Power equipment company Barloworld Power’s multimillion-rand gas-powered generator plant solution is in full opera-tion at banking firm Standard Bank’s offices in Rosebank, Johannesburg, Barloworld Power sales manager Nalen Alwar tells Engineering News.

The plant was in operational readiness in December 2011, but it only became fully functional in January 2013 when Standard Bank took occupancy of the building and electricity was required to power the facility.

The gas-powered solution consists of a 1 MW Caterpillar G3512E gas-powered generator set, a heat exchanger – for heat recovery – and an absorption chiller.

Alwar explains that the generator set runs on natural gas supplied to the bank by Johan- nesburg-based natural gas reticulator Egoli Gas and that the electric power produced supplies one-fifth of the bank’s electric power demand, with the generator set’s thermal energy recovered for the bank’s hot water and air conditioning requirements.

“Banks are data centres and a power supply system must satisfy the operating objectives of both reliability and energy efficiency. The bank thus has access to State-owned power utility Eskom’s power supply, gas engine power plant supply and diesel backup as components contributing to enhanced system reliability,” he states.

However, he points out that, unlike diesel-powered gensets, which are typically used as standby sets to provide a backup power source in cases of utility power failures, the gas generator set is used to run on a continual basis to reduce the building’s requirement for utility power.

“Attractive gas tariffs result in an encour-aging equivalent cost of electricity; however, the total energy efficiency is achieved with the recoverable heat from the gas engine used for the building’s thermal energy requirements, such as hot water and air conditioning, which further offsets utility consumption,” states Alwar.

Barloworld Power is the Southern African dealer for equipment manufacturer Cater-pillar and is responsible for the design, supply, installation and commissioning of power plant solutions in the region.

Alwar adds that the gas generator set, which is integral to the power plant solution, is a product manufactured by Caterpillar, whose power equipment business has sig-nificant global market achievements.

Advantages of Gas Generators

Alwar believes that many opportunities exist in the gas-to-combined-heat and power sphere in the South African market, owing to the power constraint challenges the country faces as well as the escalating cost of utility power.

He says that the production of combined heat and power is a driver for energy effi-ciency, simultaneously providing a business case for reliability when gas power plants operate in parallel with the utility supply.

“From an environmental perspective, gas generator sets enable the reduction of methane, a greenhouse gas about 20 times more detrimental than carbon dioxide. Gas generator sets also have lower exhaust emissions – particulates and nitrogen oxides – than utilities using diesel or coal.

“Gas-powered generators require fuel gases with some level of methane content, such as that found in natural gas, for which there is an existing gas supply infrastructure in South Africa”.

Further, he points out that biogas, which is produced by breaking down organic matter and which contains sufficient methane levels, is also suitable for gas-powered generators.

Alwar says that the rate of biogas use remains low, owing to the technology used to process biogas efficiently for use in power generation still being in its infancy in South Africa.

“Biogas is a cheap fuel, which is highly sustainable as a source of power generation in the long term,” he emphasises.

Alwar adds that other types of gases suitable for gas-powered generators include landfill, coal-bed methane and propane gases.

Industry Interest

Barloworld Power has seen a keen interest in gas-powered generators in the industrial, commercial and farming industries.

“Local municipalities that have sewage- treatment plants are progressing with the option of gas generators, using biogas produced from their wastewater treatment plants, to produce power. “This is becoming an increasingly attrac- tive energy efficient option for municipalities.

Maintaining correct operating temperature parameters during waste digestion using recovered heat from the genset not only improves biogas yield for electric power, but also increases throughput of waste through proper biodigestion processes, thus deferring capital expenditure for sewage storage space,” he explains.

Community Waste-to-Gas-to-Power Initiatives

Last year, Alwar came across project devel- opers looking to collect waste from an infor-mal settlement community in the Western Cape for use in a biogas processing initiative to provide electricity for the informal settle- ment.

He believes that these types of initiatives drive a positive culture of recycling waste in a productive fashion and, even with the most rudimentary of biogas technologies, the resultant and relatively cheap electricity improves quality of life.

However, he stresses that for biogas-powered plants to become a reality, small and informal communities will require cofunding partners from either government entities or private companies to assist in raising the capital to establish such plants.