A heat exchanger for providing heat exchange between fluids (24, 25), such as in a solar power plant, wherein said heat exchanger comprises - a container, wherein said container is configured to house a first fluid - a first pipe connector and a second pipe connector, each pipe connector (13, 14) comprising a cavity, wherein each of the first and second pipe connectors (14, 15) comprises a plurality of pipe connection points distributed at the pipe connectors (14, 15), and - a pipe bundle arranged inside said container and extending between the first and second pipe connectors (13, 14), wherein said pipes (17a-17n) of the pipe bundle are configured to guide a second fluid, wherein said pipe bundle in the container is connected to the first and second pipe connectors (13, 14) at the pipe connection points so the inside of the pipes (17a-17n) of the pipe bundle is in fluid communication with the cavities of the first and second pipe connector (13, 14), wherein said heat exchanger is configured to provide a heat transfer between the first fluid and second fluid through the pipe walls of the pipes (17a-17n) of the pipe bundle, wherein pipes (17a-17n) of the pipe bundle are arranged next to each other and extend together between the pipe connectors (13, 14) in a meandering manner providing a plurality of crests (20a, 20b) on the pipes (17a-17n) between the pipe connectors (13, 14), and so that crests of pipes (17a-17n) of the pipe bundle are arranged to extend into recesses provided by one or more crests on other pipes(17a-17n) of the pipe bundle, and wherein said pipe bundle comprises a plurality of layers of pipes (17a-17n) distributed in a direction transverse to a longitudinal direction of the container, where each of said plurality of pipe layers comprises pipes (17a-17n) extending in said meandering manner, wherein the layers of pipes (17a-17n) extend substantially in parallel, characterized in that the layers of pipes (17a-17n) are of different width in a direction transverse to a longitudinal direction of the container and layers of smaller width comprise fewer pipes (17a-17n) than layers of larger width. - a container, wherein said container is configured to house a first fluid - a first pipe connector and a second pipe connector, each pipe connector (13, 14) comprising a cavity, wherein each of the first and second pipe connectors (14, 15) comprises a plurality of pipe connection points distributed at the pipe connectors (14, 15), and - a pipe bundle arranged inside said container and extending between the first and second pipe connectors (13, 14), wherein said pipes (17a-17n) of the pipe bundle are configured to guide a second fluid, wherein said pipe bundle in the container is connected to the first and second pipe connectors (13, 14) at the pipe connection points so the inside of the pipes (17a-17n) of the pipe bundle is in fluid communication with the cavities of the first and second pipe connector (13, 14), wherein said heat exchanger is configured to provide a heat transfer between the first fluid and second fluid through the pipe walls of the pipes (17a-17n) of the pipe bundle, wherein pipes (17a-17n) of the pipe bundle are arranged next to each other and extend together between the pipe connectors (13, 14) in a meandering manner providing a plurality of crests (20a, 20b) on the pipes (17a-17n) between the pipe connectors (13, 14), and so that crests of pipes (17a-17n) of the pipe bundle are arranged to extend into recesses provided by one or more crests on other pipes(17a-17n) of the pipe bundle, and wherein said pipe bundle comprises a plurality of layers of pipes (17a-17n) distributed in a direction transverse to a longitudinal direction of the container, where each of said plurality of pipe layers comprises pipes (17a-17n) extending in said meandering manner, wherein the layers of pipes (17a-17n) extend substantially in parallel, characterized in that the layers of pipes (17a-17n) are of different width in a direction transverse to a longitudinal direction of the container and layers of smaller width comprise fewer pipes (17a-17n) than layers of larger width.