"The DiGeSPo project concept is a modular 1-3 kWe, 3-9 kWth micro Combined Heat and Power (m-CHP) system based on innovative Concentrated Solar Power (CSP) and Stirling engine technology. This CSP m-CHP will provide electrical power, heating and cooling for single and multiple domestic dwellings and other small commercial, industrial and public buildings. It integrates small scale concentrator optics with moving and tracking components, solar absorbers in the form of evacuated tube collectors, a heat transfer fluid, a Stirling engine with generator, and heating and/or cooling systems; it incorporates them into buildings in an architecturally acceptable manner, with low visual impact. Four main themes have led to the development of this proposal: (i) technical improvements in large scale, parabolic trough solar concentrators that can now be adapted for much smaller scale systems, down to the single domestic dwelling; (ii) recent studies on Cer.Met. coatings suggest that improved optical behaviour and material durability for absorbers inside evacuated tube collectors can be achieved at higher temperatures than previously possible, with very low costs achievable at high production volumes; (iii) modified Stirling cycles and new compact heat exchanger technology are improving the costs and performance of small heat engines, so that they can operate with higher proportions of Carnot efficiency on the intermediate temperatures (> 350 °C) from the new CSP collectors. (iv) increases in natural gas prices, both absolute and relative to electricity prices, can under-mine the financial viability of gas-fuelled m-CHP. There is an urgent need for alternative m-CHP systems, of which solar m-CHP , whether separately or as a hybrid, is an option with high potential."