Swedish solar heating with seasonal storage—design, performance and economy

SYNOPSIS At the present time two Swedish group solar heating plants with seasonal storage, connected to residential areas with about 50 single-family houses, have been in operation for 4 years. The Lambohov Plant has a total of 2700 m2 of flat plate collectors and a 10 000 m3 rock pit store. The Ingelstad plant has a total of 1300 m2 of concentrating collectors and a 5000 m3 free-standing tank. The emphasis of the assessment has been on system performance as a whole. Most of the emphasis has been placed on general conclusions concerning technology and economy for seasonal storage plants.