10 years of Hydro power insight

Eddie Rich, Chief Executive of the International Hydropower Association

It is clear that in this decade renewable energy will take centre stage. There are commitments from many countries to decarbonise and no country has been able to do so without a large element of hydropower.

The International Renewable Energy Agency’s figures suggest that we are going to need another 1000GW of hydropower in the next 30 years. This is equivalent to the same amount in the next 30 years which has been produced in the last 70 years – a massive increase. For this step change to occur, three actions are necessary.

Firstly, there needs to be an enabling policy framework from countries and governments. Many countries already recognise that any hydropower project, whatever its size or scale is renewable and can deliver benefits to the community and energy and water systems if planned properly and operated sustainably. However, this message needs to be re-emphasised, as hydropower developers in several countries are still met with red tape.

Secondly, the financial markets need to re-value hydropower projects. Financing hydropower projects can prove to be extremely difficult, as projects are around for over a hundred years and most financiers have a short-term view. Financiers need to recognise the benefits hydropower provides to society, such as mitigating climate change and delivering clean energy.

The International Hydropower Association (IHA) is currently working with the Climate Bonds Initiative (CBI) on green bond financing. Green bonds are fixed income loans given to finance or refinance projects or assets that help address environmental and climate risks. Some issuers have excluded proceeds from green bonds to finance hydropower projects due to a lack of clarity over appropriate sustainability standards. To solve this problem, IHA is working with partners as a part of CBI’s Hydropower Technical Working Group to agree eligibility criteria for green bonds to fund hydropower projects and we will be making an announcement soon.

Finally, hydropower projects need to modernise. Modernising the ageing hydropower fleet is critical to extend their lifetime, improve performance and safety, and to guarantee reliable and low-cost hydropower in the future energy mix. IHA is currently working with the Asian Investment Infrastructure Bank (AIIB) and the Inter-American Development Bank (IDB) on studies to identify the modernisation needs of the current hydropower fleet in Asia and Latin America and a lot of the existing fleeting is already in the process of being updated.

To mitigate climate change the power sector has to decarbonise. As countries move towards full electrification and clean energy, renewable energy will increasingly have a greater role to play. Hydropower will in particular play an important role as it can support other renewables with its flexibility services and storage facilities even when the wind is not blowing and the sun is not shining. Thus, the future will be all about ‘Renewables working together.’ This is also the theme of our World Hydropower Congress 2021 in Costa Rica, where leading decision-makers, innovators and experts from industry, government, finance, civil society and academia will gather to set priorities for the sector. 

AK Mishra, Managing Director of the Mangdechhu Hydroelectric Project Authority in Bhutan 

Over the past decade, the hydropower industry has faced serious challenges, especially in India, primarily due to the time and cost overruns in both private and public projects. In addition, in the last five years, the Government of India has allocated more resources towards the development of renewable energy such as solar and wind power, meaning that hydropower in India became a lesser priority. 

But now, there is recognition of the fact that without development of the hydropower, other renewable energy forms such as solar and wind will not succeed. It is becoming amply clear now about hydropower’s ability to act as a complementary power to solar and wind energy, and the Government of India has now started allocating adequate resources towards the addition of the new hydropower projects with focus on the development of pumped storage and run-of-river projects. 

The 720MW run-of-river Mangdechhu Hydropower Plant was commissioned by the Prime Ministers of India and Bhutan on 17 August 2019.

India, Bhutan and Nepal are now all together investing reasonable resources in the development of hydropower projects. With regards to the development of large storage hydropower schemes on this region, the distinct possibilities are less as such projects were identified long ago in all of the three countries as above. Some of the examples in India are Bursar Hydroelectric Project (800MW) in J&K, Dibang Multi-purpose Project (2880MW) in Arunachal Pradesh, similarly, in Bhutan, Sankosh Hydroelectric Project (2560MW), Kurigongri Hydroelectric Project (2640MW) and Pancheshwar High Dam (6480MW) Project in Nepal will be coming up in the next one and half decade. 

Indeed, large storage hydroelectric projects are becoming more difficult to construct due to the complex land acquisition laws and also the massive opposition by the local residents of the area. As far as climate change is concerned, future hydropower projects which shall be coming up in future will have much lesser influence due to their minimal impact on the climate change especially emission of GHG from the reservoirs. 

Other factors such as safety, aging of the Projects, economics and public acceptance etc will have some influence but they cannot stop the development of the hydropower projects. 

Hydropower development trends will have more of a positive focus in the Asian region in comparison with Europe and US. Especially Europe which is now increasingly developing wind and solar power and also with surplus power available within Europe, there is less possibility of hydropower development. 

Significant trends over the next decade pertaining to the hydropower would be based on composite development where storage and run of the river schemes shall be coming up together. 

Mangdechhu Hydropower Plant wwas built on the Mangdechhu River in Trongsa Dzongkhag District, central Bhutan as a concerted effort between the Indian government and the Royal Government of Bhutan.

Tammy Chu, Managing Director of Entura 

The rapid expansion of wind and solar power is a global trend. Australia, too, is transitioning from dominant thermal generation to an increasing proportion of wind and solar. In response to rising electricity prices and notable reliability issues, there is also heightened public and political pressure in Australia to sure up the affordability of electricity as well as its sustainability (ie the energy ‘trilemma’). Australia’s island state of Tasmania offers an excellent example of how conventional hydropower and pumped hydro energy storage (PHES) can ride these shifting market dynamics, provide a crucial stabilising element in integrated clean energy systems, and help us meet the challenges of the future.

As the electricity sector transitions, Australia’s National Electricity Market (NEM) will be characterised increasingly by low-cost variable renewable energy firmed by storage. Tasmania, powered by an extensive hydropower system, already trades in the NEM via an undersea interconnector, but stands ready to make a bigger contribution. With more interconnection, Tasmanian hydropower can serve as a ‘battery’ for the nation, offering dispatchable renewable generation as well as the storage and system support needed to enable more renewable developments and help Australia achieve a clean, reliable, affordable energy future.

As part of this ‘Battery of the Nation’ vision, we’re exploring opportunities to create new PHES (using existing storages paired with new reservoirs), as well as to repurpose, refurbish, upgrade and futureproof our existing hydropower assets to better serve the future needs of the grid. The ‘Battery of the Nation’ vision combines flexible, reliable hydro with cost-competitive, large-scale storage that can be built in stages, ensuring firming of wind and solar resources that are aligned with market drivers.  

Looking to the rest of Australia, we’re seeing a resurgence of interest in PHES, as well as increasing development of utility-scale batteries. Technology is advancing very quickly in batteries; however, I’m convinced that PHES will not be displaced as a storage solution. One advantage is that we have a greater understanding of the lifecycle costs and sustainability of PHES, whereas a number of uncertainties remain in this respect for batteries. Also, critically, batteries are not yet capable of providing kinetic inertia and fault level support required by a grid with a high proportion of intermittent renewables. Batteries also typically cannot supply the significant level of output over a longer duration that PHES or traditional hydropower can. As wind and solar plants expand in number and size, it is really only hydropower with large reservoirs that will be able to provide the multi-day storage needed in extreme events of both low wind and low solar. 

What we’re seeing playing out in the Australian clean energy sector is not unique to our region. Unlocking the potential of conventional hydropower and PHES to support dispatchability of wind and solar power will, no doubt, be a global trend. 

Tammy Chu at  Repulse Dam in Tasmania

Markus Rieck, Chief Sales Officer at Voith Hydro

With the expansion of the renewable energy sources solar, wind and biomass, more and more volatile energy producers are coming into play. Therefore the necessity of energy storage expands. This can be covered by batteries for very small and short-term power peaks, but not for larger amounts of energy and longer periods of energy feed-in and storage. So far, pumped storage technology is the only long-term technically proven form with which energy can be stored cost-effectively on a large scale and made available at short notice. For this reason, we see an increasing need for pumped storage plants as a “green battery” to also make the potential of other renewable energies fully usable.

In addition, around two thirds of all existing dams and weirs worldwide are still unused for hydropower, but offer enormous energy potential that could be utilised with Small Hydro technologies. With our StreamDiver, for example, we offer a compact and economical all-in-one solution for the small hydro sector that requires very little construction work and thus enables the potential of existing dams and weirs to be tapped. 

Voith’s StreamDiver is a compact, economical and environmentally-friendly turbine-generator unit for small hydropower, which can also be fitted to existing dams and weirs.

Besides hydropower, other renewable energy sources are playing an increasing role in the energy transition. To achieve the best possible synergies here, hybrid power concepts can be a solution for the future. The combination of windmills and/or solar parks with a pumped storage power plant ensures that the energy generated is immediately and reliably stored when it cannot be fed directly into the power grid. 

In order to advance hybrid power concepts involving hydropower, Voith and Siemens entered into a strategic partnership in 2018. Together, we provide an integrated approach to assess the technical feasibility of hybrid power plants, taking into account economic expectations. This helps decision-makers to ensure profitable business development based on technical resilience. 

In this regard it is also very interesting to have a closer look at green hydrogen production: wind and solar will not be enough to generate the green electricity demand for green hydrogen production that the world will need soon. Classical hydropower in terms of run-of-river plants, however, can serve as an enabler for the expansion of green hydrogen production by providing more than 6000 of full load operation hours per year at low costs. The first two demonstration plants for Power-to-Gas in combination with hydropower are in trial operation or under construction at the Rhine River. This is a highly interesting trend that the industry needs to follow up on. 

There are regions where we still see huge potential for large hydropower plants, for example in Africa and Asia. Looking at Africa, where almost 600 million people have no access to electricity, nearly 90% of the continent’s hydropower potential is untapped. Here, investments in hydroelectricity can have an enormous positive impact on Africa’s social economy and energy system. Taken as a whole, the Asia Pacific region offers by far the largest hydropower potential in the world. With 9.2GW of additional capacity, East Asia and the Pacific saw the highest annual growth in installed hydropower capacity in 2018 – and this trend will continue in the coming years. 

In other regions, such as Europe and especially Germany, the modernisation of existing plants plays a major role in order to achieve an increase in output and to implement ecological compensation measures such as fish ladders or sediment transfer from upstream to downstream. 

The energy sector is changing rapidly and hydropower plant operators are facing a competitive environment with increasingly volatile energy demand. Success comes to those who can ensure highly flexible plant operation. Low maintenance costs due to the best quality of the plant equipment, high availability due to wide control bands and optimized investment costs are the main drivers of economic considerations. 

Here, digital solutions offer power plant operators an opportunity to further optimize the operation of existing and new plants and to enhance their competitiveness for the future. Under the name Intelligent Hydropower, Voith offers a comprehensive portfolio of digital products and services and co-develops customer-specific solutions for every requirement together with the hydropower plant operator. 

Under the name “Intelligent Hydropower”, Voith co-creates digital solutions together with hydropower plant operators in order to increase their competitiveness for the future.

In addition to state-of-the-art automation, condition monitoring, asset and performance management systems, Voith operates local OnPerformance.Labs to provide customers with the best possible support and domain know-how. With data-based analyses and remote support, our lab experts help hydropower plant operators to significantly reduce their maintenance costs and downtimes.

Martin Wieland, Chairman of the ICOLD Committee on Seismic Aspects of Dam Design

In countries where most of the hydropower potential has already been developed or where due to political or environmental reasons no new hydropower projects can be realised, the main objective of the owners and thus the future trend will be to extend the lifespan of the existing storage dams as much as possible. This means that regular maintenance and safety upgrading of existing dams must be the top priority of dam owners everywhere. This is a long-term process, which has been ongoing. However, short concession periods may create risks if the future dam owners or dam safety authorities, who may not exist everywhere, do not take proper care of these projects. Dam safety and a long lifespan are also the main factors affecting the sustainability of hydropower projects. In Switzerland the average age of large dams is about 70 years, which indicates that these projects are sustainable.

Many large dam projects are multi-purpose projects, where hydropower is one among other important purposes such as flood control and water supply. With changes in demand and economy, water supply may become more important than power generation in the future and the mode of operation of the reservoirs is going to change in the future. Thus, the reservoir rule curves may need to be reviewed periodically similar to the safety assessment of dams. By means of this “participatory approach” we can deal with time-dependent hazards like climate change, etc.

Dam construction is an old technique and it takes almost decades to realise large storage dam projects in most countries. Therefore, a reference time frame of a decade is too short compared to the planning and construction phase of such projects, and thus, no great changes with new large dams is expected in the future. Everybody feels that more pump storage plants are needed along with wind and solar energy production, so that reservoirs can be used to regulate the stability of the grid, and so on.

These changes can be done in a much shorter time in existing storage plants compared to the construction of new dams, where today, after financing has been resolved, project approvals are the main bottlenecks. Large dams are also the civil engineering and infrastructure projects, where many interest groups with diverse objectives are involved.

Figure 1: BIM model of powerhouse of Schils hydropower plant in Switzerland (13MW) 

There are nevertheless new trends in dam construction. Indeed, they have always existed. For example, after the 1950s everybody wanted to build arch dams, even in places that were not ideal for arch dams. This was followed by RCC dams, today. In the case of embankment dams, concrete face rockfill dams have replaced earth core rockfill dams and today it is fashionable to build asphalt core rockfill dams, etc. Besides dam types, there are new techniques, which have an impact on design and construction such as the use of drones for site investigation and dam and reservoir monitoring, as well as the use of BIM (building information modelling). In Switzerland the first relatively small hydroelectric power plant (Figure 1), designed by Poyry, is presently under construction, in which only models, but no drawings are used for the design and construction. 

These will be among the design and construction trends in some parts of the world. The prerequisites for such developments are skilled people. On large dam construction sites in developing countries a major portion of the labourers are unskilled, therefore, the use of new techniques will be limited.

In conclusion, we would be very happy to see that all large storage dams comply with the same minimum safety standards, that the dams are well constructed and well maintained. Any new trend must comply with these basic requirements in order to be meaningful.