Solar Power to the Masses

Solar tops the world’s new renewable energies

As oil prices soar, solar power has been undergoing a boom, along with other renewable energies, which attracted more than US$100 billion investment last year in new power and heating capacity, manufacturing plants, research and development [1]. Investment in solar power capacity and manufacture amounted to US$31.3 billion, while US$33. 4 billion was invested in wind.

Global capacity in photovoltaic (PV) power reached 10.6 GW in 2007, of which 7.8 GW is grid-connected. Grid-connected PV has been the fastest growing power generation, increasing by 50 percent a year in both 2006 and 2007.The Spanish PV market grew the fastest with an estimated 400 MW added in 2007, four times the 2006 additions.

Apart from rooftop installations, the growth of large-scale PV power plants also accelerated during 2006 and 2007, including many kW and MW plants. Spain now has the world’s two largest PV plants of 20 MW each in the cities of Jumilla and Beneixama in Murcia and Alicante regions respectively. There are now over 800 plants worldwide with capacity greater than 200 kW and at least 9 larger than 10 MW in Germany, Portugal, Spain and the US.

Solar hot water/heating capacity increased to an estimated 128 GW globally in 2007, up from 88 GW in 2005, reflecting an annual growth rate of 20 percent over the past two years. For comparison, the world’s total wind power capacity reached an estimated 95GW in 2007.

Concentrating solar power mega-projects not desirable nor needed

The technology for concentrating solar power (CSP) uses a parabolic array of mirrors to reflect and concentrate sunlight for heating water, turning it into pressurized steam at 800 C for driving turbines to produce electricity.

The CSP industry completed a first round of new build during 2006-2007. This included a 64 MW plant in Nevada, a 1 MW plant in Arizona and an 11 MW central receiver plant in Spain. By 2007, there were over 20 new CSP projects around the world under construction, in planning stages or undergoing feasibility studies, the majority in Spain and the US, but also in some developing countries. Chinese and German partners have agreed to develop 200 MW CSP in Inner Mongolia by 2012 as part of a broader commercial framework for 1GW of CSP in China by 2020.     

It has been estimated that an area of the Sahara desert slightly smaller than Wales in the UK would generate enough solar energy by CSP to supply all of Europe with clean electricity [2]. Arnulf Jaeger-Walden of the European Commission’s Institute for Energy said it would require the capture of just 0.3 percent of the light falling on the Sahara and Middle East deserts to meet all of Europe’s energy needs. Both Gordon Brown and Nicholas Sarkozy are supporting it, and the project is welcomed by Greenpeace and other environmental groups.

Scientists on the Sahara project admit it would take many years and a huge investment of €450 billion; and by 2050, it could produce 100 GW. One reason it is so expensive is because a ‘supergrid’ needs to be built to transport direct current (DC) electricity through high tension power lines. DC power lines have an advantage over the usual alternating current (AC) power lines, in that they lose only 3 percent of the electricity in transport rather than 7 percent or more [3].

In view of the continuing debate over the adverse health impacts of high tension power lines [4] (see Fields of Influence series, SiS 17 and SiS 24), the high costs, and not least the prospect of ruining the world’s landscapes by yet more power lines and pylons, the Sahara mega-project looks distinctly undesirable and unnecessary. The better option is distributed small to micro-scale generation of electricity that could be fed back to the existing grid, as recommended in ISIS 2006 Energy Report, Which Energy? [4]. PV technologies, in particular, are maturing fast. We do not have to wait so many years nor invest hundreds of billions. The solar age has well and truly arrived.

‘Grid-parity’ rapidly approaching for PV

PV technologies for producing electricity from sunlight have been improving by leaps and bounds while manufacturing costs are falling.