Mark Walker analyses what you will need from a generator when going off the grid
Here I am living in semi-rural suburbia, concerned about the environment my children will inherit and frustrated by electricity bill increases and irritated by supply reliability. It’s time for me to take my three bedroom semi-detached house ‘off-grid’. But to me, ‘off-grid’ isn’t just about the removal of or lacking an electrical connection. I also want independence – from government policies and legislation, big multi-nationals, dealerships, service organisations, in fact, anybody. So how do I do this?
Having learnt the hard way that off-grid power generation requires a machine much more robust than those air-cooled, high speed, super-silent (yeah, right!) things found on eBay, I realised that I would have to set my budget sensibly. My strategy was to go for a name that has a reputation of longevity and reliability, putting me in the $1000+ per kilowatt league occupied by Honda, Yanmar and Kubota.
Would I be happy with such an investment? Of course I would — its state of the art technology, but there are a few things/features that they don’t give me.
For example, I want a generator that has re-useable filters (air, oil and fuel) that just need cleaning. I don’t want to have to pay excessive amounts of money to these multi-national companies for something that increases global pollution. It’s just not necessary. Am I asking too much?
I want a generator that is cheap (very) to service. I want it to be so simple that I could do it myself, or at least simple enough for a local mechanic to do it. I don’t want to be forced to use an approved Kubota service Engineer because I fear losing my (very impressive) warranty.
I want a generator with an engine so simple that I could strip the top end down myself, replace the valves, lap them in, all in my lunch hour and still have time to eat my sandwiches. Am I asking too much?
I want a generator that tells me it is well, just by the way it performs. I don’t want a CAN bus ECU refusing to attempt to start the generator because it has detected a fault #73669-b with the instruction “call your nearest dealership immediately” only to be billed a $100 call out charge to discover that my starting battery has reached the end of its life. I would have diagnosed that myself from the sound of the machine. Am I asking too much?
I want a generator that has been designed to last as long as possible – like they used to design things before the 1970s (when they discovered that ‘built in obsolescence’ is great for repeat business). I don’t want a machine whose components are all designed to fail simultaneously 13.45 seconds after the (very impressive) warranty expires. Am I asking too much?
Do I really need a three cylinder engine that will give me a perfect sine wave (with its associated additional service/parts costs)? My washing machine can cope with an imperfect sine wave (some can’t), my lights are all compact fluorescent, so they don’t care and my laptop will run on any quality electricity supply.
I want to pay less for my generator. If it was a single cylinder engine, it would be cheaper to make (and service) and more efficient. If it was made from cast iron it would be more efficient (conducts heat much less than aluminium), but no, the multinational engine manufacturers are obsessed with power density, so we have to have aluminium engines requiring us to pay more to Bosch to optimise their fuel systems so that compromise in efficiency caused by using aluminium is minimised.
I don’t care how much my generator weighs. Once it’s installed, I won’t be moving it. Do they think I want to take it for a walk every time the sun comes out? Does anybody care how much their central heating boiler weighs?
I want to be able to run my generator on different fuels, and not lose my warranty. The pub up my road still has to pay for their waste cooking oil to be taken away. I want to save us both some money and reduce both our carbon footprints by putting that waste cooking oil in my generator. Am I asking too much?
Why do I have to pay so much for my engine oil? I want to use that really cheap stuff from my supermarket. But no! In order for me to keep my treasured warranty, I have to use an extortionately expensive lubrication oil – so full of toxic additives that I have to pay again to have it disposed of safely.
I want to use a simple oil and after I’ve used it, I want to let the dirt settle and throw the clean stuff in my fuel tank with my WVO, diesel, kerosene, paraffin or whatever. Am I asking too much?
I want to be able to use the waste heat from my generator. With domestic sized generators, at least 70% of the calorific content of my valuable fuel goes to heat up the atmosphere. I don’t want to do that.
Did you know that the amount of heat dumped into the UK atmosphere whilst generating electricity is equivalent to half the nation’s heating demand? The amount of heat dumped into the atmosphere by US power stations is enough to meet the entire heating needs of Japan. I don’t want to be a part of that!
I did some digging around and asked a few Generator manufacturers (who claimed they offered Combined Heat and Power systems) if they could help. They said ‘no’; it’s not cost effective to build domestic scale CHP systems. Really!? Why!? It’s not rocket science! All I want is a heat exchanger that takes hot gases and puts the heat into water. That’s what a domestic boiler does and they’ve been around for half a century.
I can buy a ‘state of the art’ boiler for $1000. My annual heating costs are $1500. If my generator can provide my heating for free (as a by-product of generating electricity), which it can in theory, this little heat exchanger feature would pay for itself in 9 months. In what way is that not cost effective!?
Am I really, really asking too much? Apparently ‘yes’, so I’m going to build my own. Anybody want one?
Mark Walker is the Proprietor of Volvox (Engineering) Ltd.