Colas Yverdon-les-Bains

	Technical parameters

Collector technology	other or various collectors
Collector name	SRB type c2
Installed collector area (gross), m²	197.0
Installed collector area (aperture), m²	173.0
Installed collector area (absorber), m²	123.0
Installed thermal power (actual), kW_th	96.0
Solar collector loop heat transfer fluid	thermo-oil
Solar energy storage	other
Storage volume, m³	90
Kind of conventional heat source	other
Kind of fuel used	natural gas

	Economic parameters

Total investment costs (excl. VAT), €	300,000.00 (Turnkey costs including solar collectors, piping, support construction, storage, design, commissioning reduced with subsidies)
Solar loop (excl. VAT), €	(Solar collectors, piping, support construction)
Solar energy storage (excl. VAT), €
Others (excl. VAT), €	(Design, commissioning, others)
Process integration (excl. VAT), €
Subsidy, € or % of total investment costs	no subsidies
Cost for fuel replaced, €/MWh_fuel
Calculated solar thermal system life time, a
Annual useful solar heat delivery, MWh/a
Specific annual useful solar heat delivery, MWh/am²
Specific investment costs, €/m²	1522.84
Solar fraction, %

	Lessons learned

Initiative	COLAS Suisse SA, member of COLAS group, the worldwide leader in the bitumen and road coatings sector, has decided to equip one of its regional sites with a solar thermal installation for temperatures up to 200°C. The principal objective of this project was to reduce the industrial site fossil energy consumption by 60%. During 2013, a R&D project funded by the Swiss Federal Office of Energy was started aiming to analyze and optimize the thermo-economic and environmental performance of this installation, but also to evaluate the performance of energy storage in bitumen
Integration methodology	Coupled with a gas boiler, the solar collectors were installed with the dual purpose of meeting the thermal energy needs of a workshop building and to maintain two bitumen storage tanks above its melting point.
Crucial Interfaces	The control of the system seems very difficult to establish (is it better to store solar energy into bitumen when available and then transfer it to the water storage or not?, etc.) Several components (heat exchangers, heat pipes, etc) are used by both of the heat sources (solar and gas boiler) and it is not ideal because they don't have the same temperature levels, mass flow or supplied thermal power.
Construction / Commissioning	The storage tanks were existing and the whole installation had to be adapted to them.
Operation / Performance	Measurements are ongoing
Recommendations	Keep separated hydraulic circuits for solar and other heat source. Attention should be paid to the exergetic losses of the system.