Biogas is a mixture of gases (mainly methane, then carbon dioxide and nitrogen) produced by the anaerobic digestion of biomasses such as agroforestry waste, dedicated crops, livestock slurry, agro processing waste, municipal organic waste – by bacteria called methanogens. This process makes it possible to use methane that would otherwise be released into the atmosphere with obvious savings in emissions. The percentage of methane present in biogas varies from a minimum of 50 percent to a maximum of 80 percent depending on the type of biomass used and the process conditions.
Biomethane is a renewable source like solar and wind and is the result of refining and purifying biogas. It is obtained from the anaerobic digestion of agricultural and agro-industrial byproducts and organic waste. The removal of water, CO2, and contaminants such as siloxanes, sulfur dioxide and ammonia occur through this process. Thanks to this treatment, biomethane can be used onsite or in the natural gas grid without the need for plant modifications.
Technology for the production of electricity from gaseous fuels, which is based on the joint use of a gas turbine and a steam turbine.
The gas cycle produces electricity using the combustion of natural gas, while the second cycle allows the production of energy by recovering the heat contained in the gases leaving the turbine by means of a steam turbine.
Combined cycle power plants allow particularly efficient fuel use and, at the same time, allow a limited environmental impact in terms of pollutant emissions.
The liberalization of the gas market is a process which was started at the urging of the European Union in 2000 and that has led the Italian energy market to be open to the initiative of private companies. Infrastructure management activities (transportation, storage, distribution) were separated from commercial activities (production, import and sale). In the past gas was supplied by a single state-owned company, today consumers have the possibility to choose among several companies, based on their offers.
DISPATCHING / BALANCING
Gas dispatching, which ensures proper distribution of gas to consumers, is the activity that allows for a balance between gas supply and demand throughout the country. This balance is crucial, since only through dispatching managed by the operator is it possible to maintain proper functioning of the gas system in our country. In Italy, the operator Snam Rete Gas, whose network of methane pipelines reaches 35 thousand kilometers is entrusted with dispatching for 94 percent of the national network. The gas dispatching activity has its own specific weight in a gas bill, whose fixed fees are determined by ARERA (Energy Networks and Environment Regulatory Authority) and are the same for each supplier.
Distribution is the activity of transporting natural gas through local distribution networks for delivery to end customers. It includes the activity of construction, development, and operation of facilities (routine and extraordinary maintenance, emergency response, safety) and metering activities.
The distribution network is 268 thousand kilometers long, reaches 7,298 municipalities (92 percent of Italian municipalities) and serves more than 24 million customers. Natural gas distribution is a local public service historically managed at the municipal level through entrustment to a private operator or public company. The sector is evolving toward supra-municipal management, divided into 177 territorial areas.
The first step of the extraction activities always consists in an in-depth study of the identification of the deposit, its size and its profitability through a 3D reconstruction of the subsoil through the use of a seismic reflection system.
The last phase is development and extraction, where production wells are defined.
A pipeline used to transport gas for consumption by the end customer. The network of pipelines constitutes the national infrastructure for transporting gas imported from abroad to the local distribution networks that reach the end customer. The gas is transported at different pressures: at high pressure on the transportation network, at low pressures on the distribution network for direct delivery to the consumer. There are currently seven import entry points, located at interconnections with import pipelines (Tarvisio, Gorizia, Passo Grids, Mazara del Vallo, Gela) and LNG regasification terminals (Panigaglia and Rovigo).
Pollutants in the atmosphere (carbon dioxide, nitrous oxide, methane, ozone, and the chlorofluorocarbons or CFCs) that tend to block the emission of heat from the earth’s surface. Their increasing concentration in the atmosphere produces a warming effect on the earth’s surface and the lower part of the atmosphere.
LNG (Liquefied Natural Gas) is a mixture of hydrocarbons consisting mainly of methane (90-99%). Other secondary components are ethane, propane, and butane. LNG is obtained by subjecting natural gas, extracted from reservoirs below the earth’s surface, to a liquefaction process at a temperature of about -162 °C, which allows the volume of the gas to be reduced by about 600 times. LNG appears essentially as a colorless, odorless fluid with a density about half that of water.
Natural gas is now the third most widely used source of energy in the world and is the foremost raw material with which heating systems and kitchens in our homes are fueled. Natural gas is a fossil fuel formed by the fossilization (or mineralization) of organic remains of animals and plants. It is composed of a mix of hydrocarbons that varies from reservoir to reservoir: for the most part it is methane, but other hydrocarbons such as propane and butane, and other gases including nitrogen, carbon dioxide, helium, etc., may also be present.
(GAS PIPELINE) NETWORK
The national gas duct network consists of pipelines, normally of large diameter, that transfer quantities of gas from the entry points of the system (imports and major domestic production) to the points of interconnection with the regional transportation network and storage facilities. It also includes some interregional pipelines that are functional in reaching important consumption areas. On the other hand, the regional transportation network, formed by the other remaining part of the pipelines, allows the movement of natural gas in demarcated local areas, generally on a regional scale, for the supply of gas to industrial and thermoelectric consumers and urban distribution networks.
In total, the Italian natural gas network is over 300 thousand kilometers long, of which 35 thousand are part of the transmission network and 268 thousand are local distribution networks.
The price of gas is determined by the governing authorities that define the percentages for storage, transportation, and distribution. The seller can later freely define the final price at which it will sell gas to customers. The final price displayed on the gas bill consists of several elements, some are related to the chosen supplier, while others are related to the standards defined by ARERA.
The total price consists of:
- Natural gas material expenses: it includes the amounts billed in relation to the different activities carried out by the seller to supply natural gas to the end customer and is in turn made up of the natural gas procurement components in the wholesale markets (Cmem and CCR), the retail marketing component (QVD) and the component related to the renegotiation of contracts (Cpr). It represents the variable part of the gas price and depends on the cost of the raw material and the conditions applied by the selected operator. In the regulated market these cost items are updated by the Energy Networks and Environment Regulatory Authority (ARERA), while in the free market it is the seller who offers a given price and any discounts and promotions.
- Costs for transportation and meter management: includes the amounts billed for the various activities that enable vendors to deliver natural gas to end customers, the tariff components related to gas distribution and metering service and transportation, defined by ARERA.
- Cost of system charges: includes processing fees intended to cover costs related to activities of general interest for the gas system that are paid by all end customers of the gas service (e.g., energy saving, gas bonus).
- Taxes set by the state: these include excise duty, a tax on gas consumed with a rate that varies according to consumption thresholds, regional surtax, and VAT, which is applied to the total amount of the bill at a rate of 10% for consumption up to 480 cubic meters/year and 22% on consumption thereafter and on fixed rates.
Method of regulating utility prices to constrain the growth rate of an aggregate of prices or tariffs. The regulator sets the maximum rate at which a set of prices is allowed to grow for a certain number of years. Subject to this aggregate constraint, the vendor is free to set the prices and tariffs it wishes.
It is a part of the LNG chain, i.e., the process which permits liquefied natural gas to be transported on LNG tankers. The gas undergoes a liquefaction process (at temperatures of -161 °C) to become a colorless, odorless fluid that can be transported by ship. Upon reaching its destination, the gas is landed at the regasification terminal, where it is heated, returned to a gaseous state, and then fed into the methane pipeline network.
Sales is the business of commercially supplying natural gas to customers. Sales enterprises can operate on the wholesale market, buying gas for the purpose of reselling it to other sellers, or on the retail market, buying gas for the purpose of allocating it for consumption by end customers.
Storage is the deposit in underground reservoirs of natural gas withdrawn from the national transport pipeline and then fed back into the network according to market demands. It is an important part of the supply chain as it ensures the continuity of supply, offsetting differences between supply and demand and ensuring strategic reserves to cope with extraordinary situations: such as, for example, particularly cold periods (increased need for gas for heating) or international geopolitical crises with repercussions on supplies.
Our country has a storage capacity of more than 17 billion cubic meters.
Our country’s gas supply includes extraction activities on Italian territory (4%) and import (96%).
In 2021, total imports amounted to 72,7 billion/m3. Through pipelines 62.9 billion/mc were imported (equal to 86.5% of total imports). The main importer was Russia with 29.1 billion/mc, followed by Algeria (21.1 billion/mc), Azerbaijanijgian via TAP (7.2 billion/mc), Libya (3.2 billion/mc) and Northern Europe (2.2 billion/mc) or Liquefied Natural Gas (LNG) by ship (13.5%).
LNG imports – which can be regasified by physical processes to be fed into the gas network – totalled 9.8 billion/mc from the terminals of Cavarzere (7.3 billion/mc), Panigaglia (1.1 billion/mc) and Livorno (1.4 billion/mc).
In consideration of the current geopolitical situation, the Italian supplying system is changing order, valorizing the routes from south (Algeria, TAP), carrying the three existing terminals of regasification to a full use (Panigaglia has an annual capacity of 3.5 billion/mc, Cavarzere 9 billion/mc, Livorno 3.75 billion/mc) and developing new regasification capacity.
At the beginning of 2023, the first floating regasification unit, with a capacity of 5 mld/mc, should come into operation; the second FSRU, with similar capacity, should come into operation by the end of 2024.
The goal of our country is to achieve independence from Russian supplies by 2025, replacing the current volumes thanks to 25 billion/ mc of different origin, the development of renewable sources and energy efficiency initiatives.
Natural gas is transported through a network that includes mainly high-pressure pipelines. Gas is fed into the national transportation network (over 35 thousand kilometers) at entry points that include import lines from Russia, Northern Europe, and North Africa, extending to regasification plants, and production and storage centers located in Italy. The gas reaches redelivery points connected to local distribution networks and large industrial and thermoelectric users.