Introduction

Solar Thermos is a system that utilizes solar energy to heat water and store that energy in a highly insulated thermal tank which is simple, efficient, has a long lifetime and requires minimal maintenance. Stored heat is used for domestic hot water, space heating, and seasonal thermal storage to cover the energy demand from March to September. System is designed for four-person detached house, with annual electricity consumption of 20 000 kWh. Our focus has been on balancing affordability, efficiency and sustainability.

Goals

The purpose of this project is to design and evaluate a solar powered heat storage system for a detached house located in southern Finland. The system is intended to supply domestic hot water and support underfloor space heating for detached house. Our solution integrates rooftop solar panels with a 500-liter insulated hot water storage tank equipped with electric heating elements, control systems, safety devices, and necessary hydraulic components. Solar electricity is primarily used to heat the storage tank, while grid electricity supplements the system when solar production is insufficient.

Results

The system we designed is technically feasible, economically viable and environmentally responsible. The system can provide clean energy storage, which can save over 900 € per year compared to purchased electricity. The investment costs are approximately €10,000–12,000, with a payback in 12 years. In addition to performance and cost considerations, the system is designed to comply with relevant safety and pressure equipment regulations, operate reliably under Finnish climate conditions, and fit within the physical constraints of a typical residential technical room.