Year end results for 2022-23 water year

Each year, I put out these graphs of yearly generation because they are compiled from real data and tell how a small hydro actually performs. People who are still at the planning stage of a turbine installation are faced with having to make a number of guesstimates, and the biggest is whether their turbine, in the location they have for it, is going to be productive enough to make it worthwhile. By making known how my turbine performs, and drawing attention to the seasonal and yearly variations in performance that there are, I hope it helps others in the planning stages to fine tune their guesses to arrive at a reliable estimate of the worthwhileness of their project.

In each graph, the bold black line is data from the 'water year' that has just finished, ie: 1st October 2022 to September 30th 2023.

1. Daily energy and power output

Although Wales is known for its rain, rainfall in winter always comes in spells; this year was a 3 peak year, with spells in November, January and March / April,

2. Cumulative energy (kWh)

With 4,385 kWh generated, it was not the most productive year but certainly better than most.

3. Power duration curve

The pattern for the year follows the pattern for other years; note that at the 365 day point, generation was still 100 watts, and that indicates the turbine ran throughout the year with no shutdowns for lack of water.

4. Rainfall vs energy generated for the past 10 years

The graph shows how generation and rainfall follow each other intimately.

Concluding thought:

The graph which relates rainfall to energy generation shows how productivity ultimately comes down to how much it rains; but if we delve a bit deeper, we can extrapolate back further than mere rainfall; - the electrical energy we extract from a hydro is only the same energy in another form that originated from the sun, - caused water to evaporate from the ocean, - rose as water vapour into the sky, - and fell as rain onto ground which happened to be higher than the ground where a turbine is sited. So simple ! The sun is the ultimate source, - just as it is for every other energy source we use, - except nuclear and tidal.