Research activities are guided by a mind set. Our evidence is that most programs and thus the systems in which software plays a crucial role for their correct working, are unnecessarily complex, often to a point at which they become unmanagable. Thus, we strive for concepts, methods and tools that help in the construction of lean software. This includes all aspects of software construction, in particular

• software design and implementation
• software reuse and composition
• programming methodology

A pragmatic research approach requires a focus on certain domain areas. Currently we have chosen socalled cyber-physcial systems, in particular those that help reduce greenhouse gas emissions. In the past few years we have implemented an autonomous train on open tracks. The goal is to make the numerous side tracks that exist more attractive again by offering ca. 10 minute intervals between smaller trains. This is only economically feasible if the trains drive autonomously with obstacle detection. The tracks cannot be enclosed, at least not in an economic way, as is the case, for example, in the context of subways or of autonomous people movers on airports.

The autonomous train project led us in the direction of renewable energy. We are currently setting up research activities in this direction: The aim is to develop systems technology, automation and control concepts and software that will contribute significantly to the reduction of global greenhouse gas emissions for a sustainable environment. The RELab will advance the state of the art in how energy storage technology (stationary and mobile) and renewable energy sources such as photovoltaics (PV), wind, and combined-heat power are integrated into the power system. The RELab is timely due to the recent availability of cutting-edge energy storage technology, for example, the extremely cheap grid-scale liquid metal batteries of the M.I.T. start-up Ambri.com (Donald Sadoway) as well as the advancements in generation technologies such as improved DC-AC inverters. Renewable generation and energy storage are important key factors to reducing greenhouse gas emissions since they enable taking conventional power plants (coal/oil/gas), which are often running at full capacity, especially in the absence of nuclear power plants, off the grid without falling back to nuclear. The RELab is viable since software & systems technology is also in this context the essential integrator of renewable energy sources and energy storage technology. To reduce risk and speed up the design and implementation process we propose to focus first on micro grids and low voltage sub-grids, which are typically deployed in neighborhoods and smaller regions or villages.

Grid-scale Operating System (gridOS). Several smart grid pilot and demonstration projects exist already in various locations on the planet, but typically on a small scale. For example, such projects are called model regions in Austria, comprising for example about 100 houses with solar PV systems and distributed storage systems. Especially grid-scale storage systems together with renewable sources have barely been considered in the distribution grid management so far, especially on the low-voltage level. We envision to build a scalable distribution grid management system (gridOS) that assumes the availability of grid-scale storage and distributed generation technology. The design and implementation of gridOS will be derived from best-practice concepts and methods for building computer operating systems: orthogonal abstractions, distributed architecture, lean, correct-by-construction implementation methods and fault tolerance to achieve resilience of the overall system. The first versions of gridOS together with corresponding grid control strategies and algorithms will be developed by means of platform-aware software-in-the-loop simulation environments. This will allow a solid test of the functionality and scalability of gridOS. In parallel we will identify solar/wind hot spots on the planet where the local jurisdiction allows the construction of micro grids from scratch in parallel to an existing conventional grid. A potential candidate are the Hawai'ian islands. The goal is to evaluate the gridOS approach in a real-world setting with thousands (phase 1) and ten-thousands (phase 2) of solar PV systems together with local storage systems, installed primarily in residential homes.