Page 306 - Managing Global Warming

266 Managing Global Warming

8.10.6 Climate change issues 309
8.11 Hydropower in the future—Potential deployment 310
8.11.1 Energy production 310
8.11.2 Pumped-storage hydropower 311
8.12 Summary 312
References 313

8.1 Introduction

Hydropower is a renewable energy source where electrical energy is derived from the
potential energy of water moving from high to lower elevation. Hydropower is a
mature technology and widely used; in 2016, a total of 159 countries in the world
reported to have developed hydropower. Hydropower is among the most efficient
technologies for production of renewable electrical energy, with a typical efficiency
of 90% or better for, “water-to-wire.” Hydropower is cost competitive, and is today
the only renewable technology that can produce electricity at equal or lower cost,
compared to thermal energy sources like coal, oil, or gas, typically in the range of
US2–5c (kWh) 1 (2–5 US cents per kilowatt hour).
Hydropower has a high potential for carbon emissions reductions in the global elec-
tricity system due to low greenhouse gas emissions (GHG), and a large potential for
further capacity increase with low generation cost, compared to both other renewables
and to thermal power plants. In total, generation by hydropower contributed nearly
17% of the worldwide electricity supply in 2016, implying that >1 billion people cov-
ered their electricity demand from hydropower. Hydropower is the third largest source
of electricity generation, behind coal (39%) and natural gas (22%) but far ahead of
nuclear (10%) (Fig. 8.1).
Hydropower is the largest source of renewable energy in the electricity sector with
a share of 68% of the renewables, more than twice all other renewables combined
(32%). The technical potential for increased hydropower generation is large enough
to meet substantial further deployment both in the medium (2030) and long term
(2050). A realistic scenario is to double the annual generation (4102TWh in 2016)
to over 8000TWh by 2050.
Adding to its contribution to energy generation, hydropower has a vital role in
supporting grid stability, security of supply, energy storage, and balancing
unregulated generation from other renewables like wind and solar power. In addition
to energy and grid services, hydro reservoirs can deliver other important services such
as water supply, irrigation, flood control, navigation, and recreation. Environmental
and social concerns, unless carefully managed, represent challenges for further
deployment of hydropower.
The first known hydropower plant (HPP) was installed in a house in Cragside,
Rothbury, England, in 1870. Industrial use of hydropower started in 1880 in Grand
Rapids, Michigan, when a dynamo driven by a water turbine was used to provide light-
ing. A major breakthrough came when an electric generator was coupled to the water
turbine and created the world’s first hydroelectric power station (of 12.5-kW capacity)