1. Low-flush toilet

A low flush or low flow toilet is a flush toilet that uses significantly less water then a normal flush toilet, using as little as 1.6 gallons per flush as opposed to 7 gallons. They came into use in the ...

2. Experimental Solar Power

... decommissioning in 1989. A solar pond is a pool of salt water (usually 1–2 m deep) that collects and stores solar energy. Solar ponds were first proposed by Dr. Rudolph Bloch in 1948 after he came across ...

3. Solar Lighting

... 1832. In the 20th century artificial lighting became the main source of interior illumination. Daylighting systems collect and distribute sunlight to provide interior illumination; they are passive systems. ...

4. Energy recycling

... came from the production of electricity and 27 percent from the production of heat. History Perhaps the first modern use of energy recycling was done by Thomas Edison. His 1882 Pearl Street Station, the ...