Turbotricity

When we put in our Proven 2.5kw system, there was no prospect of the ESB buying back our surplus power, so we opted for a battery system. With a battery system, when you have more power than your batteries can take, you need various dumps for the surplus power, and this is done by relays wired to various dump loads (electric water heaters) that come in one at a time when the batteries get to between 28.5V and 29.5 V.

Obviously a grid-tied system has no need for all this, as the surplus is simply sold to the grid, and even at 9c per KwHr, this is more valuable than heat which typically costs 7c from an oil fired system.

I cabled for all these loads, but to be honest, we’ve hardly had to use them. Last autumn was the first time our output was so high that the dump loads got much use.

However, I fitted replacement blades to the turbine, and realise now how much the old blades were holding the system back. Over the last week, we have had surplus power every night – often about 2kw of surplus. The turbine is regularly producing the rated 2.5kw, something we have never seen it doing before….

If you have a 2.5kw Proven, check whether your blades are the old ones made from folded plastic sheeting, or are the new ones which are a properly moulded blade. The old blades frankly are rubbish. Well worth changing them out for the improved ones….