Task 11's work plan is divided into four subtasks and a number of detailed work activities on key aspects of PV hybrid and mini-grid technology and implementation. The current subtasks and activities are as follows:

This Subtask addresses the complex nature of PV hybrid system design. Tradeoffs have to be made between first cost, energy efficiency, and reliability. Oversizing a system may increase reliability but also increase first cost. Undersizing a system will decrease reliability and frustrate users. The correct choice of components and system architecture is critical. The task has the following three activities

11) Review, analysis and documentation of current hybrid mini-grid system architectures

12) Evaluation and comparison of system design methodologies and tools and development of guidelines for design tools

13) Development of best practices for design, operation, and maintenance of PV hybrid projects

This Subtask addresses the need for new coordinating control mechanisms in hybrid mini-grids to maintain grid stability and to optimize the contribution of all generation sources. It has the following five activities

21) Investigate existing methods for stabilizing voltage and frequency in mini-grids and develop new, improved methods if required

24) Evaluate the role of energy storage technologies to stabilize mini-grid operation

25) Investigate technical issues associated with autonomous and interconnected operation of mini-grids and a main utility grid.

Subtask 30 addresses the goal of increasing the use of the PV resource in PV hybrid systems and displacing fossil fuel resources. It has the following two activities

31) Develop performance assessment criteria for PV hybrid systems that allows for objective comparison of different systems

32) Develop recommendations to maximize the solar fraction in hybrid systems through demand side management, dispatch strategies and optimization of the battery energy storage system.

Subtask 40 addresses the social, political, economic, and environmental factors necessary for successful implementation of PV hybrid power systems within mini-grids. It has the following three activities

41) Develop case studies that demonstrate the social and political framework for successful operation of PV hybrid systems within mini-grids

42) Evaluate the financial aspects of PV hybrid power systems, considering both first costs and operating costs, and determine the conditions for economic sustainability

43) Evaluate the environmental impacts and benefits of PV hybrid systems with focus on greenhouse gas emission mitigation and potential for recycling of system components

In general, the Task follows a strategy, similar to previous PVPS Tasks, in which the current states of technology and design practice in the participating countries are first assessed and summarized. Further work will then focus on those areas where technology improvements or better design practices are needed. This may require new research or data, or simply an expert consensus on best practices.

All the Task 11 Subtasks are now in the final report stage. Formal Task 11 Reports will be posted on this web-site and on the IEA PVPS web-site in late 2010 and through 2011.