Energy underpins all of human activity, fueling the industrial revolution and facilitating centuries of human progress. However, the vast majority of human-produced greenhouse gas emissions come from energy usage be it from transport, power generation, or industry. Attempting to reduce energy usage and switching to sustainable sources will be one of the defining challenges of the 21st Century.
Incineration is considered the simpliest form of waste treatment. Incineration reduces the volume of waste and the hot gases produced can be used to generate electricity. However, combustion releases carbon dioxide and, dependant on the waste type, toxic gases.
(Image: "Incineration Chamber" by Roonie,02 (My Own) [CC0], via Wikimedia Commons)
What happened to the waste we threw out 20 years ago? The answer could be that it will be reprocessed from landfill sites to produce material or energy.
( Image: "Landfill Face" by Ashley Felton (Own work) [Public domain], via Wikimedia Commons)
Pyrolysis and Gasification are alternative thermal processes of waste treatment where volatile chemicals are stripped from the waste in a hot, deoxygenated atmosphere. The resulting voltatile gases can either be reprocessed and sold as fuel or burnt for direct energy generation.
Up to 60% of all rubbish thrown away can be recycled. Recycling can be an energy and water intensive process but can reduce the energy input over the total life cycle. There are numerous recycling techniques for all types of waste with many new technologies on the horizon.
(Image: "Paper recycling in Ponte a Serraglio" by H005 (Own work) [Public domain], via Wikimedia Commons)
An estimated 290 million tonnes of waste was produced in the UK in 2008. Where did it all go and are we doing enough to reduce the amount of rubbish we create?
(Image: " Shredded Solid Waste" by GST HBK (Own work) [Public domain], via Wikimedia Commons)
Waste autoclaves use high pressure steam to sterilise and reduce the volume of waste before landfilling by up to 60%. High pressure steam causes fibrous organic matter to disintegrate and plasics to soften and flatten.
This is a controversial topic. The technology that can capture up to 90% of the carbon dioxide emissions produced from the use of fossil fuels in electricity generation and industrial processes, preventing the carbon dioxide from entering the atmosphere.
Can we do what nature does better? Novel experiments use specialist equipment and chemicals to convert carbon dioxide into oxygen to produce a useful carbon based fuel.
Carbon offsetting is achieved by compensating carbon emissions with carbon reducing practices. Companies not using their full carbon quotas are able to sell their carbon credits to other companies. Is a carbon market the solution to global warming?
Is the best way to reduce carbon emissions to redesign industrial units to improve efficiency? Engineers are now designing plants with catalysts and processes that do not require as much energy to run for increased profitability as well as environmental benefits.
With increasing quantities of methane gas being released from Arctic permafrost, what are the methods to remove the potent greenhuse gas from the atmosphere?
(Image: "Global Tropospheric Methane for August 2005" by Yikrazuul (NASA/JPL) [Public domain or Public domain], via Wikimedia Commons)
Plankton photosynthesise carbon dioxide into oxygen for growth. Found naturally in the oceans, can we increase plankton numbers to reduce carbon dioxide in the atmosphere?
(Image: "A schematic showing the abundance of plankton in the oceans" by KVDP (Own work) [Public domain], via Wikimedia Commons)
Underground storage of gaseous carbon dioxide may result in future leakage. However, binding of carbon dioixde to abundant minerals and burying these reduces the risk.
In air, fuel rarely burns completely or cleanly. However, in a pure oxygen environment, fuel efficiency increases and virtually all the waste gas will be CO2 and water vapour. Energy is recovered in a heat exchanger which also condenses the water vapour, producing a high purity stream of carbon dixoide for storage.
Increasing levels of carbon dioixde in the atmosphere is leading to global warming. Carbon Capture and Storage aims to either prevent future emissions or remove carbon dioxide from the atmosphere completely.
Furnace fuel gases are bubbled through an absorber column packed with liquid solvents to absorb carbon dioxide in the stream. Medium pressure steam is then passed through to release trapped carbon dioxide, which is transported for storage.
Coal can be gasified to produce a synthetic gas made from carbon monoxide and hydrogen. Carbon monoxide is reacted with water to produce CO2, which is captured, and more hydrogen. It is then hydrogen which is burned to produce electricity.
However, this technology cannot be retro-fitted to current power plants and the economic advantage of this method over post-combustion is yet to be proven.
As deforestation occurs, the planet loses its ability to naturally convert carbon dioixde into oxygen. Can we plant forests quickly enough to prevent further increases in carbon dioxide levels?
Can we process then store pure carbon dioxide underground without consequence? The uses of carbon dioxide gas includes replacing natural gas and oil in underground reservoirs.
Apart from developing new power sources to meet increasing grid demand, will improving industrial and domestic electrical efficiency decrease the country's power usage?
Large subsea power cables connect the UK with the rest of Europe to allow for energy exchange. This allows countries which generate excess or greener power, such as France, to share the benefits in other energy markets.
The gas transmission network moves natural gas from its source to the consumer or to storage. The network stretches right across Europe and in the UK from the North Sea.
Smart meters display real-time costs of household energy usage allowing users to see which appliances use the most amount of energy. With smart meters connected to WiFi, the days of submitting meter readings are over, but will they lead to variable rate and peak energy price charges?
(Image: "Electricity meters inside metering cubicles, Hong Kong" by Mk2010 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons)
Large hydropower stations pump water up to a reservoir during the night for release during peak times, a form of energy storage. With all natural sites now utilised, what is the future of this technology?
Certain types of renewable energy sources are only available under certain conditions; solar requires sun, wind requires wind, and so on. This means energy conversion may not occur at a time where it is required. Energy storage systems allow for controlled release of renewable energy at times of peak demand.
Profits can only be fairly earned through effective market competition. With domestic customers rarely changing suppliers from the 'big six' is the current market working for consumers?
Energy distribution costs are directly related to the peak energy demand in the winter. Known as network capacity, it can be reduced by considerably increasing the price of power during the three highest peaks of the winter months. Heavy power users must manage ther demand to avoid these peaks.
In the 2014/15 tax year, 30% of electricity costs were due to government policy and taxation. With this set to rise to 45% by 2020, what are the policies in place and will they restrict growth of industry in the future?
Coal is any type of solid fossil fuel. It is used to produce electricity and heat through combustion. At least 40% of the worlds electricity is generated from coal. Emitting around 2000 pounds of CO2 for every MWh of power produced, it is the dirtiest power generation technique. Is the future the full phase out of coal power or will breakthrough carbon capture techniques see coal through until we run out?
Coal and coke can be transformed into a mixture of carbon monoxide and hydrogen by the coal gasification process. This mixture then burns as cleanly as natural gas. Is this process a step in the right direction?
Our sources of natural gas are depleting, leading to potential increases in gas prices. One method of extracting new sources of natural gas is fracking. Fracking methods are controversial and have led to a debate on the subject.
Natural gas is extracted from the earth and, with a high methane content, it burns much more cleanly than other fossil fuels. Natural gas combustion is seen as a transitional power source leading the way to much cleaner technologies. Will new discoveries of unconventional gas types or extraction techniques lead to increased use before the power source is completely phased out?
Nuclear fission is the natural process of radioactive decay of large nuclei into smaller ones. The large amount of heat emitted from the process heats water to drive steam turbines. Arguments to whether nuclear power is a safe and sustainable energy source or whether it is a threat to people and the environment are ongoing. Does current research into more efficient fuel cycles and improved waste management techniques deliver a hope for nuclear fission or are we one more accident away from it's demise?
( Image: By Pearson Scott Foresman [Public domain], via Wikimedia Commons)
Nuclear fusion binds two atomic nuclei together to form one heavier nucleus, in doing so releasing large amounts of 'binding energy'. In order to harness this energy, the net useable power must be positive - more energy must be released than inputted to begin the process. There are several different methods currently being investigated by scientists all over the world so how far away is a commerical scale fusion reactor and can they solve the planets energy problems?
(Image: By Hallioli (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commonsi)
Crude oil is a sticky mixture of useful hydrocarbons formed over millions of years from ancient organisms. Crude oil is processed at refineries to separate the many useful products. With oil products being so valuable, it may come as a surprise to some to realise that some refinery's output goes straight into the furnace at a power station. With the oil market being so volatile, will the world's oil reserves be burned by power stations or vehicles and will new types of fuel drive the planet in the future?
( Image: By U.S. Coast Guard photo by Petty Officer 3rd Class Parker Wood (https://www.dvidshub.net/image/1194628) [Public domain], via Wikimedia Commons
Biomass is only a renewable energy source when the rate of extraction is smaller than the rate of production. Plant material is generally burnt, releasing the energy stored during photosynthesis. Improved high-efficiency conversion technologies, like those in the Energy from Waste box, are possibly the future of power production from biomass so long as a sustainable supply can be grown.
Biofuel consist of different methods of fuel production from biological organisms. After processing and refining, bio-molecules, such as bioethanol, can be swapped with crude oil derviatives in fuel. Biofuel combustion still releases carbon dioxide so is it really the most sustainable option?
Hydropower can be produced from any form of moving water; water flowing through a dam, waves on the ocean or the movement of tides. More recently, research has been invested away from the flow of water turning turbines methods. Is the development of efficient and reliable methods of tidal and wave power technologies afloat or are commercial scale plants sailing on the horizion?
Electrical energy can be generated from the geothermal energy created and stored within the Earth. Water is pumped down to the lower crust and the energy from the hot spring produced is harnessed using steam turbines. Will we see an increased use of geothermal sources or will it remain a hot topic?
Solar Power is known through the conversion of the energy from photons of sunlight into electrical energy. Currently solar power has a limited use, but with the development and deployment of more efficient materials for scalable and sustainable photvoltaics, the sun may soon shine brighter for this resource!
(Image: "Full Sunburst over Earth, Giant Photovoltaic Array and Solar Land Area" by Apteva [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons)
Wind power is converted from wind energy by turbines and windmills. Many turbines together are known as a wind farm. Large wind farms can feed electrical power straight into the grid if the wind is neither too weak or strong. With many complaining that wind farms are eyesores, is the future of wind power adrift?
(Image: "San Gorgonio Pass Wind Power Plants" by Jantangring (Own work) [Public domain], via Wikimedia Commons)