BY Sinikiwe Marodza and Lisa Dutiro
Harare - The SADC region’s economy is currently facing power challenges and shortfalls, with power production capacity in most countries in the region failing to meet the current level of consumption and demand.
This shortfall has led to the unreliability or non-existence of supplied electricity.
Hydro-electricity power is the most dominant power supply in the region, although there is thermal, gas and a few other power generation methods in Southern Africa.
However, to mainly depend on hydro-electricity is no longer an option since the climate is changing year in year out, like for instance the 2019 rainy season which was affected by the El Nino drought, leaving most countries short of water supply for hydro electricity generation.
There is a need for the region to accelerate the development of its renewable energy options. An alternative and reliable form of energy which can be recommend for consideration could be geothermal generated power.
Geothermal energy is a form of renewable energy which can produce sustainable electricity using the earth’s own resources. It is generated and stored in the earth and can be captured from hot water springs or reservoirs located near the surface of the earth.
These hot springs are found where water percolates into areas of volcanic activity in the earth’s crust and becomes superheated, before forcing its way back to the surface. Heat derived from the hot water can be converted into electricity through electromagnetic induction.
Geothermal heat can provide electrical power that is not dependent on weather conditions, making it a reliable renewable source of energy. Given climate change, hydropower has become very unpredictable as droughts continue to sweep across the nation.
The region has been making efforts in developing wind and solar power plants, but Wind and solar energy are also extremely dependent on weather conditions, whereas geothermal power can be accessed through hot springs and is readily available 365 days per year. Little to no exploration studies regarding this renewable form of power have been conducted in most countries that makes the SADC region. Although estimates have been made as to its generating capacity, not much is known about its true potential. Zimbabwe for instance has several thermal hot springs situated in Binga and Manicaland.
There are over 30 known sites in Zimbabwe where hot water gushes from the ground. The heat generated from the hot springs can be used to generate electricity through geothermal power plants.
The three known types of geothermal power plants which convert thermal energy to mechanical energy and finally to electrical energy are as follows:
1. Binary plants
Binary plants pass geothermal fluid that has a much lower boiling point than water, through a heat exchanger, causing the fluid to turn into vapor and drive a turbine.
2. Dry steam plants
Dry steam plants take steam out of fractures in the ground and divert it directly to a turbine these are the oldest type of geothermal power generation plants.
Flash plants are the most common and pull high-pressure hot water into a cooler, causing the fluid to rapidly vaporise or “flash” resulting into an emission of steam which is then used to drive a turbine.
Binary plants can exploit low temperatures and do not release geothermal fluids, or environmental hazards into the environment – making them the most preferable mechanism for geothermal power generation in Zimbabwe.
Other innovative ways in which geothermal power can be generated are through the conversion of waste heat from industrial processes, power stations and transportation, into electricity through engineering that will permit the thermal (heat) energy produced from the waste to drive a turbine.
According to the Independent UK, countries like Kenya are not facing any power supply deficit as they have turned to geothermal.
Kenya is currently the largest geothermal energy producer in Africa. Kenya’s geothermal power contributes over 40 percent of the country’s electricity generation.
The East African nation has successfully harnessed its geothermal capabilities — generating 45MW in 1985 and now generating an estimate of 630MW with nearly 400MW of that production coming online since 2014. Kenya began exploring geothermal power in the late 1970s and according to the Geothermal Council Resource (a United States industry association), the rise of Kenya’s geothermal industry ranks ninth in the world.
The Infrastructure Consortium for Africa and the United Nations Environment Programme has estimated a potential of 20 000MW of geothermal energy across Eastern Africa and nations such as Tanzania, Uganda, Rwanda, Djibouti, Eritrea and Comoros have done preliminary exploration for geothermal potential.
However, for some African nations that have put efforts towards developing geothermal power are facing challenges in the process of harnessing of their full geothermal potential which includes lack of technical expertise, poor governance and corruption — factors which all tend to hinder big infrastructure projects in developing countries.
A further impediment is funding for project costs. Tapping into geothermal potential will be a long and expensive process that will involve very special expertise, requiring scientists to do geological, geochemical and geophysical surveillance.
It is time to consider advanced research and data acquisition of geothermal power and development, so that we may decipher its capabilities and possible negative impacts.
* Sinikiwe Marodza is our Harare-based correspondent, while Lisa Dutiro is a candidate attorney in the projects, real estate and mergers and acquisitions practice groups at Harare-based law firm, Manokore Attorneys.