We engineers are great at estimating energy and carbon emissions and dealing with concrete systems: pipes, wires, flues – that’s our bag. One of the things we do poorly (but for some reason are too willing to do) is financial modeling relating to low and zero carbon generation.
For the last couple of years I’ve been working alongside financial and commercial bods who actually do know what they’re on about and it’s been a real eye opener. They might not know how to size a duct but they can tell you where your business is making money – and where it isn’t.
On a recent project I was looking at small CHP engines (5 – 30kWe) on a sheltered housing scheme. As part of that work, I put together a simplified financial model (with guidance from the bods) to quickly test whether a given option was worth looking at in detail. It was hugely useful and threw up some surprising results – for example, none of the small engines I looked at could pay back its capital cost in its lifetime. Ouch.
So based on that work, here’s the model. I’m using micro-CHP as an example but it’s just as easy to use for renewables.