All our Chickens coming home to Roost

Some months ago I asked the people who run the Zambezi River Authority for some information on the river flow above Kariba Dam. They refused to give me the information and I had to ask a number of friends in the region to fill in the gaps. As a result I was the first to draw attention to the serious situation now evolving at Kariba Dam power station where water levels in the lake are approaching the point where power generation may have to be suspended altogether.

The one thing the ZRA did give me was a copy of a warning issued by the Chairman of the ZRA much earlier in the year where he drew attention to low intake volumes and the need for Zambia and Zimbabwe to reduce water offtake for power generation. Eventually, when neither country complied, they issued an order that power generation be reduced to 950 megawatts from the 1st September. In Zimbabwe the reduction was quite modest – down from 750 to 475 megawatts, but in Zambia the reduction was from almost 1100 megawatts to 475, a reduction of 60 per cent in a country that is almost totally dependent on hydro power.

Even with this sharp reduction it may be too late to prevent the complete suspension of supplies to both countries with catastrophic consequences. We will lose a metre of remaining water to evaporation and current inflows are not replacing the water being drawn through the turbines.

The fundamental facts remain – the long term sustainable throughput of the turbines was originally calculated at 1200 megawatts – installed capacity was 1400 megawatts and this seems to have been about right as only in exceptional years did we have to open the flood gates in the wall to allow surplus water to escape. Now we are in the process of raising the generation capacity to 2200 megawatts – 1000 megawatts above the long term sustainable throughput. As recent experience has shown – the temptation is to use this capacity even though it may deplete water levels as it has in the past year.

But the impact of the consequential reductions in power allocations in both countries has already been substantial and any further cuts will impact on economic activity across the region.

The fundamental problem is the slow and inadequate response by regional governments to a power crisis that has been developing over many years. In South Africa, ESKOM, long regarded as an exceptionally well managed and strategic enterprise seems to have gone to sleep. Long term plans have been abandoned or neglected and slowly South Africa has slipped into a situation where it can no longer meet its own demand, let alone exports of surplus power into neighboring States.

Compounding their difficulties, short term peak power generating capacity based on diesel has been used to meet base load demand at huge cost. New projects have been badly executed and are now years behind schedule, doubled in cost and still incomplete. Corruption on a massive scale has exacerbated the situation.

In Zambia delays in the completion of planned power stations has also resulted in the cut back at Kariba throwing the Zambian economy into reverse. Recent growth has been very much on the back of cheap and reliable power and with cuts of up to 18 hours a day the country is now experiencing mine closures and the local currency has devalued by 50 per cent in the past year.

But it is Zimbabwe where the power crisis is going to be worse and there is now an urgent need to examine all possible options. We need about 2200 megawatts to keep our economy going – Hwange with an installed capacity of 900 megawatts is generating 500 with difficulty and is hugely unreliable for some reason. Kariba is down to 475 and if climate change predictions are anything to go by and problems with the Inter Tropical Convergence Zone (ITCZ) and El Nino we could easily see the total shut down of the dam. I do not think we can operate even at greatly curtailed levels with this sort of power availability.

The only project that is anywhere ready to go is the proposed Lusulu Power Station in the Binga District and on the shores of Lake Kariba. This is planned to go to 2400 megawatts and will supply 2000 megawatts into the regional grid when complete. The first 500 megawatts by 2019 – but that is still 4 years away even if we meet the target of ground breaking on the 1st April 2016. What it does do is critical as it will provide a base load of 2000 megawatts and allow Kariba to do what it is designed to do – feed the grid when the system goes to full demand, the water turbines can then be closed down when demand falls back on a daily basis.

Even so it’s not enough and we have to try and establish another 15000 megawatts in the region to meet demand in the next decade. Coal or Gas fired power stations would seem to be the only solution as new hydro capacity will take at least 10 to 20 years to establish. Batoka Gorge and the Inga scheme on the Congo River will bring another 7000 megawatts into the system and in the even longer term Inga is the solution as it could, on its own, supply the whole of Southern Africa.

From my own perspective we need to target another large thermal unit, the same size as Lusulu – installed capacity of 2400 megawatts and delivery capacity of 2000 megawatts. We need then to develop the second power station at Cahora Bassa with some 1600 megawatts capacity to act exactly as the Kariba system – meeting peak demands in an integrated system. Ideally base load demand (about 10000 megawatts) should come from new coal fired plants – we have ample coal supplies and if the new units are modern, clean units then the impact on the environment should be manageable.

The best option available to us today is a new 2400 megawatt unit in the City of Mutare or at the Port of Beira and using LPG as the energy source. The construction lead time on such a plant could be 2 years – especially if we use prefabricated units from a decent foreign manufacturer. The LPG could be sourced anywhere in the world but most likely from Iran and is the lowest cost energy source available today. Mozambique is about to become one of the largest suppliers of LPG in the world and could slip into this role as its own vast resources in northern Mozambique come on stream by 2020.

Solar panels are another quick fix and we need to set up a system where we might support the installation of solar generators on private property with the capacity to sell surplus power to the grid. I think we could secure low cost financing for such a scheme and the private sector would do the rest – prepaid smart meters would enable private players to sell surplus energy to the grid. The problem with large scale solar farms is the cost and the need to return at least twice the present average tariff for power.

Then we have to pick up all the small schemes that are available – the sugar companies must be able to generate power and sell it to the grid. The small hydro schemes must all get the go ahead and be helped with funding. But believe me we have an emergency on our hands and must urgently find solutions beyond the plans that we are presently pursuing.

Eddie Cross
Harare 6th October 2015