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The Guide for Homeowners  a aa aa aa aa
The Interconnection Guide
Guidelines for system selection and dimensioning
3.1 INTRODUCTION
For realization of an idea or intention of a homeowner or potential user to use small RES-E (PV, wind-turbine) or micro-CHP for production of electricity, he must investigate on the following main propositions:
- To define the characteristics of the electrical load (kWh/day; kWh/week; kWh/year and the load curve for winter, spring, summer and autumn day).
- The site is stand-alone and isolated from the electricity network and accumulator batteries should be envisaged or the RES-E central or CHP can be connected to the network.
- To define the possible situation (m2 and orientation) for construction of PV or the place for a small wind generator.
- To define the economic heat load and the respective power of the micro-CHP.
- To investigate the financial questions.
For homeowners the most appropriate for producing green electricity are PV systems and small wind turbines. These technologies are different and are on the basis of solar energy or wind energy. Therefore the possibility for installing PV system should be studied (solar intensity, the available area – m2 and orientation) as well as the possibilities for a small wind turbine (the wind potential on the possible place of the wind turbine). The cases are studied when the homeowners are connected to the electrical distribution systems, i.e. no stand-alone and isolated homes.
The Grid-connected systems give the possibility in each moment the excess produced energy to be transferred and sold to the distributor, and in the cases of deficiency energy to be taken and bought from the distributor. In this case there is no need of accumulator batteries and back-up sources of energy.
Micro- CHP are constructed in the presence of permanent annual heat load. The cogeneration (CHP) has higher efficiency – about 90%. In this case the defining is the heat load, because the produced electricity can be used or sold to the energy distribution company.
The PV systems, small wind turbines and micro-CHP are different technologies. To choose the most appropriate system or several systems in relation to the concrete local conditions the different technologies should be compared, as well as the available conditions for their application and the requirements for the produced electrical and heat energy.
In the next chapter we look at the characteristics of the different technologies, which are defining for their choice in relation to the local conditions.
3.2. TECHNOLOGY
 3.2.1 PHOTOVOLTAIC / PV/ SYSTEMS
3.2.2 SMALL WIND
Description of the available RES-E and micro-CHP technologies
The PERCH “Guide for Homeowners” deals with renewable energy sources as well as combined heat and power generation and the requirements of these technologies for grid interconnection. Due to the European Renewable Electricity Directive (2001/77/EC), member states of the European Union have to ensure guaranteed access for green electricity producers to the grid. The PERCH project (Production of Electricity with RES & CHP for Homeowners) deals with this issue to clarify the diversified regulations in the different member states of the European Union and to give helpful hints and clues for homeowners who are planning the installation of distributed energy resources (DER) for their full sustainable heat and power supply.
PERCH wants to give an overview about the technical, contractual, supporting schemes and metering issues, which have to be confronted between the owners, the utility and the local authorities before a DER can be implemented and connected to the grid. Small RES & CHP applications for grid connected electricity generation may include photovoltaic in buildings, small wind units, mini and micro CHP, fuel cells or combinations of these technologies.
The following pages present an overview about the available residential small scale RES-E and CHP systems. Therefore, the PERCH “Guide for Homeowners” explains the technological principles in brief and reveals arguments for the implementation of DER systems.
Micro-CHP
Photovoltaic
Small Wind
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