Tag Archives for " wind energy "

The Duck Curve, or the Difficulty of 100% Renewable Energy Systems


Why’s it so hard to go to a 100% renewable energy system?

We often hear how renewable energy systems could easily power the world. Just throw up some solar and wind, add some hydro, and voila! we’re running on clean energy.

Unfortunately, though, it’s not that easy. Transferring to 100% renewable energy is fraught with difficulties, Today we’re going to focus on one huge issue with renewable energy: controllability.

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How Much Does Wind Energy Cost?


Comparing the cost of wind energy to the cost of solar energy.

You might’ve heard that, at least for utilities, wind energy is a ridiculously cheap form of electricity – cheaper than any other method. But what if you want to install a small wind turbine on your own property? How much does wind energy cost? Is it a wise financial investment? How about when compared to solar?Continue reading

How to Choose the Best Home Wind Turbine


6 suggestions to help you select the best home wind turbine

Just like with solar, which ranges from huge solar farms to small-scale residential solar installations, you now also have the option of installing the best home wind turbine for your particular situation.

Wind energy has seen a huge popularity increase over the last 10 years, mostly pushed forward by utility-scale wind farms–the rows of giant white wind turbines you’ve seen driving through the desert or plains.

Case in point: in 2016, our total wind capacity in the US equaled 82,000 megawatts. Compare that to our capacity in 2000 of just 2,539 MW and you begin to comprehend how much the industry has grown!Continue reading

What Can We Learn From Samso, the 100% Renewable Island?


Samso is a small island located on the east side of the Danish peninsula.

Home to 3,800 inhabitants, Samso became world famous in 2008 for becoming the first island run on 100% renewable energy. The project initially began in 1997, when Samso won a government competition to produce 100% of their electricity from renewable sources.

Since Samso became 100% renewable, cities, countries and islands across the world have made pledges to also go 100% renewable, including Hawaii, San Diego, and Grand Rapids, Michigan. In fact, several small cities and islands are already 100% renewable, including Aspen, Colorado, and Tokelau, a small island in the South Pacific claimed by New Zealand.Continue reading

China’s Clean Energy Switch Already Slowing Climate Change

Tangshanpeng Wind Farm

What China is doing about energy is already having a measurable effect on global greenhouse gas emissions.

In 2015, the first evidence of the Beijing government’s determination to reduce carbon emissions  may have been seen globally, as it continued an unprecedented increase in carbon-free energy substitutions and cut coal use by a full third in just a year.

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Nationwide HVDC Grid: Cheapest Way to Radically Cut CO2 Emissions?

HVDCA Grid wind

According to a peer-reviewed paper just published at Nature Climate Change; “Future cost-competitive electricity systems and their impact on U.S. CO2 emissions” – the cheapest way to radically cut greenhouse gas emissions from generating electricity by 2030, would be a high-voltage direct current (HVDC) grid connecting America’s prime renewable resources to 256 electricity markets.

The study concludes that electricity prices could remain flat if the US could site projects for maximum generation – unconstrained by the current lack of a national HVDC grid – connecting the best carbon-free resources to load centers.

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Can Oil Companies be Forced to Switch to Clean Energy?


A Danish oil company is bringing the first offshore wind to the US.

DONG Energy is building a massive offshore wind farm 15 miles out to sea south of Martha’s Vineyard. Their humungous 1 GW Bay State Wind project is likely to go ahead while previous attempts at developing offshore wind in the US failed.

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Australia Must Add Nearly 4 GW of Renewables in 2016

solar and wind

Australia’s coal-friendly electric retailers are falling behind targets for renewable energy.

According to the energy markets research firm Green Energy Markets (GEM), Australian utilities will need to sign 3,800 MW of contracts for new renewable energy by the end of 2016, in order to be in compliance with the renewable energy target.

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Sweden Will Be World’s First Clean Energy Powered Nation

Tiny clean energy powered Sweden is already second in the world in wind power per capita.

Sweden has almost 500 MW of wind, split between only 10 million people, so each person has almost half a kilowatt just of wind, if apportioned on a per person basis. For comparison, an average solar roof for a home is from around 2 kilowatts (if a frugal and sunny Australian home) up to about 12 kilowatts  (if an extravagant mansion in cloudy Massachusetts).

China leads the world in total built wind capacity, with some 181 GW as of the end of 2014, with the US in second place with 65 GW. But both these nations obviously have many more inhabitants than tiny Sweden with its ten million.

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Does Solar take More Space than Coal?

golf course

Renewable energy naysayers often raise the objection that renewables – like big solar projects in the deserts and gigantic wind farms on the prairies – just take up too much space and so we shouldn’t have them.

Instead, we should stick to their preferred default for our energy supply – fossil fuels.

In fact, renewable energy takes up less space than even the golf courses that fossil fuel executives love to be pampered on while raking in their billions from carbon combustion.

In a study by the Massachusetts Institute of Technology (MIT),  Future of Solar Energy the authors estimated how much land it would take to power 100% of the US entirely with big solar projects.

To supply 100% of the entire nation’s electricity needs in 2050 with solar, it would take 12,741 square miles. That sounds like a lot! But if the solar were concentrated in the sunniest part of the US where it would make the most sense and be the most efficient – like the deserts of the southwest – then the land use drops to just 4,633 square miles.

Compared to many other things we use land for in the US, including housing us in cities, growing our fruits and veggies from farmland, making all of our electricity from solar on 4,633 square miles is actually not very much land at all. Farms alone span a much greater 700,000 square miles in the US.

A coal mine compared to Ivanpah

Coaldiver.org lets you compare the size of a coal mine to a solar farm. Ivanpah, one of the largest US solar farms is greyed out under the red on the right. Even that huge solar farm is dwarfed by a coal mine in the Powder River Basin. Which won’t even last 30 years – many coal mines are depleted in 12 years.

Even just golf courses; hardly something we all need — unlike homes, and fruits, and veggies, and electricity. Yet just today’s golf courses use nearly as much land as the amount we’d need to power the nation entirely from solar by 2050.

Apparently, we devote about 3,861 square miles of land just to golf courses!

But why would we want to power 100% of our future need with just solar? Most experts agree that we will wind up supplying somewhere between a quarter  and a half of our future power from solar. Splitting that difference and estimating solar needs if we went one-third solar, they come up with around 2,702 square miles for solar.

After all – we have wind in abundance too.

wind farm

According to one study, powering another third of the US on wind energy could take a land area spanning on the order of 23,000 square miles of wind farms.

The MIT study concedes that that is a lot of land, but only twice what we’ve already devastated with coal mining, including mountain top removal. Unlike coal mines, wind farms are safe and healthy places for farming underneath, and are often combined with farms, as in Iowa and Texas.

So really, a wind farm only takes out of use the land needed for wind turbine pads and new access roads for workers to drive to maintain the turbines. That is only about 1% of the average wind farm.  So, 1% of 23,000 square miles is just 230 square miles for one third of our electricity in 2050 from wind power.

Coal uses most

How about coal? Sure, harvesting sunlight takes up land space, but chopping down mountains to harvest the energy from coal actually really uses up even more, because that land is gone for good. And that’s not even counting the average coal power plant size needed to burn all that coal. That’s usually about another square mile each.

Unlike solar and wind farms that don’t use up all the available solar and wind in each solar farm or wind farm, and have to move on to mine more sunlight and breezes elsewhere, coal mines do.

Coal mines must constantly move on once they exhaust each mined area, often in just two to twelve years, and each mined region produces relatively little electricity.

So here we have to compare GWhs generated per acre of harvested land over a period of time of harvesting, whether that is harvesting sunlight or coal.

And here, solar and wind are clear winners, according to Sourcewatch.

Coal will produce 15 GWh per mined acre over 60 years, while the average solar farm will produce 18 GWhs of power per acre, over the same 60 years. Because solar doesn’t have to move on, to harvest sunlight in the space next door the way a coal mine must, because mining depletes all the potential energy from each acre of land as it scoops up its coal.

So, looked at energy generation over time, the land footprint of coal is at least 20% bigger than that of solar.

And that is with solar at its current efficiency. And we know that solar is getting more efficient over time. The more efficient solar becomes, the less space it needs to generate each kilowatt. So a future calculation will be even more favorable to sunshine.

Image credits: via FlickR under CC license