The thermal generating units of the Volta River Authority (VRA) at Aboadze are currently operating with 100 per cent gas from the Atuabo Gas Processing Plant in the Ellembelle District in the Western Region.
According to a source at the VRA, as of yesterday morning the volume of gas delivered for powering the thermal units at Aboadze had increased to about 60 million standard cubic feet (mmscf) daily from Atuabo, higher than the 49.94 mmscf currently supplied from Nigeria.
The source said due to the high pressure and high quality of the Atuabo gas, supplies from Nigeria had now been confined to the Tema power enclave.
It said the 60 mmscf currently from Atuabo was being used to generate 185 megawatts (MW) of power at the two thermal units at Aboadze.
It said for the first time in the history of Aboadze, the turbines, which had never generated above 70MW since they were inaugurated, were being used to generate more than 100MW because of the quality of the Atuabo gas.
The VRA has, since November 24, 2014, been generating power solely from gas supplied from the Atuabo processing plant.
Based on approval by the Energy Commission and other regulatory bodies, the Atuabo plant delivered between 35 and 48mmscf of gas to Aboadze on December 3, 2014.
According to engineers at Aboadze, the quality of he Atuabo gas was higher than the lean gas from the West African Gas Pipeline (WAGP).
The quality assessment was based on the fact that most natural gas in many parts of the world usually had significant amounts of acid gases such as carbon dioxide (Co2) and hydrogen sulfide (H2S) in them.
“The Atuabo gas, however, has very little carbon dioxide and absolutely no hydrogen sulfide and its delivering bar pressure is also almost twice that of the WAGP for the same cubic feet of gas,” they said.
A source at Aboadze told the Daily Graphic that as a “result of the quality of gas from Atuabo, it is not taken through all the filtration systems at the Aboadze Thermal Plant before being injected into the turbines”.
“For the Atuabo gas, four out of the five filtration processes that WAGP gas goes through are skipped. Atuabo gas goes to the last stage of filtration before use, instead of all five filtration systems built for WAGP gas,” it said.
“To tell you in simple language, the gas from Atuabo has higher heating and combustion values and is far more efficient than WAGP gas,” it said.
According to the source, Atuabo gas was not only cost saving “but has further reduced the cost of generation. The cost of maintenance of the turbines is also set to reduce, as the corrosion level of Atuabo gas is lower”.
The required daily flow of gas from the Aboadze thermal enclave, according to the source, was pegged at between 150 and 160mmscf for all the generating units.
Engineers at Aboadze told the Daily Graphic that they were satisfied that the gas produced in country had little carbon dioxide and absolutely no hydrogen sulfide.
The VRA is optimistic that with the current quality of gas, it will invest more and also collaborate with independent power producers (IPPs) in energy generation.
The source expressed the hope that with Phase II of the Ghana Gas project and the collaboration with the ENI on the TEN Field, which has the capacity to produce about 170mmscf additional gas, the country would be energy sufficient.
At the moment, the VRA’s T4 and the 1,000MW from General Electricals (GE), as well as more power from the Amandi and Jacobson projects, which will commence next year, will position the country not only as energy self-sufficient but also a net exporter of power.