Solar Energy Perspectives - IEA

Chapter 4: Buildings
Chapter 4
Buildings
Today, residential and commercial buildings account for 35% of total global final energy
consumption, notably for lighting, sanitary water heating, comfort ambiance, cooking and
many electricity-driven devices. New buildings will see considerable reductions in these
levels of consumption, driven by more stringent regulations. Refurbishment of many existing
buildings will allow this total consumption to stay roughly constant despite demographic and
economic growth, as the supply mix shifts from direct fossil fuel consumption to renewable
energy and renewable-based electricity.
Buildings also offer large surfaces to the sun’s rays. Capturing the sun’s energy will enable
buildings to cover a share of their heat consumption, a larger share of lighting needs and
become significant sources of electricity. Furthermore, the increased use of thermal energy
storage technologies in buildings will help improve demand flexibility and reduce the need
for expensive electricity storage.
Solar water heating
Depending on the other uses of energy in buildings, domestic water heating can represent
up to 30% of the energy consumed. Solar water heaters (SWH) represent one of the most
profitable applications of solar energy today. They constitute the bulk of the current market
of solar heating and cooling, which itself produces almost four times more energy than all
solar electric technologies combined (Figure 4.1).
Figure 4.1 Capacities and produced energy of “new” renewable energy technologies
Produced energy
(TWh) 2010
Total capacity
in operation
(GW) 2010
450
400
350
300
heat
power
417
250
200
150
196
162
194
100
90
50
0
Solar thermal
heat
Wind
power
12
Geothermal
power
38 39.6
Photovoltaic
1 2.4 0.6 0.8
Solar thermal
power
Ocean tidal
power
Source: Weiss and Mauthner, 2011.
Figure 4-1
Key point
Solar heat today provides four times more energy than solar electricity.
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© OECD/IEA, 2011