Technical Aspects (Technicalities)

Energy Production

Renewable energy installations within the region in which the Energy Community (EC) operates to meet the energy needs of its members and consumers. These projects contribute to the decentralization of energy production and can strengthen the participatory role of local communities.

OVERVIEW

In the following chart, you can see renewable energy options where technologies applicable on a community scale can be implemented.

Solar

The majority of community energy projects in Europe are solar. It is the preferred technology due to its availability, modularity, lower cost and simpler planning processes.
In Southern Europe, solar energy potential is particularly high, providing significant advantages for implementing solar-powered projects.

SOLAR POWER TECHNOLOGIES

SOLAR PHOTOVOLTAIC (PV) SYSTEMS: They convert solar radiation into electricity through photovoltaic cells. PV systems can greatly vary in size and can be installed either on buildings (residences, livestock farms, agricultural warehouses, etc.) or on the ground.

There are two major types of solar PV systems:

SOLAR THERMAL SYSTEMS

They convert solar radiation into heat through the use of a collector based on the heat transmission properties. The most common applications of solar thermal systems include the production of hot water, space heating, and drying of agricultural products/biomass.

EXAMPLES:

• Minoan Energy Community (Greece) has developed 2 Solar PV parks, one of 405kWp and one of 1MWp and uses virtual net metering for self-consumption.
• Hyperion (Greece) developed their first project consisting of a 500kWp solar PV park, powering more than 120 members, 9 vulnerable households and 2 social centres generating based on collective self-consumption generating more than 90.000 kWh /year.

CHECK OUT Solar energy data tools and resources:

• Global Solar Atlas: Solar resource and photovoltaic power potential data
• PVGIS: PV performance and solar radiation tools
• PVsyst: Software that offers a user-friendly approach with a guide to developing a PV project
• Sun Path 3D: Generates 3D sun path diagrams for your location including annual and daily solar maps

Biomass

Biomass can be a renewable fuel when it comes as a by-product of other processes. It is a versatile resource that can be used to produce heat or hot water, biofuels, fertilizer, electricity or a combination of heat and electricity (CPH-Combined Heat and Power). It is considered a renewable source when it comes from sources such as:

• Forest residues;
• Food waste;
• Agricultural and Farming residues (e.g. branches, cuttings, vines, manure etc.);
• Wood processing by-products (such as wood chips, and sawdust).

When burning wood or other organic matter you are emitting CO2, but the idea is that this carbon will eventually be absorbed by new growth that replaces what is being burned. This part is crucial to ensure that the use of biomass remains a part of the closed carbon cycle instead of contributing to additional carbon emissions!
This is why biomass should only be used as part of the solution when the community can ensure that local resources are sustainably managed.

Southern European countries have a significant biomass potential, mainly consisting of large quantities of agricultural and forest residues. The available biomass potential can be used for energy production (heat and/or electricity and biofuel) either directly through combustion or after processing into gas, liquid and/or solid fuels.

EXAMPLE:

• The Energy Community of Karditsa (ESEK), operates a pellet factory that processes residual biomass into 1,200 tons of pellets annually. The biomass is composed of forest residues, agricultural residues, urban tree prunings, etc. coming from the region. The pellets produced are used for heating or cooling and its 350 members enjoy the benefit of acquiring these pellets at a reduced price, creating a localised and sustainable energy solution.

CHECK OUT:

• May success story: Creating value and social impact with residual biomass
• GREEN EMPOWERMENT: Tubular domestic-scale biogas digester manual
• IRENA: Measuring small-scale biogas capacity and production

Wind Energy

Mainly used in electricity generation, where wind turbines convert the kinetic energy of the wind into mechanical and then into electrical energy. Wind turbines can be installed either on land, in suitable locations to ensure their efficient operation and aesthetically acceptable integration into the environment, or at some distance from the coast in the sea (offshore).

A wind park can produce a significant amount of energy. An average onshore wind turbine can produce more than 6 million kWh in a year supplying 1,500 households with electricity. Wind can be an important tool to replace fossil fuels that destabilise our climate.

Key considerations when thinking about wind energy:

• Does the geography in your local area suit wind?
• Do legal rules support or block the project, or make it unprofitable?
• How would you transport a turbine to your region?

In most countries, maps of wind speeds can help you understand how feasible a turbine would be in an area. It’s also important to note that turbines are often forbidden close to military bases, airports or gas pipelines.

CHECK OUT:

• European wind atlas
• Best practice cases from the Win wind project
• A report around fostering social acceptance for wind power
• Just Wind 4 All
• Small wind systems

Hydroelectric Power

One of the oldest methods of energy production, historically used for tasks such as powering flour mills and oil presses. Modern hydroelectric projects harness the energy of flowing water to generate electricity. This process typically involves the kinetic energy of water being converted into mechanical energy through the rotation of a turbine impeller, which in turn is transformed into electrical energy via a generator. When sufficient water resources and rainfall are available, hydropower becomes a valuable renewable energy source.

While large-scale hydro projects can negatively impact communities and the environment, small-scale community projects, when carefully planned and executed, avoid these issues as they use the natural flow of rivers or streams without requiring significant water obstruction or the construction of large dams, making them environmentally compatible and sustainable.

There are two main types of hydropower schemes: high head and low head. High-head schemes need water falling from a height greater than 10 meters, are often found in mountainous areas and are generally more cost-effective per kilowatt due to reduced civil engineering needs. Low-head schemes involve large volumes of water falling from a height of less than 10 meters, such as those at old mills. The choice depends largely on the local geography.

WHAT YOU NEED:

• Good (or reliable) rainfall,
• Adequate volumetric flow and/or water pressure, (determines the amount of possible power),
• Good environmental performance, ensuring the scheme will not significantly harm natural life in the stream, river or shores,
• A water source,
• A water transport system, to channel the water,
• A flow control system,
• A turbine and generator,
• An outflow of water.

CHECK OUT:

• Technical solutions for the small hydropower sector
• Community Hydroelectricity Station