When we first came to this house in November 2009, its only electrical power came from a diesel generator. I have never been particularly interested in engines, and I knew little or nothing about this one. I didn’t know what make or model it was, what its service schedule was, how to service it, what to do if it went wrong. I had no manual for it, and no handover.
Indeed some of these things I still don’t know 4½ years later. The “gen set,” to give it its proper name, consists of three main components: the diesel engine which makes the power, the alternator that turns the power into electricity, and the controls which safely start and stop the system and allow it to be started remotely. I now know the make and model numbers for these components, and have managed to download maintenance and user manuals for them, but I still have no idea who actually manufactured the overall gen set, or who supplied or installed it.
The first picture shows the outside of the gen set (I keep wanting to call it the generator, which is how we always refer to it, but strictly speaking that’s like failing to distinguish between your car and its engine). On the left, obviously is the tank, the box in the middle houses the engine and the alternator, and the rusty box on the right houses the controls. (There is what looks like a filling cap on the right of the box but we never use that: I presume that this leads to the gen set’s own tank, which is not used in our case because the thing is fed automatically from the big green tank – this would also explain why the controls have a fuel gauge that never shows anything but nearly empty).
The second picture shows the inside: the diesel engine (which I now know to be a Kubota D1105, manufactured in November 2003) is on the right and the alternator (which I now know to be a Sincro GK4MBL) is on the left.
Since we started in November 2009, our off-grid installation has progressed in a number of steps.
Nov 2009: Generator only
May 2010: Add batteries and inverter/charger
May 2011: Add solar panels
Oct 2011: Add thermal store
May 2012: Add load controller
May 2013: Add proportional controller
May 2014: Add monitoring and optimization
I’ll blog about these steps one at a time, starting with the generator.
I didn’t start out with any intention of being off-grid or any particular interest in it; it just happened that in 2010 my wife and I bought a house that had never been connected to mains electricity, and rather than pay a substantial sum to spoil our view with overhead wires, we decided to go down the off-grid route.
My intention in starting this blog is to talk about what I’ve learned about the technology of off-grid electricity, and the economics of it. Ideally I’d like it if the blog attracted other people in a similar situation and we could exchange ideas.
The term “off-grid” does have, I am aware, a wider philosophical meaning: the idea of being independent of society’s infrastructure in a more general way; of a more self-sufficient existence. That doesn’t interest me: I think that self-sufficiency (not to mention its wilder cousin, survivalism) is a pure fantasy. No man is an island.
In fact, being off the electricity grid does not make us more self-sufficient at all. We are dependent on regular supplies of diesel; and we are dependent on complicated electronics which I could not possibly mend if they broke. And while I am very keen to be environmentally friendly, I am not under the illusion that being off-grid is necessarily particularly “green”. It might be or it might not be, it depends how you do it.
My definition of a good off-grid system would be where you visited the house and didn’t know they were off-grid. In other words I want to be able to live a normal life-style with televisions, mobile phones, computers and so on, and I want my system to be sufficiently well-automated that most of the time it will just look after itself.
In my next post I will give a high-level overview of our setup.
Running a domestic house in the UK without grid electricity