Earth Wise

A look at our changing environment.

You are here: Home / Archives for electricity

electricity

The Problem Of Gas Flaring | Earth Wise

By Leave a Comment

Gas flaring is the burning off of flammable gas released by pressure relief values during over-pressuring of plant equipment at petroleum refineries, chemical plants, natural gas processing plants, and a variety of oil and gas production plants.  Flaring is also used during plant startups and shutdowns.

A new study by Rice University concludes that reducing gas flaring would benefit both the environment and the economy. Flaring and venting of gas in West Texas’s Permian Basin and certain other parts of the U.S. have reached levels that the intended result of burning gas to allow oil extraction now looks more like wasting one resource to produce another.

At current rates, enough gas is flared in the Permian Basin to yield nearly 5 million metric tons of exportable liquid natural gas if it was captured and liquified.  At these rates, the wasted gas could fill the largest sized LNG carrier every ten days.  If that liquified natural gas was exported to China and used in a power plant, it would displace 440,000 metric tons of coal burned to generate electricity.

Burning natural gas to heat homes, power industrial processes, or generate electricity all emit carbon dioxide, but at least these things also perform valuable functions. Flaring gas produces CO2 as well as other combustion products but doesn’t even do anything useful.  The venting of unburned gas, which also takes place with some frequency, is even worse since it is dumping methane directly into the atmosphere.

Across the U.S., some 14.1 billion cubic meters of natural gas was flared in 2018, equivalent to nearly 9 million metric tons per year of LNG.  In energy terms, that is equivalent to more than one-third of the total LNG volume U.S. firms actually exported that year.

**********

Web Links

Reducing gas flaring will benefit economy and environment, says Baker Institute expert

Photo courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Solar And Wind Power In The U.S.

By 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%. 

**********

Web Links

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

By 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.

**********

Web Links

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.

SUVs And Carbon Emissions

By Leave a Comment

Global carbon dioxide emissions increased between 2010 and 2018.  The largest contributor to this increase was the power sector as electricity demand around the world continued to grow.   The second largest contributor to increased emission turns out to be SUVs, even while emissions for other cars actually decreased.

During that time period, SUVs more than doubled their global market share from 17% to 39% and their annual emissions rose to more than 700 million tons of CO2, which is more than the yearly total emission of the UK and the Netherlands combined.

This dramatic shift toward bigger, heavier SUVs has offset both efficiency improvements in small cars and savings from electric vehicles.  If SUV drivers were a nation, they would rank 7th in the world for carbon emissions.

SUVs are bigger, they are heavier, and their aerodynamics are poor.  As a result, it takes more gas to drive them.  They started to become popular in the 1980s – mostly in American suburbia – but now they have become globally popular.

The demand for SUVs is thought to be driven by perceptions of heightened safety or increased social status.  There is also the marketing and business strategy of manufacturers who obtain larger profit margins in the SUV segment.  Of course, for at least some consumers, the utility aspects of sport utility vehicles are actually important and not just the status.

For whatever reasons, SUVs are likely to be extremely popular for the foreseeable future as demand for sedans continues to decline.  Fortunately, electric SUVs are beginning to enter the market – including next year’s mass-market priced Tesla Model Y.  Such cars are the best solution to emissions from SUVs.

**********

Web Links

Demand for SUVs a Major Contributor to the Increase in Global CO2 Emissions

Photo, posted May 9, 2017, courtesy of Yonkers Honda via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Potential For Offshore Wind

By Leave a Comment

According to a new report from the International Energy Agency, offshore wind technology has vast potential for meeting our energy needs.  In total, offshore wind has the potential to generate more than 420,000 terawatt-hours of electricity each year, which is more than 18 times the global electricity demand that exists today.

Based on current policy targets and plummeting technology costs, offshore wind could increase 15-fold by 2040, becoming a $1 trillion industry and eliminating 5 to 7 billion tons of carbon dioxide emissions annually.

Offshore wind today generates just 0.3% of the world’s electricity, but its’ use is growing rapidly.  The industry has grown nearly 30% a year since 2010, and 150 new offshore projects are currently in development around the world.  The leading countries are in Europe – especially in the UK, Germany, and Denmark – but China is greatly expanding its offshore capacity and the US, India, Korea, Japan, and Canada are also expected to make large investments in offshore wind going forward.

Offshore wind is in a category of its own because it is considered a variable baseload power generation technology.  This is because the hourly variability of offshore wind is much lower than solar power or onshore wind.  Offshore wind typically fluctuates far less from hour-to-hour than the other variable energy sources.

Technology improvements and industry growth are driving steep cost reductions for offshore wind.  The cost of offshore wind is expected to be cut in half in the next five years, dropping to $60 per megawatt-hour, which is on par with solar and onshore wind and cheaper than new natural gas-fired capacity in Europe.

**********

Web Links

Offshore Wind Has the Potential to Fulfill Global Electricity Demand 18 Times Over

Photo, posted August 9, 2016, courtesy of Lars Plougmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Safe And Simple Hydrogen Peroxide

By Leave a Comment

We don’t think about hydrogen peroxide very often.  Perhaps we have a bottle of it under our bathroom sink that we haven’t touched in a few years.   But it is an important product manufactured in the millions of tons each year and the basis of a $6 billion global business.

Hydrogen peroxide is widely used as an antiseptic, a detergent, in cosmetics, as a bleaching agent, in water purification, and in many other applications.  It is produced in industrial concentrations of up to 60% in solution with water in order to maximize the economics of transportation.  This makes transportation hazardous and costly because the concentrated form is unstable.  Most applications use a far more diluted form.

Researchers at Rice University have developed a new method for producing hydrogen peroxide that is much simpler and safer than the current technology, which actually dates back to the 1930s.  The Rice technique requires only air, water and electricity to produce the chemical.  The electrosynthesis process, which is detailed in the journal Science, uses an oxidized carbon nanoparticle-based catalyst.

The process could enable point-of-use production of pure hydrogen peroxide solutions, which would eliminate the need to transport the hazardous concentrated chemical.  The use of a solid electrolyte instead of the traditional liquid electrolyte eliminates the need for product separation or purification that is part of the current technology.

In the future, instead of storing containers of hydrogen peroxide, hospitals that use it as a disinfectant could turn on a spigot and get, for example a 3% solution on demand.  Instead of storing chemicals to disinfect swimming pool water, future homeowners could flick a switch and turn on their peroxide reactor to clean their pools.

**********

Web Links

Water + air + electricity = hydrogen peroxide

Photo, posted April 19, 2009, courtesy of Robert Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Predicting Lightning Strikes

By Leave a Comment

Lightning is one of the most unpredictable phenomena in nature.  Approximately 100 lightning bolts strike earth’s surface every second, and each lightning bolt can contain up to one billion volts of electricity.  Lightning regularly kills both people and animals and sets homes and forests on fire.  It’s also been known to ground airplanes. 

Researchers at EPFL – a research institute and university in Switzerland – have developed a novel way to predict where and when lightning will strike.  The system relies on a combination of standard data from weather stations and artificial intelligence to predict lightning strikes to the nearest 10 to 30 minutes and within a radius of less than 20 miles.  The simple and inexpensive system was outlined in a research paper recently published in Climate and Atmospheric Science, a Nature partner journal.   

According to researchers, the current systems for predicting lightning strikes are slow, expensive, and complex, relying on external data acquired by satellite and radar.  The new inexpensive system from EPFL uses real time data that can be obtained from any weather station, meaning it can cover remote regions that are out of radar and satellite range and where communication networks are lacking.  The quick predictions from the system allow alerts to be issued before a storm has even formed. 

The system uses a machine-learning algorithm that’s been trained to recognize conditions that lead to lightning.  The researchers took into account atmospheric pressure, air temperature, relative humidity, and wind speed, among other things.  After training the algorithm, the system was able to predict lightning strikes accurately nearly 80% of the time.

This system is a simple way to predict a complex phenomenon. 

**********

Web Links

Using AI to predict where and when lightning will strike

Photo, posted December 14, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Dams Restores Ecosystems

By 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.

**********

Web Links

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.

Compressed Air Energy Storage

By Leave a Comment

The increasing use of solar and wind power has created a growing need for technology to store up the energy they generate for use when it is most needed.

Historically, pumped hydropower has provided the largest amount of storage capacity, but it is limited to only certain geographic locations.   Battery energy storage has been growing rapidly, with the technology becoming better and cheaper over time.  But there are various other ways to store energy that have potential and may well find their place in the changing energy infrastructure.

One of these is compressed air energy storage, which has been around for more than a century.  It has been used as a backup method for restarting power plants.  But to date, the economic viability of using it at a large scale has been lacking.

A Canadian startup company called Hydrostor is developing compressed air energy storage technology that it believes can be used on a utility scale.

The way it works is excess renewable energy is used to run compressors that compress air.  Compressing the air heats it up and the heat is captured and stored in insulated hot water tanks.  The compressed gas is then injected into underground caverns.  When energy is needed, the compressed air is released, the stored heat is added, and the warmed gas is run through turbines to generate electricity.  Additional features improve the system’s efficiency.

Hydrostore has built a 1 MW pilot project in Ontario, Canada and is now commissioning a 2MW system as well.  It is funded to build a 5 MW system in Australia next year and it is bidding for 300 MW and 500 MW systems in North America.  The company has received equity funding from Baker Hughes, a large oil-and-gas services and equipment company.

**********

Web Links

Storing energy in compressed air could finally become cheap enough for the big time

Photo courtesy of Hydrostor.

Earth Wise is a production of WAMC Northeast Public Radio.

Other Ways To Cut Vehicle Emissions

By Leave a Comment

It is pretty clear that the way to drastically reduce vehicle greenhouse gas emissions is to switch as many vehicles as possible to electric power.  As a result, more and more localities are putting in place policies that encourage electrification.

While there is no doubt that electrification is the long-term solution to vehicle emissions, a recent study by MIT and the Ford Motor Company found that, in the short term, there are some places in the US where electric cars are not the best way to reduce emissions.

The study looked at a variety of factors that affect the relative performance of vehicles.  These include the role of low temperatures in reducing battery performance, regional differences in the average number of miles driven annually, and significant differences in the way electricity is generated in different parts of the US.

The results showed that electric vehicles definitely provide the greatest impact in reducing greenhouse gas emissions for most of the country – and particularly on both coasts and in the south – but that there are some places in the upper Midwest where the greatest reduction would be achieved by the use of lightweight gasoline-powered vehicles.

In places like parts of Wisconsin and Michigan, it is mostly rural, there are cold winters, and electricity is predominantly generated by coal-powered plants.  In these places, if gas-powered lightweight cars were to be used, the overall benefit would be greater than that of electric cars.  Unfortunately, there are no high-volume lightweight gasoline-powered mid-sized cars on the market in the US.  Ironically, the only cars of that class using lightweight aluminum construction are Teslas.

While electric cars are truly the long-term solution, the study does demonstrate the benefits of reducing the weight of vehicles.

**********

Web Links

What’s the best way to cut vehicle greenhouse-gas emissions?

Photo, posted February 9, 2018, courtesy of Dave Field via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar-Powered Desalination

By Leave a Comment

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.

**********

Web Links

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.

Agrivoltaics

By Leave a Comment

A new study by Oregon State University has found that the most productive places on Earth for solar power are farmlands.   In fact, if less than 1% of agricultural land was converted to solar panels, it would be sufficient to fulfill global electricity demand.

The concept of co-developing the same area of land for both solar photovoltaic power and conventional agriculture is known as agrivoltaics.

The synergy between agriculture and solar power is not surprising.   People have been growing crops around the planet for at least 8,000 years and, long ago, farmers found the best places to grow them which turn out to also the best places to harvest solar energy.  The needs for solar panels are pretty similar to those of food crops.  The efficiency of the panels decreases if they get too hot.  Barren land is hotter than cropland, so the productivity of solar panels is less in such places.

The Oregon State Study analyzed power production data collected by Tesla, which had installed five large grid-tied, ground-mounted solar electric arrays owned by Oregon State.  The researchers monitored air temperature, relative humidity, wind speed, wind direction, soil moisture, and incoming solar energy.  With the data, they developed a model for the best conditions for solar panel productivity and they coincide with excellent conditions for agriculture.  Solar panels are kind of like people with regard to the weather:  they are happier when it is cool and breezy and dry.

Previously-published research shows that solar panels actually increase crop yields on pasture or agricultural fields.

These new results have implications for the current practice of constructing large solar arrays in deserts.  Agricultural lands may be a much better option for both solar production and crop production.

**********

Web Links

Installing solar panels on agricultural lands maximizes their efficiency, new study shows

Photo, posted April 20, 2011, courtesy of U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Solar Fuel Farms

By 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.

**********

Web Links

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.

New York Offshore Wind

By Leave a Comment

New York has passed ambitious legislation to reduce the carbon emissions that cause climate change, but the state needs to start taking action to make those reductions possible.  One such action it has taken is an agreement that will enable the construction of two large offshore wind projects.

The projects are to be built off the coast of Long Island.  One will be 14 miles south of Jones Beach and the other 30 miles north of Montauk.  The wind farms will be built by a division of Equinor, a major Danish energy company, and a joint venture between Orsted, another Danish company, and Eversource Energy, an American firm.

The two New York wind farms are expected to be operational within the next five years and have the capacity to produce 1,700 megawatts of electricity.  That is about 20% of Governor Andrew Cuomo’s overall goal for offshore wind.

Wind farms are a major energy source in the United States, now providing about 7% of the country’s electricity.  That compares with only 2% in 2010. But nearly all American wind turbines are on land.  There is only one small offshore wind farm in the US off the coast of Rhode Island.  Things are very different in Europe.  For example, Britain expects to get 10% of its electricity from offshore wind next year, which is up from less than 1% in 2010.

Developers of offshore wind farms have struggled to gain a foothold in the US.  Some projects have foundered because of cost issues, but others have faced opposition from politicians and coastal-property owners.  But assuming the New York wind projects clear permitting and environmental hurdles, offshore wind may finally be on the move in the US.

**********

Web Links

New York Awards Offshore Wind Contracts in Bid to Reduce Emissions

Photo, posted May 22, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Solar-Powered Airport

By 1 Comment

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.

**********

Web Links

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.

The Largest Offshore Wind Farm

By 1 Comment

The world’s largest offshore wind farm recently began operations in the North Sea, a notoriously gusty stretch of open water that has become home to multiple large wind farms.  The new Hornsea One wind farm is located 75 miles off the east coast of Yorkshire in the United Kingdom.

The first 50 turbines are now in operation and are generating electricity for up to 287,000 homes.  When the farm is completed sometime next year, it will have 174 turbines with a total capacity of 1.2 gigawatts, enough to power a million homes.  The farm will send electricity to the UK, Netherlands, Belgium, Germany, and Scandinavia.  The Hornsea One farm will have more than twice the capacity of the current largest offshore operation, which is also in the UK.

Because the farm is so far from shore, teams of workers will live at sea for two to four weeks at a time maintaining it.  Such operations are unprecedented and required new ways of operating to overcome the logistical and technical challenges of operating a massive power station far from land.

The UK has the largest offshore wind generating capacity in Europe, now more than 8.2 gigawatts and accounting for 44% of Europe’s offshore wind capacity.  All that capacity is one of the big reasons that the UK has been successfully weaning itself off of coal for increasingly long periods of time.

Meanwhile, the US continues to lag far behind in offshore wind with a grand total of 0.03 gigawatts of installed capacity.  That situation may be changing after the federal government auctioned off 3 major tracts of ocean late last year that potentially could generate over 4 gigawatts of power if fully developed.

**********

Web Links

The World’s Largest Offshore Wind Farm Just Came Online

Photo credit: Hornsea Project One.

Earth Wise is a production of WAMC Northeast Public Radio.

Capital Region Community Solar

By Leave a Comment

New York’s Capital Region is getting a major new community solar farm.  A community solar farm is a solar power installation whose output is shared by multiple community subscribers who receive credit on their electricity bills for their share of the power produced.  The primary purpose of community solar is to allow members of a community to have the benefits of solar power even if they cannot or prefer not to install solar panels on their own property.

US Light Energy has broken ground on the Sugar Hill Solar Farm, to be located on 40 acres of land on the Sugar-Hill/Sugar-View Farm in Clifton Park.  The 7-megawatt, ground-mounted solar project will include nearly 20,000 solar modules.  When fully operational later this year, the facility is expected to produce more than 8.6 million kilowatt-hours of energy a year.

The farm will be part of New York state’s Community Solar Program, and the electricity it generates can be supplied to customers anywhere in National Grid’s existing distribution system.  Residential and commercial properties in Clifton Park will have 30 days to subscribe before the solar energy generated by the farm is opened to the general public.  Subscribers of community solar farms typically save 10% on their electricity bills.

There are already community solar programs in operation in several Capital Region communities, but this is the first one in the Clifton Park Area.  Apart from providing savings on utility bills, community solar allows consumers to support clean, locally generated power with little or no upfront costs.  Not everyone is in a position to put solar panels on their roof, but community solar is increasingly an option for New York residents.

**********

Web Links

Construction begins on 7-MW community solar farm in New York

Photo, posted March 19, 2012, courtesy of Kate Ausburn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

100% Renewables Does Not Necessarily Mean Carbon-Free

By 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.

**********

Web Links

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

By 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.

**********

Web Links

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.

WAMC Northeast Public Radio

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