SEVERAL risks and flaws have been identified in the design of the Amaila Falls Hydropower Project (AFHP), which will threaten the project’s long-term effectiveness and prove costly and burdensome to the people of Guyana and the country.This is the contention of the Government of Guyana, after the release of a report which critically and “objectively” assessed the viability of the project. The report was compiled by Norconsult, an engineering and design consultancy firm from Norway, which was contracted by the Government of that country to complete an “objective and fact-based” assessment of the project following an agreement by the two countries.
“Though the project is just one of several renewable energy options being looked at by Guyana, Government believes that the report identifies several risks and flaws in the design of the project, which will threaten its long-term effectiveness and prove too costly and burdensome to the people of Guyana and the country as a small developing state,” the Government of Guyana said in a statement on Wednesday.
According to the report, one of the major flaws is the absence of a separate flywheel between the turbine and the generator. This was described by the company as a highly “uncommon design” and impractical for vertical shaft units of a size as in the case of AFHP.
The report stated too that this requirement is also notably absent from the Engineering/Procurement/ Construction (EPC) Contract drawings, the technical description of the project, the Bill of Quantities and in the Independent Engineer’s Due Diligence Report of 2013.
Norconsult’s report also identifies the absence of several details from the Owner’s requirement, including the “minimum requirement to overall plant efficiency, which includes the hydraulic losses in the waterway.”
The company also pointed out another major concern of efficient utilisation which was listed in its report.
“The power plant is required to yield a certain output (MW) at a certain headwater level with no maximum figure set for the corresponding turbine water flow. Therefore, the EPC Contractor could choose to diminish the cross area (diameter) of the tunnels in order to save cost and compensate by increasing the water flow. This would mean less energy production of the same amount of water and thereby a less efficient utilisation of the Amaila Falls as a hydropower resource.”
Norconsult took note too of the absence of any sediment-handling methodology in the design of the plant, which it said is quite a serious issue, since sedimentation can threaten the plant’s continued operation.
Additionally, Norconsult stated that the “19m head loss in about 3 km long headrace tunnel is higher than would be expected for a hydropower plant designed by traditional procedures for hydraulic optimization.”
The report goes on to state that “the dimensions described for the pressure shaft and pressure tunnel are also not sufficient for satisfying requirements for regulation stability.”
The company also questioned the steel lining proposed for the tunnel lining and noted that risks associated with this configuration can be reduced by an “expensive vertical core drilling from the surface and down the hole hydraulic splitting tests at different levels in the holes.”
Having examined the report, the Government of Guyana says it considers the review of “utmost importance,” as it provides “indisputable evidence” to support its position taken while in opposition that the project in its current configuration does not meet minimum requirements to ensure its viability and longevity.
“It is the view of the Government that the Norconsult Report has given credence to its position on the need for an energy mix to increase the country’s share of renewable energy by close to 100 percent by the year 2025.”
The report also provides supporting evidence that the Amaila Falls Hydropower Project would not be optimal in its current model and presents an unbalanced risk to the Government and People of Guyana,” the statement noted.
As such, they noted that rectifying the many issues identified will increase the total cost of the project substantially, thereby impacting the tariff rates from the outset. And having studied the report and conscious of the specific needs of the country, the Government of Guyana said it proposes to utilise a mix of energy options, starting with less risky options such as solar and wind, as outlined in Budget 2017.
Accordingly, the executive said that the country’s long-term energy plan for the transition to the increased use of renewable energy is expected to be presented to Cabinet by mid-January.
Minister of Public Infrastructure, David Patterson, on Wednesday confirmed that “final touches are being made to the draft document” and once Cabinet has had their input, it will be released to the wider public. He noted too that the Government is committed to exploring all avenues for the development of renewable energy in keeping with its “green” development agenda.