Thought 1 of 6: Offshore wind: false launch, or refocus ?

It is peculiar how the wind industry, originally launched to address independency, depletion and emissions, now encounters only one issue: Cost.

Without any debate this fourth issue can be accomodated by wind energy as well when all costs involved are taken into account.

Not only less tangible cost like health care etcetera, but certainly pollution cleaning operations (Exxon Valdez) and repairs to cracks in walls in areas of gas mining need to be added.

Groningen; The Netherlands. Gas exploitation causes the earth to quake.
Source: Gerdt van Hofslot

Thought 2 of 6: One wind turbine generator suffices for a whole village

One reasonable turbine provides sufficient electricity for all houses in a village with 8000 inhabitants.

One village of 8000 inhabitants has 2600 households.
On average a household uses 3600 kWh per year, which causes a village demand for electricity of 2600 x 3600 / 1000 = 9.360 MWh per year

One Turbine of 3.7 MW provides 3,7 MW working 30% of the available time; which is 30% x 24 hrs x 365 days each year. This includes maintenance and, more importantly, lack of wind.
Thus the supply equals: 3,7 x 30% x 24 x 365 = 9.723 MWh per year

If only we could store excess energy generated for use on a wind-less day.

Thought 3 of 6: Turbine growth

And you believe it stops here?

Thought 4 of 6: Foundation demand grows exponentially

The resistance required from the foundations for modern Wind Turbine Generators is growing exponentially.

Wind turbine generator capacity has grown from 2 Megawatt in 2000 to 8 Megawatt in 2016.

  • Assume for simplicity that a factor of 4 in MW growth equals the same amount in horizontal force
  • Windparks are situated farther off the coast, in more windy areas . At these sites the water is deeper, which causes a larger overturning moment at the seabed.
  • Larger turbines have longer blades. As the distance from the lowest blade-tip to sea level has to be maintained, this causes the tower to be higher again causing greater foundation loading.

To visualize the cumulative effect, I introduce a simplified measure for the resistance demanded from the foundation of a wind turbine generator as follows:

MFD = Cap x ( Wtd + Bl + A )

Overturning moment at Seabed level in MegaWatt meter
Cap MW
Wind Turbine Capacity
Wtd m
Water Depth
Bl m
Blade Length
A m
Additional meters, including clearance to Seawater level, half the Nacelle etcetera

Foundation demand in MWm

The demand starts exceeding the capacity of monopiles. Next, jackets and gravity based foundations will be required.

Thought 5 of 6 – Speech by H.M. King Willem-Alexander at the trilateral energy meeting Offshore Wind, Hamburg

March 19, 2015
You are exploring practical possibilities for future cooperation. We all know why we need each other. After all, we all want the same thing: the certainty of sufficient energy supplies in the longer term, with less negative impact on the environment and the climate. And all for a reasonable price, of course. That’s why we’re here.

read more…

Thought 6 of 6 – Sjeikh Yamani says

Sheikh Yamani, former Saudi Arabia’s oil minister, in an interview:
(The Telegraph; Mary Fagan, 25 Jun 2000 / Gyles Brandreth,)

“The Stone Age came to an end, not because we had a lack of stones, and the oil age will come to an end not because we have a lack of oil.”

15 years later, wind turbines give signs of an energy transition, both in rural fields as well as in the heart of the oil and gas industry.
Photo: Botlek area, Rotterdam.