Why wind energy is not the answer to a renewable energy future

Wind power is not the answer to energy demands.

Panel on Climate Change (IPCC) published its report on renewable energy on 8 October, the main conclusion warning the nations of the world of the importance of an immediate reduction in greenhouse gas emissions to avoid catastrophic climate change. The report emphasised the “rapid deployment of renewable energy such as solar and wind” and largely ignores the essential role that nuclear power should play in decarbonisation. The whole report ignores a fundamental truth: energy policy and land use are insoluble. The proposers, who are only renewable, have no problem mobilising against land use for the extraction of hydrocarbons.

Less optimistic were the Harvard researchers

Four days earlier, far less favourable, two Harvard researchers published an article showing that wind and renewables in an energy-intensive society with only renewable energy would require vast amounts of land. For example, current demand for electricity in the United States (not including gasoline, fuel, and natural gas as for space heating and fertiliser production) will cover an area twice the size of California with wind turbines.

Wind energy has a much lower power density than previously thought.

The study by Harvard researchers published in Environmental Research Letters shows the Achilles heel of wind energy is remarkably low power density. “The results show that the average power density (the rate of energy production divided by the total area of wind power plants) – is up to a hundred times lower than estimates. Estimates provided by leading energy experts,” said lead author Dr Lee Miller, co-author of Harvard physics professor David Keith. The problem is that most estimates of the potential for wind energy ignore “wind shadow”. It is an effect that occurs when turbines are placed too close together: the wind turbines rob the wind speed of the other turbines.

“If your perspective is the next 10 years, wind power actually has in some respects more climate impact than coal or gas. If your perspective is the next thousand years, then wind power has enormously less climatic impact than coal or gas.” David Keith

The study used real data, not estimate models.

The study by Harvard is based on US energy production data 2016 and included 1150 solar power and 411 wind power projects on land. The total capacity of the wind projects was 43,000 megawatts, which is equivalent to half of all US wind capacity in 2016. Miller and Keith concluded that solar panels produce about ten times more energy per unit of land than wind turbines – a significant discovery. But the two most important reasons the survey uses real data, not models. The latter shows that the power density of wind power is far lower than the US Department of Energy, IPCC, and many academics have previously claimed.

The new 700-meter-high turbines without increased efficiency

Although improved wind turbine design and location have increased capacity factors (as well as lower costs), it has not changed the power density. The industry has not increased the efficiency of turbines; they are only more extensive; the latest turbines are more than 700 meters high but not more efficient. Due to the wind shadow effect, the higher turbines placed further and further apart, which means that the giant turbines cover more land. When turbines get taller and spread across the landscape, they are far more visible. And the sound from the turbines is at a level where the residents can incur severe hearing damage.

What about biocapacity?

What is available of biocapacity (biological capacity) is a term used to describe the total usable physical production capacity each year of a biologically productive area, for example, one country. The criterion for biological production is the area of land and sea with significant photosynthetic activity and production of biomass, except marginal areas with vegetation and non-productive areas.

Earth Productive landmass

There are 11.3 billion global hectares of biologically productive land and sea space on the planet. The remaining three-quarters of the earth’s surface, including deserts, ice caps and deep seas, support relatively low levels of bio-productivity that are too scattered to be harvested. It is at the expense of food production and textile production, not accounted when plans presented.

Although food production is more efficient, the disadvantages of chemical pesticides and fertilisers that poison the basis for cleaner food production worldwide rarely discussed. In India alone, 250,000 agricultural workers commit suicide due to damage from chemicals used in agriculture each year. Agriculture uses chemical pesticides that harm animals and humans. These chemicals have strong carbon bonds that continue to work long after use. The soil cleaned through rainwater and since chemicals continuously used, the water is unable to remove toxins found in food production. More than 40 million people die each year from diseases caused by chemicals that over time cause chronic conditions such as cancer.

What about recycling wind power materials?

Most of a turbine can be recycled or used for other wind farms, though, and researchers estimate that the United States will have more than 720,000 tons of turbine material to dispose of over the next 20 years. This figure does not include newer and higher versions. There are no good alternatives for recycling turbine blades, and the existing ones are expensive when the industry is also relatively new. A waste problem contradicts the attitude of previous environmentalists.

Short-term profit

It is about short-term gain that is controlled by an energy industry that is eventually called Big Wind, lobbying and corruption are well known. The slogan wind energy a beautiful source of “clean” energy. The reality is that the expansion of wind energy driven by government subsidies and mandates at the government level. Wind energy cannot and will not meet a significant part of the energy needs of the future because it requires too much land. Miller and Keith’s research shows that the goal of 100 per cent renewable energy, and especially the idea of wind energy as a significant contributor to achieving the goal, is a dead end. 

What about wind compared to other forms of renewable energy?

? Heath and colleagues at DOE’s Brookhaven National Laboratory calculations of carbon footprints for various renewable energy sources shown in the table below.

Solar power

• For example, solar power varied from 14 to 45 g CO2 / kWh, depending on the type of material used. For example, thin-film solar cells recycled into shingles, glass for skylights and other building materials – have a smaller carbon footprint than photovoltaic silicon cells used in commercial energy production.

Geothermal

• The footprint of geothermal energy is similar to solar energy and varied from 11.3 to 47 g CO2 / kWh, depending on the technology used, Heath believes. Geothermal energy involves capturing heat from the earth to turn turbines that produce electricity.

Bioenergy

• Heath also mentions that the biopower – which comes from the combustion of organic materials, such as wood, landfill materials or ethanol – had a carbon footprint of around 43 g CO2 / kWh.

Water and wave power

• The best option is hydropower, and offshore power produces the lowest amount of emissions at 7 and 8 g CO2 / kWh, respectively, according to Heath. Hydropower created from moving water, often from rivers. Ocean power produces electricity from tides, waves, currents, heat and even salinity in the oceans.

Type and Energy Carbon emissions (g CO2 / kWh)

• Wind energy 11
• Coal energy 980
• Natural gas 465
• Nuclear energy 12
• Solar energy 14 – 45
• Hydro energy 7
• Ocean energy 8
• Geothermal energy 11.3 – 47
• Biomass energy 43

All numbers median or midpoint estimates, for each energy type. It explains that each wind turbine, dam or coal plant will not have the same carbon footprint, but the figures mentioned above are representative for comparison purposes. Source: Research from NREL and BN

Sources

• Harvard Study published David Keith, Observation-based solar and wind power capacity factors and power densities Gordon McKay Professor of Applied Physics at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and senior author of the papers.
• Facts and numbers Harvard study PDF
• Harvard Gazette
• Research from NREL and BNL Elvisier publishing
• Biocapacity
• Bioproductivity
• Pesticides
• Toxicology