Solar thermal energy for industrial heat with ENESTRA
"Solar thermal energy may not be the most obvious solution for industrial heating—but it becomes extremely interesting when you analyze production processes, heat demand, and energy price resilience as a whole."
(Thomas Lührs, Senior Consultant & ENESTRA Partner)
What are the advantages of solar thermal energy compared to photovoltaics for generating a stable and predictable heat demand?
An unbiased comparison of solar thermal energy and photovoltaics, which looks beyond the pure module costs to consider sensible overall systems, shows that the following advantages are possible:
Very favorable heat storage
Hot water/buffer storage tanks cost little per kWh_th and operate efficiently;
solar heat can be smoothed over hours or days; high solar shares are feasible
Direct heat,
high system efficiency
No conversion chain such as “electricity → heat pump → heat”;
low conversion losses, low parasitic loads.
(Comparable area yields are only technically more complex with heat pumps.)
Higher area yields
In Central Europe per m² per year: Solar thermal energy 400-750 kWh heat compared to 180-220 kWh electricity (if the electricity is used to generate heat, conversion losses are added).
Cost stability
Heat production largely independent of electricity price and COP fluctuations;
easily plannable OPEX (typically 1–2% of CAPEX/year).
Precisely tailored to constant demand
Continuous processes (CIP, pasteurization, washing/cleaning baths, drying) at 90–120 °C can be handled very well via return flow increase/series connection
Relieves boilers and peaks
Preheating reduces fuel consumption, starts and partial load operation, as well as emissions;
boiler only covers residual/peak loads
Robust and durable
20–25-year system service life,
no inverters, simple maintenance (pumps/fittings, heat transfer fluid checks)
Bypasses grid/power limits
Works independently of electrical connection power or grid restrictions;
no curtailment or feed-in issues
Good complement to PV
If PV areas/connections are limited, solar thermal energy provides additional directly usable heat – particularly attractive if sufficient open space and storage options are available.