September 27, 2011 | Andrew Burger

Professors and students at New Mexico State University’s (NMSU) College of Engineering are joining forces with University Agricultural Extension officers to demonstrate how state farmers and ranchers can make use of alternative energy sources such as solar power.

Long-term droughts are an increasingly urgent concern for farmers and ranchers, particularly in the Southwest where a record-setting drought occurred this year. Compounding this, electrical power isn’t readily available at more than 25,000 farms across New Mexico.

Tom Jenkins a professor of engineering technology and the head of NMSU’s Renewable Energy program, has been working with the extension service to produce training presentations related to how renewable energy sources as applied to agriculture can help to alleviate such problems. Many New Mexico farmers are looking for ways to put alternative energy sources to work for them, said Jenkins in a  Las Cruces Sun-News report.

State extension service officers are currently holding live demonstrations on how to make use of renewable energy options on New Mexico farms.

The extension officers believe that rather than merely providing information on renewable energy options, the demonstrations will more effectively pique the interest of farmers and ranchers. To move things forward with this project, Jenkins decided to engage his mechanical engineering students at NMSU to develop solutions.

With guidance from other faculty members, the students came up with the idea of putting on live field demonstrations to show how portable solar panels can be used as a power source to pump well water. To do so, the students built a portable demonstration system with the assistance of Craig Ricketts, associate engineering technology professor, to put the idea to the test.

The demo solar power unit rests on a rolling cart and consists of a small solar photovoltaic (PV) panel. The electricity produced powers a high-pressure submersible pump equipped with a control box that optimizes the power needed to regulate the speed of the pump. The pump sits in a 50-gallon storage vessel. Meters display the current and voltage produced by the panel and consumed by the pump.

The depth of the water table in New Mexico ranges over a wide scale, anywhere from ten to 1,000 feet, according to Craig Runyan, an Extension Plant Services associate. A control valve regulates water pressure at various depths up to 400 feet, which is around the maximum for this type of solar power technology today.

In order to help prospective users of the solar water pump systems determine how many solar panels, how much storage might be required on cloudy days as well as the total potential cost of the system, engineering students also developed a spreadsheet tool into which users can input information such as the depth of their well and variables such as whether it will be used for livestock or not to help them make this determination.

Wind power has traditionally been used to pump water up from wells in New Mexico, but the use of solar power to accomplish this task is growing. Each has its advantages. Both are cost-competitive, but solar may be safer and easier, as it avoids the need to climb windmill towers, Runyan told Las Cruces Sun-News.

Source: Las Cruces Sun-News