The problem that Exro is trying to solve is this: wind turbines are not nearly efficient enough to compete with fossil fuels. Yet, until we find a way to make renewables cheaper than coal, humankind will continue to struggle to reduce our carbon footprint. Although far more energy is available through renewable sources than humankind will ever need, extracting energy from these sources has so far proven inefficient, mainly because renewable energy sources (such as wind energy), are variable in nature, and present-day generators require their input source to be fixed. Though Exro is currently pursuing the MW class wind market, its technology presents broad applicability including micro-renewables, portable generators, electric vehicles, military, tidal and run-of-river markets.

A traditional electric generator is very efficient when the energy source spins its shaft at a pre-specified speed and torque, but its efficiency drops precipitously when the energy source varies up and down. In an effort to compensate for variability, engineers place sophisticated machinery between the energy source and the generator in an attempt to buffer these swings, so that the generator operates as if the energy source is stable. Historically, the reliance has been on pitch and yaw systems combined with massive gearboxes, but these are expensive and prone to breakdown. More recently, engineers have begun to link multiple generators together, typically with mechanical gearboxes, so that individual generators can be added (or taken away) in an attempt to match the generator capacity with the available energy as it swings up and down. This approach is complex and involves even more gearbox issues, but the gains in output have been greater than the cost, so efforts continue in this direction.

Exro’s patented Variable Input Electrical Generator (VIEG) takes a completely unique approach from traditional generators, which are hard wired to convert stable energy sources into electricity. Instead, the VIEG has been designed from the ground up to embrace the variability of natural energy sources, and to operate at peak efficiency across a wide band. Instead of relying on heavy equipment (gearboxes) to accommodate variability, Exro’s technology uses multiple induction units paired with and intelligent controller. The result is a generator that wastes less energy, offers double digit increases in turbine output while reducing capital costs.

Learn more about Exro’s patented technology, the Variable Input Electrical Generator.