It’s quite difficult to make generalisations about the cost to build hydro systems because of the different combinations of head (the change in water levels between the intake and discharge) and maximum flow rate, and how that affects the maximum power output and choice of turbine type.
Also the extent of any civil engineering works is very site dependent, with some new-build sites requiring everything to be built from scratch, while other retrofit projects can make use of and adapt the existing civil engineering structures.
Having said that, we’ll try to answer the question anyway to give you an idea of the ‘scale’ of costs involved. The table below is a rough ball-park estimate of typical project costs for systems requiring an ‘average’ amount of civil engineering works and grid connection upgrades and assuming access to the site was reasonable. In all cases it is assumed that good quality hardware is used throughout, which we would recommend anyway if you want a reliable hydro system in the long-term.
It is possible to install systems for a lower cost, particularly if the existing infrastructure at the site lends itself to easy adaption for a modern hydropower system so only modest or no civil engineering works would be needed. However even in the most favourable circumstances it is unlikely that the cost would reduce by more than 50% from that shown in the table.
Maximum Power Output | Estimated Project Cost | £ / kW installed |
---|---|---|
25 kW | £169k | £6.8k |
50 kW | £300k | £6.0k |
100 kW | £529k | £5.3k |
250 kW | £963k | £3.8k |
500 kW | £1.6M | £3.2k |
To estimate the cost to build hydro systems for a maximum power output between the bands shown, use the chart below and read-off the appropriate £/kW figure – for example a 130 kW hydro system would be approximately
130kW x 4,800 £/kW = £624,000.