|Waste-to-energy plants (51% renewable)||401,565||382,420||367,638|
|Combustion of landfill biogas||33,075||32,807||50,527|
|Combustion of landfill biogas in third-party plants||22,281||32,728||12,280|
|Combustion of digester biogas||20,932||21,735||19,966|
|Combustion of treatment plant biogas||6,366||5,355||6,036|
|Solar photovoltaic energy||12,179||1,827||1,971|
|Total renewable sources||497,920||477,578||458,419|
|Cogeneration operated as a service||152,449||169,589||128,194|
|Total cogeneration and turboexpansion||526,348||526,552||498,449|
|Waste-to-energy plants (49% non-renewable)||397,788||378,715||365,283|
|Total traditional sources||397,788||378,715||365,283|
The production of electricity from renewable sources is equal to 458 Gwh (-4% compared to 2016) as a result of: (i) a decrease in waste-to-energy plants as a consequence of the lower amount of waste treated and of the greater thermal energy produced for district heating systems; (ii) a reduction in the production of biogas from digesters, mainly attributable to the composting plant in Cà Baldacci (RN); (ii) a physiological reduction in the production of biogas from decommissioned landfills.
The production of electricity from cogeneration in service dropped (-41,395 MWh) due to the exit from the company perimeter of 4 plants due to the end of the contract period, whereas the amount of energy produced by cogeneration plants increased (+14,076 MWh), particularly in the Imola plants and in the Bologna Barca plant (as a consequence of the works to upgrade it). Hydroelectric production is equal to zero in 2017, due to the sale of the Cavaticcio hydroelectric plant in Bologna.
Overall net electricity produced by the Group plants, therefore, fell by 4.4%, showing a virtually unchanged mix of renewable and non-renewable sources.
Electricity produced from renewable sources is equal to 35% of total electricity in 2017, showing a stable situation compared with previous years. 37.5% derives from cogeneration and turbo-expansion, high energy efficiency systems. Together, the two categories represent 72.4% of electricity produced. The remaining production has a high level of environmental sustainability, as it is energy recovered from waste-to-energy transformation for the share exceeding 51%.
Since 2012, incentives to generate electricity through Green Certificates have been awarded to plants fuelled by renewable sources, for which IAFR (plants fuelled by renewable energy) qualification is required, and to cogeneration plants which feed district heating networks. In both cases, the quantity of incentivised electricity is not exactly equal to the amount of electricity generated. In the first case, for plants brought on line after 2007, multiplication coefficients were introduced which take into account the plant’s technology. For example, if landfill biogas is used, the recognition awarded is calculated by multiplying the energy generated by 0.8. For non-agricultural biomass with a short supply chain, instead, the energy is multiplied by 1.3.
For cogeneration plants, Italian Ministerial Decree of 4 August 2011 updates Legislative Decree 20/2007, redefining the cogeneration technologies, the calculation of cogeneration production and the performance level the cogeneration process needs to qualify as cogeneration. The subsequent decree of the Ministry of Economic Development of 5 September 2011 determined a new support regime for cogeneration: this incentive is based on white certificates and is recognised by the Energy Services Manager, following recognition of the qualification of cogeneration, according to the actual primary energy savings.
For waste-derived electricity, the energy recognised for earning incentives, and to which the above-mentioned multiplication coefficients apply, is limited to the biodegradable portion, as it is considered as biomass by European and Italian regulations. Pending the definition of more precise methods to calculate the biodegradable share (the Ministerial Decree of 6 July 2012 defines the criteria to assess the biodegradable part for new plants on a flat rate basis), current regulations indicate 51% as the part of waste to be considered for waste-to-energy plants using municipal waste downstream from separate waste collection. Therefore, 51% of both electricity and thermal energy produced by waste-to-energy transformation was considered in the calculation of the share of energy produced using renewable sources, applying the flat rate criteria. This percentage was applied to all waste disposed of in waste-to-energy plants (urban and special waste) and for all three years considered, in order to have consistent terms of comparison defined in accordance with the regulations in force. The one exception is Ravenna’s waste-to-energy plant for special waste, whose production, with a biodegradability coefficient of nearly zero for treated special waste because of its origin in industrial processes, is considered 100% non-renewable.
The total installed electricity capacity of the Group’s plants in 2017 is 299 MW, while their thermal capacity is 919 MW.
The Hera Group has equity investments in SET, Calenia Energia and Tamarete Energia, who operate three power stations respectively in Teverola (Caserta), Sparanise (Caserta) and Ortona (Chieti); these three combined-cycle plants (CCGT) provide excellent performance levels and better environmental compatibility than traditional oil- and coal-fuelled power stations. The electricity produced in 2017 by the above-mentioned companies in which the Group holds investments and which are operated by Hera was 1,078 GWh (+17% compared to 2016). In 2017, the carbon dioxide emissions from the three plants that amounted to 399 g/kWh (Teverola), 394 g/kWh (Sparanise) and 457 g/kWh (Tamarete) were in line with 2016 values; the nitric oxide released was 113 g/MWh (Teverola), 75 g/MWh (Sparanise) and 150 g/MWh (Tamarete), respectively, dropping compared to 2016. Enomondo (50% owned) which operates a biomass plant produced 70 GWh of electricity and 109 GWh of thermal energy (recording a rise in electricity and a fall in thermal energy) in 2017.