Nuclear energy is a firm base on which to build renewable generation

A term that is being used more and more frequently by the media when discussing the energy needs — and misunderstood nearly as often — is base load.

By definition, base load is the minimum amount of power needed to meet reasonable economic requirements.

Economies rely almost entirely on base load power to operate properly. Industries cannot operate effectively and grow without a stable source of power. Baseload is required 24/7, 365 days a year, to run heavy industries such as smelters, mills, hospitals and refineries. Blackouts in these heavy operations cause massive disruptions, damage equipment, put lives at extreme risk and ultimately cost the economy billions.

According to Caroline Kende Robb, the executive director of the Africa Progress Panel, power shortages diminish the region’s growth by 2 to 4 per cent a year, holding back efforts to create jobs and reduce poverty.

Base load needs to be constant, reliable, predictable and economical. It therefore generally requires the burning of fossil fuels, which have proven to be detrimental to the environment and the general population’s health.

There is also a misconception among the general public that renewables are able to supply base load power. The reason renewables cannot be considered base load is to do with the net capacity factor (NCF) of the generating plant. The NCF of a power plant is the ratio of its actual output over the stated period of time to its potential output.

According to the latest figures from the Palo Alto-based Electric Power Research Institute, wind can only achieve a net capacity factor of roughly 25 per cent, and photovoltaic solar is even less at only 20 per cent. Newer-generation nuclear power plants, in contrast, can achieve a net capacity factor in excess of 92 per cent.

The output from renewable energy is linked directly with weather conditions, which makes the technology rather unpredictable. Energy that varies with such factors is referred to as intermittent power.

Another problem is the fact that storage of renewable energy is hugely expensive and unreliable, and is therefore not yet at a point where it is economically viable. Renewable energy contributes to the grid when it is available, yet it cannot be stored economically and therefore cannot provide base load power.

Another important point to remember is the concept of the dispatchability of power. Dispatchable generation refers to sources of electricity that can be tapped at the request of power grid operators to meet demand. Because wind and solar are dependent on the weather conditions, the power from these sources is not strictly dispatchable, as it is available only when weather conditions are permitting — and in the case of solar, only during the day.

As a result, any utility that has an abundance of such sources of energy would need to install standby capacity in the form of dispatchable power such as gas or diesel generators. When considering the costs of renewable energy sources, these backup generators need to be factored into the price.

In countries where the options for base load power are severely limited, nuclear energy can be a viable and efficient solution.

For instance, Koeberg Nuclear Power Station in South Africa, is a base load power station with two 900-megawatt units and a total capacity of 1,800MW, with a net capacity factor of more than 83 per cent over the past three years. A wind farm of the same capacity would require 900 units of 2MW each with a surface area of about 112 square kilometres, and have a net capacity factor of merely 25 per cent. The surface area for the Koeberg plant is 30 sq km (this includes a 3,000 hectare natural reserve that surrounds the reactor).

This also holds true in the Middle East, where nuclear power is an efficient solution to meeting the region’s energy needs. Jordan is planning to extract 30 per cent of its energy needs from nuclear plants after the construction of four nuclear facilities. Meanwhile, in the UAE, where the energy demand is expected to grow at 9 per cent per year, one of the world’s most acclaimed nuclear programmes is under way. It will account for a quarter of the country’s electricity needs by 2020.

The other option, fossil fuels, is far more detrimental to the environment and to human health. Recent studies have shown that up to 600,000 people lose their lives per year through carbon pollution and related accidents in Africa alone. Coal power plants are also typically situated near coal mines and require an immense amount of cooling water to operate. The water is a scarce resource and poses another significant challenge for water-stressed countries.

Nuclear energy in no way competes with renewable energy sources, but rather complements them. If nuclear is to be compared to anything, it should be compared with other sources of base load power such as coal and gas, and not renewable energy.

Knox Msebenzi is the managing director of the Nuclear Industry Association of South Africa.

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