Electricity supply: We’re still in the woods

There has undoubtedly been some perceptible improvement in electric power supplies in recent weeks, thanks to the coming back into operations of thermal plants that went under some reconfiguration or maintenance.

But a recent announcement that the 1,020MW Akosombo Dam’s reservoir has fallen close to its minimum operating level of 240 feet means Ghana’s power supply security is far from assured.

That immediately prompts the over-flogged question about the robustness of the country’s electricity generation mix.

Of the approximately 2,828MW total installed generation capacity, hydro sources account for 1,580MW, comprising Akosombo – 1,020 MW, Kpong – 160MW and Bui – 400MW, while 11 thermal plants account for the remaining 1,248MW. 

While serious inefficiencies exist in the transmission and distribution sectors of Ghana’s electricity supply chain, major periodic electric energy crises that have plagued the country have been caused by the unreliable supply of primary sources of energy to produce electricity – in this case, either inadequate rainfall into the Akosombo reservoir or difficulty in securing gas and light crude oil (LCO) for the thermal plants.

It is clear that if the country is to continue to rely on these two sources of primary energy – rainfall and hydrocarbons to generate electricity – a lot of redundancy must be built into both generation capacities to ensure that when there is a challenge with one source, the other can augment supplies. 

But given that Ghana has almost exhausted its easy hydro potential, with the remaining hydro sources becoming increasingly more costly to develop and tie into the national grid, thermal plants seem to be the next best option. And increasingly, the country is betting its chances more on gas-fired thermal plants, taking into consideration its superior advantages over LCO, both in monetary and environmental terms. 

The trend of current arguments are, however, that an over-reliance on gas comes with substantial risks, at least into the foreseeable future, and therefore the need to explore and exploit other primary energy potentials available to Ghana, if it is to be able to build enough robustness into its electricity generation.

Conversation around the introduction of coal-fired thermal plants is gaining currency and some ardent following, especially from government agencies including the Ministry of Energy and the Energy Commission, charged with the responsibility of advising government on national policies for the efficient, economical and safe supply of electricity, natural gas and petroleum products having due regard to the national economy.  

“About 42 per cent of global electricity generation is coal-based,” the Chairman of the Parliamentary Select Committee on Mines and Energy, Dr Kwabena Donkor, has said, advocating the urgent need to explore other alternatives and emphasising that: “we will experience challenges in 2015 and 2016 if we don’t manage the Akosombo reservoir well. 

While the opposition to coal plants is all about its environmental implications, proponents point to massive improvements in the technology that ensures minimal pollution, such as gasification of coal for electricity production purposes.

The running costs of these three types of carbon generating thermal plants LCO, natural gas and coal favours coal.

The VRA, reportedly, requires 5,000 barrels of LCO daily to run its thermal plants and thus spends around US$500 million every 90 days in lifting oil, at current prices. Gas used to generate same amount of electricity but at half the cost the cost while a coal plant, generating similar amounts of electricity, requires even less than half the amount for importing gas to import the coal. 

If sentiments to coal plants have been negative, that to the announcement about Ghana building its first 1,000 megawatts (MW) nuclear power plant in about 10 years, has been even severer.

But if cool heads should prevail and the nuclear power plant should be introduced into Ghana’s generation mix, it would provide the robustness required more than any other source.

In addition to improvements in the safety mechanisms introduced into the construction and running of the technology, following a couple of disasters that have occasioned its use, it is estimated that nuclear plants are far more cost effective than most other technologies. By weight, a kilogramme of uranium, the energy fuel used in nuclear plants, generates 50,000 kilowatts hour (kWh) of electricity, as against the same weight of crude oil and coal generating 4kWh and 3kWh respectively. 

Other important sources being pushed are solar and wind sources. Following the passage of Renewable Energy Law, at the end of 2011, the Energy Commission has been inundated with applications for licence to set up RE generation units. Of about 23 provisional licences issued, only one is for a wind farm, the rest are for solar plants.

While solar has great appeal given the tropical location of the country with its all-year-round sunshine, coupled with zero-emissions from the technology, it is presently less cost effective compared to the other technologies in terms of cost per unit of electricity produced, not to mention the fact if it were to be configured to provide electricity at night when there is no sunshine, it could cost even more. 

Solar technology, as stand-alone units in off-grid communities would be useful, just as it is for households and street lighting, but as a grid-fed source, it will be difficult for it to compete with other sources to fill the demand gap, as exists in Ghana today, and make any meaningful contribution in the creation of redundancy in the generation system that could take care of the periodic shortfalls that are a constant characteristic of Ghana’s hydroelectric plants.

The round figures are instructive. The VRA 2.5MW Solar PV Plant in the Upper West Region covers an area of 3.4 hectares and produces a daily average of 9,500kWh only. Thus the land surface area alone that would be required for the installation of solar panels to generate about the 200MW to 300MW shortfall will deprive the use of vast swathes of land for other purposes such as agriculture. And that is, not even mentioning the fact that the offering price of solar electricity is far higher than PURC’s grid feed-in tariff of GH¢0.20. 

Obviously, if Ghana is to be able to develop substantial robustness in its electricity generation by building redundancies into its generation system at affordable end-user prices, then the coal and nuclear options are imperative. GB