Thermogalvanic Effect: Harnessing Waste Heat

By: Kaylee Verhoeven

The discovery of fire was a turning point in human history, it offered portable warmth, light, protection, and a new way of preparing food. It was also one of mankind’s most successful attempts to harness energy. Because energy is almost always lost in the harvesting phase, researchers around the world have spent decades seeking ways to harness this wasted energy.

Researchers at MIT and Stanford have found a new way to transform waste heat into electricity. Electricity is considered high-grade energy because it can be converted into other forms of energy for use and storage without significant losses. Thermal energy is low-grade energy, which means that attempts to transform heat back into other forms of energy is costly and inefficient. Most of the time, thermal energy is written off as waste heat and released into the environment. Converting low-grade energy back into high-grade energy is an uphill battle, but there are new thermoelectric products that could be our best bet. Efficient and low-cost thermal energy-harvesting systems are needed to utilize the tremendous low-grade heat sources.

The new technology uses available materials and could be used to recycle the large amounts of wasted heat generated in industrial processes and electric power plants. The new system allows waste heat to raise the temperature of a battery, and thanks to the thermogalvanic effect, the battery can now be charged at a lower voltage than would normally be required. The battery is then cooled down, and because the charging voltage is lower at high temperatures than at low temperatures, once it has cooled the battery can deliver more electricity than what was used to charge it. That extra energy, of course, does not just appear from nowhere: it comes from the heat that was added to the system.

Imagine the potential of thermoelectric-powered devices, Engineers are working diligently to find the most cost-effective approach and I don’t know about you but just the possibility of charging a cell phone by using body heat is something to look forward to!

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A Bi-Directional Method for Bionic Design

By: Kaylee Verhoeven

This paper is available for 2 PDH credits towards your PE license

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The World's First Seawater and Solar Powered Farm

By: Kaylee Verhoeven

A state-of-the-art tomato farm has begun operations in Port Augusta, Australia. What makes this farm unique is that it runs completely on seawater and solar power. There are tomatoes growing in the desert! Thanks to the efforts of Sundrop Farms Holdings LTD 37,000 lbs of tomatoes will be on shelves every year. This is paramount since traditional agriculture is wasteful in terms of water and fossil fuels. Instead of soil, pesticides, fossil fuels, and groundwater, Sundrop Farms uses only Solar Power and desalinated seawater on its 49-acre farm.

The increase in population has influenced scientists, researchers, government officials and many other professionals to address food, water, and energy shortages. In this pilot facility, water is pumped from the Spencer Gulf 1.2 miles and then desalinated with solar power. The farm's solar power is generated by 23,000 mirrors that reflect sunlight towards a 377ft high receiving tower. 118 million gallons of fresh water each year, will be created. That’s 180 Olympic sized swimming pools. This process makes it the optimal environment to grow tomatoes. Seawater-soaked cardboard keeps the plants cool and solar heat keeps the greenhouse warm in winter months. The seawater sterilizes the air and plants are grown in coconut husks allowing them to thrive without pesticides.

Extreme weather events make it difficult to consistently provide consumers with products each year. Agriculture in different areas is devastated by weather. One solution to this problem was put to the test last week during a once-in-50-year storm that wreaked havoc in South Australia. Sundrop Farms was able to take the brunt of high winds and continue operations despite a massive blackout that crippled many industries in the areas making them inoperable. While other companies suffered massive setbacks Sundrop Farms is "living proof" that its groundbreaking technology could work on a large scale.

Other solar/seawater farms are being developed from the U.S. to Portugal and Africa. Each company and facility will be fulfilling local needs as well as sculpting the agriculture of tomorrow.

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