[source] 350-mile dedicated power line will connect a substation at the wind farm with a substation near Tulsa to deliver the wind energy to customers.
Will be the largest in the US and 2nd largest in the world. Invenergy will cooperate with General Electric on The Wind Catcher project and install 800 GE 2.5 MW turbines. Operational mid-2020. Cost: $4.5 billion, including 350 miles of dedicated, extra-high-voltage power lines.
[invenergyllc.com] – Invenergy and GE Renewable Energy Announce America’s Largest Wind Farm
Article discusses the question whether storage should be part of EROI considerations and calculations. Take-away points:
1. A shift from an electrical system based mostly on energy stocks (with built-in energy storage function) to one based mostly on natural flows (with the construction of storage devices required to ensure large-scale availability) will probably be constrained by the energetic demands of the VRE-storage subsystem. Or in other words, high penetration of VRE will require the large-scale deployment of storage solutions, but there might be biophysical limits to how much storage can be deployed if the energy system is to remain viable.
2. Lithium-ion batteries, which are the fastest growing form of electrical storage today and are increasingly being touted as capable of supporting the energy transition to renewables, could probably only usefully contribute a short-term role to buffering VRE. The energetic productivity/EROI of an energy system reliant on lithium-ion batteries (and other similar electro-chemical storage devices) would indeed rapidly fall below the minimum useful EROI for society. The energetic requirements of pumped hydro storage, on the other hand, are sufficiently low to enable a greater displacement of conventional generation capacity and penetration of VRE, but wide scale deployment is dependent upon regional topography and water availability.
3. Storage technologies that would enable a full displacement of conventional generation capacity and 100% penetration of VRE at the current system reliability level are, as of today, unavailable. New storage solutions may emerge as a result of current and future research activities, but in order to assess their potential it will be necessary evaluate their energetic performances within the VRE-storage subsystem, all along the energy transition pathway. Only if these performances are markedly superior to existing technologies will storage potentially constitute the ‘holy grail’ of the energy transition that many expect.
VRE = Variable Renewable Energy.
EROI/EROEI = Energy Return On (Energy) Investment
[biophyseco.org] – Storage is the ‘Holy Grail’ of the Energy Transition – or is it?
There is a lot of confusion about the real value of the EROI of wind energy. Time for a back-of-an-envelope calculation.
By far the largest energy input in the construction of a wind turbine from iron ore is realized in the steel mill. How much energy does it take to produce 1 ton of steel? Here is an old Dutch study (1986) from the Energie Centrum Nederland:
[ecn.nl] – Energy Consumption For Steel Production
On p20 we see that the lowest value for steel production is ca 20 GJ/ton or 5555 kWh/ton. We can safely assume that in 2017 the amount of energy required is lower, but we will accept this figure anyway to be on the prudent conservative side.
A 6 MW offshore wind turbine has roughly the following weight distribution:
Energy cost for the steel production: 3300 * 5555 = 18331500 kWh
In the North Sea this 6 MW wind turbine on average produces 144,000 kWh/day, see:
[deepresource] – Gold Mine North Sea
Payback time in energy terms therefore is: 18331500/144000 = 127 days
There are of course extra energy costs. Say you need to get the iron ore from Australia, the worst case in transport energy terms, from a Dutch perspective.
[withouthotair.com] – Sustainable Energy – without the hot air, David JC MacKay
This source claims a shipping transport cost for dry cargo: 0.08 kWh/ton-km
Australia-Rotterdam = 20,000 km, in other words: 1600 kWh/ton. Or 3300 * 1600 = 5280000 kWh for the entire wind turbine. Divide it again by the daily energy production of 144,000 kWh of our 6 MW turbine to arrive at 37 days extra work for the wind turbine to earn itself back.
Total energy payback time: 127 + 37 = 164 days.
In other words: the offshore wind turbine must work for less than half a year to “earn” itself back in energy terms.
The remaining items like rotor (3 * 25 ton), construction of the gear, generator, maritime handling, installation, etc, have far smaller energy cost. Add a 22 days (wet finger in the air) to conveniently arrive at exactly half a year.
Things get even better if it is realized that these days about 1/3 of the world’s steel production comes from scrap metal, which requires far less energy to turn into new steel than iron ore. If in the future the windturbine has arrived at end-of-life, you can reuse the steel of the old turbine. You don’t have to get the iron from Australia anymore and recycling of steel costs far less in energy terms than producing steel from ore.
Summarizing: assuming a very conservative [*] life cycle of 30 years for the turbine, EROI for our offshore 6 MW wind turbine is therefore 30/0.5 = 60 or higher.
[*] The Eiffel tower is around since 1887 or 130 years. Experts estimate that the tower can easily survive another 300 years. Likewise it is absurd to assume that an offshore wind tower will fall over after 30 years.
P.S. After writing this post we discovered this calculation by Jan-Pieter den Hollander:
[duurzaamgebouwd.nl] – Energiebalans van een windmolen
Onshore wind turbine: 0,6MW, height = 50 m, rotor diameter = 40 m
|Part||Energy in GJ|
|Maintenance (20 year)||774|
Energy yield per year: 5015 GJ
Energy payback time: 7-8 months
In essence a comparable value to ours. In the example of Jan-Pieter den Hollander we are dealing with an onshore machine with less yield than offshore. Although it must be said that in his calculation there are counter-intuitive high values for installation and maintenance. Perhaps we will update this post in the future to have look at those.
Dutch language, English subtitles
Prof. Sinke is in the Netherlands the #1 authority in the field of photo-voltaic energy. For his contribution to the development of solar energy he was nominated as “Knight in the Order of the Netherlands Lion”. Prof Sinke is optimistic regarding the prospects of solar energy world-wide and believes that the EU policy of phasing out fossil fuel by 2050 and replace it with renewable energy is feasible.
[ecn.nl] – ‘100 procent duurzame energie is haalbaar’ Geridderde professor Wim Sinke voorziet spectaculaire groei van PV-markt
[wikipedia.org] – Order of the Netherlands Lion
Youtube text: “A number of projects are under way around Japan’s coast to develop offshore wind power Japan has developed an advanced form of this platform that it expects will create demand in the rest of the world.”
Norway is of central importance in the design of a pan-European renewable energy base. The country is sparsely populated and has mountains with large lakes, that can function as hydro storage basins for excess renewable energy from offshore wind from countries like the UK, the Netherlands, Germany and Denmark. Although Norway is not a member of the EU, it does closely cooperate on many areas with Brussels, including energy.
Natural conditions for the production of HP in Norway are very favourable. Yearly precipitation in most of the country varies from 300/500 up to more than 2000 mm, and precipitation is rather evenly distributed over the year. There are large mountainous areas and mountain plateaus with high elevation and steep falls/short distances down to the lowlands/coastal areas. The high number of lakes provides ideal conditions for establishing reservoirs. They are key elements in the hydropower infrastructure as precipitation falls as snow 3-5 months during the winter season when runoff is at its lowest and electricity demand at its highest.
[regjeringen.no] – Energy and Water Resources in Norway
[springer.com] – The Master Plan for the Management of Watercourses in Norway
[brage.bibsys.no] – Hydropower in Norway
[sciencedirect.com] – Implicit Environmental Costs in Hydroelectric Development
[deepresource] – Norway Wants to Become Europe’s Battery Pack
[deepresource] – Norway Europe’s Green Battery
[deepresource] – NorNed
[deepresource] – Green Light For British-Norwegian Interconnector
[deepresource] – European Supergrid Submarine Cables – Inventory & Plans
[deepresource] – 1 kWh (=lifting a car to the top of the Eiffel Tower)
Current e-vehicles use lithium ion batteries. Solid state batteries with higher energy density do exist but they are too expensive for an average car. Toyota however seems to be in a position to produce affordable solid state batteries by 2022. Apart from higher energy density per unit of weight and extra advantage is that these batteries can be charged in minutes.
[reuters.com] – Toyota set to sell long-range, fast-charging electric cars in 2022
Swedish company Vattenfall completed the installation of the Sandbank offshore wind farm in the German part of the North Sea. The plant went operational on July 23. 288 MW worth of wind power was installed with 72 Siemens turbines. A Munich-based utility company Stadtwerke München also participated (49%). Investment volume 1.2 billion euro.