Finding unique solutions for harvesting Qatar’s solar energy

Solar energy has always been in the sights of Qatar’s planners. With some summer months producing over 14 hours of daylight with minimal cloud cover, it would only be natural to look to the sun for energy.

When Qatar Environment and Energy Institute (QEERI), part of Hamad Bin Khalifa University, first began to consider a solar option for the country, it naturally looked to the US and Europe for the most advanced technology. The underlying challenge of solar and wind energy has been storage: how to provide continuous energy when the sun goes down or the wind stops blowing. Batteries that can store power do not necessarily have to look or act like the same sort of D-cell used in flashlights.

Early in this century, solar scientists began focusing on researching the potential of Concentrated Solar Power (CSP) for electrical generation. By using arrays of thousands of parabolic mirrors intense sunlight is concentrated on a tower which contains molten salt at a temperature of 800 degrees Celsius. The molten salt is, in effect, a storage battery because the retained heat can still power the generators long after the sun has gone down.

The leading innovator in CSP technology is Spain. CSP technology would be a promising technology for future developments provided the electricity production costs are reduced, due to its capacity to integrate storage and to produce electricity 24 hours a day. However, CSP technology faces some barriers in Qatar’s desert environment. The reason for this is explained by an energy scientist who runs the Energy Center at QEERI, and oversees QEERI’s Outdoor Test Facility (OTF) at Qatar Science and Technology Park (QSTP), part of Qatar Foundation Research, Development and Innovation.

“For a CSP plant to work effectively, it has to be built in an area that has excellent Direct Normal Irradiance,” says Dr. Veronica Bermudez, Senior Research Director at QEERI’s Energy Center.

“Arizona and Spain both have clear blue skies, which is a sign of excellent Direct Normal Irradiance with high irradiation levels. Qatar, on the other hand, has relatively poor direct radiation from the sun due to a wide aerosol and high diffuse atmosphere.

“This relatively low Direct Normal Irradiance leads to a reduced conversion efficiency, limiting the potential economic competitivity behind CSP, as it is more expensive than conventional solar panel arrays combined with battery systems.”

CSP-generated electricity cannot compete with power generated from photovoltaic solar panels, which is the subject of QEERI’s comparative studies. The growth in the solar panel industry and falling prices equate to lower production costs, and photovoltaics can deliver energy in places where CSP cannot, because they can produce power from diffuse radiation.

During the past seven years, the OTF has tested and monitored 23 different types of solar energy technology. In Qatar’s harsh summer climate, it takes a more robust technology to withstand the unique elements that can affect the performance of any instrumentation that is operating outside of a controlled environment.

“Qatar is a unique environment where challenges can be transformed in opportunities,” says Dr. Bermudez. “There are unique combinations of corrosive effects, not only from the particulate matter in the atmosphere, but because the humidity is detrimental, as is the salinity in the atmosphere and the extreme temperatures. The Direct Normal Irradiance quality is poor due to a combination of these factors.

“Our job is not only to determine the most efficient and cost-effective technology to harvest solar energy, but also to figure out the most efficient use of that energy. Although solar is more environmentally sustainable than electricity produced from gas-fired turbines, we have to think about excess capacity and what to do about that. Solving the puzzle of where and how to fit renewables into the energy mix in Qatar is one of our biggest challenges.”