What is renewable energy?
Renewable energy is the term used to describe energy flows that occur naturally and continuously in the environment, such as energy from the wind, waves or tides. The origin of the majority of these sources can be traced back to either the sun (energy from the sun helps to drive the earth’s weather patterns) or the gravitational effects of the sun and the moon. This means that these sources are essentially inexhaustible. The key issue is how to extract this energy as effectively as possible and convert it into more useful forms of energy. This can range from directly using the energy from the sun to heat water to using mechanical devices, such as wind turbines, to convert the kinetic energy in the wind into electrical energy.
Why use renewable energy?
Climate change. Energy underpins virtually every aspect of our economy and day-to-day lives. However, the use of fossil fuels, which currently provide the bulk of our energy, releases greenhouse gases (such as carbon dioxide) into the atmosphere. Due to factors such as population growth and changes in lifestyle, the demand for energy has increased to levels where the burning of fossil fuels is releasing enough greenhouse gases into the atmosphere to begin to directly affect our climate system.
There is now a scientific consensus that climate change is real and that it poses an immense threat to the world we live in. Impacts of climate change will make global problems such as drought, famine, flooding, disease, regional insecurity and population displacements worse, and seriously hinder poor countries’ efforts to tackle poverty.
To help lessen the effects of climate change, we must reduce the level of greenhouse gases emitted. This can be achieved by generating our energy from sources that emit low or even zero levels of greenhouse gases, such as renewable energy. We can also make sure that we use energy as efficiently as possible. However, these are not either/or options.
General pollution
As well as countering the effects of climate change, using renewable energy will also help to reduce other forms of environmental and social damage arising from the use of fossil fuels. For example, it will minimize the impact of acid rain on water and forest ecosystems, or reduce localized air pollution and its subsequent health impacts.
Security of supply
Another important reason for alternative forms of energy is security of supply. We need to take steps to make sure that we continue to have the energy that is vital for our economy. The energy industry still relies on finite, diminishing sources of fossil fuel such as coal, oil and gas. Using indigenous renewable sources of energy will reduce our dependence on imported fossil fuels and will bring diversity and security of supply to the energy infrastructure, as well as helping to improve the environment and minimize the impact of climate change.
Which renewable energy source provides the greatest contribution at the moment?
Biomass. Biomass includes electricity generation from landfill gas, the biodegradable portion of municipal solid waste, and co-firing of biomass.
Which renewable energy source is growing most quickly?
Wind energy, both onshore and offshore.
How efficient are renewable energy technologies?
The efficiency of renewable energy technologies can vary markedly. For example, the efficiency with which a hydro plant converts the potential energy of running water into electrical energy is around 90 per cent, but the efficiency with which a commercial solar cell converts solar energy into electrical energy is currently only around 10 to 15 per cent. However, comparing the efficiency of renewable energy technologies with others, such as gas turbines or coal plants, can be misleading because for the majority of renewable technologies the fuel is free. A more useful comparison is the cost to generate a unit of energy.
Aren’t Renewables expensive?
With the exception of large hydropower plants, most renewable energy is not as economic as fossil fuel generation – although landfill gas and onshore wind in favorable locations are becoming reasonably close. However, there is significant scope for cost reduction. For example, wind costs have declined by over 80 per cent in the last two decades, with room for further improvement. Many renewable technologies are expected to become cost-competitive with fossil fuels in the next 10 to 20 years, especially as fossil fuel prices rise as reserves begin to decline. Renewable energy’s competitiveness will also be enhanced by policies that begin to incorporate the environmental and social costs of using fossil fuels, which are not currently reflected in their price (such as global warming, acid rain, air pollution and its effect on human health, etc).
Does the use of biomass involve a lot of antisocial odors and emissions?
Properly designed combustion chambers used for the burning of biomass will minimize emissions of particulates and poly-aromatic hydrocarbons (PAHs) to the atmosphere. The atmospheric emissions from a 1-megawatt woodchip-fired biomass boiler used to provide district heating are equivalent to the emissions produced by a single domestic coal fire. Anaerobic digestion treatment stabilizes slurries, significantly reducing odors. A properly managed anaerobic digestion scheme will also contain the intense nutrients found in animal slurries and food residues which can otherwise leach out in high concentrations and pollute soil and water courses.
How much potential for geothermal power is there?
Geothermal power, using high temperature grades of heat, is only relevant to certain geographical and geologically suitable areas. It requires the presence of ‘hot rocks’ that are fractured and relatively near to the surface, and that can be tapped into by drilling. Advances in drilling technology have increased the interest in this area.
Geothermal hot water with medium temperatures provides energy for a combined heat and power system and dominates the binary type plants commonly installed in the US. Ground-source heat pumps, which exploit lower grades of thermal energy (10–20°C) just beneath the surface, have much greater potential in the US, and can provide a highly efficient method of heating.
Murphy International works to provide reliable, affordable energy, produced in a safe and environmentally responsible manner. As part of our broader energy development strategy, we are actively engaged in developing cleaner, diversified energy resources that are commercially competitive. Our approach to pursuing potential energy sources is based on the fact that such investments compete in the marketplace against conventional energy sources and must be considered in context of the Company's broader energy development strategy.
Murphy International is actively pursuing selected renewable energy technologies as part of a larger effort that includes investing in alternative energy sources, energy efficiency, cleaner fuels, natural gas, gas-to-liquids, and other promising advanced energy sources and technology. The Company's objective is to maintain a balanced, economically sound energy portfolio while continually working to minimize the environmental impacts of energy development and use.
Murphy International
Development, LLC
65 Redding Road
Georgetown, CT
06829-0807 USA
phone: (203) 544-8303
info@murphyintldev.com
Murphy International Development services independent power producers and developers of renewable and conventional plants including; solar, wind, Biomass, hydroelectric, geothermal, CHP, cogeneration and alternative fuels projects.
