When something is renewable it can be used over and over without running out. Hence the term ‘renewables’ which has been given to energy sources that are not depleted when consumed or converted into other forms of energy.
Renewables include solar energy, hydro-electricity, geothermal energy, wave power, and wind power.
Renewable energy technologies have experienced double-digit annual growth rates for more than a decade. Worldwide, the renewable share of additional global power generation (excluding large hydropower) climbed from 5% in 2003 to 23% in 2008.
Currently renewable energy power plants are generally more expensive to build and to operate than coal and natural gas plants. However, the costs of renewable energy are reducing, particularly with solar power. In areas with good wind resources, wind-generating plants have proven to be economically feasible when combined with tax credits.
Reliability of renewables is also a critical issue: wind and solar resources are naturally impacted by weather fluctuations. The generation costs of renewable energy must continue to decrease, and its reliability increase, if it is to make a significant contribution to Australian and global energy security.
In 2009 the Australian Federal Government established, under its Clean Energy Initiative, the Australian Centre for Renewable Energy (ACRE). The aim of ACRE is to promote renewable energy, its enabling technologies, and their competitiveness in Australia, including through funding and the management of development programs.
At least 66 countries have policy targets for renewable energy supply. [PDF] Overseen by the Federal Government’s Office of the Renewable Energy Regulator, the Australian Government’s Renewable Energy Target (RET) aims to ensure 20% of Australia’s electricity supply being generated from renewable sources by 2020. [visualise] The target is considered challenging and represents a four-fold increase on the Mandatory Renewable Energy Target (MRET), which began in 2001, However, the Federal Government believes Australia’s abundant renewable energy sources will enable RET to be achieved.
Through its Renewables Directive, the European Union has also a binding goal to source 20% of the bloc's energy needs from renewable sources by 2020. The United States has set no mandatory renewable energy targets. Despite this, the renewable energy industries are supported with subsidies, feed-in tariffs, tax exemptions, and other financial measures. [PDF] The Obama administration has budgeted more than $108 million in funding for the FY2011 for wind, solar and geothermal energies, plus a further $300 million for the Advanced Research Projects Agency – Energy (ARPA-E) which provides grants to a wide field of energy projects, including renewables.
Wind energy involves the generation of electricity from the naturally occurring power of the wind. It is currently the cheapest renewable energy source.
Wind energy capacity grew by 31% worldwide in 2009, according to the Global Wind Energy Council, a trade association based in Brussels. China accounted for a third of the new capacity. The global market for wind turbine installations is worth US$63 billion.
Harnessing offshore wind offers great potential. Offshore wind stations experience mean wind speeds at a height of 80 meters that are 90% greater than those over land on average. As technology develops and experience is gained, the offshore wind industry plans to move into deeper water and further from the shore.
Europe is the world leader in offshore wind energy generation with a cumulative capacity of 2,056 MW spread across 38 offshore wind farms in nine countries. The EU’s offshore wind power market grew 54% in 2009. It is estimated that 2027 will be the first year in which the EU’s market for offshore wind turbines exceeds its onshore market. [PDF]
Denmark is the leading wind power nation in the world, with wind providing 21% of domestic electricity. Spain is second at 12%, followed by Germany at 7%.
From 2008, more wind power was installed in the EU than any other electricity generating technology. By leading the EU power sector for the first time, wind accounted for 36%, or 8,484 megawatts (MW), of new capacity. Ten EU member states now each have more than 1,000 MW of installed wind energy capacity (Germany, Spain, Denmark, France, Italy, the Netherlands, Portugal, the UK, Sweden and Ireland). [PDF]
Australia currently has 47 operating wind farms, with a total operating capacity of 1476 MW. Around half of the nation’s installed total capacity is in South Australia. A further 6,000 MW of large-scale wind farm energy projects have been proposed, with planning permission already granted.
Solar power harnesses energy from the sun.
It is generated in two ways. The first is directly with photovoltaics - that is, solar panels. The second is indirectly, by concentrating sunlight via lenses or mirrors, and using it to boil water, or a more volatile liquid, which is then used to provide power.
Concentrated photovoltaics uses the same principal of concentrating sunlight to shine it on solar panels to increase efficiencies. Solar photovoltaics are the fastest growing energy technology in the world. Over 1.5 million homes worldwide have rooftop solar PV feeding into a grid. [PDF]
Global uptake of solar energy is increasing dramatically. [visualise] The country with the greatest total PV capacity is Germany. The highest installed capacity per capita is Spain. [PDF]
Despite having the highest average solar radiation of any continent in the world, Australia has only a very small number of working solar thermal power systems. The largest is at the Liddell Power station in the New South Wales Hunter Valley, which is a demonstration plant of around 1.5 MW. However, a larger system is being planned for the site. The CSIRO is also constructing a 0.5 MW solar thermal power station in Mayfield, New South Wales.
In 2009 the Federal Government announced the $1.5 billion Solar Flagships Program to help fund the construction and deployment of up to four large-scale solar power stations of around 250 megawatts, of which two can be solar thermal.
Around 7% of Australian households use solar energy for heating water. Government incentives have also encouraged PV installations to rise dramatically in recent years: between 2007 and 2008 there was an increase of 80%. Of this, nearly 69% were grid-connected. [PDF]
Solar Credits are a Federal Government incentive that offers tradeable Renewable Energy Certificates (RECs) for the installation of eligible small-scale solar PV, wind and hydro electricity systems. Generally owners transfer the right to create RECs to their installer in return for a discount on the price of the system being installed.
Further support for the installation of PVs is provided under the Australian Government’s Solar Cities Program. The cities in the program are Adelaide, Alice Springs, Blacktown, Central Victoria, Moreland, Perth and Townsville.
The current cost of solar energy remains one the largest impediments to its growth: compared to hydrocarbon fuels it is significantly higher.
Whereas coal-derived electricity averages about 5 cents per kilowatt hour, photovoltaic generated solar power averages about 20 cents per kilowatt hour, depending on whether it is generated at a solar power plant or on a house or small building.
However, recent improvements in photovoltaic systems and solar reflectors have the promise to improve operating efficiencies and decrease costs substantially in the next decade.
Geothermal energy is derived from heat transferred from the Earth's interior. This can be by means of steam, hot water, or hot rocks lying fairly close to the surface.
Direct-use of geothermal energy is primarily using for heating and cooling buildings: more than two million groundsource heat pumps are used in 30 countries for this purpose. [PDF]
The top five countries using geothermal directly for heat pumps, district heating, and heating water are China, Sweden, USA, Turkey and Iceland. [PDF]
The top five countries using geothermal energy for electricity production, in terms of running capacity, are the U.S., Philippines, Mexico, Indonesia, and Italy. [PDF]
Here in Australia, the Federal Government body Geoscience Australia has established a geothermal energy project aimed at improving knowledge of geothermal resources in Austalia, and encouraging their use.
The Federal Government is also providing funding for two demonstration projects. The first is the Geodynamics 25 MW Geothermal Demonstration Project in the Cooper Basin in South Australia, which is expected to be commissioned in 2013. It will be the world’s first multi-well hot fractured rock powerplant.
The second is the 30MW Paralana Geothermal Energy Project adjacent to the Beverley uranium mine in South Australia. It is expected to produce Australia’s first commercial flows of geothermal energy in 2010.
Overall reliability of geothermal plants remains an issue requiring further development: estimates of the aggregate operating time of geothermal plants in the U.S. range from 80% to a low of 65%. This is due to the sometimes harsh nature of naturally produced steam.
Geothermal powerplants also have high upfront costs. However, at least two recent reports have suggested that geothermal energy is cheaper than coal when tax incentives and low interest rates are available for powerplant construction.
Hydro
Hydroelectric power is the world’s most important source of renewable energy, representing 19% of total electricity production.
The vast majority of this is produced by hydroelectricity, where electricity is generated through the gravitational force of falling or flowing water. China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the U.S. Hydroelectric plants range in size from small units generating 1 MW to the world’s largest, China’s Three Gorges Dam, which generates 18,200 MW.
The continued development of hydroelectricity is hampered by the high investment costs of dams, their environmental impacts, and their need for reliable supplies of fresh water.
With the exceptions of Tasmania and the Snowy Mountains, Australia generally lacks the rainfall and topography for major hydroelectric development. Tasmania is the only state that uses hydroelectric power as the main means of electricity, but drought affects its generating capacity. The Snowy Mountains Scheme, completed in 1974, remains the largest hydroelectric complex in Australia, with a generating capacity of 3,756MW.
Ocean Energy
The other source of power from water is ocean energy. This can be tapped and used to generate electricity in three main ways. The first is thermal: by extracting energy from the temperature difference between the ocean’s warm surface waters and deeper colder waters. The second is wave: by harnessing the mechanical energy of surface waves, and pressure variations below the ocean’s surface, using buoys, platforms, and other devices. The third source of power from ocean energy is tidal: by capturing the mechanical energy in tidal flows using barrages, dams, and other means.
As a relatively recent technology most projects are at the prototype or testing phase, but it is already clear that ocean power offers enormous potential as a renewable energy source. France has led with the world with a tidal power station at Rance River, in the north-west of the country, which has been operating continuously since 1966.
With our vast coastline, Australia has the potential to reap the benefits of ocean energy in the future. Currently there is only one wave powered generation plant operating. Situated at Port Kembla in NSW, it generates 0.5 megawatts.
The Federal Government has granted $66.4 million for construction of a 19 MW wave energy power plant off Portland, Victoria. Another smaller plant near Fremantle in Western Australia that will generate 5MW is also planned. Around Australia, a further 915 megawatts of ocean power is currently being evaluated.
Biomass energy is the solar energy stored in plants through photosynthesis.
Biomass energy projects use chemical, bacterial, and thermal techniques to convert this energy from trees, crops, and the plant waste of other industrial processes.
Biomass energy can be used for direct heating, to generate electricity, or converted into liquid fuels, called ‘biofuels’. Combined, this energy source represents about 14% of the world’s primary energy supply. [PDF]
The largest biomass energy resource is currently wood. Pulping liquor - a waste product from the pulp, paper and paperboard industries - is the principal fuel source. The second largest source of biomass energy is from municipal solid waste, manufacturing waste, and landfill gas.
Despite being a renewable resource, biomass energy production can have both positive and negative environmental impacts. The combustion or gasification of its fuels generates emissions, including CO2 and particulates. Other significant environmental impacts can result from the growing and harvesting of timber and crops for biomass energy, and the transport and storage of them. On the other hand, growing more biomass can also remove CO2 from the atmosphere.
The cost of biomass energy varies depending on financing, location, power plant design and the costs of its fuel. Electricity generated by biomass is still more expensive than that generated by coal or gas, but improved gasification systems could reduce costs to a few cents per kilowatt hour.
The world’s leading country in the use of biomass is Finland: almost 30% of total primary energy consumption is met by biomass, including 20% of its electricity.
Abundant resources and favourable government policies are enabling bio-power to expand in Northern Europe (mostly co-generation from wood residues), and in countries producing sugar cane pulp. In both the OECD and emerging economies small projects are also proliferating. [PDF] The US government has mandated that biofuel production is to be increased to 36 billion gallons by 2022, with 21 billion gallons to come from advanced biofuels, defined as those that cut greenhouse gas emissions by at least 50%.
Despite Australia having an abundance of biomass resources, bioenergy supplies only 0.9% of our total electricity supply. In early 2007, the Federal Government commissioned the development of the Australian Bioenergy Roadmap to create a national development policy. The Roadmap’s appraisal of resources resulted in a bioenergy target being set for electricity generation by 2020 of almost 4%. [PDF]
Carbon offsets are financial credits that organisations and individuals can purchase to ‘offset’ the greenhouse gases they generate by investing in activities that reduce emissions, or sequester CO2.
Carbon offset projects most typically invest in tree planting, energy efficiency projects, the avoidance of methane emissions, and renewable energy. The most recent estimate of the global carbon market puts its worth at US$126 billion. [PDF]
Carbon offsets are measured in metric tons of carbon dioxide-equivalent (CO2-e), and may represent six primary categories of greenhouse gases. As well as being purchased voluntarily, carbon offsets are purchased by governments and businesses to help meet CO2 emissions compliance targets, such as the Kyoto Protocol.
A variety of quality international standards for carbon offsets have emerged, including the Clean Development Mechanism, the Voluntary Carbon Standard, and the Gold Standard for voluntary emission reductions.
In Australia, the National Carbon Offset Standard provides official guidance for businesses and consumers on what constitutes a genuine, additional voluntary carbon offset.
More information
Expanding clean energy through carbon capture and renewables, isn't enough to reduce current carbon dioxide emissions to meaningful levels. Achieving greater energy efficiency is also critical.
Improving energy efficiency impacts on every facet of modern life, including buildings, appliances, transport, and processes- from the generation of energy to manufacturing. Energy efficiency is not just about systems: it requires changing human behaviour. If people aren't committed to it, it doesn't happen. [PDF] This is why governments and organisations are investing so heavily in energy efficiency education and training to further encourage its uptake. And here on NewGenCoal, we provide you with a daily update of Actions you and your colleagues, family and networks can take to use energy more efficiently.
Taking personal and collective action is critical. Without achieving greater energy efficiency, the global growth in energy demand will outstrip the positive contributions of clean energy. One estimate suggests that growth in global energy demand could be halved if US$170 billion was invested in efforts to boost energy efficiency before 2020. As well as making positive inroads to tackle climate change, the cost savings would be significant.
Of the countries with the largest GDP, the most energy-efficient is Japan, followed by Denmark, and Switzerland. With no oil resources, all three have aggressively adopted energy efficiency to reduce their fuel bills, and to also control their emissions. The EU has pledged to cut its annual consumption of primary energy by 20% by 2020. To achieve this it is working to motivate the public, decision-makers and market operators, and also set minimum energy efficiency standards and rules on labelling for products, services and infrastructure.
In the US, the American Clean Energy and Security Act (2009) aims to cap national greenhouse gas emissions by 17% by 2020. Besides new renewable requirements for utilities, and incentives for carbon capture and storage technologies, the Act includes energy efficiency incentives for homes and buildings.
Here in Australia, is estimated that an increased uptake of commercial energy efficiency opportunities could improve Australia's GDP by almost A$1 billion a year. Energy Efficiency Opportunities is a Federal Government program which encourages large energy-using businesses to improve their energy efficiency. Participation in Energy Efficiency Opportunities is mandatory for corporations that use more than 0.5 petajoules of energy per year. There are more than 220 corporations (incorporating around 1200 subsidiaries) currently registered with the program. They are required to undertake detailed energy assessments in order to identify opportunities to improve energy use, and to report publicly on the outcomes.
The Federal Government also operates a broad range of support initiatives for householders to encourage domestic energy efficiencies, like solar hot water, and energy ratings.
The Government is also working with energy suppliers to introduce smart energy meters, which identify consumption in more detail than conventional meters.
If you have ideas about how to be more energy efficient, we encourage you to submit them here. Every action and every idea adds up to make a big difference.
In terms of energy efficiency coal too already plays a role in reducing greenhouse gas emissions through use of advanced power generation technologies, such as Supercritical and Ultra-Supercritical power generation technologies.
Incorporating carbon capture and storage (CCS) technologies into coal-fired power stations is essential if we are to reduce greenhouse gas (GHG) emissions from coal. Equally important is improving the efficiency of coal-fired power plants so they generate more electricity from the same amount of coal. With more efficient use of coal to meet our electricity needs, GHG emissions will be lower. This is achieved through the use of supercritical (SC) and ultra-supercritical (USC) coal-fired power plants.
Conventional electricity generation using pulverised coal (PC) produces most of Australia's electricity, having been used as the technology of choice since the 1950's. Improvements since those early plants have led to increased thermal efficiency allowing later plants to produce more electricity from the same amount of coal. In the 1970's, typical thermal efficiencies of power stations were around 23%. By the 1980's, the efficiency of the new plants being built had been increased to around 35% using steam temperatures of 538 degrees Centigrade.
Developments in materials science have produced new metal alloys which have allowed power stations to use higher pressure and higher temperature in the boilers and steam turbines above the critical point for steam. The progression through Supercritical (SC) and Ultra-Supercritical (USC) generation plants (using steam temperatures of 565 and 600 degrees Centigrade respectively) continue this improvement path.
The late 1990s saw the introduction of Supercritical plants into Australia with the construction of Callide C, Tarong North, Millmerran and Kogan Creek Power Stations. These stations run at around 40% efficiency. The construction of these new supercritical plants to replace the plants from the 1970's reduces energy input, and therefore GHG emissions, by 42% per unit of electricity.
While Ultra-Supercritical power generation technology has been available as demonstration plant since the late 1990's it has only more recently become commercially available. There are no USC plants in Australia as yet. Most recent plants being built in China are USC and these plants deliver efficiencies around 42%.
Further development is underway with a new generation of higher temperature Advanced Super-Critical (ASC) plants undergoing testing. These plants will increase steam temperatures from around 600 degrees Centigrade used for USC plants to 700 degrees Centigrade and will lift thermal efficiencies further to above 50%.
The improvements in efficiency are important for two reasons. As mentioned above, they result in decreases in GHG emissions. A further significant advantage is that the increased efficiency improves the economics, and therefore the feasibility, of fitting Carbon Capture and Storage (CCS) to SC and USC plants. This is because the higher efficiency plant has the double benefit of not only reducing the quantity (tonnes) of GHG required to be captured but also reducing the amount of energy required to capture each tonne.
Supercritical and Ultra-Supercritical coal fired power stations are proven technologies that have been adopted in many countries. By reducing GHG emissions, they will facilitate the introduction of CCS to coal fired plants that will continue to provide the cheap electricity Australia relies on. The next generation of Advanced Supercritical power stations are currently being developed which will further improve efficiencies and the ability to fit CCS.