**5. Conclusions**

The proposed methodology allows integrating solar thermal energy, in a profitable way, and replace, totally, the use of fossil fuels (scenario 1).

In the event of any restriction such as an available space of 50% respect scenario 1 (scenario 2), cost savings can be up to 12% during the two hours that the thermal load can be supplied directly, with a payback time of the solar device of 2.61 years, eliminating completely the use of thermal storage. The reduction of the requirement of hot utility was 80.62% being 19.40% by integration from solar energy.

Whenever solar energy is integrated, there is a reduction in greenhouse gas emissions, but when the first objective is to reduce GHG, there should be no limitation in the economic aspect to achieve the objective. Because current international prices of conventional fuels constitute a determining restriction to integrate solar heat to industrial processes. Therefore, economic speculation of conventional fuel prices constitutes a relevant challenge to be considered in the proposal and implementation of energy policies that really intend to encourage business models with renewables, and more specifically, with solar thermal energy.

Np Number of branches or lines in parallel, dimensionless.

Qi Thermal load provided by a series of n collectors connected in

Ti Temperature of the fluid at the entrance to the collector, °C.

<sup>n</sup><sup>1</sup> Outlet temperature of one minus to the n-th element, °C.

ΔTTS Delta temperature variation of the thermal storage system, °C.

γ<sup>2</sup> Raisers diameter adjustment parameter, 1576.96 USD/m<sup>2</sup>

γ<sup>3</sup> Raisers diameter adjustment parameter, 32.576 USD/m. γ<sup>4</sup> FPSC area adjustment parameter, 994.1 USD/m<sup>2</sup>

γ<sup>5</sup> Pumping costs adjustment parameter, 3.52 USD h/m kg.

γ<sup>8</sup> Pumping costs adjustment parameter, 1.00 dimensionless.

γ<sup>10</sup> Pumping costs adjustment parameter, 261.61 USD m h<sup>2</sup>

.

.

.

.

/m<sup>5</sup> .

.

.

/kg.

To Outlet temperature of the fluid from the collector, °C.

<sup>n</sup> Outlet temperature of the n-th element, °C.

ΔTML Logarithmic mean temperature difference, °C.

γ<sup>0</sup> Materials adjustment parameter, 6768.82 USD. γ<sup>1</sup> Raisers adjustment parameter, 202,822.47 USD/m<sup>3</sup>

γ<sup>6</sup> Pumping costs adjustment parameter, 0.14 h<sup>2</sup>

γ<sup>9</sup> Pumping costs adjustment parameter, 0.54 m.

ρ Density of the thermal fluid, kg/m3

γ<sup>7</sup> Pumping costs adjustment parameter, 0.45 h/m<sup>2</sup>

VTS Volume of the thermal storage system, m<sup>3</sup>

Ns Number of series collectors, dimensionless.

Qh Minimum requirements for heating, kW.

Q Total thermal load required by the process, kW. Qc Minimum requirements for cooling the process, kW.

Nt Number of tubes, dimensionless. qi Enthalpy change of i-th stream, kW. qj Enthalpy change of j-th stream, kW.

*Solar Energy in Industrial Processes*

*DOI: http://dx.doi.org/10.5772/intechopen.97008*

series, kW. QTS Total heat load to be stored, kW. t Storage time of the system, h.

Tinlet Stream inlet temperature, °C.

Toutlet Stream outlet temperature, °C.

W Width of the solar collector, m.

ΔT Temperature difference, °C. ΔTmin Delta temperature minimum, °C.

To

To

**471**

Greek symbols
