Using 2020 data, Wind Harvest analyzed 6944 wind farms from thewindpower.net’s database of 33,108 wind farms using UL Windnavigator’s predicted wind speeds. The analysis shows that 18% of existing onshore capacity have average annual wind speeds >6.5 m/s at 15 or 20 meters (50′ or 65’) above the ground.
In most regions of the world, wind projects in that wind speed can be profitable, especially if the developers can reuse the land and infrastructure as is possible with vertical axis wind turbines installed beneath the canopy of taller turbines.
According to International Renewable Energy Agency (IRENA), onshore wind farm capacity was 699 GW in 2020 (124 GW more than reported by thewindpower.net). It is reasonable to assume the 18% found in thewindpower.net’s database can be extrapolated to IRENA’s number. 18% of 700 MWs would result in 126 MWs of understory VAWT capacity in good to excellent wind speeds in the wind farms that were in operation in 2020.
Note that this assumes on average that VAWTs only double the capacity of the wind farms. In California, a more detailed analysis shows that in addition to the 6000 MWs of HAWTs, the state’s Wind Resource Areas could add 15,000 MWs of VAWTs.
According to IRENA, wind farm capacity increased by an average of 10.5% per year for the past three years. Statista predicts it should increase by 8.3% per year from now until 2030. At these rates, the market for understories of VAWTs would reach 244 GWs by 2030 and 408 GWs by 2034.
In large wind farm projects, VAWTs like Wind Harvesters™ are expected to sell for around $2.5 million per MW. Estimated to be 184 GWs by the end of 2024, the understory wind farm market today is worth over $400 billion and, at the 8.3 growth rate, would surpass a trillion dollars in 2034.
There are two main factors that create the conditions for excellent mid-level wind speeds in 18% of wind farms, and they are related:
- Wind Shear. Most wind farms have wind shear exponents of 0.2 and higher. Most wind farms with excellent wind speeds nearer the ground have wind shears under 0.12. Since the energy in the wind is the cube of the wind speed, a site with twice as high a wind shear exponent is going to have much lower wind speeds at 15m above the ground than at 60 or 80m above ground level. Low wind shear is caused in part by wind funneling.
- Wind Funneling. Topography that funnels wind (a fluid) into a narrower space causes that fluid to speed up. This is the core of Bernoulli’s Principle. Wind speeds up when it squeezes through mountain passes (e.g. San Gorgonio and Tehachapi Passes), over ridgelines (e.g. Jawbone Canyon), over mesas like those in Texas and New Mexico or coastal bluffs (e.g. Australia). In locations with an inversion layer, there is a top to the funnel which increases the wind speed even more.
The map below shows the gigawatt potential of H-type VAWTs in the top 14 countries with excellent mid-level wind resources. To find details on a country by country basis, visit our Library!
By 2030, in the understories of 20% of wind farms alone, 280 GWs of our types of turbines could be installed worldwide. This amount would be the case if we only doubled the wind farm’s capacity. In most wind farms in California, our turbines could triple the energy output.
With an average wind speed in the center of their rotors of 15.7mph (7m/s), Wind Harvesters would produce 3 GWh per 1 GW (1000 MWs, 14,200 70kW turbines) installed. If we built out all of this untapped resource, we would generate over 840 GWh per year of new energy. This amount doesn’t include the potential 10% increase this buildout should produce from the taller turbines.
Let’s give some context to this amount of energy:
- Electricity supply for ~168 million global households (assuming each uses 5 MWh annually).
- A replacement source for 840 trillion pounds of CO2 each year from fossil fuels. The equivalent of 400 large 500 MW coal plants.
- Power for 240 million EVs driving 10,000 miles per year.
We innovate and design utility-scale vertical axis wind turbines that harness the energy from turbulent mid-level winds that standard “propeller-type” turbines cannot. Our turbines are designed to optimize and increase the energy output of wind farms and synergistically work with solar and batteries to create a more efficient and effective renewable energy distribution grid. We develop our own renewable energy projects to prove our technology and develop our many markets.
Mid-level wind is 15-100 feet above the ground. This layer of wind accelerates and increases in turbulence intensity and energy when it funnels through mountain passes, over ridgelines, hills and mesas, around the tips of mountainous islands, and similar locations.
Several factors make our proprietary Wind Harvester turbines unique. The most noticeable differentiation is that, traditional propeller-type turbines are two-dimensional and are usually more than 350 feet tall –- taller than the Statue of Liberty.
Below is a list of additional traits unique to our Wind Harvesters:
- Categorized as H-type vertical axis wind turbines
- 3-three-dimensional vertical design makes it easier for birds and bats to see
- Shorter; the top of our blades can be as low as 55′ above ground level.
- Are placed less than feet three apart increasing the energy density per row.
Additionally, our turbines work synergistially with existing tall propeller-type wind turbines already located on 20% of wind farms throughout the world, increasing the reliability and output of renewable energy projects.
We use data from our own prototypes to improve and validate our suite of aeroelastic models for vertical axis wind turbines. With this feedback loop and a team of excellent engineers with experience in designing and testing our prototypes, we have confidence in our turbines’ simplicity, durability, and ability to inexpensively produce energy.
There is a huge opportunity to capture turbulent mid-level winds in many existing wind farms. Wind Harvest will be the first to certify and sell turbines designed specifically for this untapped source of clean, inexpensive energy. – Kevin Wolf, CEO, and Co-founder
Traditional Propeller-type turbines experience shaking and irregular forces when their blades pass through turbulent wind. Turbulence is often associated with mid-level wind layers and wake from other tall turbines. The shaking causes problematic fatigue issues for their gearboxes, blades, and bearings.
Although placing propeller-type turbines on shorter, less expensive towers in locations with excellent mid-level wind speeds (i.e., most wind farms in California) would be preferable, this is not practical due to the fatigue damage they would endure. Instead, they are installed high above the ground, where the wind flow is smoother, more laminar, and often faster. Horizontal axis wind turbines also must be placed far enough apart to escape turbulent wake shedding from their neighbor’s blade tips. On the plus side, the wind speed is usually faster above the ground, making up for the added costs of making and installing taller towers and leaving the mid-level wind resource unused.
Vertical axis H-type turbines like Wind Harvesters can be extremely durable and have long been considered much more capable of withstanding turbulence because of the following:
- Two connection points from each blade to the rotor shaft prevent the shaking and unsteady forces that propeller-type blades experience in turbulence.
- The physics involved with the Wind Harvester’s NACA 0018 shaped blades causes them to stall in high winds. This naturally regulates blade loads and keeps the rotor from overspeeding.
- When a propeller turbine is not facing directly into the wind, its blades experience added fatigue loads. Vertical axis wind turbines don’t have a “yaw” mechanism and are immune to any added loads due to changes in wind direction.
- A vertically oriented driveshaft is not subject to cyclic loads due to gravity – unlike the horizontally aligned driveshaft of a propeller turbine.
- Propeller-type turbines work best when the wind is steady and the turbulence is low. In contrast, the blades of vertical axis turbines are designed to withstand a cyclically varying wind speed and extract energy from turbulence while having little impact on their fatigue life.
- Three-bladed vertical axis turbines have been shown to be less susceptible to harmful harmonic resonance conditions.
Locations with trees, buildings, and steep terrain topography that offer a rough surface for wind lead to high wind shear (the rate the wind decreases in speed as it nears the ground) and lower mid-level wind speeds as well as more significant turbulence close to the ground. However, Bernoulli´s Principle tells us that when air flows through a narrower space it speeds up which means that when wind funnels up over a ridgeline, hill, or through a mountain pass, it accelerates. This acceleration creates a lower wind shear and increased turbulence intensity, both of which increase the energy Wind Harvesters can extract.
The Capacity Factor of a wind farm is the ratio of actual energy produced to the hypothetical maximum possible (i.e., the energy produced from continuous operation at full-rated power). Most wind farms reach Capacity Factors of 25-40%. In many of these, they operate at full capacity less than 5% of the time. Nevertheless, farms must size the substation and transmission line for the full-rated power.
Wind Harvesters installed under and around the existing turbines will use existing roads, transmission lines, storage batteries, etc, and capture the mid-level wind unavailable to tall turbines. Making double use of existing infrastructure is why these projects can return the most energy per money invested.
Wind Harvest is committed to avoiding harm to birds and bats. Ornithologists predict that birds will see and avoid H-type turbines better than they do propeller-type turbines. This hypothesis is due to H-type turbine’s 3-dimensionality and slower-moving blades. We typically install bat and bird high definition camera-based motion detection systems as part of the commitment to avoid harm. These systems enable us to slow down the turbines or stop them entirely if we detect oncoming winged animals.
This is an interesting question and the outcome of mid-wind turbine technology is not a given. We think energy density will drive design because these super energy-rich mid-wind sites are small in area (e.g. the San Gorgonio Pass in Southern California). H-types can be placed less than 3´ from each other and produce beneficial vortices. The company that comes to the market first with the best patents will win a large share. Maybe new technology will produce even better vortices and draw more fast-moving wind towards the ground but we think our patents and turbines which will last 40-50+ years will always have a good share of the world’s massive market of untapped mid-wind resources.
Our vision is to be the leading manufacturer of mid-level wind turbines with a large share of the $250 billion and growing wind farm understory market. In 5 years, we believe that we will:
- Achieve $1 billion in annual sales
- On the path of owning $500+ million in projects
- Be a publicly-traded company
- Be on a path to 10,000 MW of Wind Harvesters installed by 2030
- Stimulate the wildlife-friendly development of the world’s mid-level wind resources
Yes. Mid-level wind is sometimes also referred to as near-ground or above ground wind.
Vertical mixing means adding a layer of short turbines beneath the tall ones. Closely spaced H-type turbines produce wakes that are beneficial to a wind farm. The vortices they shed draw speedier wind from higher up toward the vortices. This faster-moving wind produces more energy from the tall turbines and reduces the distances rows of Wind Harvesters have to be placed downwind from one another. Vertical layering maximizes wind resources and will result in more profitable wind farms and the more intense development of the world’s best wind resources on the same environmental footprint.
Sketch of the five layers in the vertically-staggered mixed wind turbine array boundary layer. Credit: Benefits of Co-locating Vertical-Axis and Horizontal-Axis Wind Turbines in Large Wind Farms. Shengbail Xie, Cristina Archer, Niranjan Ghaisas and Charles Meneveau, Wiley Online Library, 2016
H-type vertical axis wind turbines are not new, but Wind Harvest is positioned to be the first company to be on the verge of international certification of a full-scale model ready for mass production and Technology Readiness Level 9 (bank financeability).
The design and engineering of the Wind Harvester evolved directly from the combination of modern computer modeling paired with field-tested results from prototypes. Our success is a result of years of investment in moving our turbines through the difficult technology readiness level process.
Because wind is intermittent and not reliable, wind turbines alone aren’t a consistent source of energy. Because there can be days without wind, storage alone needs to cover short and long periods without the turbines producing energy. But if solar is added, especially where it is windy at night as it is all summer in California’s windy areas, then reliability dramatically increases. When it is raining and there isn’t much sun, it is often windy. The type and amount of storage will depend on an analysis of historic wind and solar data.
Each Wind Harvester comes with a 50, 70, or 75kW generator, depending on the wind resource. In places like Barbados, where mid-level wind speeds rarely exceed 22 mph (10m/s), using a smaller, 50kW generator lowers the cost of the turbine while losing little energy produced. Sites with wind speeds averaging closer to 19 mph (8.4m/s), such as Simpson Ridge in WY need a 75 kW generator to turn the many hours of higher wind speeds into extra energy. Most projects will use a 70kW generator, which we will use here to explain how much energy Wind Harvesters produce.
By selling our turbines in pairs or longer arrays, clients are able to take advantage of the 10-20% increase in energy output that our technology creates. The table to the right shows the energy output of a pair of 70kW turbines at different wind speeds. The Capacity Factor is calculated by dividing the energy produced by the total energy possible from a turbine that operated for 8760 hours at its full capacity for a year (613 MWh).
The energy produced by Wind Harvesters in different average annual wind speeds is calculated from its projected power performance curve matched against a Rayleigh wind bin speed distribution (e.g. how many hours per year does the wind blow at 12, 13, 14 etc mph).
| Wind Speed (m/s) | Wind Speed (mph) | MWh/year per turbine pair | MWh/year per MW | Capacity Factor |
|---|---|---|---|---|
| 5.0 | 11 | 134 | 957 | 10.9% |
| 5.5 | 12 | 244 | 1,743 | 19.9% |
| 6.0 | 13 | 302 | 2,157 | 24.6% |
| 6.5 | 14.5 | 362 | 2,586 | 29.5% |
| 7.0 | 16 | 422 | 3,014 | 34.4% |
| 7.5 | 17 | 478 | 3,414 | 39% |
| 8.0 | 18 | 532 | 3,800 | 43.4% |
| 8.5 | 19 | 582 | 4,157 | 47.5% |
| 9.0 | 20 | 628 | 4,486 | 51.2% |
| 9.5 | 21 | 670 | 4,786 | 54.6% |
| 10 | 22 | 708 | 5,057 | 57.7% |
Power Performance Curve
This image compares the power performance of the Wind Harvester Models 3.1, 4.0 and 4.0 with the coupled vortex effect.
Wind Harvesters will typically be installed very close to each other in groups of 2-7+ turbines to take advantage of the Coupled Vortex Effect. An open space between each array in a row is left to allow wildlife to more easily pass through. Modeling shows that the next row downwind needs to be five times the rotor height from the first row in order to produce the same amount of energy as the first row, which for Model 4.0 is 215 ft downwind. Theoretically, 125 MW of Wind Harvesters could be placed in a square mile using this basis for calculation. In reality, terrain and erosion concerns, bird and bat flyways, internal roads, and other factors will result in a less dense concentration.
LiDAR data from the Pilot Project will confirm how far apart rows of Wind Harvesters can be installed and still produce as much energy as the upwind row.
Yes. In addition to being synergistic with large, propeller-type turbines, our Wind Harvesters can be synergistic with solar and battery projects. Wind often is strong at night and can be used to charge the batteries then, after the sun has set. Many energy-demanding businesses are on properties with setback easements that prevent tall turbines from being permitted and installed. The bottom of Wind Harvester blades can overhang the downwind edges of buildings where the roof acts like a mesa and causes mid-level wind to speed up. If they already have tall, megawatt scale turbines on their property as Anheuser Busch does at its Fairfield, CA brewery, another MW of Wind Harvesters could be installed under and around these turbines
For example, with a 15-mph wind speed resource 14 Wind Harvesters whose foundations would cover less than a quarter of an acre would produce more than 2700 MWhs per year. To produce this much energy from solar panels, at least seven acres of rooftops or land would need to be covered.
We make a margin on the turbines we sell. We profit from the projects we develop and the energy they sell. We will license our patents to future competitors because the markets for mid-level wind turbines are so massive that we won’t be able to supply them on our own. We will make extra money on warranties, 24/7 monitoring service contracts, and more.
The main difference between the power curve (electrical power vs. wind speed) of the large propeller-type turbines and Wind Harvesters is at the top end of the curve. This is because most traditional wind farm turbines have pitchable blades (they can be twisted at their root) to control the forces on the blade; this allows them to precisely maintain their maximum output power. Wind Harvesters do not have pitchable blades but control the maximum power by allowing the flow of air over the blades to stall in high winds; this is less precise but does not rely on bearings, actuators, and a control system; it is, therefore, simpler, more robust and less expensive. Wind Harvesters will most often come in pairs or longer arrays because they realize ~20% increase in energy output when installed one meter apart from each other. It is in this position that their predicted power performance curve and resulting Annual Energy Production nears that of the best of their taller cousins.
There are two reasons for this:
- The first is that turbines create a wake, an area where the wind slows down. The downwind turbine must be located sufficiently far downwind to where the wind has sped up again, and the energy generation does not suffer. The optimum spacing for rows of conventional turbines is seven to ten times the diameter of the rotor. Since that diameter can be as much as 400 feet, the spacing of the rows is up to 4,000 feet.
- The second is that propeller-type turbines do not handle turbulent wind well. They must be placed far enough apart to escape the turbulence shedding from their blade tips.
Wind Harvesters create less visual impact than propeller-type turbines due to their shorter stature. If desired, customers can paint them to blend into their background, making them more difficult to see. There will be some added visual clutter in a wind farm, depending on the viewer’s perspective. Still, when installed among their taller cousins, Wind Harvesters shouldn’t significantly change the view compared to the impact of the original installation.
The mid-level wind turbine market is currently free of commercial competition. There are other H-type turbine companies, but they have yet to make a full-scale model and achieve Technology Readiness Level 6. Our breakthrough is that we have developed and validated a suite of aeroelastic models that no competitor has yet developed.
Many high-energy-using facilities have smaller properties with set-back easements that do not allow for the placement of tall propeller-type turbines. In these cases, a 20m tall Wind Harvester can line parking lots and squeeze in along the edges of buildings.
We will place a sophisticated Doppler LiDAR ~400m downwind to measure the wake and turbulence that arrays of Wind Harvesters create. The purpose of the LiDAR is to evaluate the following:
- How far downwind it is before the wind speed returns to normal.
- What happens to the wind speed and turbulence above the arrays, and how far downwind the effect lasts.
The LiDAR can efficiently and rapidly collect this data in different wind conditions. Modelers then use that data to validate their algorithms and predictions. The predictions are for how much Wind Harvesters increase wind speeds for the taller turbines based on the height of the tall turbines’ towers and the size of their rotors, topographies, and other factors.
NASA, the military, aviation, and many other industries use Technology Readiness Levels (TRL) to plan a path to full commercialization of their products. TRL consists of nine rigorous stages, each with its own parameters, that a technology must pass before becoming fully certified. Wind turbine development also needs to go through these different levels.
Wind Harvesters and their earlier prototypes have completed the first six levels. In February 2022 Model 3.1 entered TRL 7 (pilot project). In 2023 we expect our Model 4.0 to complete TRL 8 (international certification) and enter TRL 9, the final step which is completed when banks will use the new technology as collateral on long-term project loans. Achieving TRL 7 is something that no other H-type turbine company has yet achieved, giving Wind Harvest a big step up on the competition.
Wind Harvester blades are at least 13 feet above the ground. A tractor or a combine can easily pass under them. In addition, because the foundations are installed underground with only four small pillars breaking the surface, they would take almost no land away from grazing.
Barbados is representative of energy markets and ecosystem conditions most islands face. Almost all small island utilities import expensive fossil fuel to run large diesel generators. As a result, energy prices for island businesses and residents are significantly higher than for mainlanders. At the same time, many islands have the right topographies and steady, strong trade winds that make them well suited for mid-level turbines. Wind Harvesters, being the height of medium size palm trees help address a confluence of other challenges that islands face in attempting to harvest the wind with traditional tall turbines. These include visual impacts on tourism, limited infrastructure (roads, ports, etc.) and environmental considerations, all of which our turbines should solve. In addition, most islands have the capacity to assemble the turbines, and three islands in the Caribbean including Barbados have existing manufacturing companies that can make most of our turbines’ components. The resulting high-paying local jobs that aren’t reliant on tourism are a political plus. This is above and beyond the benefits the islands receive from not having to import fuel. Wind blows free across the island, waiting to be harvested.
Turbines, like most products, drop in price as production numbers increase. The 20+ turbines we will order in 2022 will cost almost twice as much as the 20,000 turbines we expect to make annually five years later. These first turbines though will be profitable because they will either be installed in extremely high wind locations such as Simpson Ridge in Wyoming or they will be installed on lower wind speed properties like in Barbados where expensive diesel fuel is now used to produce electricity. And government subsidies such as tax credits will make many medium-strength wind projects profitable in places like the US. The levelized cost of energy produced from Wind Harvesters will range from $0.04 per kWh to $0.15/kWh depending on all these and other factors.
Wind Harvest does not plan on owning any manufacturing facilities, with the possible exception of strategic sub-assembly facilities in key countries. Our technology is specifically designed so that many existing facilities with ISO 9001 certifications can fabricate, forge, machine, and assemble our turbines’ components. This flexibility has distinct advantages over the highly specialized manufacturing requirements for traditional large turbines. 1. Manufacturing and developing projects in the same location increases public support and government funding opportunities while also meeting local content requirements. 2. Local fabrication costs can be much lower than importing our turbines from the EU or the US. 2. Volume discounts can be available for expensive components like permanent magnet generators, power converters, and bearings for locally manufactured Wind Harvesters. 4. Wind Harvest doesn’t have to invest its capital in building and manufacturing facilities. It can put its capital into financing more projects. We see countries as large as the United States and as small as Barbados supplying and assembling Wind Harvester components and turbines.
IEC 61400 guides the certification of all aspects of large and small wind turbines. Everything from the structural integrity and power performance to acoustics and manufacturing is covered and requires third-party companies like UL to do the evaluations. A subset of the international certification process is the US Small Wind Certification that Wind Harvesters 4.0 will undergo at the UL Advanced Wind Turbine Testing Facility in Texas in 2023. The full process should take 6-9 months to complete.
Multiple facilities will be involved in the manufacturing of each Wind Harvester. We will contract the production of its components to companies that can best make them in the countries and regions that will be installing the turbines.
While we plan to own most of the projects that buy our turbines in 2021 and 2022, we won’t manage their development and construction. Wind Harvest has strategic relationships with project developers such as AltaTerra Energy LLC and Clean Energy Holdings LLC that will do this work. Large projects that buy our turbines will mostly use Engineering Procurement Construction and Management (EPCM) companies that handle all aspects of the project including product and energy production warranties. Wind Harvest helps projects get started and will help finance many of the early ones. Once a project is permitted and a PPA is secured for the sale of its electricity, a local project management company takes over.
Data from our prototypes has improved and validated our suite of aeroelastic models for H-type wind turbines. With this feedback loop and a team of excellent engineers with experience in designing and testing our prototypes, we have confidence in Wind Harvesters’ simplicity, durability, and ability to cost-effectively produce energy.
- The Model 3.1 Wind Harvester is undergoing Technology Readiness Level 7 at UL’s Advanced Wind Turbine Testing Facility in Texas.
- The final commercial turbine, Model 4.0 will be installed and begin the certification process (TRL 8) in 2022.
- Projects are advancing in California, Wyoming and Barbados that would order 20+ turbines in 2022.
- Near Palm Springs California is the three prototype array of Windstar 530Gs turbines installed between 2000 and 2002. Though no longer operating, the array is still there. The 530G array provided data key to proving the coupled vortex effect.
Almost none is expected due to our turbines’ close proximity to the ground. For example, zoning by Solano County of the ranch land under the Travis Air Force Base flight zone limits the tops of wind turbines to 100′ (30m). Regular wind farm turbines are three to four times taller while the tips of Wind Harvesters are under 75′ and thus can be permitted in this wind area.
Because our technology has passed through the pilot project step in the commercialization process and our computer models have been field-validated, bringing our turbines into sales is not a significant risk. The biggest risk for any company moving new, utility-scale technology into sales is running short on capital. To overcome this problem, we need to continue developing projects and succeeding in our crowdfunding campaigns.
When arranged in close proximity to one another, a pair of H-type wind turbines creates a synergistic effect, which we’ve titled the “Coupled Vortex Effect.” They increase wind speeds through their own and their neighbors’ rotors and enhance aerodynamic efficiency. This physical phenomenon was discovered, proved, and patented by Wind Harvest Co-Founder Bob Thomas. Field data followed by computer modeling and analysis showed that the coupled vortex effect could increase the turbine’s efficiency by ~20%.
Field Data
Thomas and his team gathered the field data through a three-turbine array in 2001 and 2002. They installed the three Windstar 530G turbines in the highly energetic wind farms of San Gorgonio Wind Resource Area in California. First, they installed a single turbine that operated through a range of wind speeds, modeling the typical operation of the turbine. After one year of data collection, they installed two additional turbines one meter away on either side of T1, labeled T2 and T3. They measured the average daily power of T1 for each wind speed. As they tabulated the data, it became apparent that there was a significant increase in energy capture with the array configuration.
Computer Modeling
Drs. Ion and Marius Paraschivoiu, renowned aerodynamic modelers, and their team at IOPARA Inc, used the data from the three Windstar 530G turbines to model the Coupled Vortex Effect (CVE). IOPARA’s analysis corroborated Thomas’ field data, finding “excellent agreement” between it and their modeling results.
IOPARA conducted additional modeling and analysis with grant funding from the California Energy Commission in 2010. Their primary finding was that while lower solidity turbines (like the modern Wind Harvesters) reduce the Coupled Vortex Effect, it will still benefit their output by ~20%.
For articles written on the Coupled Vortex Effect visit our Library!
As stated in the recent book “Light on Fire: The Art and Life of Sam Francis” by Gabrielle Selz, this world-famous abstract artist invested over $6 million in today’s dollars in the original Wind Harvest Company. Since Wind Harvest was incorporated in 2006, another $12+ million has been invested in our technology and project developments.
The goal of this Wefunder offering is to raise up to $2.5 million. This raise helps set up Wind Harvest for an expected $8 million Series B round and a possible additional $2.5 million third crowdfunding raise. All of this new capital and the capital from an expected arge Series C in late 2023 should be more than sufficient to aggressively grow the company and fund the projects we have in development.
By sometime in 2025, we anticipate having sold over $50 million in our turbines to our own projects with a net income from the sales of over $10 million. In 2025, we expect that this income will exceed our expenses and we will have become profitable.
Yes. Two central studies have tested the Coupled Vortex Effect.
In 2010, Dr. John Dabiri and his researchers at CalTech University studied the increased efficiency and synergistic effect of fish swimming in school formation. They wondered if closely spaced and counter-rotating H-type wind turbines might exhibit similar efficiency-boosting capabilities. Subsequent field testing of small turbines corroborated their hypotheses.
In 2014, a French and Belgian team studied the effect of closely spaced H-type turbines. They conducted a series of wind tunnel experiments coupled with measurements of flow field effects. They concluded that the spacing, rotor rotational direction, and synchronization of two-bladed turbines could increase efficiency by 10% to 20% for each turbine in the pair.
An aeroelastic model is a computer code that programs the configuration and physical properties of a turbine and the nature of the ambient wind flow. The model will predict the loads and stresses in all of the critical components under the specified conditions.
Validating an aeroelastic model involves comparing the computer predictions with measurements from the operating turbine. After achieving this agreement over a range of conditions, the model is considered to be validated. It can then be used with confidence to predict the effects of changing the turbine in any way and how new versions and similar products will perform.
In fall 2021, Wind Harvest moved another step towards validating the aeroelastic model through the static load test run on Model 3.1. The successful “pull test” validated our Frequency Response model by providing matching data between the modeling and the field data. The Wind Harvest blog details the story of the test, and the results can be found in this report.
99% of each Wind Harvester turbine is made from aircraft aluminum, steel, and concrete, all of which, when well-maintained, have a usable life of over 70 years.
Our Sandia National Labs-based aeroelastic computer models of turbine loads, aerodynamic efficiencies, harmonic resonance and fatigue have been validated with data from our models 3.0 and 3.1. The LIFE fatigue model takes this information and predicts the life expectancy of the components based on the loads the turbine will realize over its lifetime. The LIFE model, for example, predicts that our old blades would have a life expectancy of 27 years, but our new blade design should last for 74 years.
Key to a turbine operating for 70+ years is to refurbish key components on a regular basis. For example every 20 years, the owners of our turbine can:
- Replace the bearings
- Rewire the generator
- Replace the power converter,
- Replace key fasteners and retorque the rest
- Replace control and brake components
We expect the refurbishing to cost around 15% of the initial cost. The foundation, galvanized steel rotor, aluminum blades, and well-protected “nacelle” will not need reconditioning.
We have designed the Wind Harvester to operate in and survive wind conditions specified in the internationally accepted standards. One of those conditions corresponds to a severe hurricane. If this event were to occur, the blades would experience high bending loads. The turbine might automatically stop but would be unlikely to withstand any damage. Should damage occur, we could quickly and inexpensively repair our technology.
The components for our Wind Harvester turbines are transported to the site on standard flat-bed trucks or in land-sea containers at ~$4-5/mile per truck and installed using small truck-mounted cranes or a Rough Terrain crane and a bucket lift. One trained manager can install the turbines with a crew of 2-3 people who have basic mechanical skills. We anticipate it will take one crew per turbine to fully install and start operating a turbine in a large project.
In comparison, multi-megawatt traditional propeller-type turbines require specialized trailers on eight or more trucks for transport. These trailers are overwide, over-height, and overweight and require special permitting. Costs averages are over $50/mile per truck.
Wind Harvesters’ operations and maintenance costs per kWh should be significantly less than that of large, traditional propeller-type turbines ($0.003 -$0.007 vs. $0.004-$0.010). The main factors behind this expectation include:
- The access to Wind Harvester parts needing maintenance is 13-50 feet above ground level. The access point for large turbines is 160-300+ feet above ground level.
- The only annual maintenance that Wind Harvesters need is the replacement of their auto-pump grease cartridges for the drive shaft bearings and generator.
- Tall turbines need semi-annual maintenance and checking on more components (e.g. blade pitch mechanism, yaw bearings, large amounts of lubricant). Wind Harvesters don’t have these mechanical components.
- The large turbines need more skilled labor and workers who aren’t afraid of heights.
