Energy from My Backyard - The Renaissance of Renewable Energy - page 235

Figure 7.6. The DESERTEC project to supply solar power to the Middle East and North
Africa and part of Europe by 2050. The red squares indicate the land area covered by CSP
plants that would be needed to meet global electricity consumption (17,000 TWh per
year), the consumption by the member states of the European Union (3,200 TWh per
year) and by the countries in the Middle East and North Africa (600 TWh per year). The
square marked “TRANS-CSP Mix 2050” indicates the area needed to supply energy for
seawater desalination and two-thirds of electricity consumption in the Middle East and
North Africa and about one-fifth of European electricity consumption (2,940 TWh per
year) in 2050. Source: DESERTEC ( 2009 ) .
DESERTEC, though still embryonic, is an inspiring example of what could be achieved
with regional cooperation. But it does not deliver a model of sustainable energy supply that
can be applied globally. That task was recently taken up by Mark Jacobson, a professor of
civil engineering at Stanford University, and Mark Delucchi, a researcher in transportation
studies at the University of California. In 2011 they published a rigorous plan for supplying
all energy for all purposes (electric power, transportation, heating, and cooling) from a
mixture of renewable sources (Jacobson and Delucchi 2011a , 2011b ) . They excluded from
their model all forms of combustion, even biomass, focusing instead only on wind, sun,
and water.
Figure 7.7. Because wind and solar power are intermittent, Jacobson and Delucchi
considered ways to ensure steady power supply using different sources at different times
of day and night. This diagram projects California's mid-summer electricity demand
satisfied by renewables only in 2020. Geothermal provides base-load supply (instead of
fossil fuels), wind and solar work alternately at night and during the day, and peak-load is
met by hydropower. Sources: Jacobson and Delucchi ( 2009 , 2011a , 2011b ).
They propose the following mix of technologies deployed in suitable locations: 51 per
cent of global demand from wind thanks to 3.8 million 5-megawatt turbines; 40 per cent
from the sun, through 89,000 photovoltaic (PV) and CSP plants and 1.7 billion rooftop
PV systems; and 9 per cent from tidal, geothermal and hydroelectric plants. According
to the authors, only 0.59 per cent of the world's land surface would be required to fulfil
this model. To ensure a reliable energy supply everywhere, such a system would need to