Guyana, known as the land of many rivers, is located on the northeast coast of South America and borders Surinam in the east, Brazil in the south and Venezuela in the west. With an area of 212,000km2, it compares in size with the UK or the state of Idaho in the US. The highland region – the Pakaraima mountains, is the source of the most attractive hydro power sites. These mountains give rise to rivers such as the Mazaruni, the Potaro and the Kuribrong which have runoffs varying from 0.05 – 0.08m3/km2 and which cross a major escarpment to drop over 244m. The freefall of the magnificent Kaieteur Falls (pictured above) on the Potaro river is about 225m.
Hydro potential
Guyana has enormous hydro power resources and hydroelectricity has long been considered as a possible alternative to thermal based generation.
The Canadian Bauxite Company contrived the first plan for constructing a major hydroelectric station during the early 1950s. A feasibility report for a power site at Tiger Hill was completed in 1959 which considered developing hydro power as an alternative to a thermal station. For various reasons, including the construction period and cost, a thermal plant was built instead of a hydro station.
During the mid 1950s, British Consolidated Goldfields constructed the first hydro power station in Guyana at Tumatumari Falls on the Potaro river. It has an installed capacity of 1500kW and uses 2 x 750kW Francis turbines. The electricity generated was used to power gold dredging operations at Tumatumari. The station is inoperable at present.
Since this initial endeavour to develop hydro power, the country’s dependency on energy imports has continued and the associated economic problems have become more acute.
With the coming of independence in 1966, the government sought to develop hydro power and embarked on a comprehensive hydro power programme. Terra Survey Canada was contracted in 1966 and aerial topographical mapping commenced in 1968. The work was completed in 1975 and topographical survey maps with a scale of 1:50,000 and contour intervals of 15.24m now exist for the entire country.
Various international companies were contracted to investigate and prepare the framework for hydro power development. Such companies include:
• Energy Project Engineering and Consultant Company (Yugoslavia).
• SWECO (Sweden).
• Motor Columbus (Switzerland).
• Montreal Engineering Company (Canada).
• Harza (US).
Through a grant from the United Nations Development Programme (UNDP) in 1974, a major hydroelectric survey was carried out. UNDP appointed the International Bank of Reconstruction and Development as the executing agency and the Montreal Engineering Company was contracted as the consulting firm. The survey included a hydro resource reconnaissance and inventory for all of Guyana, and pre-feasibility studies of a limited number of sites.
The primary objective was to develop suitable hydro power facilities to provide low cost electricity for an aluminum smelter, mining minerals, general electrification of the country and the future supply of power to areas that already have electrical power services.
All hydro power sites with a capacity of at least 20MW at 30% annual capacity factor (average 6MW of power) were considered in the survey. The country was divided into the following major river basins:
• Cuyuni river basin.
• Mazaruni river basin.
• Potaro river basin.
• Ireng and Takutu river basin.
• Essequibo river basin.
• New river basin.
• Northwest coastal region.
From the inventory, 15 sites were selected as the most promising for development.
The total potential is estimated between 7200-7600MW. Out of these studies came an attractive scheme – the Upper Mazaruni hydro project. It is a diversion scheme and preparatory works (an access road and an on site workers’ camp) commenced. The project was planned to be developed in phases with an initial installation of 750MW to be increased eventually to 2500MW with the main electrical loads being an aluminium smelter and a fertiliser plant. Unfortunately, this project had to be discontinued because of financial constraints.
In 1980, as a follow-up of the hydroelectric power survey of 1974-1976 and through a loan from the World Bank, the government of Guyana contracted the Montreal Engineering Company to conduct studies of small hydro power developments to satisfy the power demands of three important areas in Guyana: the northwest region; the Rupununi, region 9;
and Tumatumari/ Konawaruk/ Mahadia area, region 8. These studies were conducted in three phases. Phase I covered the pre-feasibility studies, phase II dealt with the feasibility studies and phase III considered the bidding documents.
Current situation
In the past, Guyana’s pursuit to develop its hydro power resources had been stymied by high investment costs and remoteness from the main load centres. Recently the legislative and institutional transformation of the energy sector and the formulation of a modern regulatory framework have served to rekindle interest in the hydro power sector. These regulations facilitate the participation of private investments. This is evident at Moco-Moco, a small hinterland community near the Brazilian border, where the government constructed a 2 x 250kW mini hydro power station with technical and financial assistance from the People’s Republic of China. The Hangzhou Regional Centre (HRC) for Small Hydro Power provided consultancy for the project.
Two private developers, Dessinaide Consulting Engineers and Synergy Holdings, were granted a licence to develop the Tumatumari and Amaila Falls hydro power sites respectively. As a result, Synergy Holdings in association with Harza International is currently engaged in pre-investment and environmental impact assessment studies for the development of a 100MW facility at Amaila Falls. The Amaila Falls project is located on the Kuribrong river, a tributary of the Potaro river, and lies adjacent to the Kaieteur catchment.
Dessinaide and Hydro-Quebec are also in the process of finalising a power purchase agreement with Omai Gold Mines, which is located close to the Tumatumari hydro power development. The installed capacity of the proposed project is 50MW. It is located 15km upstream of the confluence of the Potaro and Essequibo rivers. This reach of the Potaro river is downstream of the confluence of the Potaro and Kuribrong rivers,where the Amaila Falls is located.
Contrary to strategies adopted in the past, hydro power development in Guyana is now being pursued through private investment initiatives.
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