by Elena Gerebizza and Leonardo Setti
taken from Altreconomia‘s Fossil Free column
The new mantra of the green economy (or supposedly so) is ‘green’ hydrogen. Last April, the winners of the call for proposals for the National Recovery and Resilience Plan (NRRP) budget line for the production of hydrogen in abandoned industrial areas were published. With a total budget of EUR 500 million, the budget line includes a few dozen projects spread across various regions, mainly in central and northern Italy. The one presented by the multi-utility Hera together with Snam, the publicly-owned corporation that manages gas transport infrastructure, stands out because it won the entire funding made available for the region Emilia-Romagna: 19.5 million euro.
The project, called IdrogeMO, envisages the creation of a hub for the production of ‘green’ hydrogen in the municipality of Modena through the upgrading of the exhausted landfill in Via Caruso. This is one of the first hydrogen valleys in Italy, which should represent the basis of the hydrogen backbone, the hydrogen transport backbone desired by Snam and relaunched by the Meloni government as part of the ‘South H2 Corridor’ linking North Africa to Germany.
IdrogeMO envisages the construction of a 6 MW photovoltaic park connected to an electrolyser: a device that allows fresh water molecules to be ‘broken’, separating hydrogen from oxygen, and which will allow the production of up to 400 tonnes of hydrogen per year. In order to be able to power the plant even at night, the pole will be supplemented by batteries for storing electricity. According to the description provided by the promoters, the total investment amounts to EUR 20.8 million. The fuel produced should supply both local public transport companies and part of the area’s industrial sector.
The project leader, Herambiente Spa, will take care of the photovoltaic plant. While Snam will build the hydrogen production and distribution plants. On paper it is a virtuous work, cloaked in a layer of green. Howerver, analysing in depth the available data, ‘green’ hydrogen seems to be just a nice fairy tale again. For a production of 400 tonnes of hydrogen per year, in fact, one would need at least 21 MW of photovoltaic power installed and dedicated solely for this purpose. That is, no less than 25-30 hectares of photovoltaic park, with a significant increase in the economic investment and space required to realise the project.
In any case, electricity production would be concentrated during daylight hours, when the photovoltaic plant is in operation. It would be necessary, as indicated by the promoters themselves, to use lithium-ion batteries to transfer the capacity to produce green hydrogen also at night for at least 60,000 kWh of accumulated capacity. In concrete terms, to reach the target of 400 tonnes of hydrogen, it would be necessary to run an electrolyser and a compressor with about 5 MW of electrical power for seven thousand consecutive hours per year. To do this, 24,000 mWh of electricity would be needed: but a 6 MW photovoltaic plant would probably be able to produce around 7,200 mWh annually, which is about one third of the requirement.
The other two-thirds – needed to reach the maximum production capacity of the electrolyser – would have to be taken from the medium- or high-voltage electricity grid, which includes a significant share of energy produced from gas- and coal-fired thermal power plants.
Goodbye green dream, then. Also because, as there are no dedicated gas pipelines between Modena and nearby cities, it is presumable that the hydrogen will be transported to the places of use by trucks equipped with a cryogenic tank (each of which has a capacity of about 3.2 tonnes, for a total of 125 trips in a year) or tank wagons for the transport of compressed hydrogen weighing just over 450 kilograms each (in this case, 889 trips per year will be needed). A ‘transition’ certainly not in the name of sustainability.
The hydrogen produced in Modena should serve both local public transport and the local industries in a decarbonisation perspective. In reality, however, 400 tonnes of hydrogen is not that much. Looking at projects for the use of this fuel in local transport, one that stands out is that of the Municipality of Bologna, which, in agreement with the local transport company Trasporto passeggeri Emilia-Romagna (TPer), and thanks to a 90 million euro grant from the Italian Recovery plan, has announced the purchase of 127 hydrogen-powered city buses with delivery by 2026.
Given the figures, the 400 tonnes per year that will be produced in Modena would barely cover the needs of these vehicles, which, according to TPer, make up only 12 per cent of the regional capital’s vehicle fleet. According to our calculations, when fully operational, each bus would cover between 30,000 and 60,000 kilometres, around 100 kilometres per day. A hydrogen bus is a kind of hybrid vehicle with an electric motor powered by a hydrogen cell and a lithium-ion battery. This type of bus will consume an average of about 3,650 kilos of hydrogen in a year. The total requirement of the 127 Bologna buses should therefore be around 464 tonnes per year, far more than the amount produced by IdrogeMO’s plants.
To the overall cost must then be added the expenses for the purchase of the vehicles, those for transporting the hydrogen by trucks with cryogenic tanks or by tank wagons, as well as those for building the distribution stations. Not forgetting, of course, the authorisation procedures for the production site and for building the hydrogen distributors. In addition, hydrogen-powered buses are fitted with a battery, combined with a fuel cell made from specific platinum catalysts, an element rarer than gold. Last but not least, the issue of fresh water consumption: the production of 1 tonne of hydrogen requires up to 9,000 litres of water. Consequently, Modena’s hydrogen valley would have an annual consumption of around 3.6 million litres.
But what if the municipality of Bologna decided to buy 127 electric buses instead? The cost would be much lower and the efficiency higher: 4 MW of photovoltaic system would be enough to produce the approximately 4,821 mWh per year needed to power them. This type of vehicle would need 43,180 kWh of accumulated capacity in lithium-ion batteries (less than those needed to run the hydrogen system), with recharging times of just 30 minutes per bus (for 104 kWh per day).
Between EUR 40 and 60 million would be needed to purchase them (compared to EUR 90 million for the hydrogen ones). In addition, they could be recharged from a low- or medium-voltage station powered by all the renewable energy installations that make up an energy community. The production of hydrogen, on the other hand, requires large and constant committed electrical power, which by its very nature requires dedicated facilities and transport systems for the energy carrier.
Battery electric buses can therefore be part of an energy-sharing concept that is inconceivable to manage through the production of hydrogen. Looking therefore at local public transport, if both Bologna and Modena had chosen to proceed with the purchase of a fleet of electric buses, the 6 MW photovoltaic plant installed at the Modena site would have been sufficient to power both.
As things stand, the IdrogeMO project’s contribution to the decarbonisation of both the industrial sector and local transport seems very limited, while its real costs could be much higher than those presented. And with a ‘hidden’ impact to be absolutely taken into account. On the other hand, the use of green hydrogen for urban transport is among the least efficient and sustainable, and its development should not be incentivised through public resources of the National Recovery and Resilience Plan or other streams of public funding. To date, the Modenese hydrogen valley does not seem a real step in the direction of a just and locally-led transition. But eventually even in this case it is the interests of the companies that count most.
