Small Hydropower Economics: Head & Flow, Power Output, Flow Duration Curves, Annual Energy, Residual Flows, Feed-In Revenue and Payback

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Work out the gross and net head of the fictional Brookmere Mill scheme, convert flows from litres to cubic metres per second and turn five flow cases into electrical power in kW.
• Read the head loss of the chosen pipe from a fictional loss table, express it as a share of the gross head and calculate the head loss and net head for six flow cases.
• Rank 24 fictional sample days of river flow, turn the ranks into exceedance percentages and read the flows that the river reaches or exceeds 50 % and 95 % of the time.
• Keep a fictional residual flow in the river, cap the usable flow at the turbine's design flow, switch the turbine off below its minimum flow and size the turbine in kW.
• Read a part-load efficiency from a fictional curve, turn flow bins into megawatt-hours, add them up to the annual energy with SUMPRODUCT and work out the capacity factor.
• Split each month's energy into own use and export, value it under a fictional fixed tariff and under fictional market prices and find the energy-weighted price the scheme really captures.
• Add up the fictional capex of the scheme, work out the first year's running costs, escalate them over 25 years and build the yearly net cash flow.
• Compare the simple payback of the scheme in a dry, an average and a wet year, find the NPV and IRR of the 25-year average case and chart the energy of the three scenarios.