Multi-Country Scale Assessment of Available Energy Recovery Potential Using Micro-Hydropower in Drinking, Pressurised Irrigation and Wastewater Networks, Covering Part of the EU

Abstract

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.

Energy Self-Sufficiency Aiming for Sustainable Wastewater Systems: Are All Options Being Explored?

“…Another important result about the geographical distribution was the demonstration of an interest for the technology almost worldwide [20,21,23,47,48,52,79]. Regarding this, it is important to remark that the sites shown in Table 2, are only the real cases found following the described methodology.…”

“…If trends point to decentralized systems, these imply smaller plants, with their inherent characteristics and limitations to implement renewable energies technologies. The main appeal of hydropower is its flexibility, accessibility, and worldwide application [26,48,52,72,79], without interfering in the treatment process itself and without the strict limitation of scale that other technologies do present [14,25,38,92,93].…”

“…In this way, the technical and economic feasibility of any hydropower system is calculated. Based on that, several authors recently studied the potential of small hydropower for improving the sustainability of urban water systems in general [46][47][48][49][50][51] and wastewater systems in particular [20,[52][53][54][55].…”

Innovative Projects and Technology Implementation in the Hydropower Sector

“…If this facility would have been built with two standard turbines, the cost would have been increased by 60%. Energy recovery in aqueducts is also a sector in rapid development, and in this chapter, a 150-kW Francis turbine with variable speed was described [44].…”

Hydropower Technology for Sustainable Energy Generation in Wastewater Systems: Learning from the Experience

“…Previously published academic research on hydropower application to wastewater systems, either developed and applied methodologies for global potential assessment at a country [62,63], or multi-country level [64], or conducted individual feasibility studies at a plant level, experimental as in [65] or theoretical as in [53]. However, no methodology has been proposed to be applied for potential assessment at an intermediate level.…”