179Losses on a 3500 km-long HVDC line, including conversion from AC to DC
and back,would be about 15%.
Sources: Trieb and Knies (2004); van Voorthuy-
sen (2008).

182 According to Amonix, concentrating photovoltaics would have an average
power per unit land area of 18 W/m2.
The assumptions of www.amonix.com
are: the lens transmits 85% of the light; 32% cell efficiency; 25% collector
efficiency; and 10% further loss due to shading. Aperture/land ratio of 1/3.
Normal direct irradiance: 2222 kWh/m2/year. They expect each kW of peak
capacity to deliver 2000 kWh/y (an average of 0.23 kW). A plant of 1 GW
peak capacity would occupy 12 km2 of land and deliver 2000 GWh per year.
That’s 18 W/m2.

Solar chimneys. Sources: Schlaich J (2001); Schlaich et al. (2005); Dennis
(2006), www.enviromission.com.au, www.solarairpower.com.

183Iceland’s average geothermal electricity generation is just 0.3 GW. Iceland’s
average electricity production is 1.1 GW.
These are the statistics for 2006:
7.3 TWh of hydroelectricity and 2.6 TWh of geothermal electricity, with ca-
pacities of 1.16 GW and 0.42 GW, respectively. Source: Orkustofnun National
Energy Authority [www.os.is/page/energystatistics].

Further reading: European Commission (2007), German Aerospace Center (DLR)
Institute of Technical Thermodynamics Section Systems Analysis and Tech-
nology Assessment (2006), www.solarmillennium.de.