Egypt is suffering a power crisis, and not just a political one. Over the weekend the Egyptian president, Abdel Fattah al-Sisi, made an appeal to the Arab world's most populous nation for patience after a series of serious blackouts.

The daily blackouts have caused the metro in Cairo to grind to a halt during rush hour, business to be disrupted, and the city's already terrible traffic problem to get even worse. The power cuts left parts of the capital without running water, and caused 2,000 mobile phone signal boosters to fail. Mass protests have been held calling for the resignation of the Electricity Minister.

Sisi is very well aware that these energy outages could even topple the military government, as it was one reason for the uprising against Islamist President Mohammad Mursi.

"This is a battle for our existence," Sisi said. "We need to carry out a huge power generation development."

It is ironic that this is happening in a country blessed with so much solar power that in 1913 it was chosen as the site of the world's first solar power station by American and British engineers.

Yet in his speech to the nation this weekend the president made absolutely no mention of renewable energy or energy efficiency.

Solar engineer Frank Jackson, who recently returned from conducting a solar electricity training course in Cairo, told me by email that "they really should have started with all this energy stuff 20 years ago. The people I was working with are trying – but with a city that size...."

Cairo, a city of 18 million people, contains no pedestrian crossings. Jackson says that energy efficiency is not even on the agenda. It "holds millions of cars and air conditioning units battling the 40^oC heat, and is slowly running out of energy".

Instead of solar the country seems to be hell-bent on operpetuating its doomed reliance on fossil fuels. It even seems to be seeking military solutions to its energy problems. There have been reports that in the summer he permitted Qatar to use the Egyptian airbases to bomb sites in Libya and, if true, were likely to be in return for favours that include access to oil.

That it would even be thinking like this is perfectly in keeping with the fact that Sisi was the former army chief who deposed Mursi

The situation is so desperate that Sisi's voice was heavy with emotion as he appealed to the Egyptian people on Saturday. "Have we developed our electricity production to meet our needs? Made stations to meet our needs? This did not happen because the financing required is large," Sisi said. "We must understand that matter cannot at all be resolved and remedied overnight. If we work together on this, if we accept this challenge, if we are patient, we will succeed in putting Egypt in the place where it deserves to be."

Egypt needs to add 12,000 megawatts to its grid over the next five years at a capital cost of about $12 billion, he said, but did not say what kind of plant. Reuters have reported that oil-producing Gulf countries have helped Egypt since Sisi took power. Sisi said that electricity was not the only sector in need of investment; thousands of villages lack proper sewage systems and the government is struggling to recruit new teachers.

How Concentrating Solar Power can help

Concentrating Solar Power (CSP), rather than photovoltaic power, at a large scale is perfect for Egypt's climate and weather. It produces thermal energy that drives conventional turbines and so can work in tandem with fossil fuel plants.

Modern plants contain energy storage systems enabling them to produce power at night and can have natural gas backup. A plant in Spain (Gemasolar, right) of this nature has a capacity factor of 63%. There is more solar energy available in Egypt than in Spain, so this figure would be higher there.

(The capacity factor of a power plant is defined as the ratio of the actual electricity produced per year to the electricity that could in theory be produced based on the nominal peak power and technical availability of the PV system 24/7. It is given as a percentage. The higher the better.) 

A typical capacity factor for a natural gas plant is 42.5% and for a coal plant, 63.8%, so CSP with storage and backup compares well. The upfront costs are high, but Operation and Maintenance (O&M) costs of CSP plants are low compared to those of fossil fuel-fired power plants. A typical 50 MW parabolic trough plant requires about 30-40 employees for operation, maintenance and solar field cleaning. Automation can reduce the O&M costs, including fixed and variable costs, and insurance by more than 30%. 

The annual full load hours that can be supplied by CSP vary based on the level of thermal storage, latitude, and annual solar irradiation (DNI). Egypt benefits from 2.1–2.7MWh per square metre, with the most in the east. This is a massive resource.

For this, a plant with collectors covering an area of 12,000 m² could generate around 4, 600 MWh of electricity with six hours of storage. A third more with 12 hours of storage.

In this type of plant, synthetic oil, steam or molten salt are used to transfer superheated steam to power a Rankine cycle generator.  Molten salt is typically used for thermal storage; capacity can be up to 15 hours. To provide this the solar field (i.e. mirrors and heat collectors) must be oversized with respect to the nominal electric capacity (MW) of the plant. 

Right: Schematic diagram of a CSP plant with storage. Excess heat is sent to the heat exchanger and warms the molten salts going from the cold tank (top) to the hot tank. When needed, the heat from the hot tank can be returned to the heat transfer fluid and sent to the steam generator to produce electricity or heat or both. 

And then there is the potential for saving energy. Egypt could do well to adopt American or European standards, as a far cheaper way of solving its energy shortage problems than by building more plant.

I'll leave the last words to solar engineer Jackson, talking of conditions in Cairo: "It's extreme but there are plenty of places like it. Egypt has had 7,000 years of cities …. Makes one think."