The Raiki project is a biological microgrid for underprivileged urban and areal areas that takes advantage of the natural functions of plants combined with energy harvesting technology. The biological plant design is based on the research of current tree functions, triboelectric technology, incorporating data on wind velocities, and leaf shape analysis.

The Raiki project has been presented at The Biodesign Challenge in New York, Dubai Design Week in Dubai and Design Indaba in Cape Town.

BACKGROUND – It is estimated that today, 1 in every eight people still have no access to electric energy, a problem that has a big impact rural areas in developing countries, that is why “Ensuring access to affordable, reliable, sustainable and modern energy” is the UN’s 7th sustainable development goal and one of the biggest global environmental and health challenges today.

Most common attempts for renewable and sustainable energy sources are facing unexpected environmental challenges considering the growing need for energy. They affect wildlife, plant population and people’s lives and perception of landscapes in a negative way.

OFF-THE-GRID – Off-grid solutions are a growing topic of research as a way of diminishing the dependency of energy from big power plants such as nuclear and hydroelectric, by providing energy generated locally, with less energy waste during transportation from source to consumer, and less material and infrastructure necessary to transport this energy through long distances, being excellent alternatives especially for places with difficult access to the energy where solar and wind power are usually used, with significant negative impact.

From fuel cells to nanoscale energy harvesting, microgrids and distributed networks can also be extremely supportive during disasters such as earthquakes and storms, events that can interrupt the energy supply and communication systems.

DESIGN – The design is based on the research of current tree functions and its material compositions, triboelectric technology, incorporating data on wind velocities and leaf shape analysis for the design of its leaves. Raiki main requirement is that its leaves have optimized movement in the wind: the more contact times the bigger is the energy output.

The effectiveness of a triboelectric energy harvester depends on the tree height, branch and leaf distribution, leaf shape, composition, area, and area of contact with a second surface, necessary for contact electrification of the leaf. These aspects formed the basis for the shape design for a different aspect of our tree: Raiki is a structure designed to grow under ideal weather and care conditions at a 5-year pace.

TECHNOLOGY – In order to transform a tree into a real efficient energy source and harvester we used and researched triboelectric and plant synthetic biology techniques. Our tree will grow naturally and as it grows it will take the ideal shape it was designed to have.

Triboelectric nanogenerators (TENG) are based on triboelectrification and electrostatic conjunction and through this materials can become electrically charged when, by touching, pressing or rubbing, they come in contact with another material according to their charge affinities and the charges can be conducted out of the surface through an electrode to be used as electrical energy.