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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.

Energy Trends For A New Year

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With a new year upon us, there are several energy trends to watch out for.

The most important one is that the fundamental shift toward slow-carbon technologies is continuing. This shift is taking place despite diminishing government policy support and even active government efforts to thwart it.  There is just too much momentum to stand in the way of low-carbon energy technologies.

Analysts at Bloomberg New Energy Finance estimate that over the next 30 years over 11 trillion dollars will be invested in energy power generation and power storage assets with 85% of it aimed at zero-carbon emission.  Dramatic reductions in green energy costs have resulted in legitimate cost competition between zero carbon sources of energy and fossil fuel generation.

In the coming year, battery technology will continue to play a growing role both as a storage medium for energy generated by sun and wind and for powering vehicles.

Another trend is that the world’s wealthiest economies are learning to grow without growing the demand for electricity.  This is important in the battle to reduce overall emissions.

Another key issue is addressing the energy needs of people who have no meaningful access to it and there are around 1.5 billion people in that category.   Emerging technologies based on solar power, wind energy, microgrids and other innovations mean that traditional power grids that remain out of reach to these people are not necessary.  There is the potential to address those needs without contributing to climate change.

The world is struggling to deal with the growing problem of the changing climate, but there are trends that provide at least some hope that we can move in the right direction.

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Top 3 clean energy trends to watch out for in 2019

Photo, posted April 5, 2013, courtesy of Flickr. 

Earth Wise is a production of WAMC Northeast Public Radio.

New Ocean Energy Technologies

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The ocean energy sector is still at an early stage of development.  Despite the fact that the ocean is permanently in motion, extracting energy from that motion on a major scale continues to be a challenge.  But the potential benefits of ocean technologies are compelling enough that many approaches continue to be pursued.

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More Power From The Sun’s Heat

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When we think of solar power, we usually are talking about the panels that generate electricity using the photovoltaic effect.  These panels are on millions of rooftops around the world and in utility-scale solar farms.   There are also solar water heating systems that use the sun’s heat to provide hot water for homes and businesses.

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Solar Plus Storage In The Caribbean

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The Caribbean is home to nearly 30 island nations and more than 7,000 individual islands with a combined population of around 40 million.  All of the islands are susceptible to disasters such as hurricanes that can leave residents without electrical power for extended periods of time.

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Trouble With China And Climate Progress

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With the United States backing away from the Paris climate agreement and with Europe taking a less active role in climate negotiations, China has become the bellwether on global climate change.  Recent climate negotiations in Bonn, Germany were rather acrimonious as countries accused other countries of not doing their part or keeping their promises.

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Saildrones For Science

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Nine years ago, engineer Richard Jenkins broke the world land speed record for a wind-powered vehicle with a sailboat on wheels driving across a dry lakebed at 126 miles per hour.  After years of engineering development, his technology has now taken on the form of a saildrone that can autonomously sail the sea gathering ecologic, oceanic and atmospheric data.

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Mandatory Solar In California

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In May, California became the first state in the U.S. to require solar panels on almost all new homes.  Under new standards adopted by the California Energy Commission, most new homes, condos and apartment buildings built after January 1, 2020 will be required to include solar systems.

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A Milestone For Energy Storage

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The United States has now added the capacity to store a billion watts of power for one hour and it may double that total by the end of this year.   According to the firm GTM Research, the energy storage industry – previously nearly invisible – is undergoing rapid growth.  Much of the growth has been in homes with products like the Tesla Powerwall but has also been on the scale of the electric grid, where power companies can use storage to control when to deploy excess electricity generated from renewable sources such as solar power.

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Farming In Solar Farms

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Utility-scale solar installations have been expanding rapidly.  The amount of land used for solar projects is becoming quite substantial.  The National Renewable Energy Laboratory (NREL) predicts that 3 million acres will be devoted to solar farms by 2030, and 6 million by 2050.  These numbers pale in comparison with the land used for corn, soybeans, and wheat, but are more than used for such familiar crops as oats, barley and rice.

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