Maya Pedal's pedal-powered machines make energy-intensive tasks easier for rural residents.

Courtesy of Curry Stone Design Prize

Imagine living without electricity and all the gadgets that make your work or home life relatively convenient, like being able to grind food in a blender, for example. If a bike came along that let you use your pedaling legs to complete the same task so you no longer have to do it manually, your life would change entirely.

Or imagine being a woman with no access to the hygiene products you rely on to get you through your monthly cycle—if someone came up with a way to make those products using local resources so that they are affordable to you (and environmentally sustainable), your life, again, would be changed.

Those are two real-life situations, the first in Guatemala and the second in Rwanda, and the projects are now finalists for the Curry Stone Design Prize. Every year, the prize recognizes visionary designs that address social issues like access to clean air, shelter, healthcare, energy, or education.

This year's finalists showcase innovative ideas with efficient use of resources to meet local needs—the runners-up will receive $10,000 and the winner, a whopping $100,000.

Chile: Attractive Affordable Housing

Chilean design firm ELEMENTAL has come up with a "transformative design" for public housing in Santiago that the designers are already spreading to cities in Brazil and Portugal. The design involves stacking duplex units and positioning them diagonally from each other.

Bustler explains that the founders "have not only solved the problem of density, but maximized the $7,500-per-unit budget by building 'starter' homes that allow people to easily expand and individualize their spaces. As Aravena likes to say, each unit has 'the DNA of a middle-class home.'"

Sustainable Health Enterprises, or SHE, is filling the menstrual pad void in Rwanda, where girls and women miss up to 50 days of work or school annually because of this should-be-easily-fixed problem.

The group has designed feminine hygiene products using banana fiber, a renewable and ubiquitous material in the country, and laid the foundation for a local micro-capital industry. The hope is to also combat the issue on a larger scale using community education and business skills training.

Guatemala: the Bicimaqunas

Maya Pedal is a local nonprofit that makes pedal-powered machines from used bicycles that make household, agricultural, and small business tasks easier for rural residents who have little or no access to electricity.

The mostly volunteer-run group has designs for everything from plowing to shelling nuts to pumping water to washing clothes—and the designs are open-source, meaning anyone is allowed to build them. (Instructions available for download right on their site.)

Visit the Curry Stone Design Prize site for more info, and stay tuned for the $100,000 winner, which will be announced on October 13.