9 months ago

Climate Action 2011-2012

Steps to Sustainability

Steps to Sustainability hydropower © iStockphoto Hydropower has a global installed capacity of around 950GW. Hydropower and climate change 142 By Cameron Ironside, Programme Director, International Hydropower Association (IHA) Hydropower already satisfies a significant portion of the world’s energy requirements. Its influence will increase in a climate changed world as it not only facilitates adaptation through water storage, but also enables the large-scale integration of renewables into energy systems. Hydropower plays a unique role in advancing global renewable energy systems and has the ability to respond to global energy needs. Hydropower is a renewable energy source generating electricity through the movement of water from a higher to lower elevation. Its energy conversion rate of 90 per cent is the highest of any known energy source. Hydropower has a global installed capacity of around 950GW – 19 per cent of worldwide installed electricity capacity – and generates approximately 16 per cent of the electricity used worldwide. This installed capacity represents a small portion of international hydropower potential, especially in the areas where it will be most required in a climate changed world. For example, Africa currently only utilises approximately five per cent of its hydropower potential. Impact of a changIng clImate on hydropower It is clear that changes in climate will impact on hydropower: as different areas go through climatic changes, these changes will impact on the rivers that feed hydrological systems. The changes in river runoff will thus dictate the changes to the availability of hydropower as a resource. While there are currently no global figures predicting the effects of climate change on the technology, a recent study by Hamadudu and Killingtviet (2010) which analysed the changes to river flows, as predicted by 12 different climate models, to consider the effects globally on existing hydropower, provides some indication: while the results indicate significant changes on a country or regional level, they suggest that the total global change to the hydropower system is small (around 2.5 per cent). Hydropower has a role to play in both mitigating against and adapting to the effects of climate change. These results match the anecdotal evidence from within the membership of the IHA. While some countries, such as Australia, are already experiencing negative impacts, others such as Norway are anticipating increases in potential. Again, while more detailed studies are required, it is clear that changes will vary by region and will be both positive and negative. Currently, it is thought that the overall impact will be small, and possibly slightly positive.

Upper Reservoir Pumped storage in action. High demand/Generation Power Station Low demand/Pumping Lower Reservoir hydropower’S role In a clImate changed world Hydropower has a role to play in both mitigating against and adapting to the effects of climate change. The UN Climate Change Conference in Cancún provided an acknowledgement that adaptation must be addressed with the same priority as mitigation with the establishment of the Cancún Adaptation Framework. A central pillar of adaptation is water, and within the negotiations there was recognition of the need to better manage water, most importantly the need for storage to ensure flexibility and address supply issues. Hydropower has a key role to play in developing this capacity. It is one of the few users of stored water able to provide substantial revenue streams that can fund the required infrastructure. As the variability of water supply increases and demands further storage and management, hydropower provides a means both of supplying clean renewable energy, and funding infrastructure development. In mitigating against the impacts of climate change, hydropower plays a role both as a renewable energy in its own right, and as an enabler of other renewable technologies. It provides a large portion of the current mix of renewable energy, representing around 80 per cent of currently installed renewable capacity, and as it has been used for over 100 years is considered technologically advanced. In the form of dams, it provides numerous ancillary benefits such as storage (as mentioned above), flood control, irrigation and recreation. Hydropower offers both base load provision, for example through large run of river hydropower SuStaInabIlIty aSSeSSment protocol If sustainability aspects are not taken into consideration, construction and operation of hydropower dams can have significant environmental (e.g. adverse impacts on natural river systems and quality and security of drinking water, wetland destruction) and social impacts (e.g. forced displacements, adverse effects on of agricultural and fishing activities). Reflecting the recognition of its increasingly important role, the hydropower industry has worked with concerned stakeholders and partners over the past three years to develop the Hydropower Sustainability Assessment Protocol. The Protocol is an enhanced sustainability assessment tool which is being used to measure and guide performance in the hydropower sector. It assesses the four main stages of hydropower development: Early Stage, Preparation, Implementation and Operation. Assessments rely on objective evidence to create a sustainability profile against some 20 topics depending on the relevant stage, and covering all aspects of sustainability. The development process of the Protocol involved field trials in 13 different countries and stakeholder engagement with 1,933 individuals in 28 countries. Storage showing actual capacity on a normal scale. Discharge Time (hr) (hr) 100 100 90 90 80 80 70 70 60 60 50 50 Pumped Storage Hydro Hydro 40 30 CAES 20 20 10 10 0 0 0 1000 2000 0 1000 2000 Rated Power (MW) Rated Power (MW) PSH Pumped Storage Hydro Na-S Sodium-sulfur CAES PSH Compressed Pumped Storage Air Hydro VR Na-S Vanadium Sodium-sulfur redox EDLC CAES Dbl-layer Compressed capacitors Air L/A VR Lead-acid Vanadium redox Ni-MH EDLC Nickel-metal Dbl-layer capacitors hydride Zn-Br L/A Zinc-bromine Lead-acid Li-Ion Lithium-ion FW Flywheel Ni-Cd Ni-MH Nickel-cadmium Nickel-metal hydride Zn-Br Zinc-bromine Li-Ion Lithium-ion FW Flywheel Ni-Cd Nickel-cadmium 143