Sunlight, which is plentiful in South Africa, will not, like uranium and coal, become depleted.

Yet Eskom, the national power utility, plans to invest far more on coal-fired and nuclear power than on solar or wind energy. Of the additional 40 000 megawatts (MW) Eskom plans to build, about 20 000MW will be generated from nuclear.

Eskom has already earmarked more than R185 billion to build new coal power stations, including demothballing, upgrades and new plants.

Nuclear and coal present the environmental risks of dangerous waste and high carbon emissions. Eskom’s pilot wind farm in the Western Cape has already contributed to the avoidance of 11 000 tons of carbon dioxide emissions.

Despite strong evidence of the benefits of renewable energy, Eskom’s investment plans in this regard are slim. Of the R204 billion approved for generation projects, R1.1 billion has been allocated for renewable energy, a 100MW wind farm that is likely to be operating in 2010. Over and above this, about R2 billion is allocated for subsidies on installing solar water heaters in homes and businesses. Eskom has also investigated a 100MW concentrating solar power plant. By 2025, when Eskom should be generating about 80 000MW, the power utility plans 1 600MW to be from renewable energy.

In a world where carbon emissions are increasingly threatening the environment and as demand for nuclear fuel and coal rises, increasing the cost of these fuels and accelerating their depletion, should Eskom not be pushing renewable energy a lot harder?
Wind power

Wind power is a mature technology, used widely in Europe. In Germany it produces 20 000MW. According to a Merrill Lynch report on renewable energy published in August, the cost of wind power is declining.

“For plants in the best location, wind energy is fully cost comparative with fossil fuel,” the report says.

Unfortunately, South Africa is not the best location; there is just not enough wind to generate sufficient sustainable electricity supply. Ompi Aphane, chief director of electricity at the department of minerals and energy, says windy areas in South Africa are on the coast.

To generate large amounts of electricity from wind turbines would require large tracts of land. A wind turbine that generates 5MW could have a 12m diameter. In comparison, an Airbus A380’s wingspan is 80m. So to generate a large amount of power, say Koeberg’s capacity of 1 800MW, you would need about 380 5MW wind turbines.

The BBC has reported some opposition towards wind turbines as an eyesore. In response to this, some wind farms in the UK are now being built out at sea.

The Guardian reported the government had approved a £1.5 billion (R20.5 billion) scheme to build the world’s biggest offshore wind farm in the Thames estuary. The scheme could generate 1 000MW, or about 1 percent of the UK’s energy requirements.

A UK 2005 department of trade and industry report said offshore wind power could provide 3 213 terawatt hours (3 213 million megawatt hours) of power – more than eight times the electricity the UK uses now.

Offshore wind power holds promise because wind speeds rise the further out to sea they are, and public opposition drops because of the lower visual impact. But, despite this, the UK, like South Africa, is pursuing nuclear energy.

Eskom needs to add generating capacity as quickly as possible to ensure reliable base load supply to support economic growth and increase its reserve margin from the current range of 8 percent to 10 percent, to the internationally accepted 15 percent.

Wind and solar power do not yet meet the energy parastatal’s criteria for large-scale generation potential. Aphane says that assuming the additional capacity required could be derived from renewable energy, supply must meet demand simultaneously, as it is impossible to store large amounts of electricity.

Wind will be a small part of South Africa’s future energy mix. Solar power holds more promise as an environmentally friendly solution to South Africa’s energy crisis.

Already in South Africa there are well over 200 000 households, rural institutions and water pumps using solar panels, according to a February 2006 report titled The Potential Contribution of Renewable Energy in South Africa.

The report was prepared by RAPS Consulting and Nano Energy for the Sustainable Energy and Climate Change Project (SECCP) of Earthlife Africa. It forecasts that by 2050, solar panels could constitute 14 percent of electricity supply in South Africa.
Two approaches

Aphane says there are two approaches to solar power. One is on the distribution side, which includes solar home systems for lighting, equipment and water heating, and the second is solar generation.

Eskom will subsidise a mass roll-out of solar water heaters. But the biggest challenges are the initial capital outlay, which is far higher than a standard electric geyser, and limited capacity in the solar water heating industry to implement this plan. The cost of a solar geyser is R15 000 to R25 000, depending on the size, while an electric geyser costs R5 000 to R8 000.

Aphane says South Africa could get a Chinese solar water system for R3 000 to R5 000 excluding installation. “But we have to be careful not to procure rubbish just because it’s cheaper,” Aphane says.

The SA Bureau of Standards has certified several solar water heater suppliers that participated in a Central Energy Fund pilot programme earlier this year. Solar geysers would save up to 70 percent of the total electricity used for water heating. On average, water heating accounts for up to 40 percent of a household’s energy consumption.

But solar generation is not as promising yet. The world’s largest solar power plant is a 40MW project of 1 million solar panels. By contrast, the world’s largest wind power plant is 20 times the size at 780MW. “Solar is far less suitable for large-scale roll-out of renewable energy,” says the Merrill Lynch report.
Solar costs

But an Eskom feasibility study on a 100MW solar generating project in the Northern Cape found that a pilot scale concentrating solar power plant built in South Africa could produce the lowest-cost solar electricity in the world to date.

The Northern Cape site offers one of the best solar resources in the world, where a concentrating solar power plant could be designed to meet evening peak loads. But the unit cost of concentrating solar power will be more than Eskom’s cost of coal power for the foreseeable future. Nevertheless, the economics of renewable energy are expected to become more attractive.

The SECCP/EarthLife Africa report says: “Although speculative … somewhat surprisingly, renewable energy options are likely to be the most cost-effective options for energy supply in the future.

“Fossil fuel pricing is difficult to predict but if prices do continue to rise it will not be long before solar thermal technologies in particular present a large-scale, economically viable power supply option.”

In the cost of generation, not much will beat coal … yet. According to the SECCP report, based on data in 2006, the cost of solar panels is about R1.20 a kilowatt hour (KWh) but this is forecast to decline to about 30c/KWh by 2050.

Solar generation costs about 38c/KWh and is forecast to decline to about 16c/KWh in 2050. Wind power costs about 25c/KWh and will remain below 40c/KWh in the future.

Generating electricity from existing coal-fired power stations costs about 12c/KWh.

But new base load coal-fired power costs about 25c/KWh and is forecast to rise to almost 40c/KWh by 2050.

What is also not factored into the cost of coal-generated electricity is the externalised cost of coal power, such as the impact on health and the environment. Likewise, it is impossible to factor in the cost of storing nuclear waste for thousands of years. Coal and uranium are finite resources; as these reserves decline, they will become more expensive.

Tristen Taylor, energy policy officer at EarthLife Africa, says South Africa’s coal reserves will last an estimated 200 years, perhaps even less.

Taylor says renewable energy is inevitable as there is just not enough fossil fuel. “Solar and wind energy can provide large scale base load capacity for South Africa. No one thinks we can achieve this tomorrow but eventually we can reduce our reliance on coal for base load electricity supply.”