Jul 25, 2008
Solar tower sheds light on little-used technologyBack
Construction|Concrete|Hahn & Hahn MD Alan Dunlop|PROJECT|Turbines|Water|Germany|Spain|Electricity|Energy|Power Generation|Power-generation|Solar Tower Technology|German Government|Jorg Schlaich|Power|Turbines|Water|Koss R-200 Consumer Headphones|The Namibian|Solar Tower Technology|Thermodynamics
© Reuse this A
The proposal states that the solar tower, aptly named the Greentower, will be 1,5 km high and 280 m in diameter. Dunlop says that the tower can be likened to a chimney that would cause an updraft to the drive turbines, generating 400 MW of electrical power.
Air within the solar tower is heated in a large circular green-houselike structure, and the resulting convection causes the air to rise and escape through the tower. The moving air drives turbines, which then produce electricity.
Solar tower technology has been slow to develop over the last 30 years. Between 1979 and 1989, a German engineer, Professor Jorg Schlaich, designed a solar tower 200 m high, which was built in Spain and financed by a grant from the German government. The tower ran trouble-free for eight years, producing 50 kW of electricity, until it was decommissioned.
Dunlop states that interest in the technology faded in the 1990s, until it was announced that a 1 km-high solar tower, capable of producing 200 MW would be constructed, and would be functional, in Aus-tralia by 2010.
Turbines can be installed in a ring around the base of the tower, with a horizontal axis, as planned for the Australian project, or, as in the prototype in Spain, a single vertical axis turbine can be installed inside the chimney.
He adds that the Australian tower, as well as its Namibian counterpart, will be built out of reinforced concrete, using technology developed for building high-rise buildings.
“Several thermodynamics, civil struc-ture, wind loading and power generation experts have developed an executive summary for a R6-million prefeasibility study, and a R200-million bankable feasibility study for the Namibian project,” he says.
In addition, it is proposed that the base of the tower will incorporate a 37-km2 greenhouse, in which cash crops can be grown.
The greenhouse will be used to develop soil humus to transform barren land to fer- tile soil that retains moisture and nutrients to enable rapid plant propagation.
Dunlop says that studies have shown that plant-linked humidity does not reduce the uplift in the tower by which the turbines are driven, and even represents a store of latent energy that can be drawn on after sunset.
Water for the plants in the greenhouse can be supplied by desalinating sea water or purifying groundwater, using known technology and a supply of energy, which is only a small fraction of the energy generated.
He adds that the Namibian project is eligible for carbon credits under the Kyoto Protocol and offers opportunities for countries such as Germany to further develop solar tower technology.
Edited by: Laura Tyrer© Reuse this Comment Guidelines (150 word limit)
Other Renewable Energy News
Article contains comments
Article contains comments
Updated 6 hours ago Independent, black-owned and managed investment holding company Southern Palace Properties has acquired an 8% stake in Growthpoint Properties from the Public Investment Corporation’s (PIC’s) Government Employees Pension Fund (GEPF) for R4.5-billion. Standard Bank...
Updated 6 hours ago Shareholders of JSE-listed real estate investment trusts (REITs) Octodec and Premium Properties have approved the proposed merger of the two companies, creating a combined property fund that will attract a market capitalisation in excess of R5-billion and comprise...
Updated 6 hours ago The Metal and Engineering Industries Bargaining Council (MEIBC) this week called on employees and employers to exercise restraint as the metals and engineering industries resumed operations following a four-week strike, stating that it regretted the strike’s...
Recent Research Reports
Real Economy Year Book 2014 (PDF Report)
This edition drills down into the performance and outlook for a variety of sectors, including automotive, construction, electricity, transport, steel, water, coal, gold, iron-ore and platinum.
Real Economy Insight: Automotive 2014 (PDF Report)
This four-page brief covers key developments in the automotive industry over the past 12 months, including an overview of South Africa’s automotive market, trade figures, production and the policies influencing the sector.
Real Economy Insight: Construction 2014 (PDF Report)
This five-page brief covers key developments in the construction industry over the past 12 months. It provides an overview of the sector and includes details of employment in the sector, infrastructure and municipal spending, as well as insight into companies’...
Real Economy Insight: Electricity 2014 (PDF Report)
This five-page brief covers key developments in the electricity industry over the past 12 months, including details of State-owned power utility Eskom’s generation activities, funding and tariffs, independent power producers and prospects for the sector.
Real Economy Insight: Road and Rail 2014 (PDF Report)
This six-page brief covers key developments in the road and rail industries over the past 12 months, including details of South Africa’s road and rail network and prospects for both sectors.
Real Economy Insight: Steel 2014 (PDF Report)
This four-page brief covers key developments in the steel industry over the past 12 months. It provides an overview of the global and South African steel and stainless steel markets, South Africa’s major steel producers and events that have shaped these markets.
This Week's Magazine
Multinational semiconductor chipmaker corporation Intel announced its national campaign to further acquire partners to drive its She Will Connect programme, an initiative that aims to expand digital literacy skills to young women in developing countries, further into...
South Africa's MeerKAT radio telescope array programme should get back on schedule within a few months. This assurance has been given by SKA South Africa (SKA SA) associate director: science and technology Prof Justin Jonas. Early last month, Science and Technology...
The Passenger Rail Agency of South Africa’s (PRASA’s) Metrorail service will remain a subsidised service following its current multibillion-rand rolling stock, station, depot and signalling upgrade programme. PRASA group CEO Lucky Montana has allayed fears that...
The uncertainties around the remediation of affected areas as addressed in the Contaminated Land Provisions in the National Environmental Management: Waste Act No 59 of 2008 will possibly spark litigation and disputes between landowners and businesses, contractors...
South Africa is currently the largest component of the African Development Bank’s (AfDB’s) active portfolio in Southern Africa, comprising 62.5% of the bank’s $7.9-billion exposure to the 12-country region – the second largest beneficiary is Mauritius, which...