Key factors of a successful cogeneration plant: 8 mistakes to avoid
Intergen, the energy division of IML Impianti that specialises in cogeneration, completed a study on a dozen real cases in the manufacturing sector. Results were presented recently at mcTER in Milan. This sector event showcases cogeneration, Biomass, Biogas and Energy Efficiency.
Lomagna (LC), July 2015 – Intergen, the energy division of MIL Impianti, Italian leader in building and maintaining cogeneration plants, recently did a presentation at the preview of the mcTER event, which was held in Milan. This presentation presented the results of their own research on a dozen real cases in the industrial, civil and agricultural-livestock sectors. The company was able to identify the key success factors as well as the mistakes to avoid in order to ensure return on investment in the planned timeframe.
Intergen identified eight mistakes to avoid in the construction and management of a cogeneration plant, from project to management, to the useful life of the plant. Each mistake has an impact on the efficiency of the system, the energy production level and the management costs. Their combined impact varies according to the plant type, however the common result is the lengthening of the return on investment.
A factor that very often determines the start of the cause chain of dangerous mistakes is the miscalculation of the costs of the characteristics the plant should have according to best practices. The underbid may be caused by the aggressive commercial strategy of the supplier, or pressure from the buyer who often does not take into consideration all critical aspects connected to the construction of a cogeneration plant. A negative element that can be identified in the project phase is the under sizing of the heat exchangers, which then causes a loss of around 3% of the energy generated. In a few cases, over sizing of the internal combustion engine was observed. This oversizing had been planned based on the wrong forecast of an increase of electric or thermal energy. Forecast errors like this may eat up 15% of the total expected return. Moving on to the construction phase, the selection of inappropriate plant components may increase the management and maintenance expenses by 10%, since these components will fail prematurely and will be replaced by similar parts, without conducting an engineering correction analysis.
When the only selection criterion of a component is cost, leaving aside its technical characteristics and its quality, the plant’s productivity may drop several percentage points (the estimates of this study show an average of 6%) thus invalidating the profitability study carried out during the project phase.
The second group of mistakes to avoid was identified during the plant’s operation phase. Poor performance in this phase can be identified by the wrong behaviour in two extremes: on one side, to entrust the complete operation to vendors, in the belief that the technological plant is too complex to manage with the owner’s own resources, which then causes additional, unforeseen expenses; on the other side, there are cases of an extreme DIY attitude, that is often combined with the wrong belief that the plant can be run on its own without any direct operation in place. On average, the poor operation of a plant may cause a 5% loss of the potential availability, which is then added to losses caused by other issues. In practice, a cogeneration plant is a delicate and complex system that becomes productive and efficient when reliable personnel operate it and it is maintained by specialized firms. Competent specialized resources must service all main components. For example, if the internal combustion engine (that is the key component on which the whole system relies) is serviced by the official dealer, big mistakes rarely occur. The representatives of the manufacturer are the only ones who can provide certified services and original parts. In the case of Intergen, they are the exclusive representatives of WM in Italy.
When calculating the total impact, Intergen estimated that the combination of all mistakes described above could cause a reduction of the plant’s capacity from 98% to 70%, its productivity from 86% to 62% and an extension of the break-even point from the initial forecasted two years to 3.6 years. Clearly, such a deviation causes a disruption of any economic plan and may have a cascading effect, for instance, on the financial expenses.
“The eight mistakes to avoid – highlights Gianluca Sciuto, Aftersales & Service Manager, when commenting the results of the survey – can be prevented in different ways. The mistakes at the project and construction phases can be resolved with the selection of a qualified supplier, with proven experience and the financial ability to tackle even the most complex assignments. However, once these mistakes are made, they cannot be fixed. The maintenance of the plant, when entrusted to expert suppliers like Intergen, can make a difference. This means a guarantee of the effective inspection and reliability of the plant’s components through their useful life. We have more than 200 MWM engines under contract in Italy and abroad, and we are ready for any challenge.”
