Geoscience Reference
In-Depth Information
form of waves into electricity. However, this is easier said than done, and experts in the
field suggest that wave power technology is now where solar panel technology was about
20 years ago—lots of catching up still required. But tidal power in particular has one key
advantage over solar and wind—it is constant. In any country, for energy supply to be
maintained at a constant level, there has to be at least 20 per cent production guaranteed,
known as the baseline requirement. With the switch to alternative energy, new sources of
this consistent baseline need to be developed.
Hydroenergy
. Hydroelectric power is globally an important source of energy. In 2010, it
supplied 5 per cent of the world's energy. The majority of the electricity comes from large
dam projects. These projects can present major ethical problems as large areas of land
must be flooded above the dam, causing mass relocation of people and destruction of the
local environment. A dam also slows water flowing down a river and prevents nutrient-
rich silt from being deposited lower down. If the river crosses national boundaries, there
are potential issues over the rights to water and silt. For example, one of the reasons why
Bangladesh is sinking is the lack of silts due to dams on the major rivers in India. There is
also a debate about how much GHG hydroelectric plants save, because even though the
production of electricity does not cause any carbon emissions, the rotting vegetation in the
area flooded behind the dam does give off significant amounts of methane.
Geothermal
. Below our feet, deep within the Earth, is hot molten rock. In some locations,
for example in Iceland and Kenya, this hot rock comes very close to the Earth's surface
and can be used to heat water to make steam. This is an excellent carbon-free source of
energy, because the part of the electricity you generate from the steam you use to pump
the water down to the hot rocks. Unfortunately, it is limited by geography. There is,
however, another way the warmth of the Earth can be used. All new buildings can have a
borehole below them with ground-sourced heat pumps. Cold water is then pumped down
into these boreholes and the ground warms the water up, cutting the cost of providing hot
water to buildings and can be used almost everywhere in the world.
Nuclear fission
. Energy is generated when you split heavy atoms such as uranium and this
is nuclear fission. It has a very low direct carbon signature, but a significant amount of
carbon is generated mining the uranium, building the nuclear power station, and decom-
missioning the power station and safely deposing of the nuclear waste. At the moment, 5
per cent of global energy is generated by nuclear power. The new generation of nuclear
power stations are extremely efficient, producing nearly 90 per cent of the theoretically
possible energy production. The main disadvantages of nuclear power are the generation
of high-level radioactive waste and concerns about safety, though improvements in effi-
