The sun powers our earth, bringing energy to every living thing. We receive most of our energy indirectly through processes like photosynthesis. Photosynthesis is a process in plants and other organisms that converts light energy from the sun into chemical energy. This chemical energy, made up of carbon dioxide and water, is a food source for plants. In turn, the plant transforms the carbon dioxide and water into oxygen and glucose. Many ancient people respected the sun as a powerful symbol. Today, human ingenuity and technological advancement harness the power of the sun, along with wind, water, and heat from the earth. The earth provides renewable energy sources that regenerate throughout our lifetime and irreplaceable, non-renewable energy sources that do not regenerate. Petroleum, natural gas, coal, and nuclear electricity are not renewable in one lifetime and, in many cases, in generations. Hydropower, biofuels, wood, wind, and solar are renewable energy sources.
Currently, renewable resources make up only a small portion of the energy produced by the United States. However, organizations like Architecture 2030 are working to utilize solar, wind, hydropower, and other renewable energy sources to power the energy needs of urban life. The largest renewable power source of electricity in the United States is hydropower. Scientists, engineers, mathematicians, and technologists research new forms of clean, renewable energy to power human needs. Utilizing natural forces for energy production leads to power diversification, new jobs, energy savings, and reduced greenhouse gas emissions.
Nature fuels us!
Activity 1 – Solar Energy
Energy exists above us in the radiant heat from the sun. One hour of sunshine on earth could satisfy global energy needs for an entire year if we were able to harness it! Solar power and solar thermal panels mounted on roofs of houses and buildings are becoming more visible in our communities. Solar thermal, more efficient and less expensive than some other forms of energy production, provides hot water for homes while solar cell collectors generate electricity. Fields of solar panels locally harness the sun for larger corporate buildings without dirtying the air or needing cross-country distribution. Solar power collected at point sources wherever the sun shines fuels our buildings and our cities. Germany is currently leading the world in point source solar collection. The solar industry is growing! Check out NEXT.cc’s Solar Energy Journey and draw a diagram of the flow of energy from the sun as it travels through a solar panel to a transformer to an electrical plant.
Activity 3 – Geothermal
Renewable energy exists underground, just beneath our feet! Have you ever noticed how cool a basement is in the summer and how warm it is in the winter? Geothermal energy draws warmth when it is cold and coolness when it is hot from the constant temperature of the earth itself. Did you know that below the earth’s crust, the average temperature year round is 45-75˚F? Digging deeper, geothermal draws from the temperature of hot water beneath the surface and, even lower, from the steam of molten rock. Iceland produces 25% of its electricity using geothermal. Look at this house changing 55 degrees to warm a house in the winter and to cool a house in the summer! The 55 degrees offsets winter range of temperatures -10-40 degrees and summer range of temperature from 60 - 95 degrees. Make a thermal diagram of an office building circulating water underground for heating.
Activity 5 – Biomass
Biomass energy is stored energy from the sun retrieved from the decay of living organisms. Biomass converts to methane gas or ethanol and biodiesel fuels. When directly burned, chemical energy is released as heat. For example, wood and wood waste heat buildings when burned in chimneys and stoves. Drawing off gases from decaying algae blooms, grass cuttings, and even forest residue, stored energy is released through the natural process of decay. Landfills full of crops and waste materials generate electricity when burned, which converts to biogas. Methane gas is a derivative of landfill gas. Biogas discharges when garbage and other waste decomposes in digesters. Sugar and corn crops ferment and produce ethanol fuel for cars. Animal fats and vegetable oils ferment and produce biodiesel fuels. Brazil powers 21% of its industrial sector with biomass energy. Currently, biomass fuels about 5% of United States energy production with 43% from wood biomass, 46% from biofuels, and about 11% from landfills. Draw a pie chart of the percentages of bio fuel production.