IEA correctly emphasizes that Africa has abundant hydropower and fossil resources, but the organisation seems to underestimate the costs and time required to bring these resources to the market. In the Outlook report, the rapid growth of hydropower is the most striking feature. Installed capacity of hydro doubles by 2025, and doubles again by 2040 to 104 gigawatt, to become the largest source in terms of installed capacity. There is no doubt hydropower in Africa has the technical and economic potential to quadruple by 2040; the main question is whether the political and administrative hurdles for projects like the 4,5 GW Inga III project, including the thousands of kilometres of cross-border connection lines, can be overcome within the timelines assumed by governments and by the IEA.

Similar objections can be raised regarding the time and costs of bringing 60 new gigawatts of gas fired power on stream during the coming decade, power plants that for the most part rely on gas infrastructure yet to be built. Recent studies have confirmed that construction of large fossil infrastructure projects almost systematically require more time, and cost more money, than decided.

The consequence of the delayed energy infrastructure projects is that Africa’s nations are becoming more and more dependent on expensive and polluting diesel and heavy fuel oil to meet its fast-growing power demand. IEA estimates that Africa in 2012 spent more than 5 billion dollars yearly on such "emergency" power generation. Adding the extensive use of diesel generators in the private sector, the number is even higher. Solar PV is an available, scalable and quick-to-deploy resource that can alleviate the short- and medium term burden of Africa’s mounting fuel-bill, while at the same time playing an integral cost-competitive part of the countries’ energy-mix.

The explanation for IEA's failure to address this opportunity can be found in the "Indicative levelised costs of electricity" for on-grid generation in Africa.

The figure indicates that the cost of large-scale solar PV is three times that of large hydropower, and 150-50 % more expensive than gas-fired power generation. The figure is highly misleading, for several reasons:

As stated in IEA's Roadmap report the cost of solar PV in Africa could be cut to less than 100 USD per MWh already tomorrow, if we assume the same cost of capital as in Germany. The experience from South Africa, where more than 800 MW was built the last 18 months and another 1 GW is under construction, holds an important lesson. The average South Africa cost of solar PV dropped more than 50 percent in two years, and is now according to Eskom cheaper than building new coal power. Similar progress will happen in other parts of Africa, provided governments are prepared to introduce predictable and stable targets and incentives. Strangely enough, IEA's Energy Outlook does not even discuss what the rest of Africa can learn from South Africa’s Renewable Energy program.

Sceptics may argue the growth in wind and solar PV projected in IEA's Hi-Ren scenario is impossible without an expensive upgrading of the electricity grid with the inclusion of storage capabilities. Some additional grid reinforcements are undoubtedly required to accommodate a combined 30-35 % market share for PV and wind by 2040. But as IEA concludes in their recent study on the integration of variable renewables, the additional costs are far smaller than normally assumed, less than 5 % of total electricity costs if carried out gradually. In other words, the gradual grid-related costs of accommodating a 30-35 % share of variable renewables will be much smaller than the savings African countries can obtain by systematically allowing solar and wind to replace fossil fuels as quick and comprehensive as possible.