Renewable Energy Sources: Stanford
Renewable energy is everywhere and always there; sun, wind, heat from the earth, waves, gravity, biomass and waste. When we consider all these sources of energy and we have the knowledge and technology available to make use of it, it is ludicrous not to use it. The beauty of it is that it is free. Nobody ‘owns’ the wind or the sun; it is there for all to use. No greedy business person can manipulate the price of sunlight (sell it, stockpile it to create an artificial demand shortage, sell futures in it and do all the other things to make money).
When we aim to become more sustainable, it is always sensible to look at what is available around you. In Croatia, for example, they have water and mountains (thus gravity as a source of energy). The first hydro power station was the first alternating current (AC) power system in Croatia, the first commercial hydro power plant in Europe, and second in the world. It was set in operation on 28 August 1895 at 20:00, three days after the Adams Power Plant on the Niagara Falls. It was designed to power the street lights in Šibenik, making it the third city in the world with street lights powered by a polyphase system of alternating current (AC)[i]. In Iceland they use thermal power from the natural geysers, the Egyptians used wind to power their ships along the Nile river some 7 000 years ago and, of course, humankind discovered fire (biomass) some 300 000 years ago.
The Overberg is rich in renewable energy sources; we have ample sun, wind, biomass (especially all the aliens that we are trying to get rid of), waves from the Atlantic, we create a lot of waste and sewerage that is not used (and cost a fortune to get rid of!) and mountains (but not enough water!). Nevertheless, when we are thinking about an energy transition in the Overberg, we need to think about our own sources. The last thing you want is to transport energy over thousands of kilometres at a great cost and with great waste.
Sun energy is expressed as Daily Solar Radiation (kWh/m2/d). The amount of solar energy (kW) falling on unit area (square meters) over a stated time interval (per day). In the Overberg (as measured at Bredasdorp – data from NASA, see RETscreenPlus) we have an average of 5.28 kWh/m2/day as measured over one year. To put it into perspective; Germany’s average is 3.01 kWh/m2/day and “On midday of Saturday May 26, 2012, solar energy provided over 40% of total electricity consumption in Germany, and 20% for the 24h-day. The federal government has set a target of 66 GW of installed solar PV capacity by 2030, to be reached with an annual increase of 2.5–3.5 GW”[ii]. The point is that we are well endowed with solar energy.
Wind energy is expressed as Daily Wind Speed in meters per second (m/s). Again we have ample wind, often an irritation, but we are blessed to have all this free energy. We have an average of 6.8 m/s wind measured over one year. In Cornwall, for example, the measured average annual wind speed at one of their turbines is 5.7 m/s[iii]. Cornwall makes extensive use of wind power
Biomass energy. The Department of Environmental Affairs launched the Working for Water Programme in 1995. One aim is to remove alien plants in order to restore the ecosystem and ensure a more productive and sustainable use of water. The yield of biomass from this programme is massive; “a biomass yield of approximately 2.3 million tonnes per annum over a 20 year period for the Agulhas Plain, with Acacia saligna and Acacia cyclops dominating the species composition”[iv]. This biomass can be better used as a source of energy. The 2015 budget from government for this programme was R 1,55 billion. Again, an available source that is ‘free’ and abundant.
|Average Daily Solar (kWh/m²/d)||Average Wind Speed (m/s)|
No wonder that study after study and just good common sense tells us that we are blessed with ample sources of renewable energy. The Department of Environmental Affairs commissioned a study (by CSIR) that identifies areas where large scale wind and solar PV energy facilities can be developed in a manner that limits significant negative impacts on the environment, while yielding the highest possible socio-economic benefits to the country. These areas are referred to as Renewable Energy Development Zones (REDZs)[v]. The Overberg is one of these REDZs!
[iv] DE LANGE, W. J. & LE MAITRE, D. (2010) Multi-criteria decision making and public participation
processes in natural resource management decision-making: Applications to utilising invasive alien plants as a bioenergy feedstock. Council for Scientific and Industrial Research, Report number: CSIR/NRE/RBSD/IR/2010/0081/A, Stellenbosch.