Task 45
Task 45
SHC Task 45

Large Scale Solar Heating and Cooling Systems

Simple Tools for Calculating Large Solar Systems with Seasonal Storage

Simple Method Application (SMA)

The design and performance evaluation of Central Solar Heating Plants with Seasonal Storage (CSHPSS) is a complex task and a challenge for urban planners, architects and engineers.

The Simple Method Application available in this web site is a user friendly feasibility tool developed in the framework of Task 45 activities specifically oriented to perform preliminary analysis of CSHPSS, providing:

  • A quick analysis of the monthly and annual performance of a CSHPSS
  • Information to pre-design the size of the main plant components: solar field area and volume of the seasonal storage
  • Economic feasibility and estimation of the environmental benefits, contributing also to establish optimization and design criteria of CSHPSS

The software can be freely downloaded in a PC from this web site. It consists of six subsections, corresponding each to a different window:

  • Main window,
  • Solar collector field,
  • Seasonal storage,
  • Heating demand,
  • Economic evaluation and
  • Environmental assessment based on the Life Cycle Assessment methodology.

Reasonable default values have already been implemented in the software as default values, allowing to the user a quick evaluation just selecting in the main window: the location, the number of dwellings, the ratio RAD (Ration Area of solar collector per unit of Demand) and the ratio RVA (Ratio Volume of seasonal thermal energy storage per Area of solar collector). More parameters can be adjusted in the application for advanced users (for details please see: Simple Method – User Manual).

In a few seconds the main annual and monthly energy flows, the obtained solar fraction, the system efficiency, the pre-designed sizing of the solar field and seasonal storage tank, as well as an estimation of the investment costs, solar heat cost, total heat cost and greenhouse gas emissions will be presented in the main window.

Please note that:

  • The ratio RAD can be adjusted by the user to increase/decrease the solar fraction. The ratio RVA should be adjusted to properly size the seasonal storage, e.g. a seasonal storage that would be fully charged at the end of summer period and at the beginning of heating season. It is recommended to limit the Ratio RVA between 1-7 m3/m2. Specific recommended ratios can be found in previously referred Simple Method – User Manual for different locations.
  • The application has been developed to calculate CSHPSS for space heating and domestic hot water with a solar fraction between 25% and 90%.
  • Only systems with uniform charging and discharging trend should be considered.
  • Results of over or undersized designs are not accurate but their trend can be analyzed: an oversized storage generates low temperature problems and an undersized storage produces problems such as overheating, among others, and might be required to reject heat in summer.

For the detailed and accurate design of a CSHPSS is strongly recommended to elaborate detailed analysis with a specialized dynamic simulation tool. This feasibility tool is a complementary tool that does not intend to substitute specialized design applications.

Download Simple Method Application (SMA):

Other Relevant Simple Tools

In European projects on Solar District Heating (SDH) some simple tools for this specific type of systems have been made.