Conduit Hydropower Potential in City’s WDS P1-1 GDS 2055 workshop Conduit Hydropower Potential in City’s Water Distribution System

Conduit Hydropower Potential in City’s WDS P1-2 Intro CHP in City’s WDS Title: Energy generation from distribution systems Period: 2 years Funding: Water Research Commission with a number of collaborating organisations

Conduit Hydropower Potential in City’s WDS P1-3 What is conduit hydropower?What is conduit hydropower? DescriptionDescription Identifying potential sitesIdentifying potential sites Potential sites in TshwanePotential sites in Tshwane PvRCHPPvRCHP FeasibilityFeasibility Way forwardWay forward Layout of the presentation CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS Conduit hydropower is where excess energy available in pressurised conduits (pumping or gravity) is transformed into clean, renewable hydroelectric energy by means of a turbine.Conduit hydropower is where excess energy available in pressurised conduits (pumping or gravity) is transformed into clean, renewable hydroelectric energy by means of a turbine. The excess energy is normally dissipated by means of pressure control valves but by conveying it through a parallel dissipating system, the water turbine, the pressure head and flow is utilized to generate hydroelectric power.The excess energy is normally dissipated by means of pressure control valves but by conveying it through a parallel dissipating system, the water turbine, the pressure head and flow is utilized to generate hydroelectric power. What is conduit hydropower? P1-4CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS What is conduit hydropower? P1-5 ΔH max = 83.2 m, Q min = 0 m³/s Q max = 1.42 m³/s, ΔH min = 15 m ΔHΔHΔHΔH CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS What is conduit hydropower? P1-6 When flowing at 70% of design capacity ΔH 70% = 47.1 m, Q 70% = 1.0 m³/s CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS “Conduit hydropower” – energy generated from pressurised conduits Description P1-7CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS Drivers for a municipality to consider “conduit hydropower”: –Renewable energy source –Rising energy costs –Reduced revenues –Financial incentives –Public perception –Job creation –Extending the operational life of control valves –Remote power (alarms, communications etc.) Description P1-8CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS P1-9 Q, H, generation time and assurance of supplyQ, H, generation time and assurance of supply Accessible?Accessible? Reservoir storage to accommodate fluctuating demandsReservoir storage to accommodate fluctuating demands Generated electricity consumption?Generated electricity consumption? Bypass alternativeBypass alternative Safety mechanismsSafety mechanisms FeasibilityFeasibility Identifying potential sites CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS P1-10 Potential sites in Tshwane Geographically speaking the City of Tshwane has a lower elevation then the bulk service Reservoirs of Rand Water which is the main water supply. Water is then distributed through a large water system that includes 160 reservoirs, 42 water towers, km of pipes and more than 260 pressure reducing installations (PRV’s) that operates at pressures of up to 250 m. CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS P1-11 Potential sites in Tshwane CHP in City’s WDS

Conduit Hydropower Potential in City’s WDS P1-12 Potential sites in Tshwane Reservoirs TWL (m.asl) Capacity (kl) Pressure (m) Flow (l/s) Yearly Potential power generation (kWh) # Garsfontein Wonderboom Heights LL Heights HL Soshanguve DD Waverley HL Akasia Clifton Magalies Montana Total calculated yearly power generation in Tshwane from 10 reservoirs - (Nearest kWh) CHP in City’s WDS