Small scale biogas boom in Cuba
A massive societal transition is looming in Cuba as relations with its former ”arch-enemy”, the US, began a normalisation process in 2015. This transition will impact, not only Cuban society but also on its energy profile. Yet Cuban farmers already have much greater experience in biogas than farmers in many more technologically advanced countries.
Cuba is still a poor developing country, with a very shaky power supply system, but stands out for its free education, free health care and cultural and sporting success. On the other hand Cuba stands out for its very serious shortcomings in terms of democracy, freedom of speech and influence for the individual citizen. As an occasional visitor one could hear complaints about power outages, notice a glaring lack of housing, the rundown infrastructure and of all the obstacles for those who wish to start their own economic activities in order to improve their standard of living.
However, today many Cubans observe a trend towards a more open climate not least when it comes to farming. Because pork is the most widely consumed meat in Cuba, many private farmers and families raise pigs. This is one of the reasons why the Ministry of Science, Technology and the Environment is promoting the installation of biodigesters, to help boost biogas production.
During the two last years the authorities in Cuba installed six larger facilities, which are now providing biogas. The country has today around 2 000 small scale biodigesters and, according to Cuban Ministry of Mines and Energy, some 700 biogas plants operate on state farms and in the private farm sector, where this technology is being promoted to conserve energy and protect the environment. The country needs to build an additional 7 000 units, mainly using pig and cow manure.
– Most of all Cuba needs an additional 500 industrial biogas plants using the residue from distilleries, canning factories, sugar mills, slaughterhouses and pulping factories, the Cuban Vice-Minister of Energy recently stated.
The energy ministry is also considering cogeneration at sugar mills and alcohol plants. According to an official study, Cuba has the potential to produce more than 400 million Nm3 of biogas annually, which if administered appropriately could support 85 MW of power generation capacity. By doing so, this would avert 3 million tonnes of carbon dioxide (CO2) emissions and save around 190 000 tonnes of oil.
Cooking help by pigs and cows
The agricultural cooperative near the Cuban city of Gardenas is typical. Surrounded by astonishingly beautiful and lush tropical vegetation this cooperative grows crops like corn and fruits like bananas and mango. In addition, the cooperative has a considerable number of cows and pigs. The director of the cooperative, Hector Correa, says that it was during his visit to the Soviet Union in the 1980’s when he got the idea to use animal droppings for the generation of biogas. He saw several small-scale farm holdings in the context of his round trip. Hector has even lectured and consulted on biogas production around the Cuba.
–In that way Cuban agriculture has become a net producer of energy. Biogas and biofuels can be produced and consumed locally. A cow produces up to three kilowatt hours (kWh) of energy per day. The farms that have a surplus can sell it even to a local market, but biogas is still used mostly for cooking in Cuba, said Correa.
Another staff member, Cladys Marrero, has witnessed firsthand how the daily cooperative life has changed. Replacing the use of firewood, kerosene and petroleum-based products with biogas makes household work more humane. She demonstrated how the manure is led via open canal from the pig barn to a large fermenter. It is placed about 4 meter deep under the earth. After the digesting process the raw gas is pumped from the fermenter to storage and from there to cooperative kitchen.
The costs for building a complete local small scale digester for fermentation of pig or cow manure in Cuba lies around US$2 000. Cuban farmers make use also of simple method to store and distribute biogas, large plastic bags. After digestion the raw biogas is then carried in bags to the neighbors who gratefully receive gas. According to officials, the biodigesters help to reduce soil and groundwater pollution, and curb the cutting of trees for firewood.
Plans for more Cuban biogas
The Biogas Promotion and Development Centre at the Cuban Swine Research Institute is drafting a national plan to encourage the use of biodigesters in state companies and agricultural cooperatives. One of biggest biogas plants in the country has recently been completed at Guayos in the central province of Sancti Spiritus. The facility will have some 740 m3 of biogas capacity, which will supply up to 1 MWh of electricty a day to the grid. This agro-industrial complex will run the first generator that is connected to the national power grid on the island. It will have an average production of 350 kW per hour of which 310 kW are destined for internal consumption at the complex with the excess supplied to the grid. It takes advantage of all available resources of the farm sector to give rise to a source of cleaner energy.
In its current draft, the national plan projects the construction of some 1 000 biodigesters a year by 2020. Nine projects implemented by the Agriculture Ministry and the non-governmental National Association of Small Farmers, will receive financing from the United Nations Small Grants Programme. Residues from sugar cane have so far been used as fuel for production of rom, but there is a huge untapped capacity for the production of biogas. There are calculations which show that Cuba within a few years could replace all its fossil oil consumption with biogas from the sugarcane industry. That would mean a further reduction in CO2 emissions and independence of Venezuelan oil imports.
However, there is still many challenges in Cuba regarding more environmental friendly power supply. Nearly all the energy in the form of oil is imported cheaply from Venezuela. The huge and ecologically very dirty nickel mine can be seen even from the space. Lot of waste is still dumped in sea inlets. Cuba’s economy is simply not yet an example of sustainability more than any other poor country in Africa or Asia. Hopefully that is all set to change as US-Cuban relations turn a page to begin a new chapter.
Text & photos Markku Björkman
This article was first published in Bioenergy International no. 2-2016. Note that as a magazine subscriber you get access to the e-magazine and articles like this before the print edition reaches your desk!