The phenomenon of urban heat islands has been well known since the 19th century. The materials from which city buildings and roads are made reflect much less solar radiation and absorb more of it than the vegetation they have replaced. The absorbed energy is then radiated in the form of heat into the surrounding air making cities warmer.
In recent decades, ocean temperatures in many places have warmed by nearly 3 degrees Fahrenheit. An effect of this warmer water is the decimation of what were once luxuriant giant kelp forests in eastern Australia and Tasmania. There used to be thick canopies covering much of the region’s coastal sea surface, but they have wilted in the intolerably warm and nutrient-poor water.
Researchers at Columbia University have demonstrated a potential new energy harvesting technique based on the natural evaporation of water. Every day, vast amounts of water evaporate from the surfaces of lakes and rivers, a process powered by the heat energy of the sun. The amount of energy involved is enormous but generally speaking is not something we can tap into.
One of the most exciting possibilities for future solar energy technology is that of solar cells that can be sprayed or printed on to surfaces like the windows of skyscrapers, the roofs of sports utility vehicles, or the walls of houses. And the expectation is that such technology would be far cheaper than today’s silicon-based solar panels.
Installing solar arrays on the surface of bodies of water is an idea that is catching on around the world. Such installations are especially attractive in places like Japan, where land resources are scarce. In the UK, there are a couple of these so-called “floatovoltaic” projects underway – one outside of London and one near Manchester.
