What is investment/outcome ratio for wind energy in terms of energy (EROEI)?

Question

Merchants say that I can have 1 watt of energy per every $1.5 invested. Yet, I have heard from people "from the business" that the installation alone (forget mining the ores and smelting the parts) takes so much energy that the wind will never pay it back. I could not figure out the costs from this huge Wikipedia article at all at all. Can you expose the balance? How much is it different than one?

I see that there is a similar question regarding the Solar Power. It introduces

Energy Returned On (Energy) Invested, also known as EROI and as EROEI. It is calculated by dividing the total energy delivered by the system throughout its whole lifetime, divided by the total energy required to build, operate, maintain (and ideally decommission) the system.

which I also want answered.

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Update

The expert says that EROEI of 18 for the wind

assumes turbine lifespan of 30 years whereas it is 10-20 years indeed, which trims the EROEI at 12. Furthermore, the constant wind is assumed, which is not true and EROEI is only 5.5. Next, dismantling costs reduce EROEI to 3.0. It is not known if concrete production (it is very energy-consuming), used in the basement, is accounted or not.

Is it right correction?

Answer 1

Summary

We typically get about 20-30 times as much energy out as energy in. The range in the literature is wide: 4.6-40.

Overview

The ratio of energy generated to energy invested will vary, depending on a lot of issues.

Here, I'll only consider grid-scale wind power, i.e. turbines of 0.5MW rated capacity upwards. That's because they represent the overwhelming majority (by generated power and by economic value) of existing and of potential installation. The Lifecycle assessments in the references include materials, construction, foundations and decommissioning.

source: (4)

For a case where total energy input is higher (such as offshore wind), and total energy output is low (nearshore, downwind from land), you might get 18 times as much energy generated as put in. But as we only have one commercial offshore wind farm in the world that's reached the end of its design life (Vindeby, built 1991-2), it's still generating electricity (beyond its expected 20-year life), and is quite different to more modern wind farms (a lower-capacity onshore turbine installed very close to shore), these are best estimates.

Lenzen (1) looked at the quality of deployment site, as well as variations in transport and country of manufacture, and found a range of 4.6-40 for a relatively small turbine of 500-600 kW_peak

For cases where total energy input is low (easy onshore wind site), and total energy output is high (no obstructions, few turbines downwind from other turbines, high wind speeds), you might get 40 times as much generated as put in. We don't have many years experience of modern 3MW turbines, so it's unclear whether the lifetime is more likely to be 20 years, or 30. Standard calculations assume 20 years.

Larger turbines make for a lower environmental impact per unit energy generated (2).

Sources

In the literature, you find quite a few references to EPBT, rather than EROEI. EPBT is Energy Pay Back Time: the amount of time, from the start of generation, until the input energy is paid back. As a crude rule of thumb, you can divide this into the expected lifetime to get the ratio of energy out to energy in (EROEI aka EROI).

1. 4.6-40, Capacity factors 18-70% , Lenzen, M. (2004). Wind turbines in Brazil and Germany: an example of geographical variability in life-cycle assessment. Applied Energy, 77(2), 119–130.

2. Caduff, M., Huijbregts, M. a J., Althaus, H.-J., Koehler, A., & Hellweg, S. (2012). Wind power electricity: the bigger the turbine, the greener the electricity? Environmental Science & Technology, 46(9), 4725–33.

3. 21-23 850kW & 3MW, 20-year design-life, capacity factor 33-34% Crawford, R. H. (2009). Life cycle energy and greenhouse emissions analysis of wind turbines and the effect of size on energy yield. Renewable and Sustainable Energy Reviews, 13(9), 2653–2660.

4. 36, 20-year design-life, capacity factor 30%. Vestas (2006). An environmentally friendly investment: Lifecycle Assessment of a V90-3.0 MW onshore wind turbine.

5. 35-36 20-year design-life, onshore capacity factor 30%, offshore 54%. Vestas (2006) Life cycle assessment of offshore and onshore sited wind power plants based on Vestas V90-3.0 MW turbines. 2nd edition.

Answer 2

First - claimed "translation" is not a translation. I said nothing about "constant wind". 2-nd. If you calculate EROEI of standalone wind turbine on the island in the middle of the Pacific ocean, you can get 30 or 40. If you place 100000 of wind turbines into middle of USA and connect them to the grid, you need to take into account that you need to have equivalent reserve capacity provided by the traditional power stations. Big chunk of that reserve should be "hot" as in running at reduced power (meaning much lower fuel efficiency). Rest should be provided by power stations with short cold startup meaning natural gas turbines. Which are 1) expensive and 2) not as efficient as traditional steam turbines. Denmark is extremely lucky in this respect - they can use hydro power from Sweden and Norway and don't have to have reserve capacity.

Another concern is dismantling costs. (you remember 14000 abandoned broken turbines in California?) You need to get crane big enough to the "big" wind turbine. Then you need to work for 3 days to 4 weeks, as you need low wind conditions in high wind area to operate crane reaching to 100-150m and capable of lifting 75-100 tonnes. Then there are additional costs of experienced workers to do the dismantling at 150m off the ground. Resulting cost of just getting generator from the top of the mast will easily reach $1M. So just to pay for it's dismantling 2MW turbine needs to work for more than 7 years out of its 20 years of the lifetime. Yes, then if you are lucky you can reuse foundation (1000+ tonnes of reinforced concrete) and mast (150 tonnes of steel). Or you will need to remove them too. If you add recycling of the turbine, foundation and mast you probably will need additional funding over what turbine earned during it's lifetime. (you remember 14000 of abandoned turbines? They never earned enough to even pay for proper maintenance!)

Adding the fact that EROEI for turbines is usually based on 30 years at utilization greater than 0.3, while actual turbine life is less than 20 years and actually closer to 15 years, and actual average utilization is under 0.2, just this two things drop the EROEI of wind turbines from 18 to 6. Add reserve grid capacity and you will be lucky to get over 1. Add dismantling - and you will be firmly under 1.

I understand that probably there are some factors I don't know regarding wind turbines. So there could be mistakes in my calculations. But still even if any one of the angles proves to be reasonable - wind power EROEI is greatly exaggerated.

PS: Just couple of weeks ago one of the biggest wind farm operators in Europe announced that they are not able to pay their investors: http://laroucheirishbrigade.com/2014/01/24/germanys-biggest-wind-energy-operator-goes-bust/

Yes, I'm an author of that LJ post. Regarding parts that are not EROEI - They actually should be accounted for in EROEI. You need to spend lots of energy to build crane capable of lifting 100 tonnes to 100 meters. You need to spend lots of energy to build fleet of concrete mixers capable to deliver 1000+ tonnes of concrete to the remote mountain. Add concrete pumps, rebar, fuel, new roads to remote mountains, and all of the building machines required to comission wind turbine. It all will come to loads of energy. There is no easy direct way to account for that energy. But it could be roughly estimated from the monetary cost. As money are a common denominator for everything. So we can try to convert money into energy. 20 to 30% of price goes to profits. 40 to 50% goes into taxes. Rest we can divide by price of kWh and get rough total energy estimate. So 1000 USD which is usual price for tonn of steel will come to be roughly equivalent to more than 5000 kWh of electrical energy @ $0.04 per kWh.

All of the estimates and calculations were done by me based on numbers from Wikipedia or from the links on the first page of Google search. I'm not paid to do this research so I can't spend thousands of dollars to purchase original scientific studies that can contain any additional substantiation for my estimates.

PS. Just in case, I've designed power and cooling for couple of the supercomputers that are still present in the Top500.org list after several years. So my estimates tend to be accurate enough most of the time...

PPS. I don't understand how comment/answer system works on this site. So probably in couple of days I will forget this discussion.

PPPS. To add to this answer/discussion I would say that many of the links provided in other answers show data "aquired" by wind turbine manufacturers. I was unable so far to find actual raw data on what is the actual price of wind turbine per mW of capacity? What is actual price of wind turbine installation per MW of capacity? PPPPS. Don't forget that sustainability is not only about fossil fuels. (it is still unproven that crude oil is fossil fuel...) Sustainability is also about if you actually can provide more "sustainable" energy than is available by other means.