Updated 12/20/2010

WindFuels Scale-up

The two most common problems with most of the renewable energy ideas is either they are not competitive or they are not scalable to the multi-terawatt level. We don't just need an alternative solution that can competitively produce a million gallons/year, but rather one that can ramp-up to tens of millions of barrels/day. Industrial ramp-up rates greater than 20% annually are never easy to sustain more than a decade. However, we’ve seen industrially driven scale-ups in the past of greater magnitude than what is needed here, and it can be instructive to reflect on some of the amazing past successes – the automotive, aircraft, petrochemical, television, computer, cell-phone, wind power, and drug industries, to name but a few. Common denominators in the successes are profitability within a reasonable time frame, constantly escalating demand, and ample raw materials that can be easily exploited and meet a continuously escalating demand.

In the Economics Overview, we’ve shown that WindFuels would be very profitable in a short time frame. One of the most important reasons for this is that there is a growing supply of very cheap off-peak energy in regions of high wind penetration. As we show on the Off-peak Wind page, and in a recent article on Deployment, Off-peak Wind energy will continue to be an order of magnitude cheaper than CSP and most other renewable resources. Most of the equipment needed for Windfuels is very similar to that which has been used in the petrochemical industry for the past 60 years or more. It is cheap compared to what is needed for algae oil or cellulosic ethanol because it doesn’t involve complex cellular extractions.

As traditional crude production gradually diminishes and must be replaced by more expensive and polluting fossil alternatives, there is an assured demand for scale up for WindFuels. We therefore need to assess the feedstocks, then we’ll look briefly at the challenges which would be faced by rapid scale-up.

Cheap off-peak energy; the scalability of Wind.
The availability of low cost energy will be influenced by the growth of the wind power industry. Wind energy is clearly competitive, and it has proven for the past 15 years that it is scalable, as shown here.

As we explain in detail on the off-peak energy page, the RFTS plant will simply connect to the grid in an area where projections show a lot of clean off-peak energy. Doing so would provide a market for off-peak wind energy and stabilize the grid for the variability of wind. This would enable continued growth of wind energy. (It may be decades before a wind farm is installed primarily to support an RFTS plant.) At least eight multi-billion-dollar companies around the world (Vestas, Gamesa, GE Wind, Enercon, Siemens, Clipper, Mitsubishi, and Hyundai) have demonstrated they can build and install multi-megawatt wind turbines at a remarkable rate. As of late 2010, over 200 GW of peak wind power (about 70 GW of average power) was installed worldwide.

The growth rate in wind energy has recently slowed – partly because of the financial crisis and partly because of of the grid stability challenges from the lack of a suitable energy storage solution. Energy storage, a primary obstacle to continued wind-energy growth, disappears when the excess off-peak wind energy is converted to clean, liquid fuels within a few hundred miles of the wind farm.
The steady drop in prices seen in the three decades prior to 2006 ended for two years, but it has recently returned. Additional manufacturing capacity has been added, and the economy-of-scale price reductions seen over most of the last 20 years, have returned. Other large international manufacturing companies (such as aircraft and truck manufacturers) will likely enter the fray as it becomes known that WindFuels will make wind energy a 70-year growth opportunity.

The cost of wind turbines dropped 20% from early 2008 to late 2010. The levelized mean cost of energy is now under $40/MWhr for wind, compared to $170/MWhr for CSP and $220/MWhr for PV. Off-peak wind energy is becoming widely available at under $12/MWhr in areas of high wind penetration.

One of the biggest obstacles to maintaining the 22% annual growth rate in wind energy has been that of power transmission and grid connectivity. China has shown that high voltage DC (HVDC) is quite cost effective for electrical transmission over distances greater than 1100 km. However, that still does not address energy storage issues, the transportation sector, or the cost of on-ramps to an HVDC grid – should it be built. These primary obstacles to continued wind-energy growth disappear when the energy is converted to clean, liquid fuels within several hundred miles of the wind farm. There is no doubt that wind energy can resume its phenomenal growth rate as soon as the new growth opportunities that WindFuels will create are appreciated.

Again, we should emphasize that the RFTS plant will be essentially independent of both the wind farms and the CO₂ separation processes at coal power plants, though they will be connected through open markets. The WindFuels plant will create an almost insatiable market for CO₂. It will eventually close the loop on CO₂ and eliminate the need for carbon sequestration.

The largest component of the RFTS plant is the water electrolyzer. They initially will be expensive, but their prices will come down quickly. We return to each of the key subsystems shortly.

The Wind Resource.
Some have argued that that the available global wind resource is considerably less that the 100 TW_PE figure that came from an extensive study about seven years ago. However, each successive studies show the potential wind resource is even larger. The latest study shows the global resource at 700-1200 PWhr/yr [2], while the world’s total primary energy usage (grid, transport, industrial, residential, agricultural) is ~150 PWhr/yr. There is sufficient point-source CO₂ available in the U.S. (over 4 Gt/yr) and sufficient wind energy potential (~80 PWhr/yr) to synthesize over twice the current U.S. liquid fuel usage (~0.7 Gt/yr) and supply over twice its other energy needs (~20 PWhr/yr). The domestic wind potential is similarly favorable in China, Russia, Canada, Australia, the U.K, Brazil, and some other countries.

Wind Turbine Progress.
There are many opportunities for further improvements in the economics of wind turbine manufacturing. For example, a new grade of high-strength glass fiber has become available that should soon increase the performance per cost of wind turbine blades by 20%. However, the biggest single advance may be the introduction of carbon-fiber-reinforced composites, which have only within the past four years become competitive for some purposes in the automotive industry and are not yet being utilized in wind turbines. The production cost of commercial-grade carbon fibers has dropped by a factor of four (in adjusted dollars) in the past 25 years (though their market price has seen considerable volatility). The global market in 2010 will be ~50M kg. The manufacturing cost continues to drop and production capacity is expected to continue to increase at the rate of 11%/yr, driven mostly by new automotive and aerospace applications. More than a factor-of-two drop in real price (from $35/kg to $15/kg) appears likely over the next 15 years, and they will soon begin being used in some wind turbines. The first large carbon-fiber reinforced blades may be coming from Global Blade Technology within two years using carbon fibers by Zoltek Corp of St Louis, MO.

Another advance of perhaps similar import is the ever-increasing size of the wind turbines. The 160-m rotor diameter of the 7.5 MW wind turbines currently under development by Clipper is about 2.5 times the wingspan of the Boeing 747. As the blades become longer and the towers higher, the available wind resource increases, as the turbines extract more energy from higher altitudes. and yields far more energy per square mile of land.

Some of the wind turbines of a decade ago experienced pre-mature failures because of an insufficient understanding to the need to limit peak stresses in composites to a few percent of the yield limits when the part needs to withstand tens of millions of stress cycles. However, it is also not difficult to find examples of wind mills that have worked steadily for 70 to 80 years. About 96% of the larger turbines (by Bonus, a predecessor of Siemens) installed in the mid-1980’s in California are still running well, more than 20 years later, now with only minor annual service. Several firms are introducing versions with direct-drive generators, which could reduce routine service from annual to every second or third year. As more experience accumulates on the latest designs, we should soon begin to see 40-year lifetime guarantees; and 60-year lifetime guarantees can be expected within a decade.

The RFTS Plant.
The second biggest subsystem is the RFTS plant. Investments in related GTL plants over the past six years have totaled tens of billions of dollars, as huge new plants are rapidly being built to convert stranded gas and coal into methanol and diesel. The largest NG-to-diesel plant, for example, is being built by Shell in Qatar to produce 140,000 barrels of NG-GTL diesel per day. There would be more differences than similarities between such a plant and one for making mid-alcohols, gasoline, light olefins, and high-value chemicals from waste CO₂ and wind energy, but there will also be a lot of common equipment requirements. The existing suppliers of process equipment for conventional GTL plants will be quite capable of re-tooling to supply much of the equipment needed for the RFTS plants at the rate needed after the design details are worked out.

The advances made by the automotive industry in SUV hybrid generator, motor, and power-conditioning technology will be of enormous value in developing the motor/generator technology needed for the variable-speed expanders and compressors. (The power-plant companies generally don’t like to leave their comfort zones of steam and 50/60 Hz, and that won’t work here.) The recuperators and condensers will utilize technology that has already been developed by the air-conditioning industry. There are enough international GTL, hybrid motor/generator, and AC condenser players, both large and mid-sized, to keep the pricing competitive.

Chemical processes, unlike agricultural processes (including growing and harvesting of algae) are much more compatible with scale up [5]. One of the first rules in limiting costs in chemical processes is to avoid reactions and separations that involve a solid phase – as seen in algal oil and cellulosic ethanol, for example. Coal-to-liquids plants typically produce fuels at the rate of 1 billion gal/year [4]. The US market needs a supply of 200 Bgal/yr of sustainable, carbon-neutral fuels. Meeting even 4% of that need with cellulosic ethanol would require over 100 Mt/yr of feedstocks, (two-thirds the current total hay production in the U.S.), which could drive the price of cellulosic feedstocks to $500/ton and put the price of cellulosic ethanol at $6.50/gal.

CO₂ Separations.
The third largest area from a total capital perspective for WindFuels will be the large CO₂ separation systems at point sources (coal power plants, cement factories, biofuels refineries...) , but like the wind turbines, this too will be independent of the RFTS plants. As explained on the CO₂market page, the RFTS plant will simply purchase CO₂ on the rapidly expanding open market.

There has been strong support by many governments (including the U.S. DOE) and oil companies over the past five years for reducing the cost of CO₂ separations at power plants, and this will bring separation costs down considerably over the next five years. The processes being developed for CO₂ sequestration are aimed at about 97% CO₂ purity, as currently used in large quantities in enhanced oil recovery (EOR). The additional purification needed for WindFuels will be straightforward and not very expensive. The WindFuels plants will create an enormous market for CO₂. An extensive CO₂ pipeline infrastructure is already beginning to be built for immediate needs in EOR and soon for sequestration. See the Physical CO₂ Market for more information.

Electrolyzers.
After the wind turbines, the next largest subcontracted “component” is the water electrolyzer. (The RFTS plant and the CO₂ separation processes at the coal plants are not “components” in the normal sense of this word.) Commercially available electrolyzers above the 250 kW level have been achieving 73% HHV efficiency for the past 8 years, and steady progress has been made in oxygen-evolving catalysts and electrolyte formulations. Commercial products are available at least to the 2.2 MW level. Alkaline electrolyzers have demonstrated HHV stack efficiencies of 92% at low currents and 84% stack efficiency at full power; and PEM electrolyzers have demonstrated low-current stack efficiencies up to 95%, though they are still quite expensive. Moreover, we have shown in a pending patent how it is possible to convert the waste heat from electrolyzers to electricity much more efficiently that has previously been thought possible.

Water usage by a WindFuels plant will be at least an order of magnitude less than needed for nuclear, shale oil, or biofuels. The WindFuels simulations carried out thus far have all assumed dry cooling. Supplying the needed pure water for the electrolyzer will not be a problem even in areas where water shortages occur, as there has been enormous progress in reverse osmosis (RO) water purification over the past decade. The cost of removing 99.8% of the salts and other impurities from seawater (or other water resources of similarly poor quality) will soon be under $0.1/ton. The water purification membrane industry now exceeds $4B and is growing at about 8% annually. The additional cost of getting the water purity needed (de-ionized) for the electrolyzer from RO-quality water is minor. Alternatively, methods can be implemented to utilize double-RO water in the electrolyzer.

Sustained Scale-up.
Some of the oil, gas, and coal companies may not be sufficiently motivated to help develop a tough, new, competing industry. Unfortunately, the kind of approach we have generally seen at the DOE for the past 3 decades will also not work. Without a complete transformation, oil prices could be over $1000/bbl in 15 years.

The wind turbine, chemical, air conditioning, and other established industries can play major roles in the new RFTS industry. But success will depend even more crucially on new, highly sophisticated, RFTS general contractors with the expertise needed to manage the new developments and bring all the components together cost effectively.

References:

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http://pepei.pennnet.com/display_article/346401/6/ARTCL/none/none/1/Turbine-Tech-Drives-Wind-Into-the-Generation-Mainstream/

2. X Lu, MB McElroy, and J Kiviluoma, “Global potential for wind-generated electricity”, PNAS, 10.1073, 2009.

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14. J Ivy, “Summary of Electrolytic Hydrogen Production”, NREL/MP-560-36734, 2004, http://www.nfpa.org/assets/files/PDF/CodesStandards/HCGNRELElectrolytichydrogenproduction04-04.pdf

15. JI Levene, “Economic Analysis of Hydrogen Production from Wind”, WindPower 2005, Denver, NREL/CP-560-38210, 2005. http://www.nrel.gov/docs/fy05osti/38210.pdf

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18. http://www.nrel.gov/wind/advanced_technology.html

19. http://www.wwindea.org/home/index.php

20. Wind turbine service records, http://www.renewableenergyworld.com/rea/news/article/2009/08/keep-the-blades-turning?cmpid=WNL-Wednesday-August26-2009

21. K Harrison, G Martin, T Ramsden, G Saur, “Renewable Electrolysis Integrated System Development and Testing”, NREL PDP_17_Harrison, 2009, http://www.hydrogen.energy.gov/pdfs/review09/pdp_17_harrison.pdf .

22. MW Kanan and DG Nocera, “In Situ Formation of an Oxygen-Evolving Catalyst in Neutral Water Containing Phosphate and Co2+”, Sci., 321, 1072-1075, 14 Sept., 2008.