Clean and green farming is feasible

REDUCING the dependence of food systems on fossil fuels by using renewable energy is feasible.

Renewable energy can also be used for transporting raw food feedstocks, processing food, distributing finished products and cooking.

In poor countries, renewable energy presents opportunities to provide much needed basic energy services such as in post-harvest stages that are important for reducing food losses. In Sri Lanka, for example, wood biomass is being used to dry spices.

Farmers, fishermen and food processing businesses have opportunities to install technologies to generate wind power, solar power, micro-hydropower.

With the exception of biomass energy crops, the land area required for renewable energy projects is usually relatively small.

It is calculated that the fraction of land needed to displace global fossil fuel use with solar and wind energy technologies would use around 1.5 percent of the approximate land area currently used for agriculture.

Generally, wind turbine equipment occupies about 5 percent of the land and the remaining 95 percent can continue to be used for farming or ranching. Large solar photovoltaic arrays can occupy several hectares, but are often located on building rooftops.

Small hydro run-of-river projects usually need only a small area of land for the turbine house.

At present, renewable energy meets over 13 percent of global primary energy demand. Almost half of this energy comes from traditional sources of biomass used for cooking and heating.

Animal wastes, crop and forest residues, by-products from food processing , food wastes from retailers, households and restaurants are examples of biomass originating from different stages of the food supply chain.

The Intergovernmental Panel on Climate Change (IPCC) said early this year that there is good potential for the share of modern renewable energy to rise to over 70 percent by 2050.

As more knowledge and experience is gained, the costs for renewable energy technologies are likely to continue to decline and, in some cases, be economically competitive.

For example, in remote rural areas without access to the electricity grid, autonomous renewable energy systems are competitive because they allow users to avoid the high expenses in connecting to the grid.

The diversification to bioenergy could provide economic incentives for much needed investments in capital and skills in agriculture.

The mitigation of saline soils in Australia though agro-forestry biomass production linked with food production is an example of the potential benefits of bioenergy development.

Energy crop management can also help maintain, and in some cases, enhance soil fertility for future food production.With careful management, biomass can be produced sustainably in ways that do not compete with food for land or water and do not contribute to greenhouse gases emissions.

There are opportunities to develop bioenergy production systems that can help achieve both food and fuel production, for instance through integrated food energy systems.

A market analysis of 15 case studies in Latin America made by the Food and Agriculture Organization confirms that bioenergy from small-scale, on-farm projects can be used to produce heat, power and biofuels for local use, contribute to rural livelihoods, reduce imported fossil fuel dependence and offer new opportunities for rural communities.

All with no impact on local food security.

Energy crops, such as corn, sugarcane and oilseed rape, are being purposely cultivated in some countries to provide biomass for conversion to liquid biofuels for transport and combined heat and power.

Mauritius is already obtaining close to 40 percent of its total electricity supply from combined heat and power systems using sugarcane bagasse.

Residues generated along the food chain are another potential option to produce energy. The costs of collecting and delivering this biomass supplies to an energy conversion plant vary widely depending on the scale of production, the average distance required for transport and the type of biomass produced.

The IPCC estimates that in food processing plants where biomass (such as kernels and bunches from palm oil production) is already collected on-site as part of processing activities, costs can be relatively low. Their use as a source of energy can even save money in cases where it eliminates waste disposal costs.

Crops grown specifically to produce bioenergy have higher delivery costs since production, harvesting, transport and storage costs all need to be included.

Modern thermo-chemical conversion technologies such as combustion, gasification and pyrolysis are largely mature.

This is also true for some bio-chemical conversion processes such as anaerobic digestion in which microorganisms break down material in the absence of oxygen. This is used for industrial or domestic purposes to manage waste or to release energy.

Recently, interest in using aquatic plants and algae as feedstocks for liquid biofuel production has grown because of the potential these organisms to sequestrate carbon.

In lakes and coastal waters, harvesting aquatic plants can help reduce excessive nitrogen and phosphorus levels caused by nutrients coming from urban centers or agricultural lands.

Oil yields per hectare can be several times higher than those for vegetable oil crops. However, numerous demonstration projects have confirmed that separation of cell mass and usable substrate is still costly and the systems require relatively high energy inputs.

In the future, algae-based biorefinery systems and seaweed production to assimilate dissolved nutrients combined with intensive fish or shrimp culture may be a viable option.

The interaction between biomass production and food prices is a controversial issue.

The IPCC says that the volatility of energy markets can have a potentially significant impact on food prices and this would have serious implications for food security and sustainable development.

The integration of energy and food production from biomass crops is technically feasible under many situations, but it needs to be managed carefully. SOURCE: FAO

 

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