192 page pdf-dated jan 2008
===
Some highlights
- Renewable energy, which includes production from
geothermal, wind, solar, biomass, hydroelectric and
tide/wave/ocean sources, is gaining interest from
politicians and developers due to global warming
predictions and the high cost of oil. - Renewable power capacity of about 240 GW in 2007
(ex. large hydro) represents almost 6% of total global
power capacity (~4,300 GW) and the share is
increasing. - The most important renewable energy source with
respect to electricity generation is hydropower,
which represents almost 89% of the total
generation. This share is similar for all the
continents except Europe, where wind energy plays
a considerable role. Hydropower also has a
significant share in the total electricity generation
worldwide or 16.5%, with a growing rate of 2-5%.
The largest markets are in the USA, Canada, Brazil,
Norway and China. - Hydroelectricity generation will primarily
grow in non-OECD countries such as China, India,
and in Latin America. Biomass growth will be
strong, especially in OECD countries. - Each of the respective renewables has certain
limitations; some are better suited for electric
energy production and others for direct heating.
Solar panels and wind mills can be easily installed
and in a short period of time, whereas hydro power and geothermal energy tend to be more time consuming, especially large projects. Solar energy
obviously depends on daytime sun light and nighttime
storage, wind can be intermittent and also
depends on storage, hydropower is subject to
drought and limited site, biomass depends on a
supply of fuel and can contribute to greenhouses
gases and particulate emission, tide and ocean
energy is limited to areas where sufficient
oscillations are available and where it does not
interfere with navigation, and even though
geothermal energy is base load for power and can
supply the full load for heating, it is site specific.
The development of the various renewable energy
sources is not only dependent upon the technical
aspects mentioned above, but are also influenced by
the support (or lack of) from government policies
and financial incentives. Thus, all renewables have
limitations, but must be supported as they can
complement each other. It is very important for the
proponents of the various types of renewable
energy to work together in order to find the optimal
use of energy resources in the different regions of
the world.
........................................
also peruse page 81/97
"The possible role and contribution of hydropower to the mitigation of climate change" by Richard Taylor Executive Director, International Hydropower Association (IHA)
- The capacity of individual hydropower units ranges
from 0.1 kW to 700 MW; annual generation ranges
from 1000 kWh from the smallest of units, to the
world record of 93.4 billion kWh delivered by the
Itaipu powerplant (Brazil/Paraguay) in 2000.
The largest hydro powerplant in terms of capacity is
the Three Gorges powerplant (China), nearing
completion with 32 turbines totalling 22.4 million
kW. - The world total of hydro generation in 2005 was 2,836
TWh, with an installed capacity of 778 GW (WEC,
2007). Some 30 GW of new capacity has been added
in 2006/07 and this could be expected to bring the
total up to around 3,000 TWh/year (Wilmington
Media, 2007). - Hydropower, therefore, currently provides about 7%
of global primary energy and 16% of total electricity
supply. By capacity, hydro provides 87% of globalrenewable energy power generation.
- Hydropower units can be switched from standstill to full supply in very short
periods of time, so they can be used to meet suddendemand.
- Hydro provides some level of power generation in 159
countries. Five countries make up more than half of
the world’s hydropower production: China, Canada,
Brazil, USA and Russia. - A recent survey of hydropower developers confirmed
that the costing of hydro development is quite sitespecific.
Low-head schemes tended to have higher
costs than high-head developments. Economies of
scale and the availability of national contractors and
equipment suppliers also influence costs considerably.
Installation costs tend to be in the range of US$ 1
million to >5 million per MW, with an average of <2
million/MW. - Many economically feasible hydropower projects are
financially challenged. High up-front costs are a
deterrent for investment, despite zero fuel costs. The
structural elements of a hydropower project tend to
make up about 70% of the initial investment cost
(UNWWAP, 2006). Also, hydro tends to have lengthy
lead times for planning, permitting, and construction.
The operating life of a reservoir is normally expected
to be in excess of 100 years. Equipment
modernization would be expected every 30 to 40
years. In the evaluation of life-cycle costs, hydro often
has the best performance by comparison with other
generation technologies. This is due to annual
operating costs being a fraction of the capital
investment and the energy pay-back ratio being
extremely favourable because of the longevity of the
powerplant components.
Key Messages:
- Currently, hydropower offsets the fossil-fuel
equivalent of 13 million barrels of oil each day. It
offsets several types of air pollution (not just GHG
emissions). By working in unison, hydro can also
directly reduce emissions from fossil-fuelled
powerplants. - Hydro can be developed in synergy with the complete
family of renewables, thereby greatly improving the
aggregate quality and security of supply. - Despite high upfront costs, hydro offers low and
predictable operational costs. - Hydropower does not consume the water it uses; by
managing freshwater, it can make it available for
multiple purposes. In this way it can contribute to
adaptation to climate change (IPCC, 2007a). - Hydro also offers security against drought and
protection against flood, thereby offering further
climate change mitigation services.
No comments:
Post a Comment