Friday, 9 September 2016

Time in the sun

Continuing our series exploring alternative methods of power generation, including Micro-CHP and Surface Water Source Heat Pumps, we turn our attention to photo-voltaics (PV). This week, we explore the work done by Dr. Cynthia Skelhorn, Qatar Green Building Council and Dr. Maria Muhlbauer, UnionBent GbR, Management Systems, Germany in determining the potential of PV in the two countries.

All countries and forward-thinking governments are aiming to address two main issues in developing long-term energy policies.  First, from a demand perspective, they must consider how to decrease energy consumption by implementing energy efficiency policies and technologies. There are several benefits to this; it can lower the Government's own energy bills across the national portfolio of publicly owned buildings common to many countries, it can lower the household and business bills of a country's citizens, and it reduces a country's reliance on imported energy, increasing that country's self sufficiency.

Micro-generation using PV is a promising avenue for renewable initiatives
Secondly, from a supply side, they must consider their best options for alternative energy sources in order to reduce the CO2 emissions that accompany the consumption of fossil fuels. Carbon-intensive methods of energy generation are first on the chopping block, with Governments across the world exploring ways to switch from coal, oil and gas to renewable alternatives like wind and tidal. Despite a leveling or declining trend in the US and OECD countries, consumption of liquid fuels continues to increase on a global scale.

Qatar Green Building Council (QGBC), a member of Qatar Foundation for Education, Science and Community Development (QF), hosted Dr. Maria Mulhbauer from UnionBent GbR in Germany in order to develop and adapt her expertise in Building Integrated Photovoltaic (BIPV) management systems to the climate and economics of Qatar and the GCC region.  Dr. Mulhbauer is investigating the potential for demonstrating a BIPV system in Qatar’s first Passivhaus, located in Barwa City, developed in cooperation with Barwa Real Estate Group and Qatar General Electricity & Water Corporation (Kahramaa), and other numerous private companies and organizations operating in Qatar.

Germany aims to generate 60% of its power using renewables by 2050
Building up photo-voltaic  micro-grid generation could be one of the most promising approaches for supply-side policies. However, the integration of BIPV has its own drawbacks. Every country that seriously wishes to distribute PV micro-generation must have comprehensive information on risks and benefits for its citizens.  Additionally, PV systems must be adapted to the environmental conditions, the economic situation and the requirements of the inhabitants. Matching these requirements will be more sustainable than temporary subsidies or exorbitant feed-in tariffs, as adopted in some European contexts.

To demonstrate this statement, two different countries - Germany and Qatar - are compared.

Annual Solar Radiation
German annual solar radiation amounts to approximately 1000 kWh/m2. High temperatures and dirt are not frequent problems. While the radiation is five times higher in the summer than in the winter, the level of solar radiation on any particular day depends on the cloud cover, the number of daylight hours, and the altitude above sea level. Moreover, the position of the sun, which is determined by the various seasons and the geographical latitude, influences the intensity of the sun and so the output of the PV system.

Energy security fears are driving countries in the
Arabian Gulf to explore renewable generation
The annual number of daylight hours in Germany stands at about 1,300 to 1,900 hours (compared to 8,760 hours in a year). Management systems that can automatically switch on different appliances to match the consumption to the small PV energy peak during the daytime present a means for the most effective utilization of energy in systems that are not yet developed for storing the energy generated.

In contrast, Qatar, as a member of the Gulf Cooperation Council (GCC), belongs to one of the most productive solar regions with some of the highest summer temperatures in the world. It is fortunate in having a high annual irradiation level of 2190 kWh/m2 and up to 3400 daylight hours. This represents an environment for utilizing solar energy, but also with some drawbacks, such as reduced efficiency of the modules by these high temperatures and near-permanent covering of the modules with sand and dust. Therefore, the PV systems need additional equipment for cleaning and cooling to reduce these extreme climate effects.

The Pay Back Time (PBT)
The PBT is often used as a guide to cost effectiveness. If the PBT is significantly less than the expected lifetime of the system, the project is considered to be cost-effective. Electricity tariffs play an important role in this cost-effectiveness of BIPV systems.

In Germany, the grid parity was reached in 2012. Therefore, the price for electricity for private consumers is similar to the costs for own-produced energy, as in the BIPV system.  This leads to an estimated PBT of 6 – 8 years to repay the costs of manufacture and installation, depending on the proportion of own-consumption.  The conditions for the extended micro-grid generation currently are very good and in the coming years it is likely that 20-30 % of the entire electrical power supply will be covered by PV energy.

Qatar experiences some of the highest summer temperatures in the world
The current low electricity tariff in Qatar leads to a high PBT of more than 100 years for both south tilted and horizontal BIPV. In order to promote the additional advantages of renewable energy in this particular situation, the government must develop and provide additional incentives to its citizens.

Because of the current low cost of electricity, the motivation for adoption of renewables in Qatar must be based on something other than energy cost savings.  Several other motivations might include: the desire to be viewed as a pioneer in renewable technologies within the GCC region, adopting a policy of saving energy resources internally in order to export the savings to the international market, or perhaps taking the lead in placing a value on CO2 emissions and using this as a platform for increasing alternative technologies.  Whatever the motivation might be, it is clear that Qatar certainly has the right environmental conditions for developing and utilizing PV and BIPV in its energy policy plans for the future.

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