College Students Bring Low-Cost Solar and Wind Drip Irrigation to Developing Nations

The National Collegiate Inventors and Innovators Alliance (NCIIA) combined with the support of the Lemelson Foundation provides $1.5 million to student and faculty programs and ventures annually. Today's featured project by the University of Massachusetts Lowell (UMass Lowell) is a low cost solar/wind drip irrigation system currently being tested in Peru. The project is called the Village Empowerment Peru Project, and has been designed to aid small farmers and their agricultural businesses.

The aim of this project was to provide small farmers in developing countries with an affordable solar drip irrigation system that will help promote the sustainable use of water and energy. The world's food security relies on finding affordable, improved, and effective means of irrigation for the small farmers in developing countries. The most common irrigation practice in these areas is flooding the fields with seasonal water gravity fed systems, which cannot produce year-round crops, or gas/diesel pumphttp://cm.howstuffworks.com/article-template.php?step2s, which is neither efficient nor cost effective.

The solar pumps being designed and tested by UMass Lowell are clean, efficient, and offer much lower maintenance than standard gas/diesel powered pumps. Drip irrigation (DI) is 40% more efficient than furrow, which is the process of digging water trenches to allow water to flow through crop rows in order to provide moisture to the soil. Depending on the crop, DI will enable Peru farmers up to four harvests per year, rather than just the one during the rainy season. The increased crop yields will help generate more income for the farmers to help pay for these photovoltaic solar pump system.

We spoke with professor John Duffy and Carolina Barreto (masters student) about this project:

Tell us more about this solar/wind drip irrigation project.

Carolina Barreto: This project started at the university and has been running for the past twelve years. I started my masters in solar energy engineering in 2006 and this project was developed as part of my masters thesis. One prototype is already installed, which is the solar prototype. We are working this semester on the wind prototype, and the idea is to develop a product that can allow small farmers in developing countries to increase their income through solar energy.

Right now the irrigation used in developing countries is very inefficient. Using solar technology makes irrigation more reliable and decreases the risk of not having water just because it didn't rain. Depending on the regenerate nature of the plant, farmers can get up to four crops a years instead of one. The NCIIA grant is currently helping us to develop more of these systems for small farmers in the area who are already demanding it.

Are you developing the actual pump, or just the energy going to the pumps?

CB: We are not developing a new motor, we are just putting together a system that is the lowest cost possible. The pumps that some of the farmers already have is a big problem in developing countries. They have diesel and gasoline motors with around 16 horsepower. What they need for their farms is a half horsepower. Their farms are very small, anywhere from one to four hectors.

This is a very unsustainable way to farm, so we are proposing the use of a very small diaphragm solar pump, DC powered, that is one of the cheapest in the solar market right now. The idea is to make this system as affordable as possible. Farmers are currently spending a lot of money on their big motors and they are now realizing that with a small pump, they can do the same amount of work. They do like their diesel pumps, but when a gallon of diesel is $4 that is when they start to look for alternatives like everybody else in the world.

What sort of technology will you be using for the wind power portion of the project?

CB: We are not generating electricity, we are working on a mechanical wind pump. These are very low cost systems that have been very successful in Nicaragua, which is where I am from. We are adapting this system to make it as simple and efficient as possible. We are using an American windmill pump design which has the proven technology of hundreds of years. They work with very low wind speeds, which is part of the reality that we have with the region that we work. We are really looking forward to the results of this experiment.

How does the windmill work?

John Duffy: If you can imagine pulling a rope through a pipe but having a washer every foot or so, and as it pulls through, it pulls the water ahead of the washers. It goes to the bottom of the well and lifts the water through the pipe and then it spills over like an old-fashioned pump would. We had a couple of mechanical engineering undergraduates working on this. Our aim is to make the different parts of these windmill systems available locally, so that folks in the area could start small businesses manufacturing them.

Why have you chosen these two specific designs?

JD: Part of the reason is to compare the two. We may find that the photovoltaic (PV) is more reliable over a number of years, even though it costs more up front. The PV pays for itself in just a few years because the farmers are able to get more crops per year. In this particular valley, there is an afternoon wind which typically picks up. We have installed a sensor which records the winds. When we go back in June, we will be able to get that data and predict more accurately what we are working with, as far as wind power is concerned. In areas without sufficient winds, we will use PV, in areas with sufficient wind, we will use the windmills. This is why we are developing and testing both approaches.

What types of crops are grown in this area?

CB: This brings up another important thing we would like to work on with the NCIIA project. The farmers grow asparagus, which has very good vitamins, but they sell everything. They do not use it for their own consumption. This is something we want to explore. The main food in this area is potatoes, rice, and beans. They do grow tomatoes, but they are locally consumed in very small quantities. Unfortunately, since most of the vegetables are not used for local consumption, they have problems with malnutrition.

JD: Farmers raise chickens and have the eggs, but they will sell the eggs and the chicken before their own family will eat them. This is because they need the money so badly. You would think these farmers who grow their own food would be in good shape, but in fact, many are not.

CB: Guinea pigs are also their big consumption for special celebration. Your readers probably won't like that (laughs).

What have you learned from this project which may be useful to our readers?

JD: When you work with people who really have to struggle to get drinking water, you really appreciate the water we typically have available here in the US. Where we are working is one of the driest places on earth. For example, in Huarmey, which is right on the Pacific ocean, the typical rainfall per year is a half inch.

We also learned a lot about water conservation. The drip irrigation method is 40 percent more efficient than the typical irrigation, so part of our focus is also on water conservation for food production. The readers should be aware that it takes a lot of water to raise food, but that there are ways to do this more efficiently and save water.

Thanks so much, John and Carolina, for sharing your experiences with us in regards to this project. We wish you luck this coming June when you go back to Peru to continue your work. I would also like to mention that if any readers are interested in donating to this project, you can get in touch with John through the Village Empowerment website.

View videos about this project.