Block’s Indicator of Sustainable Growth

by Ray Block

Concentrating solar power (CSP) grew strongly in the 27- country European Union and Switzerland in 2008, with new installed capacity increasing by 27 per cent to 3.3 GW.

Germany, Europe’s biggest CSP market grew to 1.5 GW in 2008, an increase over the year of more than 120 per cent.  Spain the second largest European market rose by 58 per cent to over 300 MW, and Italy rose by 295 MW.

In Spain, there are 22 CSP projects in development, with 1.2 GW new capacity under construction, with another 13.9 GW scheduled to be constructed by 2014.

To get to the Greenpeace estimate of CSP making up 25 per cent of world energy by 2050, you have to think big.

 One way of thinking big is the Financial Times report  (June 16 2009)  of a German consortium of 20 companies, including Siemens, Deutsche Bank and Munich RE contemplating a network of  hundreds of north African CSP power plants, supplying power by underwater cables to Europe.

The German Aerospace Centre estimates the project costs at Euros 395 billion, with the powerlines alone costing Euros 45 billion. It’s great to think big, but you need big pockets too.

Another think big project, but on a smaller scale, involves a Japanese consortium of 16 companies including Mitsubishi Electric and IHI in a US$21 billion Japanese project to build a giant solar power generator in space to beam electricy to earth without cables.

Bloomberg (August  31 2009) tells us that the trade ministry and the Japan Aerospace Exploration Agency, which are leading the project, plan to launch a  small satellite fitted with solar panels in 2015, and test beaming the electricity from space through the ionosphere, the outermost layer of the earth’s atmosphere.

Bloomberg also report that NASA and the US Department of Energy have spent $80 million over the last 30 years to study solar generation in space.

 Back in more conventional technology territory, CSP installations in United States rose by 922 MW in 2008 to reach a total installed capacity of 7.76 GW. Under development in the US are  24 projects, which in coming years will add further capacity of 6.09 GW.

 Unlike solar PV (photovoltaics) on rooftops, which generate electricity directly, CSP systems use lenses or mirrors and tracking systems to focus a large area of sunlight onto a small beam to deliver steam, which is piped into a turbine to generate electricity in a power plant.

As Michael Kanellos reported in Greentech Media (April 28 2009), CSP systems can be by way of  a tower, a trough, a dish, or a plate. In a trough, rows of curved mirrors focus heat on a tube filled with oil. The oil, which heats to 750 degrees Celsius boils water to make steam.

In a tower/heliostats combination, such as employed by BrightSource Energy, water is placed in a tower in the centre of a field of mirrors.  The field heliostats, which are air cooled or cooled by hybrid systems can tilt in two directions, and allows for higher temperatures to be used.

BrightSource Energy is currently in the process of building CSP power plants involving 2.6 GW of projects with the two dominant utilities in California. One of these is 1.31 GW for PG&E in northern California, and the other 1.3 GW for Socal Edison in southern California.

A related market to CSP in power plants is the CSP thermal steam market, where the same technology is used to turn water into steam to directly clean equipment, pump liquids from the ground or kill germs. BrightSource Energy has a contract for a 29 MW thermal plant at Chevron’a oil field in Central California.

BrightSource now wants to expand its operations to China and India, and has put out feelers.

The main proponent of the solar dish is Stirling Energy Systems, which focus heat on a Stirling engine. The difference in air temperature drives a piston. Stirling’s 25 kilowatt SunCatcher enable a more than 25 per cent efficiency on average.  There are four projects in development, involving  more than 1.6 GW of generating capacity. 

A SunCatcher is made up of a parabolic dish of  40 mirrors( formerly 80 mirrors) to focus the sun’s rays onto a receiver, which transmits heat to a Stirling engine. The engine is a sealed system filled with hydrogen. As the gas heats and cools, its pressure rises and falls. The change in pressure drives the piston inside the engine, producing mechanical power, which in turn drives a generator and makes electricity.

A new player in the US market is Solar Millenium, owned by two German companies-  Solar Millenium in partnership with MAN Ferrostaal, which is developing  two  parabolic trough systems each of 242 MW. This is part of a contract with SoCal Edison in southern California to supply up to 726 MW of generating capacity.

With such a long schedule of CSP projects to develop, some large contracting companies have become involved with the solar firms, which should speed progress. Bechtel, one of the US largest engineering contractors is involved with BrightSource Energy.

Bechtel  will become an equity investor in Ivanpah solar generating system, which involves three power plants in California’s Mojave Desert totalling 440 MW.

The aerospace contractor Lockheed Martin is working on a 290 MW  CSP plant near Phoenix Arizona for the developer Starwood Energy Group.