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, 15 March 2016

The UK "Energy Performance Certificate".

There might not seem to be any relevance on a blog devoted to a Powerspout for me to be writing about the UK Energy Performance Certificate (EPC).  Yet for readers in the UK, and this entry is really for UK readers alone, there is great relevance. Not only is the matter relevant to owners of Powerspout turbines but to owners of all 'domestic scale' hydros in the UK.

To rehearse the background: an EPC is required by law whenever a property is built, sold or rented.  It contains info about a property's energy use and typical energy costs, and it gives recommendations about how to reduce these. The certificate gives a property an energy efficiency rating on a scale from A (most efficient) to G (least efficient), is valid for 10 years and is issued following an energy assessment undertaken by a qualified assessor.

The origin of EPC legislation lies in the UK government's efforts to reduce carbon emissions and influence global warming: the energy we use for heating, lighting and power in our homes produces over a quarter of the UK's CO2 emissions. The certificate makes explicit this link to CO2 by including another scale which quantifies how good or bad the property is in terms of CO2 emissions for each energy efficiency rating A to G.

So you would logically conclude from all this that a property which is lucky enough to have a  hydro, which is to say a zero carbon energy source working 24/7, that such a property ought to score pretty well, at least in respect of that part of the assessment which deals with electrical energy consumption.

Moreover, you could not possibly expect the benefits from a hydro to be excluded when the certificate recommends one way of improving a property's EPC is to instal a wind turbine, - a technology which produces a far inferior energy flow compared to a hydro.

But you would be wrong if you concluded and expected these things: the reality is no electric generation from a hydro is permitted to count in the domestic energy assessor's survey of the property. The contribution from a hydro contributes not a jot to the calculation of the energy performance rating of the property.

The back story behind this completely daft anomaly is convoluted. It does not bear telling in full here. I have been arguing it this past 6 months all the way to the Minister of State for Energy, the Rt Hon Andrea Leadsom MP.  Her explanation in one sentence, though in the way of politicians she took several, is that assessing the contribution from a hydro is too complicated, therefore to train the energy assessors would be too expensive, and there are too few hydros to make it all worthwhile. End of matter.

So good bye fairness, logical thought, coherent reasoning, plausible argument and sensible decision taking in the legislative process !  Those of us with hydros simply have to take it on the nose that the point on the scale where the EPC places us will be lower than it ought to be, - in the process placing a lower value on the property, and in my case, dictating that I receive a lower Feed in Tariff payment for my solar generation.

As the French might say: "tant pis pour nous" (hard luck for us).  Which is indeed the only way to accept it, - but accepting it does nothing to suppress the irritation which still wells up because of such idiotic legislation.

2 comments:

regen said...

Hello Bill,

Hope the PV has been performing well of late.

Dave

Bill said...

Aye, it's picking up a bit now, just as the hydro is winding down a bit. If I can keep to 20 kWh per day between the two, I'll be content.