More energy, a greener world are possible

ZIMBABWE has two potentially conflicting needs, to boost energy output rapidly to drive the economic growth we all need and to slash our carbon emissions by 40 percent from present levels as our contribution to a cooler planet.

But the two goals need not be contradictory. The carbon side is the easier part. By 2050, when we need to have reached this goal of cuts, all vehicles will be electric powered and a lot of other processes which can create greenhouse gases will be using electricity or other cleaner energy.

Electric motors and other electrical equipment tend to be exceptionally efficient compared to equipment using fossil fuels. Even if you burn coal to produce the electricity for electric cars you still slash the carbon footprint by at least 75 percent since, to be blunt, internal combustion engines are not that wonderful, just convenient. So the more critical area is how can we expand, several fold a decade, our generation capacity without adding a lot of carbon dioxide to the atmosphere.

To some extent the emissions will rise, at least for a while. Although our largest power station, Kariba South, is hydro, which is a renewable energy that does not emit greenhouse gases, the next blocks of generation capacity are coal fired. We are at the moment in the midst of the double programme at Hwange Thermal to finish replacing and refurbishing the boiler-turbine-generator units at Hwange Thermal and adding two large 300MW units.

The net result is that we are pushing our thermal capacity from an effective level of just over 400MW to 1 520MW. In other words, we will be burning almost four times as much coal as we are today quite soon. Even the next major power station is likely to be coal, although if the Muzarabani gas field can be confirmed and tapped by the decision day, we can build a gas station instead, and that emits a lot less carbon dioxide with the more efficient technology used, although a fossil fuel is burned.

But we can do a lot better with renewable energy and, in particular, direct solar power and the new hydro scheme at Batoka Gorge.

But as President Mnangagwa noted in his addresses to the United Nations General Assembly meeting on sustainable development goals and the high level dialogue on energy in New York, both need money, especially when it comes to the high capital costs involved. As the President noted, developing countries tend to be short of capital so more global financing will be needed.

The President also stressed the need for external investment into energy. The Batoka scheme has already been planned as an investment vehicle, since neither Zimbabwe nor Zambia, who will share the output, have the cash available to build another huge dam at this time. Borrowing is now harder than it was in Kariba days, and interest rates are a lot higher.

Zimbabwe has opened its grid to new coal power stations. While none of the major initial applicants has shown much interest in going further, one of the large steel investors has already started building a multi-stage station with the first, fairly small, unit coming onto the grid very soon with plans to add more units over time until a fairly respectable new and privately-owned station will be in place. Part of the reason for the investment is that the steel maker will need power and it makes a lot more sense to have a coal station near Hwange feeding the grid, while buying power from Zesa a few hundred kilometres away, than trying to truck coal halfway across the country. Solar is clearly the other big renewable generation technology besides hydro that fits Zimbabwean conditions. Things like wind and tidal power are obviously not on the cards and while our major city rubbish dumps could be engineered into methane producers for modest gas stations, this again required a lot of capital injection and technology transfer.

Already some of the company-size solar installations are being connected to the national grid so that the owners of the panels can sell to the grid during the day to offset their consumption at night. AT the moment the amounts are very small, but we have to start somewhere. Solar farms are another step, again expensive to set up although cheap to run.

The downside of solar is that the sun does not shine at night, and output is cut when it is overcast. But up to a fairly decent limit Zimbabwe has a very good battery, Lake Kariba. The Kariba South station is a lot larger than the lake inflows could supply 24/7, even in a run of normal years, but was designed to give Zesa flexibility by allowing an output surge at peak hours and a major cut back at other times.

Solar fits in rather well to this management system, taking an ever higher fraction of the daytime needs while Zesa keeps that part of its water ration in the lake, and then as the late afternoon peak arrives starts opening the intakes to all eight turbines and keeps most of them open all night when there is no solar. There are other openings for renewable energy regionally. The best hydro-electric power station site in the world in at the Inga rapids along the Congo River between Kinshasa and the sea. The Grand Inga station could more than double Southern Africa’s power output, and there are other sites for rally large stations along the Congo River. Again we are talking about some rally serious money, but the capacity is there.

So Zimbabwe can meet both goals, and at the same time push forward with economic growth and raise standards of living. Development in this part of the world can, and should, mean less load on the environment, not more.

But we, like many others, will need support from the global community to do this with no climate change and in any case are likely to need external investors taking an interest along with the Government itself and Zimbabwean investors.