CENTRE FOR RENEWABLE AND SUSTAINABLE ENERGY STUDIES

OTHER ENERGY TECHNOLOGIES

GEOTHERMAL ENERGY

Geothermal energy is thermal energy stored in the earth. The high temperatures are generated mainly from radioactive decay of minerals and volcanic activity and are a source of renewable energy already used for generating over 10 GW of electricity and providing more than 28 GW of heating worldwide. The temperature difference between the higher temperature geothermal source and ambient temperature (or other lower temperature source) is exploited to generate electrical power. The process typically used in this conversion uses an organic rankine cycle or steam cycle where the high temperature steam or working fluid expands through turbine blades causing the turbine blades to rotate. This rotation of a shaft in turn drives a generator that produces the electrical power. For more information on Geothermal energy in South Africa and more detail on the working principles please follow the links below.

http://thinkgeoenergy.com/archives/6119

http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how-geothermal-energy-works.html

Geo Thermal Energy

SMALL HYDRO

Small hydro plants refer to hydroelectric installations in the typical electrical production range of less than 10 MW. In general the application of small hydro is for remote communities or off-grid industrial applications. The civil engineering component (dam wall, road construction, etc.) is largely absent and most small hydro plants rely on run-of-river or diversion fed installations where little to no water storage is required and minimal penstock construction needed. Currently approximately only 34 MW installed small hydro plants exist in South Africa. For more information on Small hydro energy in South Africa and the working principle please refer to the links below.

http://www.microhydropower.net/rsa/

http://en.wikipedia.org/wiki/Small_hydro

http://mg.co.za/article/2009-09-03-scope-for-sa-mini-hydro-power-real-but-finite

Small Hydro

ENERGY EFFICIENCY

Energy efficiency is primarily divided into two application categories namely domestic and industrial. The primary focus of this focus area is using low-consumption appliances or streamlining of production processes in order to save electricity usage. In domestic applications this is facilitated by use of compact flurecent bulbs in lighting applications, low-power or efficient appliances and building design (natural light, insulation, building layout etc.). In industrial applications efficiency is achieved by using restructured process flows, energy management software, waste heat recovery and implementation of VSD’s on electric motors. For more information on energy efficiency consult the links below.

http://www.capetown.gov.za/EN/ENVIRONMENTALRESOURCEMANAGEMENT/ENERGYEFFICIENCY/Pages/EnergyEfficiancyatHome.aspx

http://www.businessday.co.za/articles/Content.aspx?id=138366

Energy Efficiency