in terms of producing and using renewable power.  At the start of 2016, China had installed a total of 145,000 megawatts of wind power, which is 3,000 MW more than all 28 European Union countries combined.  And this has occurred even though China only started developing their wind power industry 30 years later than the first EU countries.

Until 2009, China exported almost all the solar panels it produced.  But gradually China began to use solar energy in a big way.  The industry took off in 2014, and growth has been exponential.  Solar power production in China is now almost as extensive as wind power.

One has to consider that much of China’s electricity production is used by industries that produce products for the rest of the world.  In effect, these are exported emissions.  China has a long way to go in replacing its fossil fuel generation and we all have a stake in China succeeding in the task.

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China’s rapid development of solar and wind power

Photo, posted November 12, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar-Powered Desalination | Earth Wise

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About 1% of the world’s population is dependent on desalinated water to meet daily needs, but water scarcity is a growing problem that experts believe will affect 14% of the world’s population within the next five years.

Desalination takes much more energy than, for example, transporting fresh water over large distances.  In general, desalination costs are much higher than those associated with fresh water, but beyond costs, freshwater is simply not always available.

Researchers at MIT and Shanghai Jiao Tong University in China have developed a completely passive solar-powered desalination system that could provide more than 1.5 gallons of fresh drinking water per hour for every square meter of solar collecting area.   Such a system could provide an efficient, low-cost water source for coastal areas that are off the grid.

The system uses multiple layers of flat solar evaporators and condensers topped with transparent aerogel insulation.  The key to its efficiency is the way it uses each of its multiple stages to desalinate water.  At each stage, heat released by the previous stage is harnessed instead of wasted.  The proof-of-concept device, which was tested on an MIT building rooftop, produced more than twice as much water as the record amount produced by any previous passive solar-powered desalination system.

The researchers plan further experiments aimed at optimizing the choice of materials and configurations and to test the system under realistic conditions.  The hope is to have a technology that can play a role in alleviating water scarcity in parts of the world where electricity is scarce, but seawater and sunlight are abundant.

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Simple, solar-powered water desalination

Photo courtesy of MIT/researchers.

Earth Wise is a production of WAMC Northeast Public Radio.

Figuring Out Photosynthesis | Earth Wise

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Plants have been harnessing the sun’s energy for hundreds of millions of years. Algae and photosynthetic bacteria have been doing the same for even longer, all with remarkable efficiency and resiliency. 

People have used the energy of the sun in one way or another for millennia, but only recently have we gotten sophisticated about it by using devices like solar panels and sensors.  And we still have a long way to go to get anywhere close to the efficiency of plants. It’s no wonder, then, that scientists have long sought to understand exactly how photosynthesis works.

Scientists from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, and collaborators at Washington University in St. Louis, recently solved a critical part of the age-old mystery of photosynthesis, studying the initial, ultra-fast events through which photosynthetic proteins capture light and use it to initiate a series of electron transfer reactions.  Electrons in plants have two possible pathways to travel but only use one.   

But as a result of their efforts, the scientists are now closer than ever to being able to design electron transfer systems in which they can send an electron down a pathway of their choosing. 

By gaining the ability to harness the flow of energy, it may be possible to incorporate new design principles in non-biological energy systems. This could allow us to greatly improve the efficiency of many solar-powered devices, potentially making them far smaller. Understanding the intricacies of photosynthesis creates a tremendous opportunity to open up completely new disciplines of light-driven biochemical reactions, perhaps even ones that haven’t been envisioned by nature.

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Scientists unravel mystery of photosynthesis

Photo, posted June 14, 2017, courtesy of Alex Holyoake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Extreme Heat From Solar Power | Earth Wise

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Renewable sources are playing a growing role in meeting our energy needs, but one place where they have continued to fall short is in industrial processes that require extreme heat.  These include the cement, steel, and glass industries, among others.  These industries account for a significant amount of CO2 emissions because the most effective way to reach the necessary temperatures continues to be combustion of fossil fuels.  The cement industry alone accounts for 7% of global emissions and the need for cement continues to grow.

A previously stealthy startup company backed by Bill Gates and fellow billionaire Soon-Shiong has made a breakthrough in the area of using solar energy to achieve high temperatures.  The company, called Heliogen, has created a solar oven that is capable of generating heat above 1800 degrees Fahrenheit, which is enough for high-temperature industrial processes.

The Heliogen technology uses concentrated solar power to generate heat.  Concentrated solar power uses arrays of mirrors to reflect sunlight and focus it to a single point.  That technology is not new;  there are systems that use it to produce electricity and, to some extent, heat for industry.  But it could not achieve high enough temperatures for producing cement or steel.

The new system uses computer vision software, automatic edge detection and other sophisticated technologies to focus the sun’s rays far more finely than ever before and thereby generate far higher temperatures at the focal point.

Heliogen is now focused on demonstrating how the technology can be used in a large-scale application, such as cement-making.  The selling points to industry are that not only will there be no emissions generated, but that the fuel needed to obtain their extreme heat will be free.

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Secretive energy startup backed by Bill Gates achieves solar breakthrough

Photo courtesy of Heliogen.

Earth Wise is a production of WAMC Northeast Public Radio.

More Solar And Wind Power In The U.S.

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According to the U.S. Energy Information Administration, both wind and solar power are contributing more and more to total electrical generation in the United States.  For the first 8 months of 2019, the combination of wind and solar power accounted for almost 10% of U.S. electrical generation.

Solar, including small-scale PV systems on home rooftops, grew by almost 14% compared to the first eight months of 2018 and accounted for more than 2.7% of total electrical output.  In fact, small-scale solar generation increased by 19% and provided nearly a third of all the solar power in the country. 

Wind energy in the U.S. increased by 4.4%, accounting for almost 7% of the country’s electricity.

Overall, renewable energy sources – which include biomass, geothermal, hydropower, solar, and wind – accounted for 18.49% of net domestic electrical generation during the first 8 months of 2019.  The non-hydro renewable sources actually accounted for over 11% of total electricity production and saw a year-over-year growth of 6%. 

Outside of renewables, nuclear-generated electricity declined by 0.6% and coal power dropped by almost 14%.  Much of the coal generation was replaced by natural gas, which grew by 6.5% compared to the previous year.

Renewables now accounting for nearly 20% of overall electricity generation in the US represents significant progress.  But the variations by state continue to be substantial.  For example, while Vermont gets 99% of its power from renewables, Ohio gets only 2%. 

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Solar and wind energy provide almost 10 percent of total generation in the US in 2019

Photo, posted April 8, 2019, courtesy of City of St. Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Stranded Coal Assets In Japan

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Japan is facing a looming financial problem as a result of heavy investments in coal technology that may quickly become stranded assets as renewable energy sources become increasingly inexpensive.

Japan is gradually adding more ambitious policies with regard to climate change including goals to reduce emissions and to have renewables become the main source of power over the next three decades.  But despite these policy efforts, Japan is still investing heavily in coal power.  Japan currently has 21 new coal projects with over 11 GW of under-construction, permitted or pre-permitted coal capacity.  But these tens of billions of dollars in assets would have to be closed prematurely in order to remain consistent with the goals of the Paris Climate Agreement.

According to a new report by the Carbon Tracker Initiative, a financial think tank, and the University of Tokyo, offshore wind power will be cheaper than coal in Japan by 2022, new solar cheaper by 2023, and onshore wind less expensive by 2025.  The price of offshore wind is already comparable to existing coal power in Japan.  Japan had a total of 55.5 GW of solar capacity last year and has the potential to reach 150 GW by 2030.

The report notes that 42% of the global coal fleet likely became unprofitable last year and this could rise to 72% by 2040.  The authors contend that building coal power today equals high-cost power and financial liabilities tomorrow.  The planned and operating coal capacity in Japan is partially protected by regulations that give coal generators an unfair advantage in the marketplace.  Ultimately, the stranded coal assets are likely to be passed down to consumers through higher power prices.

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Land of the Rising Sun and Offshore Wind

Photo, posted April 25, 2019, courtesy of Jen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar-Powered Desalination

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Turning seawater into drinking water is an energy-intensive process and is therefore pretty expensive.  Worldwide, one third of people don’t have reliable access to safe drinking water and they are the least able to afford expensive ways to get it.   By 2025, half of the world’s population is expected to live in water-stressed areas.

At a newly-constructed facility in Kenya, a nonprofit company called GivePower has built a desalination system that runs on solar power.  The system started operating in the coastal area of Kiunga in July 2018 and can create nearly 20,000 gallons of fresh drinking water each day – enough for 25,000 people.

GivePower started in 2013 as a nonprofit branch of SolarCity, the solar-panel company that ultimately merged with Tesla in 2016.  However, GivePower spun off as a separate enterprise shortly before that.

GivePower mostly focuses on building solar-energy systems to provide electricity across the developing world. 

Desalination technology is not new, but it is notoriously energy-intensive because it requires high-power pumps.  The GivePower system is integrated with a solar microgrid that makes use of Tesla batteries to store energy for when the sun is not shining. 

Local residents pay about a quarter of one cent for every quart of water from the system.  The Kiunga community has faced ongoing drought and before the GivePower system was installed, was forced to drink from salt water wells, which present serious health risks.

The GivePower system cost $500,000 to build and is expected to generate $100,000 a year, to be eventually used to fund similar facilities in other places.

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A solar-powered system can turn salt water into fresh drinking water for 25,000 people per day. It could help address the world’s looming water crisis.

Photo courtesy of GivePower.

Earth Wise is a production of WAMC Northeast Public Radio.

A Solar-Powered Airport

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The Chattanooga Metropolitan Airport in Tennessee has become the first airport in the United States to run entirely on solar power.  The small airport operates over 60,000 flights a year and has recently completed work on a 12-acre, 2.64-megawatt solar farm that generates enough clean electricity to account for the airport’s total energy needs.

The project was funded largely by the Federal Aviation Administration, cost $10 million, and took nine years to complete.   The facility uses onsite batteries to help power operations at night.  The installation is expected to last 30 to 40 years.

The solar farm is in the southwest corner of the airfield on land that is unusable for aviation purposes.  It is visible from the two runways at the airport.

Officials from nearly 50 airports around the world have visited or contacted the Chattanooga airfield in recent years to learn about its solar operations.  Several major airports, including San Diego and London’s Gatwick, have also installed solar panels that provide a portion of their power needs.  The world’s busiest airport – Atlanta’s Hartsfield-Jackson – is looking into constructing renewable energy microgrids to power part of its operations.  Airports generally have plenty of vacant land that can be used for solar panels that can lower their power bills.

The largest airport solar installation is actually Cochin International in Kerala, India, which became 100% solar powered in 2015.  It is the 7th largest airport in India.   Its solar array has nearly 30 megawatts of capacity.  Airport managers there were fed up with huge electric bills and invested about $9 million to install the solar array.  It is expected to have paid for itself in the next couple of years.

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Chattanooga Becomes First U.S. Airport to Run Entirely On Solar

Photo courtesy of Chattanooga Metropolitan Airport.

Earth Wise is a production of WAMC Northeast Public Radio.

100% Renewables Does Not Necessarily Mean Carbon-Free

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Hundreds of companies around the world have committed to use 100% renewable energy in order to fight climate change.  But a new study from Stanford University points out that 100% renewable energy does not necessarily mean 100% carbon-free energy.

The problem is that the carbon content of electricity can vary a lot over the course of a day in many locations.  Using yearly averages can overstate the carbon reductions associated with a particular power source, in some cases by significant amounts.

Suppose a California company purchases or generates enough solar power to match 100% or more of their electricity use over the course of the year.  In reality, it may generate far more electricity than it uses during the afternoon and sell the excess.  Then, at nighttime, it purchases power from the grid, which would be far more carbon-intensive if it involves the burning of fossil fuels.

But in Britain, for example, the situation is very different.  With a high reliance on wind power, grid carbon intensity is actually lower at night.  So very different consumption patterns over the course of a day would be less carbon-intensive.

If sufficient energy storage capacity can be implemented into the grid as well as suitable long-range transmission, these time-based fluctuations in the electricity supply could be ironed out.  Until such time, electricity consumers need to evaluate the environmental benefits of their renewable strategies on an hourly basis rather than using averages.  And the best strategies are entirely dependent upon the characteristics of the specific grid they interact with.  The need for this kind of analysis will only grow as renewable generation expands.  Transparent, precise and meaningful carbon accounting is necessary.

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100% renewables doesn’t equal zero-carbon energy, and the difference is growing

Photo, posted January 29, 2013, courtesy of U.S. Fish and Wildlife Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The World’s Largest Storage Battery

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Many homeowners are installing solar energy systems with battery backup.  Energy stored in the battery can be used when the sun isn’t shining.   As battery prices come down, utility-scale solar installations are also turning to battery-based energy storage.

Florida Power & Light has announced plans to build the world’s largest solar-storage combination facility in Manatee County.  The 409-MW Manatee Energy Storage Center will be the largest solar-battery system by a factor of four.  The specifics of the technology and source of the battery system components have yet to be announced.

The system, which is scheduled to be completed in late 2021, will be charged by a nearby FPL solar power plant.  The plan is to discharge batteries during times of higher demand, thereby offsetting the need to run other power plants.  As a result, there will be reduced emissions and customers will save as much as $100 million through avoided fuel costs.

Installing the mega-sized battery system will accelerate the retirements of two nearby 1970’s-era gas-fired generation units.  At peak efficiency, the Manatee energy storage system will be able to power 390,000 homes for up to two hours.

FPL has already been pursuing the use of battery storage technology.  Last year, they added a 10 MW battery storage system to its 74.5 MW Babcock Ranch Solar Energy Center in Charlotte County.

These large battery systems are increasingly practical because of dramatic reductions in lithium-ion battery costs.  The levelized cost of electricity from lithium-ion batteries has declined a remarkable 38% just since the beginning of 2018.  The economics of clean energy continue to get better and better.

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FP&L Plans World’s Largest Energy Storage Battery To Support Its Renewable Energy Goals

Photo, posted April 21, 2010, courtesy of Frank Starmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lots Of Renewable Energy In Germany

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As the contributions to the electrical grid from renewable sources continue to rise, people have expressed concerns about what might happen as sources like wind and solar energy become dominant.  Not many years ago, there was a common concern that if wind and solar contributed more than about a quarter of the energy mix, the grid might become unstable or unreliable.  Theoretical models looked at this situation but there hadn’t been much real-world data to look at.

One place where there is now real-world data on a large scale is Germany.  Germany has been aggressively deploying both wind and solar energy for years as part of a national initiative called the Energiewende or energy transition.  Germany recently increased its renewable energy goal from 55% to 65% by the year 2030.   The increased share of renewables takes into account the decommissioning of aging nuclear and coal power plants.

A demonstration of the feasibility of such a goal occurred in the first week of March when renewable sources actually supplied nearly 65% of Germany’s electricity.  Wind power alone provided nearly half of the country’s power.  As a result, fossil fuel plants ran at a minimum output and nuclear facilities were shut down at night.

Germany has a very large domestic coal industry and indeed lignite coal generated an average of 24% of the country’s power last year.   However, recently that share was down to just 12%.  During that first week of March, solar power contributed more than 5% of Germany’s electricity, biomass 7.6%, and hydropower 3.5%.

While the week with 65% renewable set a record, the ongoing trend is very positive as well.  In 2018, renewable energy generated an average of more than 40% of Germany’s electricity.

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Renewables Generated a Record 65 Percent of Germany’s Electricity Last Week

Photo, posted April 28, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Renewables Without Storage In Texas

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Texas has a Texas-sized appetite for electricity and relies most heavily on natural gas, coal and nuclear power to get it.  But in recent times, wind power has grown tremendously in the Lone Star State and it has already leapfrogged past nuclear power.  Coal could be the next domino to fall.

In the past few years, solar power has become competitive with wind in terms of price.  Texas is a large, coastal state in the sunny southwestern U.S. and has significant solar resources.  As a result, the amount of solar power in Texas is now growing rapidly.

In order for a combination of solar and wind power to address the bulk of electricity demand in Texas, there needs to be a way to provide reliability that these intermittent sources don’t necessarily provide.  Energy storage is a solution that ultimately is likely to be part of most electricity grids, but currently it is still expensive on a utility scale.

A new study from Rice University looked at the complementarity of solar and wind power in Texas.  Complementarity refers to balancing the output of solar and wind systems.  The peak performance of wind and solar occurs at very different times in different regions of the state.  The study suggests that the right mix of solar and wind systems in the right parts of Texas could provide a continuously reliable energy system.  On both a yearly and daily basis, wind and solar power resources in Texas complement each other in terms of peak performance.  It is a matter of locating the solar power and wind farms in the right places.

With the Texas solar industry really starting to boom, there is a real opportunity to integrate far more renewable energy into the Texas grid.

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More Renewables with Less Energy Storage: Texas Shows How

Photo, posted June 8, 2018, courtesy of Laura Lee Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Liquid Fuel From The Sun

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Most forms of energy we use ultimately come from the sun in one way or another.  Even fossil fuels are the end product of millions of years of plant life that captured solar energy.  The advantage fossil fuels have over direct solar power is that they are, in fact, fuels and therefore can be stored for use when needed.

Scientists in Sweden have now developed a specialized fluid that absorbs some of the sun’s energy, holds it for months or even years, and then releases it when needed.  This solar thermal fuel is like a rechargeable battery for heat rather than electricity.

The special fluid is pumped through transparent tubes where ultraviolet light from the sun excites its molecules into an energized state.  A compound called norbornadiene is converted into quadricyclane. The quadricyclane is a quite stable substance until it is passed over a cobalt-based catalyst, which causes it to turn back into norbornadiene and release copious amounts of heat.

Such a solar thermal fuel could be stored in uninsulated tanks in homes or factories or piped or trucked to where it was needed.  It could then be used for water heaters, dishwashers, or clothes driers.  The room temperature fluid quickly warms to about 183 degrees when passed over the catalyst, plenty warm enough for heating a home or office.  Both the fuel and the catalyst are damaged very little by the reactions, so the process can be recycled many times.

There is much development work needed to optimize shelf life, energy density, good recyclability and other properties before this technology can be commercialized but there are at least 15 groups around the world now studying this intriguing way to get liquid fuel from the sun.

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Scientists transform sunlight into a liquid fuel that can be stored for 18 years

Photo, posted August 17, 2009, courtesy of Hiromichi Torihara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Smog And Solar Power

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China has been struggling with some of the worst air pollution in the world.  Beijing frequently sits under a brown blanket made of exhaust gases from industry, cars and coal fires, which dump harmful particulate matter, soot, sulfur dioxide and nitrogen oxides into the air.

The human health consequences are severe.   According to the World Health Organization,air pollution contributes to about 1.6 million premature deaths in China each year.  World-wide, air pollution is implicated in over 7 million deaths annually.

Faced with this air pollution crisis, China has undertaken a wide variety of measures to improve its air and curb carbon dioxide emissions alongthe way.  Among other things, China has invested heavily in the deployment of solar power and has plans for ever greater expansion of solar power in the future.

A study by researchers at ETH in Zurich looked at the impact of China’s air pollution on the production of solar energy.  The smog in China’s cities reduces the amount of solar radiation that reaches the ground and therefore significantly reduces the power output of solar energy systems. According to the study, solar radiation would increase by an average of 11% nationwide as a result of strict air pollution control measures.  In some places, cleaning up the air would result in 26% more energy production.

China’s electric power industry is the world’s largest electricity producer, having passed the United States in 2011.  Two-thirds of the electricity in China still comes from coal, which, apart from the serious climate and health consequences associated with its use, continues to make it more difficult to switch to clean solar power.  Much work remains to be done.

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Fighting smog supports solar power

Photo, posted February 7, 2014, courtesy of Flickr. 

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)