[en] The growth of energy demand has led to overexploitation of conventional primary energy sources, leaving the use of renewable energies in the background. Climate change and other harmful effects are a direct or indirect consequence of the current energy system. Among these conclusions is, for example, the increase in fuel prices suffered over the last decade. Taking into account the speed of development of climate change, we can appreciate that reducing emissions is necessary. Given that the industry uses around 30-70% of the final energy produced, the efficiency of these processes would have to be improved to the maximum. In this sense, heat waste recovery technologies have been the main method for reducing fuel consumption, reducing released emissions, and improving productive efficiency. As has been shown, the industry occupies a large part of the total energy used in the world. In addition, a high percentage of this total energy used is wasted as heat emissions without any practical use. Approximately 60% of these emissions are considered heat waste at low temperature. As explained below, the most suitable technology for the recovery of these low quality heat residues is the ORC. This is very similar to the Rankine cycle, but in this case instead of using water as a working fluid, it uses an organic working fluid with a lower boiling point. On the other hand, although ORC systems are suitable for the recovery of industrial heat residues, they are also useful for transforming energy from renewable sources into electricity, among others. Once the installation potential for ORC configurations is very high, it becomes a very interesting option to comply with the restrictions imposed by the European Union (EU).

[eu] Eskari energetikoaren hazkuntzak energia primario konbentzionaleko iturrien gehiegizko ustiatzera eraman du, energia berriztagarrien erabilera bigarren plano batean utzita. Aldaketa klimatikoa eta kaltegarriak diren bestelako efektuak, gaur egungo sistema energetikoaren zuzeneko edo zeharkako ondorioak dira. Ondorio hauen artean adibidez, azken hamarkadan jasandako erregaien prezioaren igoerak. Aldaketa klimatikoaren garatze abiadura kontuan izanda, 〖CO〗_2 emisioen murrizketa beharrezkoa dela ikus daiteke. Jakinda industriak, energia erabilera finalaren %30-70 bat inguru erabiltzen duela, prozesu hauen efizientzia ahal bezain beste hobetu beharko ziren. Zentzu honetan, bero-hondarrak berreskuratzeko teknologiak izan dira erregaiaren kontsumoa murriztu, askatutako emisioak murriztu eta produkzio efizientzia hobetzeko metodo nagusia. Azaldu den bezala, industriak munduan erabilitako energia totalaren zati handi bat betetzen du. Gainera, erabilitako energia total horren portzentaje handi bat bero emisioak bezala kanporatuak izaten dira, inongo erabilera praktikorik gabe. Emisio hauen %60 bat inguru tenperatura baxuko bero-hondarrak bezala kontsideratzen dira. Aurrerago azalduko den bezala, kalitate baxuko bero-hondar hauek berreskuratzeko teknologia aproposena ORC da. Hau Rankine zikloaren oso antzekoa da baina, kasu honetan lan-jariakina bezala ura erabili ordez, lurruntze tenperatura baxuagoa duen lan-jariakin organiko bat erabiltzen du. Bestalde, ORC sistemak bero-hondar industriala berreskuratzeko aproposak izan arren, erabilgarriak dira ere iturri berriztagarrietatik lortutako energia elektrizitatean bihurtzeko, beste batzuen artean. Behin ikusita ORC konfigurazioentzako instalazio potentziala oso altua dela, oso aukera interesgarria bihurtzen du Europar Batasunak (EB) ezarritako murrizketak betetzeko.