renewable energy

More Solar And Wind Power In The U.S.

January 2, 2020 By EarthWise Leave a Comment

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.

Solar And Wind Energy And Groundwater

December 30, 2019 By EarthWise Leave a Comment

The use of both solar and wind farms has been expanding all over the country as a way of lowering carbon emissions from the electric power sector. According to a new study led by Princeton University, these renewable energy sources have another important benefit: they keep more water in the ground.

The study focused on drought-prone California where both solar and wind power have been expanding dramatically. California is the largest agricultural producer in the United States and has also experienced one of the most severe droughts on record between 2012 and 2017.

The study determined that increased solar and wind energy can reduce the reliance on hydropower, especially during times of drought.

The study looked at multiple scenarios in order to determine how much solar and wind energy should be used to maximize economic revenue and to see how solar and wind power could ensure groundwater recovery. They created a framework to quantify the optimal pathways for maximizing hydroelectricity and agricultural income while avoiding groundwater depletion.

During the long drought, California’s agriculture industry relied heavily on tapping into groundwater stores, which is an unsustainable practice. With more droughts likely to occur in California as well as increasing water demand from the growing California population, the burden on the state’s groundwater supply will only grow.

According to the researchers, it is far more practical to impose further regulations on groundwater use if sufficient solar and wind power is deployed. They caution that these resources need to be deployed long before groundwater aquifers are depleted, or it will be too late for them to do any good.

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Solar and Wind Energy Preserve Groundwater for Drought, Agriculture

Photo, posted December 11, 2014, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Dams Restores Ecosystems

November 1, 2019 By EarthWise Leave a Comment

In many parts of the country, dams that sometimes date back as much as 100 years are being removed and are giving way to the revival of migratory fish and their river ecosystems. Since 1912, more than 1,600 dams have been removed in the U.S., but the pace of dam removal has greatly picked up in recent years. 2017 and 2018 were the highest years ever with 91 and 99 dams removed, respectively.

When dams are removed, the response from migratory fish can be almost immediate. A large dam removal project on the Penobscot River in Maine in 2012 opened up 1,000 miles of habitat with a quick return of shad and alewives, followed by salmon.

In 2022, four large dams across the Klamath River will be removed. The dams, which are located at the California and Oregon border, were facing an expensive re-licensing process and, because of their age, could no longer be run at a profit.

Re-licensing the dams along the Klamath was going to cost as much as $400 million. On the other hand, uncapping the Klamath River has tremendous commercial and tourism potential. Two states, tribal nations, and other stakeholders have all seen the virtues of restoring the landscape to its original form.

Opposition to dam removal is typically driven by aesthetics or recreational preferences. But dam economics are getting increasingly worse. Now that electricity can be produced far more cheaply with wind and solar power, many American dams have become artifacts of an older manufacturing era. Meanwhile, rural towns near decommissioned dams are likely to now have more robust fishing industries.

In rivers big and small, migratory fish and river ecosystems surge back to life as old energy structures are taken down.

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Take Down That Dam: River Ecosystems Bounce Back As Removals Soar

Photo, posted June 11, 2016, courtesy of the Bureau of Land Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Amazon And Climate Change

October 30, 2019 By EarthWise Leave a Comment

Online shopping giant Amazon has unveiled a Climate Pledge, committing to meet the goals of the Paris climate agreement ten years ahead of schedule, and to be carbon neutral by 2040. This is the company’s most ambitious push yet to reduce its carbon footprint, which currently rivals that of a small country. In fact, Amazon is responsible for 48.9 million tons of carbon dioxide last year, which is about 85% of what Switzerland typically emits in a year.

Amazon, which ships more than 10 billion items a year on fossil fuel-intensive planes and trucks, has ordered a fleet of 100,000 electric vans that will start delivering packages to doorsteps in 2021. The vans will be made by Rivian, a Michigan-based company that Amazon invested in earlier this year.

Amazon plans to get 100% of its energy from solar and other renewable sources by 2030. Currently, it gets about 40% of its energy from renewables.

Amazon is also investing $100 million in nature-based climate solutions and reforestation projects around the world in order to remove carbon from the atmosphere.

While announcing these initiatives recently at the National Press Club in Washington, D.C., Amazon CEO Jeff Bezos said the company needs to be a leader on the climate change issue:

We want to say look, if a company of Amazon’s complexity, scale, scope, physical infrastructure, delivering 10 billion items can do this, so can you.

After revealing Amazon’s Climate Pledge, Bezos said he would talk with CEOs of other large companies to try to get them to also sign it. You can find a link to Amazon’s progress on its commitments by visiting this website.

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‘Middle of the herd’ no more: Amazon tackles climate change

Amazon: Committed to a sustainable future (track progress here)

Photo courtesy of Amazon.

Earth Wise is a production of WAMC Northeast Public Radio.

Pulling Water From The Air

October 14, 2019 By EarthWise Leave a Comment

A couple of years ago, we reported on the early development of a device that harvests water from the air that even works in the low humidity environment of a desert. Since then, the researchers from UC Berkeley have continued to improve the device and it is now 10 times better than it was two years ago.

The harvester is based on a porous water-absorbing material called a metal-organic framework, or MOF. The latest version can pull more than five cups of water from low-humidity air per day for every kilogram of the improved MOF material and that is more than enough water to sustain a person. The harvester cycles around the clock and is powered by solar panels and a battery.

Previous techniques for condensing water from air at low humidity required cooling down the air to temperatures below freezing, which is not economically practical. The MOF-based device does not require any cooling.

The Berkeley researchers have formed a startup company – Water Harvester, Inc. – which is now testing and will soon market a device the size of a microwave oven that can supply 7 to 10 liters of water per day, which is enough drinking and cooking water for two or three adults.

An even larger version of the harvester, which would be the size of a small refrigerator, would provide 200 to 250 liters of water per day, enough for a household to drink, cook, and shower. The new company envisions a village-scale harvester that would produce 20,000 liters per day, still running off of solar panels and a battery.

Water Harvester believes the water needs for many people can come out of the thin air.

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Water harvester makes it easy to quench your thirst in the desert

Photo courtesy of Grant Glover (University of South Alabama) via UC Berkeley.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Solar Fuel Farms

September 20, 2019 By EarthWise Leave a Comment

Limiting global warming will require a massive reduction in CO2 emissions from fossil fuel burning. Renewable energy sources are playing a growing role in the power grid and electric cars are becoming increasingly popular. Despite all this, carbon-based liquid fuels will continue to dominate our energy use for the foreseeable future.

Researchers in Norway and Switzerland have described a potential scheme that would help remove CO2 from the atmosphere and produce a valuable liquid fuel.

The idea is to create floating islands containing large numbers of solar panels that convert carbon dioxide in seawater into methanol, which can fuel airplanes and trucks.

A combination of largely existing technologies would be the basis of these floating islands, which would be similar to present-day floating fish farms. The researchers envision clusters each composed of 70 circular solar panels that in total cover an area of roughly half a square mile. The solar panels would produce electricity, which would split water molecules and isolate hydrogen. The hydrogen would then react with carbon dioxide pulled from seawater to produce usable methanol.

The technology already exists to build the floating methanol islands on a large scale in areas of the ocean free from large waves and extreme weather. Suitable locations are off the coasts of South America, North Australia, the Arabian Gulf, and Southeast Asia.

A single floating solar farm could produce more than 15,000 tons of methanol a year – enough to fuel a Boeing 737 airliner for more than 300 round-trip flights across the country. Floating energy islands would not be a magic bullet for limiting the effects of climate change, but they could well be an important part of an overall strategy.

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Giant Floating Solar Farms Could Make Fuel and Help Solve the Climate Crisis, Says Study

Photo courtesy of PNAS.

Earth Wise is a production of WAMC Northeast Public Radio.

Falling U.S. Carbon Emissions

September 16, 2019 By EarthWise Leave a Comment

Reducing carbon emissions is a goal embraced by nearly every country in the world, but actually accomplishing it isn’t easy. It is true that renewable energy sources are playing a growing role in energy systems, but counterbalancing that trend is growing energy demand, especially in developing countries.

Here in the US, energy-related CO2 emissions actually went up nearly 3% in 2018 compared with 2017. But the US Energy Information Administration is now forecasting a 2% drop in emissions this year.

The main reason energy-related emissions are headed lower at this point is coal-fired power plant retirements. More than 90% of the coal used in the US goes toward electric power and utilities are increasingly turning away from coal.

The rapid shift away from coal has mostly been due to the increasing use of natural gas. Natural gas is not actually a clean and green fuel, but it is definitely less carbon-intensive than coal. Overall, the total installed capacity of renewable sources – hydropower, wind, solar, geothermal, and biomass – has now actually surpassed the capacity of coal plants. Given that renewables have in many places become the cheapest power option, there is little chance that coal has much of a future, despite efforts by the current administration.

The electric power sector is gradually moving away from all carbon-emitting sources – a trend that is being reinforced by legislation in many states. The real CO2 emissions leader is petroleum, which accounts for nearly half of the total. We have a long way to go to reduce emissions from the use of petroleum. There are over 250 million cars and trucks on US roads and only a little over a million of them don’t burn fossil fuels.

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Photo, posted November 6, 2017, courtesy of Cindy Shebley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Scottish Wind Power

September 5, 2019 By EarthWise Leave a Comment

Scotland is a windy country. Most wind turbines in the European Union produce electricity at an average of 25% of their maximum rated power as a result of the variability of wind resources. The west and northern coasts of Scotland have an average capacity of 31% or more. Some wind farms in Scotland have achieved more than 50% capacity over the course of a year.

As of the end of last year, Scotland had more than 8 GW of installed wind power capacity. This included 7.8 GW of onshore wind and 623 MW of offshore wind generators. Estimates are that more than 11 GW of onshore wind could be installed in Scotland. The total offshore potential is far greater than that but would be much more expensive. There are multiple large-scale wind farms proposed or under construction in Scotland.

All of this growth in wind power has led to some remarkable results. During the first half of 2019, wind turbines in Scotland produced enough electricity to power every home in the country twice over. Scottish wind farms generated nearly 10 million megawatt-hours between January and June, which is equal to the consumption of 4.5 million homes during that period. That is enough to take care of all of Scotland’s homes plus a large portion of northern England’s.

Scotland has set a target of generating half of its electricity from renewable sources by 2030 and decarbonizing its energy system almost entirely by 2050. The recent performance of its wind power installations shows that the country might be able to reach its goal much sooner than anticipated.

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Scotland’s Wind Farms Generate Enough Electricity to Power Nearly 4.5 Million Homes

Photo, posted March 27, 2017, courtesy of Ian Dick via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lots Of Renewable Energy Jobs

August 16, 2019 By EarthWise Leave a Comment

According to the International Renewable Energy Agency, there were 11 million people employed in renewable energy worldwide in 2018. This compares with 10.3 million in 2017. So roughly three-quarters of a million new jobs were added last year. As more and more countries manufacture, trade and install renewable energy technologies, renewables jobs continue to reach new high levels.

The geographic footprint of renewable energy jobs is changing. Until now, renewable energy industries have remained relatively concentrated in a handful of major markets such as China, the US, and the European Union. But more recently, East and Southeast Asian countries have emerged alongside China as key exporters of solar technology. Malaysia, Thailand, and Vietnam were responsible for a greater share of growth in renewables last year. Overall, Asia has a 60% share of renewable energy jobs worldwide.

Beyond climate goals, low-carbon economic growth has become a driver for renewables technology. Renewables deliver on all the major elements of sustainable development: environmental, economic and social.

The solar photovoltaic industry continues to be the most dynamic renewable enterprise. It accounts for a third of the renewable energy workforce with more than three million jobs.

Biofuel jobs were up by 6% to over 2 million. Wind power supports 1.2 million jobs, with onshore projects predominant. But the offshore wind segment is gaining traction. Hydropower is still the largest installed capacity of all renewables but is now only expanding slowly. The hydropower sector employs 2.1 million people directly, three-quarters in operations and maintenance.

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Renewable energy market employs 11 million in 2018 – IRENA

Photo, posted January 11, 2012, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

100% Renewables Does Not Necessarily Mean Carbon-Free

July 16, 2019 By EarthWise Leave a Comment

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.

Complications For New York Solar Farms

July 12, 2019 By EarthWise Leave a Comment

A study by engineers at Cornell University looked at the implications of adding utility-scale solar farms throughout New York State. Adding such farms could reduce demand for electricity from conventional sources by nearly 10% in some places. But the engineers caution that winters in upstate New York could create some novel problems for the state’s power system.

Electrical energy demand tends to be low around midday when many people are not home. Electrical production from solar farms is high at that time when the sun is at its highest position in the sky. This can lead to what power system operators call “ramping”, which is the term for rapid increases or decreases in demand.

This sort of ramping was first discussed in California years ago. When people wake up and prepare for the day, there is a morning peak in electrical load, which occurs before solar production ramps up. When people get home from work in the evening, energy demands create a second peak. A graph of this lack of synchronicity of load and supply looks a little like the shape of a duck and is popularly known as the duck curve.

The Cornell engineers figured out that maximum ramping in New York – where electrical demand and electricity supply from solar farms are out of synch- will take place in the winter. In fact, when there are several days of sunshine in a row during winter, the largest ramping in the New York power system will take place.

The general issue of having solar energy available when it is most needed is one that is the driver for energy storage technology. If the energy can be provided when demand calls for it, there would be no more ramping.

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Winter could pose solar farm ‘ramping’ snag for power grid

Photo, posted September 8, 2015, courtesy of New York National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sunlight As A Cash Crop

July 10, 2019 By EarthWise Leave a Comment

It isn’t so easy to be a farmer these days. Farming has always involved long hours, hard work and the uncertainties of weather and yield. The 21st Century has added new and unique challenges such as increasingly unpredictable weather, insect infestation and disease, and low commodity prices. Add in sudden tariffs and farmers struggle even more to make ends meet. The default rate for farmers’ loans is the the highest in at least nine years.

One thing that remains reliable for farmers is the sun. It rises in the morning and goes down at night. The sun can be trusted, unlike politicians, rain, or commodity prices. These days, many farmers are taking advantage of the dependability of the sun to make money from a new cash crop: solar energy.

The trend is spreading. North Carolina has been a leading solar energy state for several years and a 2017 report found that solar energy generates 30% of the income of many farms. Typical annual rent payments for farmland by solar companies range from $500 to $1,400 per acre in North Carolina.

A growing list of states have clean energy mandates targeting 100% use of renewable energy. These mandates provide incentives for farmers that make installing solar a financially smart decision and falling prices for solar installations make it an even better deal.

Solar works well when co-located on a farm and can be built in ways that minimizes impact. It is quiet, uses almost no water, doesn’t pollute, and if it is decommissioned, the land can go back to its previous use. If the solar facilities are raised up, the same land can be used to graze livestock or grow shade-tolerant crops.

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Harvesting the sun is the new cash crop

Photo, posted December 25, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shutting Down Minnesota Coal Plants

July 8, 2019 By EarthWise Leave a Comment

One of the largest utilities in the United States, Xcel Energy Inc., announced that it will close its remaining coal-fired power plants in the Upper Midwest a decade ahead of its previously-announced schedule. In addition, the company will add 3,000 megawatts of new solar capacity by 2030.

The Allen S. King plant in Oak Park Heights, Minnesota and the Sherburne County Generating Station in Becker, Minnesota are the plants in question. The transition away from coal is a difficult challenge for such small communities. The plant in Becker, for example, employs 300 people in a town of 4,500 and provides 75% of the city’s tax base. Towns like this realize that coal is inevitably going away and must find ways to move beyond their dependence upon it. The Becker plant will not completely close until 2030, but parts will now only run seasonally, and one of the 3 units will close permanently in 2023

Xcel Energy, based in Minneapolis, serves more than 3.3 million electricity customers in 8 states. Last December, the company announced that it would deliver 100% clean, carbon-free electricity by 2050 and would achieve an 80% carbon reduction from its 2005 levels by 2035. It is the first major US utility to set such a goal.

Xcel will increase its investment in energy efficiency measures, bring 1,850 megawatts of new wind capacity online in Minnesota by 2022, and keep its Monticello Nuclear Generating Station operating until 2040, a decade later than planned. The company’s stepped-up clean energy strategy is part of a new legal settlement between the company, environmental organizations, and labor groups that involves Xcel’s proposed $650 million purchase of a 760-megawatt natural gas plant.

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A Major U.S. Utility Is Closing Its Coal-Fired Power Plants a Decade Early

Photo, posted January 3, 2016, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Two Million Solar Installations

July 1, 2019 By EarthWise Leave a Comment

Three years ago, we reported that the United States had installed its one millionth solar energy system, a feat that took 40 years to accomplish. Recently, the Solar Energy Industries Association announced that there are now more than 2 million U.S. installations.

Analysts forecast that there will be 3 million installation in 2021 and 4 million in 2023.

California continues to lead the nation in installing solar power. More than 50% of the first million installations were in that state and California accounted for 43% of the second million. Its share is nevertheless slowly dropping with the growth of the residential solar sector that is rapidly diversifying across state markets. Some places have seen extremely rapid growth. In South Carolina, there were barely more than 1,000 cumulative installations in 2016; today, the state is home to more than 18,000 solar systems and expects to add 22,000 more over the next five years.

The five leading states in terms of number of solar installations are California, Arizona, New York, New Jersey, and Massachusetts. Other states recently seeing rapid growth in solar installations are Texas, Utah, Florida, Rhode Island and Maryland. Looking ahead, Illinois is forecast to grow from only 4,000 installations today to nearly 100,000 by 2024. The top ten state markets apart from California expect to add nearly 750,000 installation over the next five years.

The United States is at least the third nation that is home to more than 2 million solar installations. (Australia hit the milestone late least year and Japan actually topped 2 million in September 2014).

According to forecasts from analyst first Wood Mackenzie, by the year 2024, there will be on average one new solar installation every minute.

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The United States surpasses 2 million solar installations

Photo, posted January 11, 2012, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Giant Solar Farm In Dubai

June 26, 2019 By EarthWise Leave a Comment

Like many places in the Middle East, Dubai made its fortune from oil. But the Emirate’s oil resources are limited, and its economy has evolved in other directions. Today, oil provides less than 5% of Dubai’s revenues; its economy relies on revenues from trade, tourism, aviation, real estate, and financial services.

Dubai is also away from fossil fuels to meet its energy needs. A monumental construction project is underway deep within Dubai’s desert interior which will be the largest solar energy facility in the world.

The Mohammed Bin Rashid Al Maktoum Solar Park – named after Dubai’s ruler – has been under development for 7 years. Total investment in the project will be nearly $14 billion when it is completed in 2030. It will have a total capacity of 5,000 megawatts, enough to power 1.3 million homes. Only some large hydroelectric power plants, the largest nuclear power plants, and a couple of Asian coal plants have more generating capacity.

Phases one and two of the project are already complete and feature more than 2 million solar panels. Phase three – well along the way in construction – will add another 3 million solar panels and should be completed next year.

Phase four will not involve solar panels but instead will make use of the world’s tallest concentrated solar power tower. It will use mirrors to focus sunlight at the top of the tower to heat up molten salt that will power steam turbines to generate electricity and will be able to operate long after the sun goes down.

Currently, the Tengger Desert Solar Park in China is the largest photovoltaic park in the world, but a colossal farm in India will take its place in a few years. Big solar is getting bigger all the time.

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$13.6B record-breaking solar park rises from Dubai desert

Photo, posted December 15, 2018, courtesy of Anoop S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Our Growing Appetite For Energy

June 13, 2019 By EarthWise Leave a Comment

Energy consumption in the United States set a record high in 2018. Overall, energy consumption reached 101.2 quadrillion BTUs or quads last year, breaking the previous record of 101.0 set in 2007. Most of us are not too familiar with quadrillions of anything, nor with BTUs for that matter. If it is any more illuminating, 101 quads are the equivalent of about 300 billion kilowatt hours. Our energy use increased by 3.6% from 2017, which was the largest annual increase since 2010.

Wind, solar, and natural gas provided the largest increases in energy supply. In 2018, solar and wind energy were both up by 0.18 quads, representing a 22% gain for solar and a 7.5% increase for wind. Over the past ten years, overall renewable energy has doubled in the U.S., with wind increasing by a factor of 5 since 2008 and solar by an amazing factor of 48.

Natural gas generation increased by 10.7%, or a total of 3 quads over the previous year. The growth in natural gas use isn’t good news, but since much of it represents replacing coal, it at least corresponds to reduced greenhouse gas emissions.

The unfortunate part of our energy consumption is that the majority of it is still in the form of “rejected energy”. It most often takes the form of waste heat, such as the warm exhaust from automobiles and furnaces. The efficiency of our cars, lightbulbs and factories determines how much waste heat is produced and in turn how much fuel and electricity can be put to productive use.

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US energy consumption hits record high in 2018, solar/wind/natural gas grow

Photo, posted April 27, 2015, courtesy of Mathias Appel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Equity for Low-Income Communities

May 30, 2019 By EarthWise Leave a Comment

A couple of years ago, the number of American roofs covered with solar panels passed the one million mark and the numbers keep growing. But nearly half of U.S. households – accounting for more than 154 million people – aren’t able to host their own solar arrays because they lack suitable rooftop space, or they rent their homes. But millions more simply can’t afford to spend tens of thousands of dollars to buy or lease solar panels.

In recent years, community solar has become popular. These are projects where multiple participants own or lease shares in a mid-sized solar facility and receive credits that lower their monthly utility bills. Community solar in the U.S. has more than quadrupled just since 2016.

However, the majority of community solar subscribers to date have been businesses, universities, government agencies, and higher-earning households. These users can generally pay steep project enrollment fees or meet various financial requirements. Meanwhile, those who could benefit most from access to renewable energy and lower utility bills – low-income residents – have largely been left out.

Low-income households on average spend over 8% of their income on utility bills, about three times more than moderate- to high-income households. So, reducing electricity bills with community solar power is a big deal for them.

Given this situation, there are now a growing number of programs that make use of community solar to reduce living expenses for low-income households. In a dozen states, new programs include a variety of mandates, financial incentives, and pilot programs targeting benefits for people with low incomes. These programs will allow them to participate in both the environmental and economic benefits of renewable energy.

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Energy Equity: Bringing Solar Power to Low-Income Communities

Photo, posted November 27, 2012, courtesy of Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Energy Vault

May 28, 2019 By EarthWise Leave a Comment

A potentially transformative utility-scale energy storage technology has won a 2019 “World Changing Idea” award from Fast Company magazine. Known as the Energy Vault, the technology seeks to be the successor to the granddaddy of grid energy storage: pumped hydro.

Shifting water between higher and lower reservoirs is still basis of the vast majority of global grid storage capacity. But it is limited both by its unique location needs and by environmental regulations.

A start-up company also called Energy Vault and based in both Switzerland and Southern California has come up with an extremely creative grid storage concept. The technology consists of a six-armed crane that stacks huge concrete blocks using a currently available source of cheap and abundant grid electricity, and then drops them down to generate electricity when needed.

The system is said to operate at about 90% efficiency and can deliver long-duration storage at half the prevailing price on the market today.

A full-scale Energy Vault plant, called an Evie, would look like a 35-story crane with six arms, surrounded by thousands of manmade concrete blocks, weighing nearly 40 tons each. When charging, the plant will stack the blocks around itself higher and higher in a Babel-like tower. To discharge, the cranes drop the blocks down, generating power from the speedy descent. This configuration can deliver 4 megawatts of power and store about 35 megawatt-hours of energy.

There isn’t even a factory needed. The company would deliver a crane from a manufacturer. The crane will then assemble the blocks onsite using recycled concrete. Operation is then fully automated. The system is expected to run for 30 or 40 years.

So far there is only a one-seventh scale demo unit in Switzerland. But this is a very intriguing idea.

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Energy Vault Wins World Changing Idea Award 2019 from Fast Company for Transformative Utility-Scale Energy Storage Technology

Photo courtesy of Energy Vault.

Earth Wise is a production of WAMC Northeast Public Radio.

Plant-Based Jet Fuels

May 9, 2019 By EarthWise Leave a Comment

The global aviation industry uses a whole lot of fuel: more than 5 million barrels a day. It is an incredibly energy-intensive industry and almost all of its energy comes from petroleum-based fuels.

While other large energy sectors such as electric power, ground transportation and commercial buildings have well-defined pathways to adopting renewable energy sources, the aviation industry does not have such a straightforward way to make a transition to sustainability. Electrifying planes using batteries or fuel cells is very challenging for a number of reasons, notably the weight restrictions on aircraft. So liquid biofuels as replacements for petroleum-based fuels remain the most promising approach.

A new study at the Lawrence Berkeley National Laboratory concludes that sustainable plant-based biofuels could provide a competitive alternative to conventional petroleum fuels if current development and scale-up initiatives are successful.

Multidisciplinary teams based at the Department of Energy’s Joint BioEnergy Institute are focused on optimizing each stage of the bio-jet fuel production process. This includes bioengineering ideal source plants and developing methods for efficiently isolating the carbohydrates in non-food biomass that bacteria can digest and bioconvert into fuel molecules.

The critical issue is cost. The theoretical cost of bio-jet fuel has come down dramatically in recent years but is still around $16 a gallon. The cost of standard jet fuel is about $2.50 a gallon. So, the real challenge is bridging that gap.

Reducing the cost of the fuel could come both from the material and process improvements that are underway as well as by finding ways to turn the leftover lignin residuals from the bioconversion process into valuable chemicals.

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Bright Skies for Plant-Based Jet Fuels

Photo, posted March 28, 2009, courtesy of Yasuhiro Chatani via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Utility-Scale Solar On The Rise

May 8, 2019 By EarthWise Leave a Comment

According to research from Goldman Sachs, utility-scale solar power capacity is expected to grow by double digits globally over the next two years. The growth will be driven by expanding use of the technology in the United States, Europe, the Middle East, and China.

Solar power is the world’s fastest growing source of electricity generation and is slowly taking market share from fossil fuels like coal and natural gas. The transition is being driven by a combination of continuously lower prices for solar power and the impact of policies aimed at reducing emissions.

Utility-scale solar is defined as installations designed solely to feed electricity into the grid, in contrast to smaller-scale residential or commercial building units. There are now solar farms larger than half a gigawatt in generating capacity. According to the Goldman report, global utility-scale solar installations will reach 108 gigawatts in 2019, up 12% over the previous year, and will then grow another 10% to 119 gigawatts in 2020.

When residential and other smaller installations are included, most analysts expect global solar power capacity to soon hit 600 gigawatts. To put this in perspective, the global capacity only reached 100 gigawatts in 2012 and was actually less than 10 gigawatts in 2007.

Even more dramatic than the growth of solar installations is the reduction in solar cost, and the two are obviously closely related. Solar panel costs have dropped from around $70 per watt of electricity generated in 1980 to 36 cents per watt currently in the United States. When favorable policies both from governments and related to corporate sustainability targets are added to the mix, the booming growth in solar power is easy to understand.

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Large-scale solar power set for double-digit growth: Goldman Sachs

Photo, posted March 7, 2019, courtesy of Hedgerow Inc via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.