Green Energy Technology, Economics and Policy Part 2 docx

8 Green Energy Technology, Economics and Policy

2000

70

60

50

40

30

20

10

0

2010

385

455

550

445

485

445

450–520

Note: Figures refer to CO2 concentrations by volume (ppm CO2). Emissions (G† CO2)

425

2020 2030 2040 2050 2060 2070 2080 2090 2100

Baseline

ACT Map

BLUE Map

Figure 1.1 CO2 concentration profiles for the Baseline,ACT and BLUE Map scenarios

(Source: ETP, 2008, p. 51, © OECD-IEA)

20 000

Renewable power generation

(TWh/yr)

18 000

16 000

14 000

12 000

10 000

8 000

6 000

4 000

2 000

2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

0

Other

Tidal

Geothermal

Biomass, waste

Solar CSP

Solar PV

Wind

Hydro

Figure 1.2 Growth of renewable power generation in the BLUE Map scenario, 2000–2050

Product shares in the world renewable energy supply, 2005: Renewables com￾bustibles and waste: 78.6% (comprising liquid biomass: 1.6%, renewable municipal

waste: 0.7%, solid biomass/charcoal: 75.6%, gas from biomass: 0.9%); Wind: 0.6%,

hydro: 17.4%, solar/tide: 0.3%, geothermal: 3.2%.

The contribution of renewables to electricity generation increases from 18% in 2005

to 35% in 2050 in the ACT Map scenario, and 46% in the BLUE Map scenario. In

the BLUE Map scenario, electricity generation from renewables (wind, photovoltaics

and marine) is projected to rise to 20.6% (about 3 500 GW) by 2050.

Up to 2020, bulk of renewable energy production will come from biomass and

wind. After 2020, solar power production will become significant. Hydro will grow

continuously up to 2050, but this growth will achieve a plateau around 2030 to 2050,

because of the constraints of finding suitable sites. The contribution of hydro, wind

and solar will be roughly equivalent in 2050.

About two-thirds of solar power will be provided by solar PV, with the balance one￾third coming from Concentrating Solar Power (CSP). As the capacity factor of CSP is

higher than PV, CSP may account for 40% of the solar power generation.

Renewables and climate change 9

The intermittency of solar power is not a problem as its peak coincides with the

demand for air-conditioning. Electricity storage capacity is sought to be increased

from 100 GW today to 500 GW by 2050 (in the form of pumped hydro storage,

underground compressed air energy, etc.) to cover the variability in the case of systems

like wind.

The BLUE Map scenario envisages a strong growth of renewables to achieve the

target of 450 ppm CO2 (Fig. 1.2; source: ETP, 2008, p. 88, © OECD-IEA).

Currently about 50% of the global population lives in urban areas, and this trend

is likely to continue in the future. Consequently, urban authorities have to figure out

ways of providing renewable energy services to the urban residents. Cities located on

the coast could tap the offshore wind energy and ocean energy. Building-integrated

solar PV (such as, solar shingles) would be most suitable to cities in low latitudes, with

good sunshine. Geothermal power could be developed for the use of cities located

near high heat-flow areas. Bioenergy is not usually suitable for the cities, except those,

which have forests nearby.