Developer Plans to Use Ancient Technology to Harness Hydropower
A property developer based in North Kingstown plans to build a hydropower project at the Natick Pond Dam using Archimedes’ screws, generators developed over two millennia ago by a Greek engineer and scientist. The ancient technology is designed to pump water upward for irrigation and drainage but has never before been used in the United States.
For develop Robert Cioe, the project has been decades in the making. He bought property adjacent to the dam on the Warwick side of the river in 1968 and built 65 houses there. He sold the homes but hung on to a strip of land on the river, thinking that someday the dam could be used to generate renewable energy.
However, in the 45 years he owned the land near the dam, he was never able to move forward with a hydro project due to legislation and tough permitting laws. But in the last legislative session, lawmakers expanded the state’s landmark distribution generation program to include small hydropower. The program sets ceiling prices for different types of renewable energy, such as solar and wind power, and requires National Grid to negotiate 15-year power purchase agreements with developers, allowing Cioe to move ahead with this ambitious plans.
Archimedes' screw consists of a screw inside a hollow pipe. The screw used to be turned by manual labour but is now often turned by a windmill. As the shaft turns, the bottom end scoops up a volume of water. This water slides up in the spiral tube, until it finally pours out from the top of the tube. While the invention was allegedly invented by Archimedes to remove water from the hold of a large ship, nowadays it is used as an efficient way to harness the downward flow of water to generate electricity. The screws also turn slowly enough — 30 to 40 revolutions per minute — to allow fish to pass through unharmed.
Hundreds of the devices are already up and running in Europe but now Cioe, working with New England Hydropower, plans to introduce the first one to the United States. Representatives of New England Hydropower say there is potential for hundreds of such projects in New England, which has about 10,000 dams. The screws at the Natick Pond Dam would generate about 1,500 megawatt-hours a year, enough electricity for about 250 typical Rhode Island homes.
The invention of the water screw is credited to Archimedes of Syracuse in the 3rd century BC. Archimedes was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and an explanation of the principle of the lever. He is credited with designing innovative machines, including siege engines Modern experiments have tested claims that Archimedes designed machines capable of lifting attacking ships out of the water and setting ships on fire using an array of mirrors.
It is remarkable that we now turn back to the brilliant inventions developed millennia ago to provide a better solution than what our technology can accomplish today.