Biojetfuel: Biofuel with a future

  The recent announcement that a South African carrier together with a major manufacturer and biofuel companies are to develop biofuel for its fleet of jets may signal the start of an entire new biofuel industry in this country. Aviation biofuels have been used by commercial and military organisations for some time now and this […]

High temperature solar thermal fuel production

  Thermal processes for the production of fuels such as liquid hydrocarbons and hydrogen from hydrocarbon gas and carbon dioxide are well established processes, but all use fossil fuels as an energy source. The development of high temperature solar thermal systems offers an energy savings alternative to the use of fossil fuels, and opens opportunities […]

Kizildere II: Geothermal energy in Turkey

  Zorlu Energy, a large Turkish contractor, is an innovative and forward-thinking firm which is a part of the Zorlu Group of companies, a huge Turkey conglomerate. Zorlu Energy entered in the geothermal arena after they purchased the 15 MW Kizildere I Geothermal Power Plant in 2008. The Kizildere site is located in the Menderes […]

Using magnetic slot wedges in hydro generators

  The stator of a hydro generator is usually designed and constructed with open slots. Windings (bars or coils) are inserted into the stator core and then fixed with the non-magnetic slot wedges. Open slots result in slot harmonics which have an effect on some of the characteristics of the generator, such as total harmonic […]

Using smart storage to enhance rooftop solar performance

  Rooftop , or own generation, solar photovoltaic (PV) systems, are being installed by many commercial and industrial users, including mines, with the aim of reducing energy costs and increasing security of supply. What many users don’t realise is that the load profile results in unused energy which may be utilised to gain further advantages […]

Promoting energy access: Meeting the challenge with cogeneration

  The International Energy Agency reports that nearly 1,3-billion people still lack access to electricity, and two-thirds of those people live in ten countries – four in developing Asia and six in sub-Saharan Africa. The agency estimates that nearly $1-trillion in cumulative investment is needed to achieve universal energy access by 2030 [1]. In its […]

Protecting off-grid PV systems

  There are many studies on the short circuit behaviour of grid connected PV and renewable energy systems but not many on the protection of off-grid PV (OGPV) systems. Many national wiring codes are beginning to include protection of PV systems, but the subject is neither well nor widely understood. This article covers the protection […]

Pitfalls on the road to urban grid independence

  Urban grid defection, also known as grid-independence or off-grid generation, is a topic which has received much attention of late. There are numerous articles suggesting that, in the not very distant future, it will be economically possible for urban consumers to operate independently of the grid with a suitable combination of renewable energy sources […]

Tapping untapped renewable energy

  In water distribution networks in South Africa, water is often fed under gravity from a higher reservoir to another reservoir at a lower level. This provides an opportunity to generate renewable energy by passing the flow through a turbine. The high pressure head at the receiving reservoir is then dissipated through the control valves […]