Climate change reality on hydropower: Zambia must innovate

Editorial
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…as a nation we cannot operate in a silo while the rest of the world innovates. The sun is still shining. It is time to mitigate and adapt.

 By Eng Geoffrey Chishimba Chiyumbe
Hydropower became an electricity source in the late 19th century, a few decades after British-American engineer James Francis developed the first modern water turbine.

In 1882, the world’s first hydroelectric power plant began operating in the United States of America along the Fox River in Appleton, Wisconsin.

Today, hydropower and thermoelectric power make up 98 percent of the world’s electricity generation.

These two most common forms of power are also the most water-intensive, which makes them extremely vulnerable to drought, competition over water resources and other water shortages.

Hydropower is the most dominant renewable and low carbon energy source generating about 16% of the total world electrical energy.

Hydropower generates energy from water and so  any change in natural water circle caused the climate change had and will have impact on the power generation (Dams convert falling water—mechanical energy— into electrical energy. Without water as in drought, there is no energy source to convert).

The effect of climate change on hydropower is mostly influenced the change of the river runoff.

The change of precipitation and temperature are the most driving factors. Increase of the extreme climate events and enlarged erosion furthermore pressures the hydropower production.

Increased temperature causes stronger water evaporation from the earth including from all water surfaces, streams, rivers and lakes. The evaporation reduces available river water, but at the same time more evaporated water origins in more precipitation.

In 2016, the World Energy Council warned, “we will start to see the effects of water scarcity on energy supplies in the very near future.”

The effects are already starting to show, as evidenced Kenya and India’s droughts and subsequent power plant curtailments.

This issue is not unique to one country or continent; power plants from Asia to Europe to Africa to the Americas are suffering due to water scarcity.

It is a global problem. According to the World Preservation Foundation one third of the world’s major rivers and lakes are drying up, and the groundwater wells for 3 billion people are being affected.

Assessing climate change impact studies conducted on the Zambezi River Basin, Dr. Richard Beilfuss, a professional hydrologist,   said the Zambezi is expected to experience “drier and more prolonged drought periods”. Over the next century, rainfall is expected to decrease between 10 and 15 percent over the basin, according to several studies cited the Intergovernmental Panel on Climate Change.

There will be a significant reduction in the amount of water flowing through the river system, affecting all eight countries it passes through.

The water that feeds the river is expected to decrease between 26 percent and 40 percent in another four decades, the study observed.

In Zambia, we are still experiencing the ravaging and devastating effects of drought – Food production dropped, leaving millions of people without access to sufficient food.

Some villagers have lost more than 50 percent of their livestock. Amidst the human tragedy of this drought, an unexpected actor faced impending shutdowns and economic losses due to water scarcity – the energy (electricity) sector.

Indeed we see that the loss of rivers, lakes and underground water reserves are impacting the livelihoods of millions of people, hitting animals, farming and electricity production, as well as threatening to exacerbate climate change further through the release of CO2 and methane.

Despite intense rainfall, world’s water supply is decreasing. Studies find that drying of soil due to rise in temperatures is not letting much water reach rivers and reservoirs.

It is established that the main cause for the drying up of the lakes is drought caused climate change impacting the inflow to the lake – resulting in significant reduction in water levels.

Increased diversion for irrigated agriculture, the building of dams and reduced rainfall over the lake’s surface, are also named as contributing factors.

Cutting down of trees is also a problem causing the drying of soils in our catchments. Plants absorb water from the soil and evaporates it to form clouds.

Deforestation leads to cutting down of trees and as a result less water is absorbed from the soil and this disturbs the water cycle. The formation of clouds becomes difficult which leads to reduced rainfall.

Where once these were moist before a storm event allowing excess rainfall to run off into rivers—they are now drier and soak up more of the rain, so less water flows into our rivers. And drier soils means farmers need more water to grow the same crops.

There is an undisputable evidence of ground water basins losing more water than being naturally replenished rainfall.

We have dry and diminished rivers all over Zambia that can be seen many bridges constructed years ago after independence, to span a body of water underneath, today only service dry lands, where water once flowed.

In 2014, while still working in South Africa, I read a disturbing report that Lake Mweru Wantipa, which was the main stay of the people of Kaputa and now Nsama district through fishing activities was drying at a very fast rate.

I did my grade two education there at Kasongole primary school then, whilst under the guardianship of my maternal grandfather Dickson Chishimba, popularly known as Kapeyeye, who was the chief under Mukupa Katandula.

Many people think of global warming and climate change as synonyms, but scientists prefer to use “climate change” when describing the complex shifts now affecting our planet’s weather and climate systems.

Climate change encompasses not only rising average temperatures but also extreme weather events.

In trying to harness the amazing power of moving water, we are confronted with increasing temperatures, lower water flow and alterations in the rainfall regime, factors which reduce total energy production from hydro power plants.

So therefore with rising temperatures arising out of climate change, more water is evaporating from soils, in turn making the soil absorb more rainfall.

Experts have wondered why despite the above studies and findings, Large dams are being built or proposed, typically without analysis of the risks from hydrological variability that are already a hallmark of African weather patterns, much less the medium- and long-term impacts expected from climate change.

“None of these projects, current or proposed, has seriously incorporated considerations of climate change into project design or operation,” noted Dr. Richard Beilfuss.

Dr.Beilfuss, including other experts, have suggested that countries in the sub-Sahara African region must focus on improving existing hydropower capacity rather than investing in new infrastructure.

“Adding new or more efficient turbines is almost always much lower-impact than building new dams.” Countries should also consider alternative sources of energy generation.

Would it then be reasonable and prudent in view of the above to continue as a nation,   investing heavily in new hydro power plants instead of investing in alternative sources such as solar?

The bible has serious wisdom concerning this. Luke 14:28 – 30 says. “Suppose one of you wants to build a tower.

Won’t you first sit down and estimate the cost to see if you have enough money to complete it?  For if you lay the foundation and are not able to finish it, everyone who sees it will ridicule you, saying, ‘this person began to build and wasn’t able to finish.’

If today in 2019 we are unable to meet electricity demand due to low water levels in our main water reservoirs,  are we going to  have enough water then  to ‘fuel’ the future hydropower plant  we are planning to heavily invest in today,  with an average life span of 50 to 100 years?

We must avoid ridicule. We have suffered enough mockery as decision makers for failure to plan timeously with insight and foresight. We need to allocate time to consult exhaustively on serious matters that affect the nation, especially ones with large capital outlay requirements.

There are sadly some leaders who have been resisting new technologies but insisting on hydropower for their relevance in the sector. We must face reality and put national interest ahead of self.

In Bemba we say “Icabu chakale chilabunsha”(one can’t resist change lest you drown). It is time to metarmophosize into butterflies introducing new renewable energy technologies and innovations.

As a nation we cannot operate in a silo while the rest of the world innovates. The sun is still shining. It is time to mitigate and adapt.

Generation mix is the future. Renewables future is feasible with currently available technologies, including wind turbines, solar photovoltaics, concentrating solar power, biomass power, geothermal, etc.

The power plant of the future will be fully connected, more efficient, and operational more hours of the year.

It will process more data, be more flexible, and still play a vital role in the future of the global energy mix. And Zambia will not be left lagging behind.

The writer is a Zambian Professional Electrical Engineer, Energy Consultant and Project Management Specialist with over 23 years post qualifying practical experience attained from Zambia and South Africa and beyond. Chairman and Team Leader for Zambia Electricity Reforms Task Force 2017-2026. Currently as Country Director for Trans Africa Projects (TAP), a subsidiary for Eskom, a South African power utility. He can be contacted on mobile +260976840325 and email: chiyumbegc@gmail.com

 

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