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Member since: Thu Feb 28, 2008, 10:49 AM
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Replacing A Coal Plant Takes An Infinite Number Of Wind Turbines

Hate to spoil the article but this is why it takes an infinite number of windmills...

Coal generation also produces 84 kg of coal ash per MWh, so that coal plant produces about 265,000 tons of it a year. Wind generation doesn’t produce any coal ash, or indeed anything like it, so an infinite number of wind turbines would be required.

From the start...

Coal is going away. What will it take to replace all of the things it provides us with? An infinite number of wind turbines would be required to replace everything a coal plant gives us.

If it was just the electricity, only 120 to 350 modern wind turbines would be required, but that’s just the start.

These are averages and capacity factor-based. It’s an approximation. Capacity factor is the percentage of a year’s potential maximum generation that is actually achieved. If a generation unit could generate 100 MWh but actually generates 70 MWh — that’s a capacity factor of 70%. It’s based on a demand, market conditions, supply, maintenance, and the like.

As coal plants are shutting down, they’ve also been dropping in capacity factor, and now have an average of under 50%. We’ll use 50% as our capacity factor for coal.

In 2016, there were 381 coal plants with just under 800 generating units. The average coal plant was running around 720 MW of capacity. We’ll use 720 MW of capacity for coal as the basis.

720 MW of capacity running 24/7/365 with a capacity factor of 50% would generate about 3.15 TWh of electricity in a year.

The average capacity factor for modern wind turbines in the US is 41.9%. The average size of new wind turbines in the USA is 2.43 MW in capacity.

The first question is how many wind turbines would be required to generated 3.15 TWh of electricity.

3.15 TWh divided by 2.43 MW capacity divided by 24 hours divided by 365 days divided by a capacity factor of 41.9% gives us about 353 wind turbines.

So the first answer is that just over 350 wind turbines are required to replace a coal generation plant which likely has 2–3 generating units. That means that about 120–175 wind turbines are required to replace a single generating unit.

So far, so good. But coal plants do more than provide electricity. What else do they provide, and can wind turbines provide that too?

edited to add link to article - https://cleantechnica.com/2020/11/27/replacing-a-coal-plant-takes-an-infinite-number-of-wind-turbines/

The world's best solar power schemes now offer the "cheapest...electricity in history"

From IEA report

The world’s best solar power schemes now offer the “cheapest…electricity in history” with the technology cheaper than coal and gas in most major countries.

That is according to the International Energy Agency’s World Energy Outlook 2020. The 464-page outlook, published today by the IEA, also outlines the “extraordinarily turbulent” impact of coronavirus and the “highly uncertain” future of global energy use over the next two decades.

Reflecting this uncertainty, this year’s version of the highly influential annual outlook offers four “pathways” to 2040, all of which see a major rise in renewables. The IEA’s main scenario has 43% more solar output by 2040 than it expected in 2018, partly due to detailed new analysis showing that solar power is 20-50% cheaper than thought.

Despite a more rapid rise for renewables and a “structural” decline for coal, the IEA says it is too soon to declare a peak in global oil use, unless there is stronger climate action. Similarly, it says demand for gas could rise 30% by 2040, unless the policy response to global warming steps up.

This means that, while global CO2 emissions have effectively peaked, they are “far from the immediate peak and decline” needed to stabilise the climate. The IEA says achieving net-zero emissions will require “unprecedented” efforts from every part of the global economy, not just the power sector.

For the first time, the IEA includes detailed modeling of a 1.5C pathway that reaches global net-zero CO2 emissions by 2050. It says individual behaviour change, such as working from home “three days a week”, would play an “essential” role in reaching this new “net-zero emissions by 2050 case” (NZE2050).


After Scotland Tour, Maine Hatches Offshore Floating Wind Turbines Plot

Floating windmills and green hydrogen

After Scotland Tour, Maine Hatches Offshore Floating Wind Turbines Plot

For those of you new to the topic, floating wind turbines are designed for water that is too deep for conventional platform construction. The US got a head start on floating wind turbine R&D during the Obama administration, but things stalled out after that.

Aside from political obstacles and potential conflicts with maritime commerce, floating wind turbines pose unique engineering challenges, which is why they have been popping up in some parts of the world but not others.

That leads to Maine, which has some of the deepest and most challenging waters for wind turbines, but also boasts sustained offshore wind speeds that are among the best in the world. According to one estimate, the state’s offshore wind resources could meet its existing electricity demand 36 times over.

With an eye on that prize, Maine policy makers have been supporting a public-private research collaboration through the University of Maine and a firm called Maine Aqua Ventus, which got an assist from the US Department of Energy back in 2015. That was quite an achievement, considering then-governor Paul LePage’s opposition to renewable energy development.

Last December CleanTechnica noted that Maine is already chock full of renewable energy, which leads one to question why should they take a risky bet on the as-yet untried floating wind turbine area.

Part of the answer may lie in that Scottish wind industry tour. Scotland has begun to leverage its powerful offshore wind industry to produce green hydrogen, and Maine has been eyeballing green hydrogen as a way to deliver more clean kilowatts despite some bottlenecks in its existing transmission system.

Just to spice the green hydrogen angle up a bit, Mitsubishi is involved in the Maine project, having acquired the newly dubbed firm New England Aqua Ventus through a joint venture with its Mitsubishi Renewables Diamond Offshore Wind subsidiary and the firm RWE Renewables. Mitsubishi is making a hard pivot into green hydrogen, so it will be interesting to see where that fits into Maine’s floating wind turbine scheme.

State policy makers may also be looking to position Maine’s offshore wind resources for energy export, deploying green hydrogen. Decarbonizing the state’s fishing industry could also be on the to-do list, considering recent activity in the hydrogen fuel cell watercraft field.


New record for a windmill

While a solar panel in a utility scale solar farm isn't much different than the one on my roof, windmills are quite different.

As the diameter of the blades doubles, the output is quadrupled. That is why they keep getting bigger.

GE Renewables has scored a new record with its Haliade-X offshore wind turbine prototype in the Netherlands, producing 312 megawatt-hours of electricity in a 24-hour period.

One spin of the turbine is enough to power a UK household for more than two days, said GE Renewable Energy.

The previous record was 288MWh in a single day, from the turbine following its uprating to 13MW.
The turbine features 107-metre long blades and a 220-metre rotor and will be able to generate 4% more annual energy production than the previous 12MW version of the prototype.

The blades, produced at LM Wind Power’s Cherbourg factory in France recently received component certification from TUV Nord.


Nashville enters into plan to build 100 MW Solar farm

Cincinnati has a similar plan in the works. With as much electricity as the Federal govt uses shouldn't this be a way to combat Climate Change? Best part, it saves money long term (utility rate creep) and doesn't require large spending bills getting thru Congress.

Nashville Mayor John Cooper’s administration has entered a partnership with Nashville Electric Service (NES), the Tennessee Valley Authority (TVA) and Vanderbilt University to construct 100 MW of utility-scale solar power under the TVA Green Invest program.

Vanderbilt will be a 25 MW co-subscriber to the solar array, thereby reaching their own 100% renewable-energy goal for campus operations. Metro-Nashville will be the first local government to pursue access to Green Invest in TVA territory.

On Metro’s and Vanderbilt’s behalf, TVA will contract with Nashville-based Silicon Ranch Corp. to build a solar array in Tullahoma, Tenn. Silicon Ranch pioneered utility-scale solar power in the Tennessee Valley and is one of the largest independent solar power producers in the U.S. The company was selected through TVA’s 2020 competitive procurement process for construction of up to 200 MW of solar power on the Tullahoma site. There will be no fiscal impact on Metro’s operating budget until the fall of 2023 when construction of the array is expected to be complete.

“Not only will 100 MW of solar power help mitigate a changing climate by affordably and efficiently meeting Metro’s 2025 clean-energy goal, it also puts Tennesseans to work and provides cleaner air during a pandemic characterized by respiratory distress,” says Cooper. “This public-private partnership will serve as a model for NES’s other large customers to replicate. I challenge Nashville’s corporate sector and major institutions to consider TVA Green Invest as a smart way to prepare for what must be a greener future.”

Metro’s 100 MW of solar power will produce the clean-electricity with a 20-year power purchase agreement. By reducing harmful air pollution, Metro’s and Vanderbilt’s combined 125 MW of solar energy will result in $3 to $6.8 million dollars of health benefits across Tennessee. Silicon Ranch Corp. estimates the construction of the array will create 500 jobs.

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