adminEng Dr Ezikiel Madzikanda
I am sure the guys back home are doing a fantastic job under the circumstances to ensure that there is electricity for both domestic and industrial needs. But the truth is electricity issues or challenges in Zimbabwe are probably way beyond us, the technicians and engineers. What is needed now is a very generous sponsor who can come and rebuild the whole infrastructure from ground zero for FREE. Yes for FREE. Zimbabwe probably requires 2000MW of power and is currently generating 400MW to 600MW at most, leaving a massive shortfall of 1400-1600MW!
You need on average US$1million to build 1MW power station. So, mathematically, we require roughly US$2bn as a minimum to bridge the shortfall. Having said that, the existing infrastructure that is, transformers, transmission lines and distribution lines among others is long overdue for overhaul.
Remember Kariba was commissioned or put into service in 1966 and so much has changed. Nonetheless, it’s infrastructure has still got some useful life but not at the same efficiency or expected efficiency. So, the $2bn I mentioned may just be chewed up overhauling the existing infrastructure.
My suggestion of a generous sponsor who can give us or loan us (zero interest) a whooping $2-4bn to build new and efficient infrastructure is the way out. Remember, this takes years (probably 5-10 years) to build a power station the size of Kariba. The other problem that faces Africa in general is the erratic rainfall.
If you rely sorely on say hydro power station; you run the risk of power shortage during a severe drought season! So, a mixture of power stations (thermal – like Hwange, solar etc) would be ideal. Solar is the buzz word in our industry at the moment but it comes with a cost until the technology is fully developed.
There are four widely used power stations (Hydro, Thermal, Nuclear, & Solar). Hydro has greater than 90% efficiency but prone to severe drought; Thermal – 60% efficiency (considered not a very clean source of energy); Nuclear – greater than 95% efficiency (considered not a safe source of energy due to nuclear reaction but the cheapest).
France is predominantly nuclear. Solar – 65% efficiency but generation is only during the day when there is sun shine and not efficient in other areas due to irradiation (amount of sun shine) patterns.
So, countries like Australia, South Africa, UK and Zimbabwe to name a few, rely on thermal power stations due to abundance of coal even though coal is the least efficient.
Coming back to a point on old thermal stations in Zimbabwe (Harare, Munyati, & Bulawayo); these should only be used as cold standby but the generation or lack of it has forced the Power Utility to run these ‘old horses’ on a daily basis with all the aggravated inefficiencies notwithstanding.
Hydro (Kariba South) is owned by the Zambians and is under severe drought restrictions at the moment. Every dam or hydro plant has a generating head (water level) and Kariba is reaching its lowest minimum, meaning, they should simply stop generating electricity.
Now, the most abundant source of energy, solar, has an inherent problem of storage. Electricity in general, cannot be stored (we deliver it fresh)! Because the sun goes down, and so goes the solar generation. There are some battery storage on the market at the moment (tesla batteries – https://www.originenergy.com.au/blog/big-picture/origin-launch-first-solar-battery-offering-with-the-tesla-powerw.html) under consideration/trial here in Australia, which are relatively, yes, relatively cheap for solar energy storage.
This is what as Zimbabweans we should start looking at. What we need to advocate for are import/sales tax/ and any other duties and taxes removal to make them affordable for an average Zimbabwean. I am designing a small solar power station (45MW for Melbourne Victoria, Australia) and currently evaluating these batteries and other options. I will be more than happy to share the findings with fellow Zimbabweans.
Engineer (Dr) Ezekiel Madzikanda is based in Australia. He is a former ZESA employee, who worked for the national power utility in Mutare. This opinion originated from discussions he had on the country’s power crisis with Musengezi High School Alumni on the whatsapp group.
Online Reporter