6.48 mm diameter nozzle delivering 0.91 l/s to the runner which is rotating at 1084 rpm and generating 225 watts into the grid at an overall efficiency of 47%.

Tuesday 13 June 2017

Work productivity - human and hydro.

Lately, the human kind of productivity has been encouraging but the hydro kind less so.  

To take the hydro kind first, - the line of the graph of cumulative kWh's generated for the current year continues to fall away from the trajectories taken in previous years:



...we have had rain, but it has been meagre and not done anything to increase energy output.  I doubt the year total will see 3000 kWh, - which would mean a 25% reduction on last year's total.

This disappointing output is not a result of any interruption in turbine operation, - it has run continuously with no interruption caused by the near miss of the tree falling next to it, - work on the clearing of which is the reason for the encouraging productivity of the human  sort:









The clearing away of the root plate of the tree is still a work in progress.  It's all being done with hand tools so it takes a while.

As I work on it, trying to remove each and every stone amongst the roots that will mean another sharpening of the chain saw's teeth, I keep telling myself "Rome wasn't built in a day", which alternates with "There are worse things to be doing in retirement"!

My thanks to my mate Paul, emptying his boot of saw dust in the picture. Without our arguments about how best to do the job, life would be less fun.

Saturday 3 June 2017

A different sort of Powerspout

Up 'til now, these diary entries have all been about my Powerspout installation. Last month I visited an elegant scheme that is quite different, - instead of being low flow with several meters of head like mine, this one was high flow with just 2.7m of head.

I'll let the pictures tell the story:











The installation comprises two Powerspout Low Head Pro turbines generating into a single 2 kW Enasolar inverter which is grid connected.  With both turbines running, the power into the grid is just over 1 kW; the operating voltage is 204v dc. Using the Powerspout calculator to 'back' calculate how much water is actually passing through the two turbines, I get it to be 82 l/s.

A lot of water is needed for these low head sites, but as can be seen, at the time of year I visited, at this site there was more than enough, - with much overspilling via the rectangular holes cut into the tank.

With regard to how noisy they were, there was so much sound from water splashing from the over flows that I couldn't hear the turbines themselves at all.

...a nice set up!  My thanks to the owner, - with whose permission these pictures are posted.