可再生能源水电(英文)

The Sustainability Imperative – Hydropower as a Renewable Energy Resource
Hon. Peter Rae
Chairman, Renewable and Sustainable Energy ROUNDTABLE
THE SUSTAINABILITY IMPERATIVE
Since the 1992 World Summit on Sustainable Development held in Rio de Janeiro, the momentum for sound international responses to climate change has progressively increased. Under the UNFCCC Kyoto Protocol, originally signed by 84 countries (and now ratified by 124), the need to reduce greenhouse gas emissions (GHG), and cap them at 1990 levels, has been widely endorsed. Further development of the Kyoto Protocol may yet take place at COP 10, scheduled for December 2004 in Argentina, if Russia ratifies to bring the Protocol into force. Even the big per capita emitters, US and Australia, who are currently standing outside the Kyoto process, have initiated bi-lateral arrangements under a Climate Action Partnership. And, as recently as August this year, Australia has signed a Memorandum of Understanding with China on Climate Change Cooperation. This will focus on key areas such as emission reductions, renewable energy and technology cooperation.
At the same time as there is a recognition of the need to cap GHG emissions, there is also recognition that energy services are essential for sustainable development. The International Energy Agency (IEA) has estimated that an additional 300 GW of new generating capacity will be required globally in the first two decades of the 21st century. This is estimated to represent a US $ 1.7 trillion investment.
To meet the Millennium Development Goal of halving the number of people living in poverty by 2015, a Framework for Action on Energy was put forward at the World Summit on Sustainable Development (WSSD) in Johannesburg in September 2002. The Summit noted that “with a sense of urgency (there is a need to) substantially increase the global share of renewable energy with the objective of increasing its contribution to total energy supplies”.
The WSSD process also initiated a Renewable Energy Action Agenda, which was progressed at the recent Bonn Renewable Energy Conference in June this year. Meanwhile, the International Energy Agency (IEA) estimates that world energy use will increase steadily through to 2030 with primary energy demand projected to increase by about 1.7% per annum. Sixty percent of this increase is likely to come from developing countries in Asia such as China and India.
There is, therefore, a clear tension between increasing risk of global warming, due to a build up of greenhouse gases (GHG), and a legitimate and growing demand for energy services. Despite the shortcomings of current international arrangements, the need for deep cuts in emissions of 50 –60% over the next 50 to 100 years remain. This poses a challenge to us all as current practices are clearly unsustainable. We are living beyond environmental limits and the root cause is primarily mankind’s ever-increasing demand for energy – energy that in the main is derived from the burning of fossil fuels such as oil, gas and coal.
THE ROLE OF RENEWABLES
Recognising that access to water and energy plays a crucial role in poverty alleviation, we are faced with difficult choices if we are to meet the growing expectations of increasing
energy and water services in a carbon constrained world. Set against this background, it is evident that the whole symphony of renewable energy technologies will continue to have an increasing role to play in meeting the Millennium Development Goals.
Whilst renewable energy resources such as wind, solar and biomass have the potential to add to the supply mix, at this stage they are making only a small contribution to the total electricity market. The contribution from wind is however expanding rapidly, and many countries have ambitious wind energy development programs that will aid the implementation of their Kyoto targets and commitments to cap emissions at 1990 levels.
The world’s most prolific renewable energy resource is hydropower. It supplies some 19% of the world’s demand for electricity and 95% of the world’s supply from renewable resources. In the process it offsets about 2.1 billion tonnes of CO2 that would otherwise be generated had thermal sources been used to supply an equal quantity of electricity. Indeed hydropower typically emits 40 times less greenhouse gas than electricity produced from a modern gas-fired generating system.
The contribution of hydropower to total renewables supplies can be increased through the upgrade and refurbishment of existing infrastructure (many hydro schemes have been in operation for over 40 years) and constructing a range of new development projects. Industry studies suggest that only 33% of the world’s technical and economic potential for hydropower has been developed. The vast majority of the undeveloped potential is in the least developed countries.
So, whilst Europe has developed 75% of its hydro potential, and North America 69%, Africa, South America and Asia have only reached 7%, 22% and 33% of their potential hydro development capacity respectively. This suggests that there is considerable scope for the implementation of new schemes, and that such schemes could be integrated with wider efforts to supply communities and industry with access to water as well as energy. Agriculture can benefit from improved irrigation from hydro impoundments, and biodiversity can be maintained with appropriate management strategies.
There are some 289 GW of new hydropower planned for development in 105 countries. These projects have the potential to deliver multiple use benefits by increasing economic activity, cutting greenhouse gas emissions, reducing poverty and providing synergies with other technologies such as desalination and remote area power supplies.
Never-the-less it has to be acknowledged that the recognition of hydropower as a legitimate renewable energy resource has been questioned by a number of interest groups. In the lead up to Renewables 2004 in Bonn for example, there had been a concern that hydropower would not be recognised as a renewable energy resource on the grounds that new hydro projects would be unlikely to meet pre-requisite WCD guidelines. However, the Political Declaration made at the conclusion of Renewables 2004 gave recognition to hydropower as a renewable energy resource, and further went on to estimate that up to 1 billion people could be given access to energy services from renewable resources - including hydropower. The Political Declaration was signed by 154 countries and is important in the context of future industry development.。