Boiler Feedwater Preheating
Many industries lack space to install a complete system for solar steam or heating generation for their processes. In such cases, they should evaluate using a boiler make up water pre-heating using solar.
Make up water temperature is usually at 25-30 deg C and it can be heated to 70-80 deg C depending on the type of concentrator used. Since solar heating systems have higher efficiency and lower cost at low temperature, boiler make up water / feed water pre-heating offers one of the best paybacks in solar thermal technologies.
Though we can implement this solution for all fuel types, currently it is economically viable (about 2 years payback) only for higher priced fuels like Diesel, Furnace Oil, LPG/LNG or CNG.
Boiler make up / feed water pre-heating offers the risk in terms for any process changes and has very minimal impact on the process operations and hence, could easily be taken up at a first step towards using solar as fuel for heating needs.