Wind energy is a big business world-wide, with billions of dollars flowing around at various levels. And as in any large and growing market, a wide variety of people are attracted to it. Most are solid, competent professionals. Some are superstars. A slightly larger percentage than in other fields are engaged in part because it’s the right thing to do, not just something they can do well and make money.
Along with all of the professional people, there is a physically optimal design that the vast majority of wind generators have converged to: the three-bladed, horizontal-axis wind turbine. This is the most efficient design due to pure physics: the blades are always flying in clean air, at the optimal angle to the wind, at the height of strong wind and have the added component of aerodynamic lift as another vector of force.
There are over 200,000 of them worldwide in sizes ranging from a few kilowatt capacity to 7 megawatt capacity both onshore and offshore, in rural and urban areas. They are generating all but a tiny fraction of a percentage of the electricity harvested from the wind in the world. They are undergoing constant incremental improvements in design including:
- Low-wind vs high-wind models
- Variable pitch blades
- Gearless vs geared nacelles
- Slight variants of blade design for aerodynamic efficiency
- Leading edge coatings
- Tower design
- Base design – rock-anchor vs concrete-base vs tethered floating vs. bottom-mounted offshore
Then there are the others. As a thought exercise, look at the picture of a simple savonius windmill below and guess reasons why it’s never going to be as efficient as a horizontal axis wind turbine.
A higher profile ‘innovation’ is Saphon, which actually got a TED spot for something that is so obviously deficient that any one remotely related to the wind industry would have laughed it off the stage. Professionals’ comments regarding it are invariably brutal.
Its failures include inability to scale due to mass of the conical device they use, no ability to feather the cone so it will likely fall over in high winds and a mechanical piston actuator that also won’t scale and introduces massive inefficiencies.The patent it claims represents its breakthrough is actually for a different device than the one they are promoting. They explicitly call out many of the myths denigrating wind generation as real in their promotional video and then claim their design solves these almost non-existent problems. The two principals have no background in wind energy, but one is a former investment banker who specialized in getting people to invest money in companies. Is there a niche where their product is better than a tri-blade HAWT? It’s extremely unlikely in our physical universe, yet this doesn’t stop them from seeking new investors, creating prototypes and getting a remarkable amount of fawning press including being shortlisted for an African innovation award recently. The principals are much better at PR than engineering.
An idea what won’t stay buried is shrouded or cowled wind turbines, where a bulky external shroud concentrates air flow on a smaller wind turbine. This idea is challenged in ways similar to the Saphon, in that scaling up produces a massively heavy and shear susceptible bulk on top of a tall, relatively slender pole. Effective harvesting of wind requires getting the generator up into the air where the wind is stronger and having a broader surface area to harvest from. All the shrouding does is reduce efficiency of a three-blade HAWT with the same diameter as the shroud. Yet this is re-invented with prototypes being funded regularly, as if no one in the history of wind energy has ever in the past thought to apply the Venturi effect to wind generation.
Many of these innovations claim to have found a way to exceed Betz’ Limit of 59.3% of potential energy harvested from a volume of wind. None have stood the test of third-party, independent testing. Some claim that Betz’ Limit doesn’t apply to VAWT technology and then point to Sandia Labs documentation which clearly says that it does. Virtually none have performed ISO standard full lifecycle cost assessments, published them and had them audited by independent third parties.
Most claim to be quieter, although virtually none publish side-by-side noise evaluation tests with similarly scaled HAWTs to prove it. Many claim to kill no birds, although there is no proof of that claim either (and of course utility scale wind generation is the best form of generation for birds from a species perspective.) Some anti-wind lobbyists have internalized these claims without understanding them and actively promote the idea that there is a better alternative for their pet concerns.
Then there are the situations where there doesn’t even appear to be a physical product of any sort. A firm in the western US received $4 million up front a handful of years ago from the municipality to build a factory for savonius-style wind turbines. It has delayed breaking ground on its factory for four years, doesn’t have a working website and is saying delays are due to bird tests (not true according to the agency that was performing them), a completely unrelated scandal many states away and the need for more money in the bank. It appears to be nothing more than a large scale scam that has already netted them around $4 million and they are hoping to get $10-11 million more. All for a conceptual variant on that barrel split in two above.
There are minor niches where alternatives to tri-blade horizontal axis wind turbines are effective. There is a vertical axis design, for example, that self-stalls in high-winds, making it effective for remote locations with regular very high winds, e.g. Antarctica. There are a few darrieus variants that are remarkably attractive kinetic sculptures that happen to generate electricity as well, where the aesthetic value makes the high cost per KWh palatable.
So, how can you inoculate yourself against putting money into a bad wind energy product? Ask these simple questions and if any of the answers are Yes, be very suspicious:
- Do they claim to exceed Betz’ Limit?
- Do they disparage other wind generation technologies to establish their technology’s superiority?
- Do they have backgrounds entirely in fields unrelated to wind energy?
- Are they claiming that their variant of a savonius or darrieus wind turbine is actually a new technology?
- Are they claiming that their product will replace utility-scale three-blade wind turbines?
- Are they starting from a product as opposed to a specific and tightly targeted market niche?
- Is their product just a design concept as opposed to at least a working and tested prototype?
- Are the only test results from tests that they have performed as opposed to independent, third-party labs?
- Are claimed patents for devices other than the one they are demonstrating?
- Are they claiming greater efficiency than existing generation technologies based on anything other than an ISO standard full lifecycle accounting that has been independently assessed?
- Are they claiming to integrate storage into their wind generation device? (Special case: GE is allowed to do this because it has proven it knows what it is doing and the market.)
The wind industry is disruptive because it is supplanting fossil fuel generation at a reasonable cost. That reasonable cost is due to decades of incremental innovation and major supply chain and business innovations, not radical technical innovations. The most effective technology was chosen a few decades ago, and it’s been getting steadily better ever since.
The wind industry isn’t going to be disrupted by someone with an idea and a Powerpoint pitch. If someone is approaching you with a great investment opportunity based on a ‘new’ wind generation technology, be aware.