Per Alex Sorensen,1* , Leo Holm 2 and Niels Aage Jensen 2

1 PlanEnergi, Jyllandsgade 1, 9520 Skorping, Denmark 2 Marstal Fjernvarme, Jagtvej 1, 5960 Marstal * Corresponding Author, pas@planenergi. dk

Abstract

In 1996 Marstal Fjernvarme (Marstal District Heating) established 8.000 m2 solar collectors that covered 13% of the yearly consumption. The solar fraction in later built district heating plants goes up to 25% covering the total summer load, but several district heating companies especially natural gas fired combined heat and power plants want a higher solar fraction in order to replace expensive natural gas. Therefore new projects with solar fractions of 50% are designed and are expected to be implemented in 2009. Design calculations show that the production price for heat from solar ther­mal plants with 50% solar fraction can compete with heat prices from natural gas fired CHP plants.

1. Introduction

This paper explains the Danish development in solar thermal plants for district heating from 1996­2008 and gives an opinion on future possibilities for solar district heating and cooling in Denmark and Europe.