Hydro

Hydropower is widely recognised as a renewable source of energy by bodies including the United Nations, International Energy Agency (IEA), International Renewable Energy Agency (IRENA) and the scientific community. It does not burn fossil fuels, no direct emissions are released into the atmosphere, and it is highly efficient, making it one of the cleanest forms of electricity generation.

Like any major infrastructure project, hydropower projects can have impacts on local communities and the environment, as well as providing benefits. Projects that are sited, planned and executed in accordance with recognised international good practices in sustainability can provide net-positive benefits to affected communities and the wider environment. As the largest renewable energy, making up more than half of global renewable energy production, sustainable hydropower is part of the solution to protecting the planet’s biosphere – and all life on Earth – by decarbonising the global economy, slowing the pace of climate change and preventing pollutants being emitted from fossil fuels. Sustainability in hydropower development is defined by the Hydropower Sustainability Standard. This internationally recognised certification scheme has been developed through multistakeholder consensus with governments, NGOs, civil society, industry and the finance sector. It covers a comprehensive range of sustainability considerations from planning to preparation and enables developers to maximise the benefits that hydropower projects deliver to society.

It’s incredibly important that local community members are heard when planning and developing a hydropower facility, with their needs and concerns helping to shape project outcomes. The Hydropower Sustainability Standard outlines good practices in communications and stakeholder consultation and practical measures that can help to build trust. Hydropower projects can, and should, be developed responsibly, with net-positive impacts on the environment and local communities. This requires them to be designed, implemented and assessed in accordance with internationally recognised good and best practices.

Hydropower is among the cleanest sources of electricity, with a low greenhouse gas emission intensity compared to other energy forms. Independent research suggests that use of hydropower instead of fossil fuels for electricity generation has helped to avoid more than 100 billion tonnes of carbon dioxide in the past 50 years alone, exceeding even the emissions averted by nuclear power. If hydropower was replaced by coal, IHA estimates up to 4 billion tonnes of additional greenhouse gases would be emitted annually, increasing global emissions from fossil fuels and industry by 10 per cent. There would also be 150 million more tonnes of air polluting particulates emitted each year (IHA analysis). Hydropower is pollutant-free and so helps to avoid the air pollution caused by fossil fuels. Notably, the World Health Organization (WHO) says around 4.2 million deaths every year occur as a result of exposure to ambient outdoor air pollution.

While hydropower has relatively high upfront construction costs, it provides very low-cost electricity over its long lifetime. The power and non-power benefits of sustainable hydropower projects can last significantly longer than those of alternative energy sources, and in some cases more than 100 years. The global weighted average cost of electricity from hydropower projects in 2020 was US$0.044 per kWh, which is lower than any other renewable energy source except for onshore wind (US$0.039/kWh), and which makes it the lowest-cost source of electricity in many markets (IRENA).

Hydropower provides an opportunity to generate significant revenue from exports to neighbouring countries. In addition, the hydropower industry directly employs around 2 million people worldwide, and many more in connected supply chains (IRENA).

Pumped storage hydropower, or ‘pumped hydro’, is by far the world’s largest source of energy storage, accounting for over 94% of installed energy storage capacity worldwide. Pumped hydro provides long-duration energy storage, which will be increasingly important in stabilising energy systems as more variable renewables are developed. Wind and solar energy can be stored in water for long periods of time, and released whenever needed at short notice. Moving away from pumped storage would mean turning to technologies such as lithium ion batteries, which are suitable for short duration (less than four hours) but rapidly lose cost effectiveness over longer periods. Other technologies still in development, such as carbon capture utilisation and storage (CCUS), are still in an infancy stage and far from being ready to be deployed at scale