Emerging Green Technologies
As the demand for cleaner, renewable energy sources increases, so does the need for more efficient methods of energy production, transmission, and storage. Emerging Green Technologies (EGTs) are those systems of energy generation either in their early stages of development, or for which there remain relatively low market shares or global interest.
As well as being environmentally friendly, these systems provide social and economic benefits. They produce less waste, and have little to no bearing on surrounding communities. Many require only routine operational maintenance, comparatively less commitment of further resources, and some serve to recycle waste produced by other industries.
Of the following EGTs, some are in the early or hypothetical stages of development, while others have been implemented for some time, albeit on a small scale. Nevertheless, they show great promise for the future of energy storage and generation.
Ocean thermal energy conversion:
Ocean thermal energy conversion (OTEC) uses the temperature difference between warmer surface seawater and cooler, deep seawater to operate a heat engine; running a turbine and so generating electricity. Regarding what resources are needed to manage this technology, a closed system does require certain coolants, yet an open system requires only water.
Although an ideal OTEC system could be used as a base load power source, current systems lack the thermal efficiency to make them viable. However, a continuously operating OTEC system has been running since 2013 in the Okinawa Prefecture, Japan, and further instalments have been planned for use in Hawaii, The Virgin Islands, and The Bahamas. Since OTEC relies upon warm water, this technology works best in tropical climates.
One of the best features of any OTEC system is its versatility. The system discharges fresh water and cold water, meaning its ‘waste’ could be used in aquaculture, air-conditioning, desalination, and chilled-soil agriculture. The system can also produce hydrogen via electrolysis.
Hydrogen-oxygen fuel cell:
This fuel cell combines hydrogen and oxygen to make water: A chemical process that produces heat, which can in turn be used to generate electricity. As the only by-product is water, and oxygen abounds, it would be a perfect system were it not for the relative scarcity of hydrogen. This has prompted various projects into hydrogen production, such as the Bush Administration’s 2003 Hydrogen Fuel Initiative. However, whether a hydrogen economy would be feasible, sustainable, manageable, or even possible, remains a point of contention among researchers.
Regardless, the hydrogen-oxygen fuel cell has some serious benefits. Provided this system receives a constant influx of chemicals it will never run out as do conventional fuel cells, such as batteries. Such reliability has seen this fuel cell used in submarines, spacecraft, and remote outposts, like weather stations.
Photovoltaic energy systems convert sunlight into electricity. Solar panels and solar cells have been in use for the past 50 years, becoming widely available after a government-funded programme in Germany in 2000. Whereas the cells on solar panels are dark and opaque, scientists have spent years attempting to create transparent solar panels–which could take the place of glass. Early attempts failed: Where it was possible to lighten the glass itself, the efficiency of the system itself suffered drastically due to power loss.
This problem has largely been overcome by converting the light to electricity in the panel of glass itself, yet the price of photovoltaic glass remains quite high, making it inaccessible to the general public. However, the potential in this method of generating power is immense: Whole skyscraper facades could be used to power the buildings themselves; greenhouses could power their own heating systems; and smartphones could solar-charge their batteries through the screen.