On the grid: Fibre optics and an expanded transmission system are in the works

The kingdom’s power sector is undergoing a number of significant upgrades focused on the electricity network and distribution system. With projects ranging from the construction of transmission substations to the installation of fibre-optic cabling, the suite of planned and ongoing projects should notably increase the overall security of Bahrain’s grid system.

Peak electricity demand has risen substantially over the past 10 years. Indeed, the country’s Electricity and Water Authority (EWA) has reported that peak power demand climbed from approximately 1540 MW in 2003 to 2967 MW in 2012, showing that the demand has almost doubled over a decade. The demand for additional power, however, has slowed to some extent recently. Peak electricity demand increased by around 2.5% between 2011 and 2012, down considerably from a rate of more than 10.5% between 2005 and 2006, according to the EWA.

As the growth rate of peak demand has slowed, the country has also expanded its electricity generation capacity. This has all but eliminated power outages, which posed a challenge for the kingdom from time to time in the early 2000s, mainly as a result of transmission and distribution conditions. The Al Dur Power and Water Company, the owner of the local Al Dur Power and Water Plant, recently reported that power generation capacity is currently around 3923 MW. There are five power plants in Bahrain, and the largest among them, the recently completed Al Dur independent water and power project, operates with a generation capacity of 1234 MW.

TRANSMISSION: Distribution and transmission in Bahrain is carried out by the EWA. The kingdom’s electrical grid network includes three transmission systems, and these run at 33 KV, 66 KV and 220 KV. According to the EWA, the kingdom maintained 109 66-KV substations, 17 220-KV substations and 10 33-KV substations in 2011. The number of new 220-KV substations has risen by around 90% over the past decade, and construction of new 66-KV substations has grown at a similar rate over the same period. EWA data, however, indicates that the number of 33-KV substations in Bahrain has remained relatively constant.

ON THE CIRCUIT: As the total number of substations has increased, transmission circuit bays have also expanded. The EWA reported that the number of reactive compensation circuits in operation grew by more than 11% between 2010 and 2011, from 36 in 2010 to 40 the following year. The number of transformer and feeder circuits in operation both rose by about 7.5% over the two-year period. Bahrain’s transmission system used a total of some 365 transformer circuits and 301 feeder circuits in 2011.

According to EWA figures, the length of underground 220-KV transmission circuit feeders stretched nearly 300 km in 2011, while that of underground 66-KV transmission circuit feeders measured more than 700 km. Overground 66-KV transmission circuit feeders were much shorter, as are underground 33-KV transmission circuit feeders, covering 22 km and 44 km in 2011, respectively. When compared to the other transmission circuit feeders in use in Bahrain’s grid network between 2007 and 2011, the length of underground 220-KV transmission circuit feeders increased the most rapidly, expanding from about 200 km in 2007 to almost 300 km five years later.

MAKING PLANS: A number of large-scale projects aimed at improving the kingdom’s transmission system are either ongoing or in the planning phase. For the past several years, work has been under way on the 220-KV transmission system, to construct 15 bulk supply points (BSPs), some of which have already been completed. EWA recently reported that three of these BSPs, which are located in Marsa Al Bahrain, Dhahiyat Al Seef and Al Areen, were commissioned in 2012.

A 220-KV station was also recently connected to the network to serve the new load generated by Tatweer Petroleum, the firm responsible for producing crude at the Bahrain Field. Both the new BSPs as well as the recently connected 220-KV station have significantly reinforced the backbone of Bahrain’s main transmission system.

Work is also under way on the kingdom’s 66-KV transmission system. Since 2009 a total of 30 substations have been added to the system, with the most recent additions being commissioned in Zallaq and West Riffa, according to recent information provided by EWA. Construction of more 66-KV transmission substations is ongoing in Sharq Al Hidd and Sahel Al Hidd areas to meet the continuous increase in the distribution load of those areas. In association with the commissioning of these new 66-KV transmission stations, significant distribution network development is also under way, and some 300 new 11-KV outlets are currently being installed.

UPGRADES: EWA also has plans to upgrade Bahrain’s 220-KV and 66-KV transmission networks. The project will focus on system expansion and reinforcement in order to overcome problems with overloading at some of the existing 220-KV and 66-KV substations as well as to meet the load demands of developments in the commercial, industrial and housing sectors. EWA has reported that eight new 220-KV BSPs will be built in addition to 24 new 66-KV city-type substations and five loop-type 66-KV substations. The largest share of planned city-type 66-KV substations – a total of eight – will be built at locations in Bahrain’s Central governorate, including areas such as Sitra and Salmabad. Locations in the Southern governorate, which is the least populated of the governorates, will receive six city-type 66-KV substations. The Capital governorate, by comparison, is scheduled to receive only two new city-type 66-KV substations.

Additional work on the 220-KV and 66-KV transmission networks will focus on installing cross-linked polyethylene (typically referred to as XLPE) cabling underground as well as pilot and fibre-optic cables to link the new substations to the existing network. EWA plans to divide the work up into a number of contract packages. These will concentrate on areas such as consultancy, cable supply and installation, switchgears, civil and soil investigation, supervisory control and data acquisition, transformers and telecoms. The authority recently calculated that the first phase of the entire project, which involves linking the new substations to the existing grid, should be completed in the first quarter of 2015, and the total budget is estimated to be BD310m ($815.7m).

STRONG SUPPORT: One of the most significant projects on the kingdom’s power network focuses on building a 400-KV transmission system that will become the grid’s backbone. The existing 220-KV network has grown considerably and has become fully intermeshed, which has led to excessive short circuit currents in several sections of the network, creating problems associated with safety, reliability and maintenance. EWA decided that the best technical solution was to build a new, 400-KV transmission network that would overlay the existing 220-KV system. This new network will mitigate problems related to short circuit levels as well as provide future transmission capability for the next 30 years and allow expansion of the 220-KV system. An additional benefit will be the less expensive transfer of bulk power within the country and within the GCC Interconnection Grid, which links Bahrain, Qatar, Kuwait, Saudi Arabia, the UAE and Oman.

The EWA engaged the consultancy Mott MacDonald to design the new 400-KV system. According to figures provided by the authority, the value of the contract, which was awarded in May 2011, is nearly BD3.4m ($8.94m). Mott MacDonald has been working closely with the EWA to determine the system requirements and scope of the project. The consultancy has found that three 400/220-KV substations in key areas of the kingdom will need to be built. Each substation will be made up of 400-KV and 220-KV switchgears, 400/220-KV transformers and associated auxiliary, protection and control equipment, which will be integrated with the existing 220-KV system.

SUBSTATIONS: The three 400/220-KV substations are due to be built in Riffa, Hidd and Umm Al Hassam. The substation in Riffa will be constructed within the perimeter of the Riffa Power Station, which is a government-owned power project with a generation capacity of 700 MW. Likewise, the Hidd substation will be constructed on the grounds of the Hidd Power Plant – a 1000-MW independent water and power project on Muharraq Island, according to data provided by the facility’s owner and operator, the Hidd Power Company. The Umm Al Hassam substation will be built within the Umm Al Hassam Transmission Station complex. Cabling will stretch from the southern-most substation in Riffa to the Umm Al Hassam substation. This will be connected to Hidd by marine cabling crossing between Muharraq Island and Manama Island.

EWA has reported that the overall budget for the 400-KV backbone project is BD280m ($736.79m). It was announced in October 2012 that some of the project’s backing would be covered by the Kuwait Fund for Arab Economic Development, a government-backed fund with capital of some KD2bn ($5.26bn).