Attleboro, MA - General Compression, Inc., the pioneer of dispatchable wind power, has successfully closed an initial round of funding for over $5,000,000. These funds will be used to accelerate the development of General Compression's revolutionary dispatchable wind technology.
The company focuses on collecting energy from the wind as compressed air, storing the compressed air in pipes and underground geologic features, and expanding the air on demand to make electricity. The company anticipates that this technology will lead to a dispatchable wind energy platform that will offer utility scale energy parks creating wind energy on demand at competitive prices.
Dispatchable wind energy can be sold when prices are high, and stored when prices are low.
Conventional turbines need to protect their generators from accepting too much energy. When the wind blows over 10 meters/second (m/s) most turbines feather their blades to begin shedding incoming wind energy. When wind speeds reach 15 m/s, most turbines stop accepting any new energy, and at 25-30m/s the machines shut down.
Their system is not limited in its output like a generator, and can accept much higher energy inputs and rotor speeds. In windy sites, this means that for the same foundation, tower, and blades, energy production can be substantially improved.
When the wind blows, lift is created on the turbine blades, spinning the compressor inside the nacelle. The compressor pumps air to over 100 atmospheres of pressure and sends the air down the tower into an underground network of high-pressure pipes.
The high-pressure pipeline network collects and stores 6-12 hours of energy. The energy collection system doubles as a storage system.
Electricity is very difficult and expensive to store on a utility scale. Capacitors can store energy efficiently on a scale of seconds, and flywheels and open flow batteries can store energy for minutes, but only compressed air and pumped hydro store energy efficiently on a time scale of days or months. If the project is sited near a geologic feature such as a salt dome, aquifer, limestone cavern, or depleted gas field, energy storage times can exceed weeks and even months.
Their expanders, that drive generators, are rated at four the power output of their compressors, greatly increasing the nameplate capacity of our windplants, and enabling us to offer the lowest installed cost per kW of any wind technology in the world.
Conventional wind farms need to reserve transmission rights based on their nameplate generating rating, even though on average they will only use 20-40% of this transmission capacity. This results in over-paying for transmission, and in over-allocating resources to the wind farm. Grid congestion during high wind periods can lead to curtailments in which conventional wind farms are ordered to shut down some or all of their energy production. The anticipation of grid congestion delays some wind farm projects for years until grid upgrades are completed.
A Dispatchable wind farm can be configured at twice the rating of a conventional wind farm and still fit through the same transmission corridor. It can also use 100% of available transmission capacity during peak price periods, and store energy rather than waste it during periods of curtailment. By shifting the time when power is sold, the wind project can sell power on peak at a higher price, be more compatible with the needs of the grid, and become eligible for capacity payments. This solution will double the profitability of wind farms.
Since intra-day peak and off-peak prices often differ by a factor of 4, substantial value is lost by not achieving peak prices. General Compression wind farms can be configured to earn peak energy prices, boosting wind farm revenues substantially.
Thanks to Rob Day of Cleantech Investing for the tip.