Hydropower ⚡ Understand Energy with Data

What is Hydropower?

Hydroelectricity, or hydropower, is a renewable energy source that creates electricity from the flow of water. Captured by turbines, the power of water from rivers and waterfalls drives alternators that generate electricity.

Dams were already used in ancient Greece and China and expanded in the medieval period to grind grain. First invented in the 19th century, the first hydroelectric turbine was installed in 1895 at Niagara Falls and still operates today. This power source has grown rapidly since the beginning of the 20th century, producing 4355 TWh in 2020, four times more than in 1970.

As the first source of low-carbon energy before nuclear energy (10.1%) and the first source of renewable energy ahead of wind (6.2%) and solar (3.3%), hydropower produces 16.8% of the world's electricity. China has tripled its hydropower production from 436 TWh in 2006 to 1288 TWh in 2020. Furthermore, 54.6% of Brazil's electricity and 61.2% of Canada's electricity comes from hydropower.

In addition to its classic role of electricity production, hydropower dams can be used to store energy by pumping water upwards. Storage can potentially help compensate for intermittent energy sources such as wind and solar power.

Is Hydropower a low-carbon energy source?

Yes, due to its relatively low lifecycle emissions, Hydropower is considered to be a low-carbon energy source.

The median estimate of lifecycle emissions from Hydropower is 24 gCO2eq / kWh. Where do our emissions numbers come from?

Wind	11 gCO2eq / kWh	Low-carbon
Nuclear	12 gCO2eq / kWh	Low-carbon
Hydropower	24 gCO2eq / kWh	Low-carbon
Geothermal	38 gCO2eq / kWh	Low-carbon
Solar	45 gCO2eq / kWh	Low-carbon
Biofuels	230 gCO2eq / kWh	Low-carbon
Gas	490 gCO2eq / kWh	High-carbon / fossil fuel
Oil	650 gCO2eq / kWh	High-carbon / fossil fuel
Coal	820 gCO2eq / kWh	High-carbon / fossil fuel

Hydropower compared to other low-carbon energy electricity sources

Most significant producers of electricity from Hydropower

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What are the pros of hydroelectricity?

To reduce global warming, hydropower has several advantages. It is a renewable energy known and mastered for a long time. It emits very small amounts of greenhouse gases. It provides storage capacities to the grid that combine well with other renewables such as wind and solar. It also provides electricity at a competitive price.

Hydropower can help reduce global warming

Firstly, hydropower is a renewable energy source that can generate significant amounts of electricity, 54.6% in Brazil and 61.2% in Canada for example, with very little contribution to global warming.

Indeed, it is one of the low-carbon energy sources that emits the lowest amounts of greenhouse gases to produce electricity (24 gCO2eq / kWh), unlike natural gas (490 gCO2eq / kWh) and coal (820 gCO2eq / kWh).

Hydropower is cheaper than coal and on par with gas

Second, hydropower prices average $72 USD/MWh according to the IEA. To compare, onshore wind costs $50 USD/MWh, solar costs $56 USD/MWh, gas costs $71 USD/MWh, and coal costs $88 USD/MWh.

Although the upfront investment for hydroelectric power plants is substantial, it largely pays for itself over time because their lifespan is almost infinite. For example, the hydro turbines installed on Niagara Falls in 1895 are still in use today.

https://www.iea.org/reports/projected-costs-of-generating-electricity-2020

Used since the 6th millennium BC, hydraulic energy keeps improving

Hydraulic power was first used in the 6th millennium BC in ancient Egypt. Signs of the first-known dams were discovered on the Nile River, which helped to cope with flooding and crop irrigation.

This technology was also used in ancient Greece by the Minoan civilization from the second millennium BC and in China from the second century BC.

https://www.mdpi.com/2071-1050/12/22/9760/pdf

http://www.history.alberta.ca/energyheritage/energy/hydro-power/hydro-power-in-ancient-times.aspx

https://www.hydropower.org/iha/discover-history-of-hydropower

Benoît Fourneyron invented the first hydroelectric turbine in 1827. This technology produced electricity from waterpower and experienced rapid development in the 19th century in France and then in Germany. Installed on Niagara Falls in 1895, it is still used today.

Hydroelectricity then developed massively in industrialized countries throughout the 20th century. Thus, the electricity produced from hydroelectric power increased fourfold between 1970 and 2020, accounting for 16.8% of electricity worldwide. Hydropower is thus the first source of low-carbon electricity. It comes in ahead of nuclear power, which represents 10.1%, followed by wind power (6.2%) and solar power (3.3%).

Hydroelectricity is a renewable energy source

Hydropower is a low-carbon and renewable energy, as are wind, solar, and geothermal energy. Indeed, once the dam is installed, it needs nothing more than the natural force of water, unlike fossil fuels that require fuel to generate electricity.

Using hydropower as energy storage

Hydropower has a key feature to achieve net-zero; it can stock energy on demand. When intermittent renewable energies (wind and solar) produce a lot of electricity, the water can be pumped upstream into the dams. And when intermittent energies produce less, stored energy from hydro can be used to compensate and thus stabilize the electricity grid.

What are the cons of hydropower?

Upfront investment in hydroelectric facilities is high.

Many hydropower facilities are major infrastructure projects requiring building dams, reservoirs, and power-generating turbines, resulting in a significant financial investment.

Therefore, the upfront construction costs are often significant. However, these facilities often last between 50 to 100 years (sometimes even longer), which make them a worthwhile investment. Niagara Falls has been in operation since 1895. This long lifetime results in a competitive average cost of between $68 USD and $72 USD/MWh. This price is more expensive than other renewables such as onshore wind ($50 USD/MWh) and solar ($56 USD/MWh), but it is equivalent to gas ($71 USD/MWh) and much cheaper than the most polluting energy to produce electricity: coal ($88 USD/MWh).

https://www.iea.org/reports/projected-costs-of-generating-electricity-2020

Hydropower facilities can have negative effects on the local environment

Hydropower, although a renewable energy source, can harm the local environment because of the implementation of hydroelectric facilities.

First, dams modify the natural flow of rivers, which can disrupt ecosystems. Secondly, in some cases, local populations may be displaced. Finally, in some cases, as in Egypt, historical monuments can be submerged by the dam.

These side effects of hydropower are generally lower with run-of-river facilities such as wave or tidal installations. However, most current hydropower systems are dams that block the flow of rivers. Based on existing case studies, new techniques are being developed to try to reduce the environmental impacts of hydroelectric dams.

https://www.science.org/doi/10.1126/science.aaq1422

Hydroelectric facilities are dependent on local geography and weather factors

While hydropower is a reliable source of energy, it cannot be installed anywhere as the installation of dams depends on the local geography.

On the other hand, the operation of dams depends on meteorological trends and especially on rainfalls. Since most hydroelectric plants depend on river water, droughts hurt hydroelectric production since they result in lower water flows. From month to month and year to year, the amount of water available to hydroelectric systems can therefore vary, affecting hydroelectricity production.

Major dam accidents can have catastrophic consequences

According to OurWorldInData, hydropower together with solar energy is the safest energy source in the world at just 0.02 deaths per TWh. It is 1636 times safer than brown coal.

Nevertheless, out of all energy sources, hydroelectric dam accidents are the deadliest. In China, the Banqiao Dam failure in 1975 killed about 85,000 people and generated between 220,000 and 230,000 total deaths from famine and disease created by this tragedy.

Significant changes of low-carbon power due to Hydropower

Region	Years	Change
French Guiana	2000 → 2001	0 → 90.6%
Sierra Leone	2006 → 2011	10.3 → 100%
Lithuania	2009 → 2011	79.8 → 14.6%
Congo - Brazzaville	1997 → 1999	92.4 → 32%
Mozambique	1996 → 1998	41.5 → 99.6%
Rwanda	1997 → 2006	95.2 → 17.5%
Uruguay	2003 → 2006	99.9 → 42.6%
Tanzania	2003 → 2006	94.2 → 41%
Lesotho	1999 → 2005	38.5 → 97.2%
Sudan	2008 → 2013	29.6 → 81.9%
Suriname	2009 → 2015	76.8 → 24.9%
Belize	2005 → 2010	19.8 → 67.1%
Latvia	1996 → 1998	29.3 → 68.2%
Kenya	1996 → 2000	87.6 → 44.8%
Albania	2011 → 2016	55.9 → 100%
Cambodia	2011 → 2018	2.8 → 50.3%
Myanmar (Burma)	1999 → 2009	22.4 → 76.4%
Namibia	1991 → 1997	76.1 → 31.7%
Latvia	2015 → 2017	37.8 → 72.5%
Zimbabwe	1998 → 2008	16.7 → 66.2%
Uruguay	2008 → 2014	55.3 → 94.8%
Burkina Faso	1993 → 1997	0 → 33.3%
Ghana	1996 → 2007	100 → 53.3%
Montenegro	2010 → 2017	69.5 → 31.1%
Croatia	1990 → 1996	25 → 61.2%
Mauritania	2011 → 2019	12.5 → 52.4%
Equatorial Guinea	2011 → 2016	4.1 → 38.1%
Honduras	2014 → 2019	38.7 → 71.5%
Greenland	2008 → 2013	50.5 → 83.1%
Faroe Islands	2010 → 2015	30.1 → 61.4%
Ecuador	2014 → 2019	47.6 → 78.9%
Kenya	2009 → 2015	55.2 → 87.4%
Uganda	2011 → 2016	64.7 → 94.3%
Rwanda	2007 → 2015	17.9 → 50.9%
Angola	2015 → 2019	54.8 → 81.1%
Panama	2014 → 2019	55.2 → 82.1%
Portugal	1992 → 1996	19 → 44.6%
Georgia	2006 → 2010	67.2 → 92.5%
Zimbabwe	2009 → 2016	64.4 → 35.9%
Armenia	2001 → 2009	51.4 → 79.7%
Nicaragua	2007 → 2014	28.4 → 53.9%
Turkey	2014 → 2019	20.5 → 43.5%
North Macedonia	2008 → 2010	9.3 → 28%
Samoa	2010 → 2014	45.8 → 25.3%
Iraq	2004 → 2005	1.5 → 19%
Guatemala	2003 → 2012	41 → 66.3%
Bosnia & Herzegovina	2010 → 2017	46.9 → 24.5%
Fiji	2012 → 2015	68.5 → 50.3%
New Zealand	1995 → 2001	83.9 → 63.6%
Guinea	1996 → 2002	40 → 60%
Kyrgyzstan	1991 → 1999	64 → 85.9%
Spain	2005 → 2010	35.4 → 53.6%
Austria	2000 → 2003	73.1 → 56.6%
French Polynesia	2001 → 2010	22.2 → 44.1%
New Zealand	2008 → 2016	64.3 → 84.2%
Costa Rica	1995 → 2000	82.4 → 99.1%
Vietnam	2010 → 2017	28.8 → 46.1%
Namibia	2012 → 2019	39.7 → 22.5%
Slovenia	2007 → 2014	59.4 → 76%
Peru	2016 → 2020	50.4 → 64.7%
El Salvador	2002 → 2010	47.2 → 64.2%
Luxembourg	2002 → 2010	2.4 → 18.5%
Kyrgyzstan	2013 → 2015	93.5 → 81.8%
Wind And Solar>12%, Nuclear<6%	2008 → 2020	35.1 → 53.7%
Australia	2009 → 2020	7.5 → 24.9%
Sweden	2001 → 2003	96.1 → 85%
Ethiopia	2008 → 2010	88.3 → 99.4%
Eswatini	2014 → 2016	30.3 → 19.4%
Venezuela	2008 → 2016	72.8 → 58.4%
People's Republic of China	2011 → 2020	18.8 → 33.4%
Morocco	2008 → 2019	5.1 → 20.7%
Uzbekistan	2000 → 2005	7.3 → 18.7%
Costa Rica	2014 → 2020	88.1 → 99.8%
Norway	2002 → 2004	99.7 → 90.1%
Morocco	1997 → 1999	15.2 → 5.6%
Serbia	2010 → 2011	33 → 23.9%
Chile	2013 → 2020	35.7 → 47.6%
North Macedonia	1993 → 1999	9 → 20.2%
Brazil	2015 → 2020	72.3 → 83%
Venezuela	1990 → 1999	62.3 → 75.2%
Norway	2008 → 2010	99.6 → 90.5%
Sweden	1990 → 1996	97.7 → 87.4%
Malaysia	2010 → 2017	6.3 → 16.9%
Belize	2012 → 2019	54.6 → 64.1%