Notes on the Renewable Energy and Sustainability Report. REN21. January 2024

Notes on the Renewable Energy and Sustainability Report. REN21. January 2024

The REN21, which presents itself as “the only global renewable energy community that brings together actors from science, academia, governments, NGOs and industry to collectively drive the rapid, fair transition to renewables”, presented a report on sustainability of renewable energy sources.The Renewable Energy and Sustainability Report (RESR) is built on year-long research and a process of multi-stakeholder and multi-sectoral consultation and dialogue. It is conceived as a reference document that analyses the benefits and potential negative impacts of renewable energy deployment.  REN21 promises that this report “maps out the arguments circulating in the public space and seeks to differentiate facts from myths”. Unfortunately, this is wishful thinking. Desire to please everyone and have a “balanced position” made the Ren21 to publish an extremely controversial product.


The report downplays impacts and ignores the most problematic issues related to renewable energy sources by omitting well known crucial facts, using questionable selection of arguments, and relying on carefully preselected sources (many of those severely outdated). All this together, at least in case of hydropower, is selling proclaimed (false) intentions of the industry as the factual green achievements of the sector and is completely distorting and misrepresenting the discourse on impacts of hydropower on ecosystems and human rights.

Same, probably, relates to bioenergy and other RE industries, but judgement on that should be left to those experts who focus on such sectors.

In contrast to largely objective and almost unbiased annual review of advances in renewables routinely produced by REN21, this product displays shameless greenwashing in the interest of the industry and neglects basic standards of fact-checking.

Some examples include:

The report actively praises “multiple-use dams”: “Hydropower dams can serve as flood control infrastructure, protecting downstream areas from flooding and potential land damage. Dams also can create opportunities for tourism, recreation, irrigation, drought management and fishing. Low-impact run-of-river systems can be prioritised where applicable “. Meanwhile “multiple use” is a favourite slogan of the industry to sell hydropower to governments and communities and even make state budgets pay for commercial electricity projects (97% of new hydro is financed from public money). All other needs could be best served by other less disruptive and far less expensive means than large dam building. Once a “multipurpose dam” is built priorities of hydropower generation usually prevail over needs in flood control, recreation or irrigation causing severe conflicts.

Discussing biodiversity impacts, the report fails to mention violation of environmental flow requirements: “Hydropower dams impact freshwater sources and surrounding biodiversity mainly through changes in sediment flow and hydromorphology, as well as through the loss of habitat and range connectivity for wildlife. Water quality can decline due to changes in sediment loads and nutrient cycles.” Failing to mention change in flow regime shows either deep ignorance or malice intent of the report compilers. But most likely they simply did not care.

Against the best available evidence, the report (quoting some obscure source) insists that “A small fraction of the world’s hydropower projects contribute an outsized share of the impacts on terrestrial and aquatic biodiversity.” So, the rest of the dams are fine…This is contrary to basic understanding of how the continuing dam building by “thousand cuts” deprives the world of most of it free-flowing river ecosystems and their services. Every year the Rivers without Boundaries teams up with allies to demonstrate that absolute majority of newly built hydropower has massive impact on ecosystems and people.  There is no discussion on loss of ecosystem services due to renewable energy projects in this report.

The report creates impression that mitigation of biodiversity impacts is always feasible: “During the design of dams, steps can be taken to protect migratory fish. These measures include using special structures such as curved bars to deter fish from turbine blades, using gentle electric shocks to guide fish safely, and creating fish-friendly pathways such as ladders, elevators and passes. These efforts help fish safely navigate around dams and continue their upstream journeys.” The report fails to mention that majority of fish passes do not work effectively, while for dams taller than 40 meters those do not work in principle.

It openly greenwashes creation of reservoirs: “In certain cases, the creation of reservoirs behind hydropower dams can lead to the formation of wetland habitats and result in increases in wildlife, as occurred with the endangered giant otter in Brazil. In Germany, the Kellerwald-Edersee National Park was established around four hydropower reservoirs in 2004 and became part of a World Heritage Site of European beech forests in 2011.”  (Source: International Hydropower Association). Sure, those were reservoirs which intentionally facilitated protection of beech forests and the giant otter and hydropower dam and inundation were just the means to achieve conservation results ….

Finally, the REN21 Report is directly promoting the ”human rights achievements” of the Hydropower Sustainability Standard using very questionable example: In March 2023, Pamir Energy’s Sebzor hydropower project in Tajikistan became the world’s first project to be certified using the Hydropower Sustainability Standard. In 2023, the Hydropower Sustainability (HS).

Tajikistan is a country with gross violations of human rights and complete suppression of independent press. The Sebzor hydropower project is being built in Gorno-Badakhshan Region, which in last 3 years has been the focus of the government’s repressions against any potential dissent, including extrajudicial killing of peacefully protesting people and mass arrest of potential opposition members. The very idea of certifying “sustainable project” in the region where any free prior informed consultation is impossible due to authoritarian repression seems demonstrate extreme lack of integrity on the part of certification bodies, which make such decisions and on the part of the Report’s editors who promote this “achievement”.


Most interesting, that at the end the Report still shows extreme risks and inefficiency of hydropower, but in such a crooked way, that it cannot be credited to the quality of the report, but just shows global reality, that steadily resists greenwashing efforts.

The report touches upon land and water use, biodiversity impacts, GHG emissions, climate risks, use of critical materials, social impact and human rights. Below we present most interesting facts, that caught our attention.

Water use.

Estimated water footprint of bioenergy and hydropower is 10-500 times greater than that of solar or wind. For hydropower it is estimated between 15 and 200 litres/kwh, mainly due to evaporation from reservoirs’ enormous surfaces.

Spatial requirements.

Land use intensity of different types of renewables is highly contested topic with the only point of consensus: hydropower sector, producing less than 15% of the world’s electricity, is the unchallenged champion in land use. The 2022 study on which the REN21 Report relies suggests that in 2020 total global land area used for electricity production was approximately 72 million hectares, with 80% of that land used for hydroelectric dams. This means that up to 60 million hectares (600,000 square kilometres) have been covered by reservoirs. The study finds that in a range of future 2050 energy development scenarios the overall direct physical footprint of electricity generation facilities will grow by 30-80 million hectares, with hydropower still occupying more land than all other electricity generation combined, while its share in generation and installed capacity will be further reduced.

However, thinking of land-use impact we need to consider the quality of the land sacrificed for different types of energy generation. The REN21 Report emphasize that the solar PV can add value to otherwise unused or degraded land, including brownfields, landfill sites and degraded agricultural land. For example, in Chernobyl, Ukraine, a 1 MW solar plant was built on land contaminated by the meltdown of a nuclear reactor.

On the other hand, it is obvious, that any hydropower reservoir inevitably takes away most biologically diverse and fertile lands in river valleys equally important for wildlife and local populations.

What Ren21 Report totally misses is that hydropower, unlike any other energy source, also destroys most scarce and endangered biodiversity realm- freshwater ecosystems. By now two thirds of the world’s longest rivers have been already dammed and remaining free-flowing rivers are severely threatened by hydropower.

Climate Risks for traditional energy are high.

 For hydropower, 11% of the existing capacity is in high-water-stress areas, and around 26% of existing dams and 23% of projected dams are in river basins that have a medium to very high risk of water scarcity. These risks may already be materialising, as persistent droughts appear to be constraining the average capacity factor. Moreover, climate change could disrupt hydropower operation and output, with one study finding that by 2050, 61% of dams will be in basins with high or extreme risk of droughts and floods.

In summer 2022, heat waves and drought in Europe affected the availability of water for both hydropower production and the cooling of thermal power plants. Many hydro and thermal power plants in Italy either halted or completely shut down their operation, and water reservoirs in Portugal had only half the capacity of seven years prior. France had to temporarily close down some nuclear reactors to avoid flushing large amounts of warm water into rivers, which themselves had warmed due to the heat waves.

REN21 Emphasizes that in addition to mitigating climate change and its consequences on water scarcity, transitioning to a renewable energy mix could reduce water stress and increase energy security. The amount of water used to generate solar and wind power is much lower, than for other types of electricity generation.

Job creation.

Renewables in 2021 employed more than 12 million people, which has been 90% increase in a decade since 2012. Solar photovoltaics industry is a champion which increased employment three times from 1.4 to 4.3 million people. Bioenergy comes next with increase from 2.4 to 3.4 million people. Hydropower takes the third place with modest 0.7 million increase from 1.7 million to 2.4 million employees (given decline in dam building and increasing mechanization of the construction process such is difficult for us to explain). Wind (“human-free” technology) closely follows with 0.6 million growth from 0.75 to 1.37 million employees.

Human rights.

Allegations of human rights abuses have occurred in several cases in the renewable energy industry as well, with reported abuses including the violation of land rights and the rights of Indigenous Peoples, forced labour, attacks on and murders of environmental defenders, and the displacement of populations.

In the case of renewables, large-scale hydropower development has historically led to negative impacts on the local economy, with effects on the availability of fisheries, on transport, and on water availability and quality. The construction of the world’s biggest dam, the Three Gorges Dam in China, led to the displacement of 1.3 million people.

According to the Ren21 Report, “ over the past 20 years, more than 300 million people have been displaced due to large-scale hydropower development worldwide” ( We checked and established that Ren21 misinterpreted the 2017 source they quote, which talks about 80 million displaced and 472 million negatively affected by creation of large dams without specifying during what period it happened).

 However, watching the World Bank efforts to support 3780MW Rogun HPP in Tajikistan, where a single project intends to displace more than 45000 people, we must agree that aggressive displacement of local communities by dams is not an issue of the past, but growing human rights problem. According to the same study that was misquoted in the Report, 82% of families resettled due to dam construction are worse of and have not fully restored their livelihoods.

Development priorities.

According to the report, nearly 40% of existing hydropower installations are at least 40 years old, and they will require refurbishment and modernisation in the coming years. Modernising hydropower plants to be more efficient can be a cost-effective way to generate more electricity from the same amount of water and land. Studies have found that retrofitting old dams with newer equipment can improve energy efficiency 4-8% and increase generation 10-30%, while being less invasive for biodiversity.

Alternatives to traditional reservoirs can be considered, such as underground pumped storage or off-stream water storage, which can reduce water loss while providing flexibility in electricity generation.

Finally, the REN21 report confirms that over the last 12 years the levelized cost of electricity (LCOE) decreased dramatically for wind (-60%) and solar (-88%), while it increased for geothermal (+36%) and hydropower (+23%). This means that by 2022 the LCOE of 1 kWh of wind energy was less than 4 cents, while solar and hydro was 5 cents per kWh. In 2024 the LCOE from solar power will be inevitably less than that of hydro.

Besides, from the IRENA we know that building a hydropower plant is twice more expensive than wind farm, and 3-4 times more expensive than the Solar PV plant with similar capacity.

Most radical energy transition scenario featured in the REN21 report, envisions that by 2050 share of electricity in energy consumption will exceed 60% and it will all come from renewables, but that does not envision any significant increase in hydropower fleet…

Although, we may make many suggestions for removal of biased inaccurate wording and improvement of arguments, the REN21 report presents sufficient evidence against further development of greenfield hydropower projects. It also shows that future transition to “sustainable” electricity will happen due to renewable sources other than hydropower.

Complied by

Rivers without Boundaries.