Although large nuclear reactors could be used for non-electrical applications (such as the production of heat for district heating or desalinated water), smaller reactors are often presented to better fit this market. The main arguments are the following:

• Co-generating SMR designs are in fact considered for replacement of existing (fossil fuel) plants in the power range of 250-700 MWth. The corresponding distribution infrastructure cannot be easily changed to accommodate a large reactor, and in many cases there is even no demand for larger capacities.

• SMR sites are expected to be located closer to the final consumer than large reactors (see the discussion in Section 9.3, and thus energy losses and the associated costs due to long­distance transport of hot water or desalinated water could be significantly reduced.

• Regarding hydrogen production, the HTGR reactors needed for this can only be small for safety reasons (see Section 4.2.3).

Many advanced SMRs provide co-production of non-electrical products. These products also have their value and, for power plants operating a co-generation mode, “… one cannot impute the total generating costs to power alone” [6.1].

Reference [6.1] suggests that “.parcelling out cost shares… is highly impractical since heat and power are genuine joint products”. Instead, reference [6.1] adopts the convention “to impute to power generation the total costs of generation minus the value of the heat produced. In order to arrive at a CHP[54] heat credit per MWh of electricity, one thus needs to establish first the total value of the heat produced over the lifetime of the plant by multiplying total heat output by its per unit value. The total value of the heat output is then divided by the lifetime electricity production to obtain the per MWh heat credit”. For plants operated in a co-generation mode, referred to in reference [6.1] as the combined heat and power plants (CHPs), a heat credit is then subtracted from total unit costs to establish an equivalent of the levelised costs of producing only electricity.

Table 6.12 presents the LUEC estimates for several of the SMRs addressed in this report taking into account the values of non-electrical energy products by applying the heat credit model described above. The estimates are based on the designers’ cost data (see section 6.1.2) and on the design specifications for the relevant SMRs given in Appendix 1. Included are the SMRs for which consistent[55] data on co-production of heat (non-electrical products) along with the electricity are available in the tables of Appendix 1.

The data in Table 6.12 indicates the heat credit to be quite substantial (~22-33%) in co-generation NPPs with SMRs producing heat for district heating and desalinated water.

Non-electrical LUEC, Heat credit: Cost of heat/

product cost USD per MWh Cost of electricity