A roadmap recently released by the Hydro Equipment Association discusses how manufacturers of equipment used in hydropower facilities are focusing on four key areas to continue to propel hydro forward as a reliable source of electricity.
By Elizabeth Ingram
Hydropower is competitive, dynamic and diverse. It can play a key role in the global transition to a sustainable energy future. And the hydro equipment industry makes a significant contribution to today’s and tomorrow’s energy challenges.
The above are just some of the reasons the Hydro Equipment Association released its Global Technology Roadmap. Rising worldwide electricity demand is resulting from a growing urban population and increases in gross domestic product. At the same time, estimates of hydropower’s technical potential (excluding pumped storage) point to about 4,400 GW worldwide.
According to this 52-page document, the primary audience is international financing institutions and policymakers in countries with hydropower potential. The HEA roadmap is broken into four sections: Messages to Policymakers, Economic and Social Benefits, Technology, and Sustainability – A Driving Force.
Messages to policymakers
The roadmap provides several key messages for policymakers. These are:
- Support the feasible exploitation of untapped potential. “Hydropower … can provide some of the lowest-cost electricity of any source.” Significant hydro potential remains to be exploited in many developing and emerging countries, particularly in Asia, South America and Africa.
- Embrace sustainable hydropower. The Hydropower Sustainability Assessment Protocol should be used more widely, the roadmap says. In 2014, the World Bank encouraged its public sector clients to use the protocol on a voluntary basis.
- Set up a suitable framework for hydropower. Governments should take steps to ensure regulatory frameworks are maintained, long permitting procedures are avoided, a level playing field is available for all power technologies, external costs of power generation (such as carbon pricing) are internalized, inconsistent grid fees are removed, and barriers to setting up local on-site manufacturing are removed.
- Facilitate hydro deployment. This can take a variety of forms, including public-private partnerships, provisions for the longevity of hydro projects in terms of long-tenure loans, streamlined licensing and tendering rules, and securing local education and capacity building in developing countries.
- Reward hydropower for the full value of ancillary services. Ancillary service provision should involve fair remuneration via market mechanisms, electricity balancing methods should take account of network power transfer limits and storage potentials, and national balancing markets should be harmonized across the EU.
Economic and social benefits
The power generated by hydroelectric plants in emerging and developing countries will lift local populations from poverty, and social and economic development will ensue.
The levelized cost of electricity (LCOE) for hydropower, when compared with other technologies, is very low. Calculations from Bloomberg New Energy Finance, the International Energy Agency and the International Renewable Energy Agency cite LCOE (expressed in US cents per kWh) of large hydro at 2 to 23 and small hydro at 2 to 27. The central estimate (or average LCOE) is 6.9 for large hydro and 7.0 for small hydro.
“Hydropower equipment manufacturers help to ensure that substantial direct economic benefits accrue to populations living close to sites of hydro construction or refurbishment.” Examples include refurbishment of the Rouna II project in Papua, New Guinea, with the total contract value divided 65/35 in favor of the local portion (locally sourced labor, supplies and services).
Equipment manufacturers also set up training centers that offer apprenticeship programs, such as: the one Andritz Hydro established in Turkey; Voith’s training center in Manaus, Brazil; and GE’s “Escola Formare” program in the Taubate region in Brazil. Manufacturing sites of hydro equipment companies also create export opportunities. And the International Renewable Energy Agency says that hydro “will be a major source of employment in 2030 for the 26 countries considered both under its reference scenario and under its REMAP 2030 scenario.”
Technology (the heart of the roadmap)
Hydropower is a mature technology, with the machines deployed today having been perfected over more than 150 years. However, power output, power density, size and efficiency have increased. At the same time, further developments and applications in material research are expected. “Hydro equipment manufacturers are responding to the request of their customers for increased flexibility, more frequent load changes and greater availability.”
In larger equipment, precision engineering can provide boosts in performance that outweigh the costs. Hydro equipment manufacturers can use a variety of computer-aided engineering tools to accomplish this, including computational fluid dynamics and finite element method techniques. Regarding potential future advances that allow even more benefits, the report says improvements are needed in modeling a variety of situations, including stochastic variations in flow patterns, pressure pulsation, rotating stall, and fluid-structure interaction.
One particular emphasis is the value of adapting hydropower to local circumstances, such as through the installation of small hydropower plants. With Francis, Pelton and Kaplan turbine designs being scalable to small ranges and significant small hydropower potential untapped, manufacturers are positioned to aid the situation. Some companies are delivering devices that are pre-assembled in arrays for very low head sites, such as Andritz Hydro (Hydromatrix) and Voith (StreamDiver).
On the other end of the spectrum are very large projects, such as Xiang Jia Ba in China. At this facility, a machine is installed with a runner diameter of 10 m, which is 0.1% more efficient than a machine with a runner diameter of 8 m, thanks to relatively smaller flow friction losses in larger machines. The report indicates performance of very large units could be improved by using stator winding voltages of 24 to 25 kV (today’s maximum is 23 kV).
Dealing with erosion is another important issue for hydro equipment manufacturers. Rather than dealing with erosion (caused by hard particles in the water) by shutting down machines at certain times of the year, manufacturers can use protective coatings on runners. “Precautions against hydro-abrasive erosion are ideally taken at the time the plant is designed. It is often not possible or expensive to correct its effects afterwards,” the report says.
Other areas covered include:
- Hydrokinetic turbines deployed in subsea tidal streams (by 2025 the technology should generate electricity at a cost that is competitive with widely deployed forms of renewable energy). One example here is GE’s Oceade 18, a three-bladed hydrokinetic turbine with a generating capacity of 1.4 MW;
- Refurbishment (a cost-effective option to restore or upgrade performance of an aging plant); and
- Hydropower’s contribution to a stable grid (particularly in support of wind and solar integration).
Pumped storage is also discussed, with an emphasis on its high “round-trip” efficiency (80%). In Europe and the USA, the role of pumped storage “is increasingly to improve grid reliability.” Case studies provide information on pumped storage plants in Europe (Malta Hauptstufe in Austria) and the USA (focused on how pumped storage contributes such ancillary services as spinning reserve, flexibility and regulation). With a trend toward greater flexibility and component robustness, the roadmap provides data on two major innovations: variable-speed pumped storage and ternary machine sets (separate turbines and pumps connected on the same shaft, with the motor-generator in between). The roadmap points to a target of having increased the lifetime of turbine runners and critical rotor parts from 10,000 stop-starts to 100,000.
Some manufacturers are seeking to gather data linked to the sustainability profile of their components. With life cycle assessments, calculations can be made of the greenhouse gas emissions and other environmental impacts created in the manufacture of the product.
In addition, manufacturers are giving attention to environment-friendly equipment. One example is fish-friendly variants of the Kaplan turbine, with water flowing at lower velocities and adjustable blades on Kaplan runners to reduce the risk fish get trapped or pinched in the gaps at the inner and outer blade peripheries.
Aeration of water is another important element in sustainability, as it can improve the quality of water downstream from the plant. Oil-free operation is another important area where equipment manufacturers are working, to ensure oil and grease in various parts of the turbine does not come in contact with water.
Sustainable approaches also are being taken with regard to infrastructure, such as improving fish passage and minimizing impacts during rehabilitation.
Visit http://www.thehea.org/gtr_.pdf to access the complete roadmap.
Elizabeth Ingram is managing editor of HRW-Hydro Review Worldwide.
About the HEA
The Hydro Equipment Association (HEA) was founded in 2001 and represents electromechanical equipment suppliers for hydropower globally. Its work is dedicated to advancing sustainable hydropower worldwide by promoting an industry with a long tradition of engineering excellence.