THERMAL power stations began to operate in Zimbabwe with the growth of towns during the early part of the last century.
The separate municipalities of Salisbury (Harare), Bulawayo, Gwelo (Gweru), Umtali (Mutare) and Gatooma (Kadoma) generated their own thermal electricity.
The Electricity Act of 1936 established the Electricity Supply Commission (ESC), which took over the power stations at Gweru, Mutare and Kadoma.
This increased the national generating capacity and the distribution network outside of the main towns.
The municipalities of Harare, Bulawayo, Gweru and Mutare continued to supply thermal power to their customers using their own tariffs.
Elsewhere, the ESC sold to an ever-increasing number of rural and urban customers.
By 1950, the ESC had a generating capacity of 54.8MW and just under 6 000km of power lines even before the Kariba hydro-electricity scheme began to supply electricity.
Today, Zimbabwe continues to rely, and even expand, on coal-powered thermal stations, despite the large amounts of pollution they emit.
In 1981, the Government of Zimbabwe sought a unified electricity supply service and established the Zimbabwe Electricity Supply Authority (ZESA).
The Electricity Act of 1985 amalgamated ZESA with the ESC.
From its inception, ZESA undertook the generation, transmission, distribution and supply of electricity throughout Zimbabwe.
Its mandate was to maintain existing services and included the examination and development of additional electrical facilities, which it has failed to achieve.
According to a report by the UN Convention to Combat Desertification (UNCCD), hydropower has shaped and promoted economic growth in developed countries as diverse as Norway, Canada and the US.
Interestingly, there is a tremendous amount of untapped hydropower in the developing world; nearly four times the capacity currently installed in Europe and North America.
As a matter of scale, if Africa were to develop the same share of hydropower potential as Canada, it would realise an eight-fold increase in electricity supply and, with complementary investments in transmission and distribution, bring electricity to the entire continent with multiple additional benefits for water management and regional integration.
On a regional basis, unexploited potential (in percent of total potential), amounts to:
- 93 percent in Africa;
- 82 percent in East Asia and the Pacific;
- 79 percent in the Middle East and North Africa;
- 78 percent in Europe and Central Asia;
- 75 percent in South Asia;
- 62 percent in Latin America and the Caribbean.
Today, solar energy is being touted as the most efficient, reliable and sustainable source of energy for Zimbabwe. Solar and wind power, where the relationship with land is less evident and not directly extractive, require land use.
While the direct impact on land productivity of wind turbines can appear to be low; the footprint of the projects can be much larger in terms of emissions caused by production and in terms of land required. Both energy sources have a measurable land footprint that needs to be taken into account when planning land use.
Though the footprint varies by type of technology, data from the US National Renewable Energy Laboratory (NREL) suggests a large fixed-tilt solar photovoltaic plant requires 2,8 acres /1,1hectares per GWh/year of generation.
Thus a photovoltaic plant spanning 32 acres/13 hectares could power 1 000 households.
Research carried out by the International Energy Initiative (IEI) in Zimbabwe shows that the country receives, on average, good direct solar irradiation which is higher than that received in other countries within the region.
While solar power offers a good alternative source of energy for Zimbabwe, what effect will the installation of countless of solar panels have on future global warming?
In contrast to wind and solar energy, geothermal electricity generation does not depend on the weather and can be applied throughout the year.
With geothermal energy generation, the thermal energy stored in the accessible upper layers of earth is converted into electricity or used for heat supply.
It is estimated that future geothermal deployment could meet more than three percent of global electricity demand and about five percent of the global demand for heat by 2050.
Geothermal/biogas energy is currently produced in 24 countries.
Five of these countries (Costa Rica, El Salvador, Iceland, Kenya and the Philippines) obtain 15-22 percent of their national electricity production from geothermal.
In Zimbabwe, promising biogas exploration is currently underway in Muzarabani.
Compared to other energy resources, geothermal energy exhibits a relatively low environmental footprint. Potential impacts range from the drilling of boreholes and of exploratory and production wells, to some gaseous pollution released during drilling and field testing.
The installation pipelines may incur similar environmental impacts to those of drilling.
The exploitation of geothermal energy does not ultimately create additional CO2 because there is no combustion process.
However, the rate of natural emissions can be altered by geothermal production depending on the plant configuration.
Geothermal development involves consideration of land and water use impacts, common to most energy projects, such as noise, vibration, dust, visual impacts, surface and ground water effects, ecosystems, biodiversity as well as specific geothermal impacts. These can alter out-standing natural features such as springs, geysers and fumaroles.
However, there are examples of unobtrusive, scenically landscaped developments and integrated tourism/energy developments; but, land use issues still seriously constrain new development options in some countries.
Successful geothermal projects need the acceptance of local people.
To secure this, there should be no adverse effects on people’s health; minimal negative environmental impacts; and the creation of direct and ongoing benefits for the resident communities such as the biogas project in Muzarabani.
Energy is the dominant contributor to climate change, accounting for around 60 percent of total global greenhouse gas emissions.
Reducing the carbon intensity of energy is a key requisite in long-term climate goals.
In a time of climate change, economic growth and social wellbeing will depend heavily on the speedy up-scaling of low-carbon, clean energy sources and their effective and efficient distribution.
Providing sustainable energy for all represents one of the biggest development challenges of the 21st Century. Affordable, reliable and environmentally sustainable energy sources can increase incomes in rural areas, open new economic opportunities and serve as a basis for broader rural development.
Sustainable renewable energy relies to a great extent on healthy and functioning ecosystems.
Production of renewable energy requires the use of additional land and water, which can affect the availability of these resources for future generations, especially in combination with the effects of climate change and population growth.
While energy supply seems to have improved of late, it is still unreliable.
It is important that Zimbabwe does not lose momentum in exploring cheaper and cleaner sources of energy. Planning sustainable land, water and energy management and supply together can be the only practical solution.
Dr Michelina Andreucci is a Zimbabwean-Italian researcher, industrial design consultant. She is a published author in her field.
For views and comments, email: linamanucci@gmail.com
